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MT PIPER ENERGY RECOVERY PROJECT
APPENDIX E BEST AVAILABLE TECHNIQUES ASSESSMENT
Mt Piper Energy Recovery Project – BAT Assessment ___________________________________________________
Report for Re.Group
ED 13034100 | Issue Number 4 | Date 13/10/2019 Ricardo in Confidence
Mt Piper Energy Recovery Project – BAT Assessment | i
Ricardo in Confidence Ref: Ricardo/ED13034100/Issue Number 4
Ricardo Energy & Environment
Customer: Contact:
Re.Group Rob Davies Ricardo Energy & Environment Gemini Building, Harwell, Didcot, OX11 0QR, United Kingdom
t: +44 (0) 1235 75 3230
Ricardo-AEA Ltd is certificated to ISO9001 and ISO14001
Customer reference:
BAT Assessment
Confidentiality, copyright & reproduction:
This report is the Copyright of Re.Group. It has been prepared by Ricardo Energy & Environment, a trading name of Ricardo-AEA Ltd, under contract to Re.Group dated 08/08/2019. The contents of this report may not be reproduced in whole or in part, nor passed to any organisation or person without the specific prior written permission of the Commercial Manager, Ricardo Energy & Environment. Ricardo Energy & Environment accepts no liability whatsoever to any third party for any loss or damage arising from any interpretation or use of the information contained in this report, or reliance on any views expressed therein.
Author:
Rob Davies
Approved By:
David Woolford
Signature
Date:
13 October 2019
Ricardo Energy & Environment reference:
Ref: ED13034100- Issue Number 4
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Table of contents
1 Introduction ................................................................................................................ 3 1.1 Background .................................................................................................................. 3 1.2 Objectives..................................................................................................................... 3 1.3 Overview of the ERP .................................................................................................... 3 1.4 Assessment .................................................................................................................. 4 1.5 References ................................................................................................................... 5 1.6 Costs ............................................................................................................................ 5
2 Background / Policy Context .................................................................................... 6 2.1 Policy Overview ............................................................................................................ 6
3 Indicative BAT Assessment .................................................................................... 10 3.1 Introduction................................................................................................................. 10 3.2 Refuse Derived Fuel ................................................................................................... 10 3.3 Best Available Techniques .......................................................................................... 10
3.3.1 Combustion Techniques ..................................................................................... 11 3.3.1.1 Moving Grate ........................................................................................... 11 3.3.1.2 Fluidised Bed Combustion ........................................................................ 11 3.3.1.3 Gasification and Pyrolysis ........................................................................ 12
3.3.2 Conclusion ......................................................................................................... 13 3.3.3 Flue Gas Cleaning Technologies ........................................................................ 13
3.3.3.1 Pollution Absorption Systems ................................................................... 13 3.3.3.2 Control of NOx ......................................................................................... 14
3.3.4 Conclusions ....................................................................................................... 14
4 Quantitative BAT Assessment ................................................................................ 15 4.1 Nitrogen oxides abatement method (SNCR vs SCR) ................................................... 15 4.2 Acid gases abatement method (semi-dry vs dry vs wet); ............................................. 15 4.3 Acid gases abatement reagent (lime vs sodium bicarbonate) ...................................... 17
5 Review of Proposed ERP against Indicative BAT .................................................. 18 5.1 Introduction................................................................................................................. 18 5.2 Reference Facility ....................................................................................................... 18 5.3 Technical Criteria ........................................................................................................ 20
6 Assessment against BATC...................................................................................... 23
7 Commentary and Conclusions ............................................................................... 34
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1 Introduction
1.1 Background This report has been produced in support of the planning application for the Mt Piper Energy Recovery
Project (‘ERP’).
The proposed ERP comprises a refuse derived fuel (‘RDF’) energy from waste (‘EfW’) plant situated at
the existing EnergyAustralia (‘EA’) Mt Piper Power Station (‘MPPS’), near Lithgow NSW.
The proposed development involves the construction and operation of a dedicated boiler and RDF
receival infrastructure with a design capacity of 200,000 tonnes per annum (tpa). The boiler will be fired
with RDF to generate steam for integration into the existing MPPS, which is coal fired. This will generate
electricity at the existing power station, augmenting the 1,500-megawatt (MW) MPPS with lower
emissions generation and reducing the amount of coal required by the power station.
The development comprises two distinct areas (the ‘Project’):
1. The ERP, where combustion of RDF will occur.
2. The ash placement facility, where ash generated at the ERP will be placed.
This report is only concerned with the first point above, the ERP.
1.2 Objectives Ricardo Energy and Environment (‘Ricardo’) was commissioned to assess compliance of the proposed
ERP development with the NSW EfW Policy requirements. The NSW EfW Policy is published by the
NSW EPA.
1.3 Overview of the ERP The steam generated at the ERP will be supplied into the Mt Piper steam system, at appropriate steam
conditions, to supply the reheat steam loop and, therefore, reducing the amount of coal that would be
required by the power station.
The RDF will be produced elsewhere for delivery to the ERP and no unprocessed municipal or
commercial waste will be accepted at the ERP, which reflects the NSW status where waste incineration
is banned.
The RDF will be delivered in either baled1 or bulk compacted form.
Bulk compacted RDF will be delivered to the ERP by bulk loader and will either be tipped or ejected out
of the trailer using a walking floor mechanism. Bulk compacted RDF will enter a concrete storage bunker
which can hold enough RDF for several days’ operation. This will be contained within the ERP building,
preventing the escape of any material. Odours will be removed by the combustion system which will
draw its air from the ERP building. Should the ERP not be operating, a standby system will operate to
prevent odours being released from the plant.
1 Bales are RDF that has been compressed into a cuboid shape, in a baling machine (a ‘baler’), and then wrapped in a plastic
wrap that seals the bale. A wrapped bale typically weighs between 1-1.5te and is more easily handled and stored without any
release of odour or material.
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The RDF will be fed into the feed hopper of the combustor (furnace) by a grab crane which can be
operated by an operator or automatically. The crane will also be used to mix the fuel to ensure greater
consistency of RDF entering the system.
The combustion system will be a moving grate, where the RDF is gradually moved down the grate whilst
it is burning, being agitated by the mechanical action of the grate thereby ensuring an even combustion
and release of heat. Air will be added to the system either through the grate or immediately above it.
The combustion process will be controlled by an advanced control system which ensures that not only
is complete combustion attained, leading to a bottom ash with a very low carbon content, but also that
any compounds present in the combustion gases are destroyed by achieving the regulated conditions
of 850°C for a minimum of 2 seconds.
The ash produced at the end of the grate will be conveyed out of the system and stored prior to transport
to the ash placement facility .
The hot flue gas will then pass into the boiler, where steam will be generated via several heat exchange
surfaces. These surfaces will be kept clean of ash by a variety of inline cleaning technologies to
maintain the efficiency of the process and any ash will be collected at the bottom of the boiler for
disposal.
The steam generated from the boiler will then be supplied by pipe to the adjacent power plant, where it
will be used to generate electricity.
On exiting the boiler, the flue gases will pass into the flue gas cleaning (‘FGC’) plant. The FGC plant,
in conjunction with the combustion control system, is designed to ensure that the plant complies with
all current regulatory requirements in relation to air emissions, and to do this in the most resource
efficient way.
The key elements of the FGC system include the injection of lime and activated carbon to react with
any acid gases or heavy metals, taking them out of the gas stream leaving the cleaned flue gas to pass
up the stack. Any ash, together with the lime and activated carbon following reaction, will be captured
by a fabric (bag) filter and stored in silos prior to being taken away from the ERP by road. Additionally,
the plant includes for the upstream injection of urea into the upper part of the combustion chamber, to
control emissions of nitrogen oxides (‘NOx’).
1.4 Assessment The assessment undertaken and discussed in this report is based upon the following brief/requirements:
a) Qualitative commentary on the “current international best practice” for “proven, well understood
technology” as described in the NSW Energy from Waste policy. The commentary includes
reference to European (e.g. Industrial Emissions Directive and Best Available Techniques
Reference document) and non-European best practice.
b) A summary of the techniques nominated in the project documents. Where techniques are not
identified in the relevant project documents, Consultant is to clarify or identify proposed measures
(e.g. operational controls) for confirmation by technology provider or Owner. The scope of
techniques/technologies to be considered includes all aspects of the Best Available Techniques
Reference document, including receipt of fuel and ash handling
c) A Quantitative BAT Assessment, justifying the techniques/technologies selected in comparison with
other technologies. In particular, considering:
i) Nitrogen oxides abatement method (Selective Non-Catalytic Reaction-SNCR vs Selective
Catalytic Reaction- SCR);
ii) Acid gases abatement method (semi-dry vs dry vs wet);
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iii) Acid gases abatement reagent (lime vs sodium bicarbonate); and
iv) Combustion technology and/or parameters.
d) Commentary with a clearly stated conclusion on whether:
i) The selected technology and techniques are “capable of handling the expected waste and
variability” and whether this is adequately demonstrated through the references nominated; and
ii) The concept design includes “Heat recovery as far as practicable”.
1.5 References The ERP is currently at the proposal stage and, whilst the key principles of the design have been
identified, the detailed design has not yet been completed. The information on which this report is
predicated has been provided by Re.Group, with additional reference information considered for the
purposes of completing the BAT assessment.
Information provided by Re.Group:
Preliminary Technical Proposal for Mt Piper Project (12 February 2019) - Steinmüller Babcock
Environment GmbH
Feasibility Report Energy Recovery Project - Technology Selection – EnergyAustralia/Re.Group
Mt Piper Energy Recovery Project Knowledge Sharing Report - Version 1.0 – 23 March 2018 -
EnergyAustralia/Re.Group
Draft Air Quality Impact Assessment, Mt Piper Energy Recovery Project – ERM July 2019
Additional reference information:
Environmental Statement 2019 – IKW Rudersdorf Waste to Energy Plant – Steag - https://www.steag-
waste-to-energy.com/uploads/pics/Umwelterklaerung2019_engl_kl..pdf (Accessed August 2019)
EU 2010 Directive 2010/75/EU of the European Parliament and of the Council of 24 November 2010
on Industrial Emissions (Integrated Pollution Prevention and Control), Official Journal of the European
Union, 17 December 2010 (the ‘Industrial Emissions Directive’, or ‘IED’).
EU 2000 Directive 2000/76/EC of the European Parliament and of the Council of 4 December 2000 on
the Incineration of Waste, Official Journal of the European Communities, 28 December 2000 (the
‘Waste Incineration Directive’, or ‘WID’).
IPPC 2006, Reference Document on Best Available Techniques for Waste Incineration, European
Commission Integrated Pollution Prevention and Control, August 2006,
http://eippcb.jrc.ec.europa.eu/reference/BREF/wi_bref_0806.pdf (accessed July 2019)
Best Available Techniques Reference Document for Waste Incineration, European Commission Joint
Research Centre Directorate B European IPPC Bureau, December 2018,
http://eippcb.jrc.ec.europa.eu/reference/BREF/WI/WI_BREF_FD_Black_Watermark.pdf, (accessed
July 2019)
1.6 Costs This report discusses the broad technical options that are available to meet and exceed the environmental requirements of the project. At this time a review of the directly associated capital and operational costs of each option has not been progressed.
A further review into the viability of these options against local costs and drivers, for example costs of effluent treatment, water quality, availability and cost of reagents and disposal routes may be required by the Client but are not within the scope of this report.
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2 Background / Policy Context
2.1 Policy Overview NSW Energy from Waste Policy Statement (2015)
EfW technology is primarily regulated via the adopted NSW Energy from Waste Policy Statement2 (“the
Policy”). The NSW EPA3 states that the Policy encourages EfW if it can deliver positive outcomes for
people and the environment and that it ensures that EfW:
• Poses minimal risk of harm to human health and the environment.
• Facility emissions are below levels that may pose a risk of harm to the community.
• Does not undermine higher-priority waste management options, such as avoidance, re- use or
recycling.
• Meets current international best practice techniques, particularly with respect to process design
and control, emission control equipment design and control, and emission monitoring, with real-
time feedback to the controls of the process.
The Policy is prescriptive and sets-out the requirements listed below. It is important to note that the
Policy sets out two levels of control for EfW processes. The first level applies to certain ‘eligible’ wastes
when treated in EfW facilities, and the second to all other waste types, with more stringent controls
being applied in facilities that are then termed energy recovery facilities.
• Eligible waste derived fuels are permitted for use in simple combustion processes with limited
controls. This is because those fuels pose a low risk of harm to the environment and human
health due to origin, low levels of contaminants and consistency over time (what is ‘eligible’ is
subject to review by NSW EPA). The Policy defines eligible wastes as:
o Biomass from agriculture, forestry, sawmills and virgin paper pulp residues.
o Uncontaminated wood waste.
o Recovered waste oil.
o Landfill gas and biogas.
o Source separated green waste when used to make char.
o Tyres in cement kilns only.
• Waste must be unavoidable residual waste, where material recovery is not financially or
technically viable.
• EfW must represent the most efficient use of the resource and be achieved with no increase in
the risk of harm to human health or the environment (referring to the Protection of the
Environment Operations Act 1997 (POEO Act), which sets the framework to ensure that human
health and the environment are protected from the inappropriate use of waste). In relation to
EfW of eligible fuels:
2 https://www.epa.nsw.gov.au/-/media/epa/corporate-site/resources/epa/150011enfromwasteps.pdf?la=en&hash=50211762E1746B2E444D3869E5E409183312B5BB 3 https://www.epa.nsw.gov.au/your-environment/waste/waste-facilities/energy-recovery
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o A resource recovery order or exemption must have been granted by the EPA.
o The emissions standards set out in the Protection of the Environment Operations
(Clean Air) Regulation 20104 must be met.
o Facilities need to meet current international best practice techniques, particularly with
respect to process design and control, emission control equipment design and control,
and emission monitoring with real-time feedback to the controls of the process.
• That ‘mass burn’ incineration (waste destruction or energy recovery from unprocessed mixed
waste streams) is not acceptable, and innovation is encouraged.
• Facilities that do not treat only eligible wastes must meet the requirements of an energy
recovery facility (ERF), in summary:
o Apply current international best practice techniques, particularly with respect to process
design and control, emission control equipment design and control, emission
monitoring with real-time feedback to the controls of the process (and the following
which are over and above the requirements for eligible waste) arrangements for the
receipt of waste; and management of residues from the energy recovery process.
o Facilities must use technologies that are proven, well-understood, capable of handling
the expected variability and type of feedstock and be demonstrated through fully
operational plants using the same technologies and treating like waste streams in other
similar jurisdictions. Must meet the following technical criteria:
▪ Meet 850°C for at least 2 seconds in the combustion chamber [equivalent to
the European Industrial Emissions Directive] or 1100°C for 2 seconds if the
waste contains more than 1% of halogenated organic substances, expressed
as chlorine.
▪ Meet or exceed the Group 6 emission standards in the POEO Act [Ricardo
assumes that the limits for ‘general activities and plant’ apply] (solid particles
50 mg/m3; NOx 350 mg/m3; SOx 100 mg/m3; H2S 5 mg/m3; HF 50 mg/m3; Cl
200 mg/m3; VOCs 40 mg/m3 or CO 125 mg/m3; HCL 100 mg/m3; Cd or Hg 0.2
mg/m3; dioxins or furans 0.1 ng/m3; type 1 (Sb, As, Cd, Pb, Hg) and type 2 (Be,
Cr, Co, Mn, Ni, Se, Sn, V) substances 1 mg/m3; smoke Ringelmann 1 or 20%
opacity.
▪ Continuous measurements of NOx, CO, particulates, total organic
compounds, HCL, HF and SO2 and available in real time to the EPA, plus
combustion temperature, pressure and temperature in stack, oxygen
concentration and water vapour in exhaust gas.
▪ Proof of performance trials as part of the licence conditions to demonstrate
compliance with emissions limits and subsequently twice-yearly
measurements of heavy metals, PAHs, chlorinated dioxins and furans, and all
to be subject to continuous monitoring if and when appropriate measurement
techniques are available.
▪ Total organic carbon (TOC) or loss on ignition (LOI) content of the slag
and bottom ashes must not be greater than 3% or 5% (dry weight)
respectively.
4 https://www.legislation.nsw.gov.au/regulations/2010-428.pdf
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▪ Waste feed interlocks to prevent feeding when required temperature
has not been reached.
▪ Air quality impact assessment must be undertaken in accordance with
the Approved Methods for the Modelling and Assessment of Air
Pollutants in NSW.
o Thermal efficiency criteria:
▪ Plants that do not recover energy are outside the scope of the Policy.
▪ At least 25% of energy will be captured as electricity (or an equivalent level of
recovery for facilities generating heat alone).
▪ Any heat must be demonstrated to be recovered as far as practicable.
o Resource recovery criteria:
▪ Feedstock must be from waste processing facilities or collection systems that
meet specific criteria, unless agreed by the EPA on a case-by-case basis.
▪ For mixed municipal waste there are limitations on waste that can be subject
to EfW depending on whether the council separately collects dry recycling,
food and green waste.
▪ Mixed commercial and industrial waste that can be subject to EfW is limited if
no separate collections are in place for all waste streams being generated.
▪ Mixed construction and demolition waste can only be subject to EfW up to 25%
by weight.
▪ Limits apply to the percentage of residues from the processing of separated
recyclables, green and food waste that can be subject to EfW.
▪ Waste wood and textiles can be subject to EfW if sourced directly from a waste
generator (e.g. manufacturing).
o Other requirements:
▪ Waste must not contain batteries, light bulbs, other electrical and hazardous
waste.
• An EfW or ERF development must be subject to public consultation; engage in genuine
dialogue with the community; ensure that planning consent and other approval authorities are
provided with accurate and reliable information; and be ‘good neighbours’, particularly when
near residential areas and employment.
Further consideration of NSW Energy from Waste Policy
Since the publication of the Policy, Federal and State Environment Ministers agreed at the 7th meeting
of Environment Ministers on 27 April 2018 to a series of 6 announcements, including investigation of
waste to energy in line with the waste hierarchy5.
“Ministers agreed to… Explore opportunities to advance waste-to-energy and waste-to-
biofuels projects, as part of a broader suite of industry growth initiatives, recognising the
reduction, reuse and recycling of waste is a priority, consistent with the waste hierarchy.
This will include support from the Clean Energy Finance Corporation and the Australian
Renewable Energy Agency.”
5 https://www.environment.gov.au/system/files/pages/4f59b654-53aa-43df-b9d1-b21f9caa500c/files/mem7-agreed-statement.pdf
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Also post-dating the Policy, the 2018 Australian Senate Inquiry into waste and recycling and an
extension of the NSW Parliamentary Inquiry into Energy from Waste6 published “‘Energy from Waste’
technology”. The objectives included: consideration of the “role of ‘energy from waste’ technology in
addressing waste disposal needs”, a review of worldwide regulatory standards for EfW and “additional
factors which need to be taken into account within regulatory and other processes for approval and
operation of ‘energy from waste’ plants”.
The inquiry acknowledged concerns over EfW, particularly whether they pose an undue risk to human
health and the environment but recognised the importance of managing waste in accordance with the
waste hierarchy and the NSW Waste Avoidance and Resource Recovery Act 2001, which dictate that
energy recovery is preferable to disposal. The inquiry report goes into a detailed discussion of the
findings of the inquiry, which is outside the scope of this review. There is however a notable reference
to the need for a reference facility and that this stifles innovation and investment.
There is also reference to the expectation of the NSW EPA publishing Energy Recovery Facility
Guidelines in early 2018, indeed its publication forms a specific recommendation of the inquiry.
However, at the time of writing the EPA website refers to this document as being in progress.
Considering these anticipated guidelines, and a further recommendation to set up an “expert advisory
body on energy from waste chaired by the Chief Scientist to examine and report on the energy from
waste regulatory framework”, Ricardo would anticipate an update to the Policy in the short-medium
term.
6 https://www.parliament.nsw.gov.au/committees/DBAssets/InquiryReport/ReportAcrobat/6146/Final%20-%20Report%2028%20March%202018.pdf
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3 Indicative BAT Assessment
3.1 Introduction This section of the report identifies the technology groupings that are currently considered “Best
Practice” internationally, drawing on experience in Europe, the USA and Asian markets (in particular
the European market). The use of these technologies can be dependent on the nature of the fuel and
wider scope of the project, and so following a review of the key policy drivers, we identify the fuel type
proposed and how it fits within the resource hierarchy.
3.2 Refuse Derived Fuel Before entering into a discussion on the different technologies, it is important to note that this project is
based upon the use of an RDF prepared from Municipal Solid Waste. The EFW Policy states very
clearly that some facility types are excluded from compliance. One of these specific categories that
excluded facilities include those that are “facilities proposing the thermal treatment of unprocessed
waste streams”.
This is an important reference as it makes clear that any fuel must first be processed to remove anything
of immediate value to the resource market leaving only residual elements with no current value to be
combusted within an Energy from Waste scheme.
A Refuse Derived Fuel (RDF) is derived from residual waste that has been through a processing
operation, removing metals and other readily recyclable items as well as non-combustible materials
(bricks, stones, glass etc) before shredding the material to a consistent size that can be transported
either in bulk compacted form or baled and wrapped for longer term storage.
Therefore, it is apparent that the Mt Piper Energy Recovery Project meets the requirements of the Policy
in terms of its feedstock, i.e. that “Further material recovery through reuse reprocessing or recycling is
not financially sustainable or technically achievable” though is not classified as one of the “Eligible
Waste Fuels”.
3.3 Best Available Techniques This section considers the Best Available Techniques (BAT) in each of the main areas of consideration
under the NSW EFW Policy document as they are seen in the EU, but also drawing on the experience
elsewhere in the world.
It should be noted that many industrialised nations draw upon UK and European standards for their
projects and define their national standards using these as a starting point. As an example, many
projects in the Middle East also refer to these standards as being best practice for any implementation
of projects. For this reason, consideration of BAT, in this report, particularly focuses on European
standards.
The NSW EFW Policy document also draws a distinction that any technology used should be “proven,
well understood technology” and therefore those technologies that are considered to be emergent or
disruptive technologies are not considered here.
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3.3.1 Combustion Techniques
There are a number of different technologies that exist for the combustion of municipal waste derived fuels. In general, the proven technologies can be grouped into 4 main categories which we discuss here.
• Moving Grate
• Fluidised Bed
• Gasification
• Pyrolysis
3.3.1.1 Moving Grate
Overview
Worldwide, the vast majority of plants used for the thermal treatment of municipal waste utilise moving
grate technology. Moving grates exist in a variety of different designs (roller grates, reverse
reciprocating, reciprocating) but each involves the use of a system that distributes the fuel across a
grate. A mechanism for moving the material down the grate as it burns, agitating and turning the
material as it does so, whilst primary air is blown through the grate to support the combustion. This
allows for good mixing of material, breaking it up as it progresses. Secondary air is commonly
introduced above the grate, creating areas of turbulence to ensure the complete burn out of volatile
compounds.
Moving grate technology can be used for a wide range of fuels as the control systems can vary the
residence time that the material remains on the grate thereby ensuring good burnout and a low TOC
content in the bottom ash.
Environmental Performance
The moving grate system is well established technology and the provision of advanced control of the
combustion system means that it can operate with low NOX levels. However, it will still not achieve the
requirements of the industrial emissions directive (‘IED’) without the addition of secondary measures.
Incorporation of SNCR (discussed later) means that the NOX levels set by the IED can be achieved
(400 ppm for ½ hr average and 200 ppm for daily average, noting that the EPAs Group 6 Emissions
from the Protection of the Environment Operations (Clean Air) Regulation 2010 limit is 357 ppm for 1
hr average).
In relation to ash generated, in general terms the moving grate presents most of the ash (~80%) as
bottom ash with the remainder being carried into the gas path to be extracted by the Flue Gas Cleaning
Plant. With the bottom ash being able to be reprocessed in some economies, this creates even more
opportunities for resource recovery.
3.3.1.2 Fluidised Bed Combustion
Overview
Fluidised bed combustion systems require a reasonable degree of pre-treatment of the fuel to ensure
that it is of a consistent size and free of non-combustible elements. It is typically used on biomass and
sludge-based fuels due in part to the high degree of consistency of the fuel and the thermal “inertia”
within the sand medium used to support the combustion process. An RDF fuel, where incombustibles
are removed, would be appropriate for this type of technology based on fuel feed characteristics.
Fluidised Bed systems exist in a number of different forms, from bubbling bed (where the bed material
remains in a contained volume within the first pass/combustion chamber) to circulating bed types (where
the material is subject to a greater primary air flow, carrying the bed material through the first pass at
the top of which it passes through a cyclone to return the bed material and unburnt material to the base
of the combustor).
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While fluidised bed combustion can lead to slightly lower NOx generation, the injection of ammonia
solution or urea is still required to achieve the emission limits specified in the waste incineration articles
of the IED and relevant BAT Reference Notes.
Environmental Performance
In general, Fluidised Bed Combustion can achieve lower NOx levels as thermal NOx generation can be
lower. However, even assuming for a pre-prepared fuel, the overall the energy efficiency of the plant
is lower due to the greater energy flows required by the process.
With regards to ash generation, the sand material of the bed has a degradation through the constant
agitation of the bed and adds a further element of material to the fly ash. The proportion of bottom ash
to fly ash is much more in favour of the production of fly ash in fluidised bed systems, whether bubbling
or circulating.
3.3.1.3 Gasification and Pyrolysis
Overview
Pyrolysis is the thermal degradation or decomposition (thermolysis) of organic materials by heat,
without combustion, in either the complete absence of oxygen or where it is so limited that gasification
does not occur to any appreciable extent. Conventional pyrolysis takes place at temperatures between
400-900°C and products include syngas, liquid and solid char. Liquid product is also known as pyrolysis
oil, olefin, or bio-oil when processing biomass. Utilising pyrolysis for waste treatment is currently less
well developed than gasification although there are some examples of these systems being installed.
Pyrolysis is a mature technology in terms of its application to coal, peat and liquid fossil fuels, however
there are limited examples in its application to waste derived fuels. There is some experience of slow
pyrolysis of MSW, but these still tend to be in development stages, and there are several examples of
project failures (for example, the MSW and clinical waste-based pyrolysis process operated by Compact
Power, later Ethos, in the UK is no longer operational). Successful examples of pyrolysis tend to be
those plants using homogenous waste streams such as tyres and wood chip. There are different
configurations of pyrolysis equipment, including fluidised bed, moving bed and rotating cone.
The design of the pyrolysis process will impact on the characteristics of the process outputs. For
example, slow pyrolysis will produce charcoal, oil and gas, whereas fast pyrolysis is designed to
maximise the production of pyrolysis oils. The pyrolysis process requires the input of energy to sustain
pyrolysis process (equivalent to 20-25% of input energy). Whilst gasification systems can be designed
to release some of the energy in the feedstock to sustain the gasification process, Pyrolysis generally
needs energy from an external source to sustain the process.
Gasification is the thermal breakdown/partial oxidation of waste under a controlled oxygen atmosphere
(the oxygen content is lower than necessary for combustion). The waste reacts chemically with steam
or air at a high temperature (>750°C). The process is sustained by the heat generated by the partial
combustion of the feedstock. The syngas (primarily consisting of CO and H2) produced by gasification
has a lower calorific value than pyrolysis gas and is dependent upon the gasification process. The tar
levels in the syngas are lower than for pyrolysis gas but depend on the actual gasification technology.
Potential syngas uses are the same as for pyrolysis.
Gasification technologies have been promoted heavily within the UK as one of the Advanced Thermal
Conversion (ATC) technologies that were eligible for additional electricity subsidies when using biogenic
wastes, of which Municipal Waste was considered eligible. A number of schemes have been installed
in the UK, but to date many have experienced problems in their construction and commissioning and
have not yet achieved their promised potential.
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Environmental Performance
Although the syngas produced by either pyrolysis or gasification has potential uses in many applications
if it can be subject to an appropriate cleaning and purification process, the only systems to have been
installed at scale are relatively close coupled systems that immediately combust the syngas to generate
steam and subsequently electricity. The char produced from the process contains heavy metals and
other contaminants and may be classified as a hazardous waste in some jurisdictions.
3.3.2 Conclusion
From the above assessment and the requirements of the NSW EPA Energy from Waste Policy, it is
clear that the most proven, and hence BAT for the treatment of municipal waste derived fuels such as
RDF is the moving grate combustion system. When fitted with an advanced combustion control system
it is able to achieve good burn out of combustion products and produce bottom ash that is low in total
organic carbon (TOC). Secondary flue gas treatment systems are still required for the control of oxides
of nitrogen as would be standard across the technology selection.
3.3.3 Flue Gas Cleaning Technologies
3.3.3.1 Pollution Absorption Systems
Basic FGT is regarded as being raw combustion gas treatment to limit the emissions of: particulate
matter or dust; acidic gases (Hydrogen chloride HCl, Hydrogen fluoride HF and Sulphur dioxide SO2);
heavy metals (mainly adsorbed on the surface of fly ash particles); and dioxins (highly toxic molecules
produced in very small amounts during part of the combustion process, absorbed by activated carbon
reagent).
NOx is treated in a separate system within the EfW plant, see below.
Carbon monoxide (CO) and TOC content requirements are addressed by controlling the combustion
conditions in the furnace.
Absorption systems are categorized into distinct systems: dry, semi-dry, wet systems and combinations
thereof:
• ‘Dry’ systems are where the chlorine and sulphur content of the waste leaves the facility as a
dry product, and no wastewater is produced. This system is commonly employed in EfW plants.
Lime is the most commonly used reagent in a dry system, sodium bicarbonate-based systems
are also specified where there is a market that is able to supply and recover the reagent.
Another differentiator between lime and Sodium Bicarbonate is the need to remove the fly ash
from the system before the introduction of the reagent, to avoid contamination. This requires
the addition of a further separation stage which would typically be an Electrostatic Precipitator
(ESP) due to its presence in a higher temperature gas stream as the optimum reaction
temperature is greater than that for hydrated lime. This means that the efficiency of the heat
recovery system is lower due to higher stack losses.
• ‘Semi-dry’ systems where hydrated lime and water are added to the gas stream, the moisture
evaporating to leave dry products. The reagents may be recirculated to reduce reagent
consumption. Both dry and semi dry systems employ a bag house filter to capture residues for
disposal.
• ‘Wet’ scrubbing systems have several processing stages. These include a wet scrubber that
produces a calcium chloride solution containing the majority of the chloride released from the
combusted waste, thereby limiting the generation of solid residues.
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3.3.3.2 Control of NOx
Waste combustion in grate fired systems results in the production of several oxides of Nitrogen
described collectively as NOx. The most commonly employed system to remove NOx from the flue
gases is Selective Non-Catalytic Reduction (SNCR).
The SNCR process entails ammonia water, or urea, injection in the upper part of the combustion
chamber of the furnace where gasses are at a temperature of 850-950°C. These temperatures are
suitable for ammonia to react with nitrogen oxide (NO) and nitrous oxide (NO2). Optimisation of the
process requires careful control of ammonia injection, flow rates and stable combustion control.
Depending on the level of optimisation, the process causes some un-reacted ammonia to leave the
boiler with the flue gas. This is known as ammonia slip.
In both dry and semi-dry FGT-systems, a certain amount of the ammonia slip is caught by the residue
in the bag house filter. The remaining ammonia leaves the plant with the clean flue gas. A typical
requirement for the maximum ammonia slip would be 5 - 10 mg/Nm³, though the slip is indicated as a
limit value in the EU Directive.
Selective Catalytic Reduction (SCR) is an alternative process that can reduce NOx levels further than
SNCR. However, it requires a catalyst to be able to operate as well as a reagent. Due to the costs and
increased complexity (different temperature range, location of injection and catalyst etc) it is considered
BAT to use SNCR.
3.3.4 Conclusions
SNCR has a lower cost of implementation but remains able to achieve the levels of NOx emissions
specified within the IED. Its effectiveness and efficiency of reagent consumption can be monitored
using analysis instrumentation to detect ammonia slip allowing the control system to vary the amount
of reagent added into the system.
For the control of dioxins, the BAT is to ensure that the process achieves the time and temperature
requirements that are specified in IED and in the NSW Policy of 850°C for 2 seconds and then ensure
the correct design of the energy recovery plant to rapidly drop the temperature of the flue gas to prevent
de novo reformation of dioxin. For residual control, and also for control of any heavy metals and
mercury, Activated Carbon injection is BAT.
The selected FGC technology is sometimes classified as a semi dry system as it operates slightly
differently to the dry system described here in that it has a flue gas conditioning/evaporative cooling
system immediately before the injection of dry reagents. This system ensures that the flue gas is at the
correct temperature and humidity, and therefore enhances the efficiency of the system, reducing the
consumption of reagents and offering improved performance to the BAT. The reagent, in addition to
the aforementioned Activated Carbon, is a dry, hydrated lime flue gas cleaning process. In this way
both reagents are injected at a similar location and reaction time is optimised through the plant control
system monitoring both stack conditions and also pressure drop across the bag filter candles.
The above technology selection confirms that the proposed project does represent BAT for the
treatment of RDF.
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4 Quantitative BAT Assessment
In this section, a quantitative / semi quantitative BAT assessment is provided, justifying the
techniques/technologies selected in comparison with other technologies.
4.1 Nitrogen oxides abatement method (SNCR vs SCR) There are two abatement methods that are available for the reduction of NOx emissions from a facility.
The difference between these two systems is that one employs a catalyst to provide the conditions for
the reaction which is typically costly in its installation and requires expensive periodic maintenance.
Selective Non-Catalytic Reduction (SNCR) systems can achieve NOx emission levels of around 100 to
150 mg /Nm³ which is well within the current daily average emission limit set in the IED of 200 mg /Nm³.
Selective Catalytic Reduction (SCR) systems can reduce NOx emissions to lower than those seen with
SNCR systems as an SCR system is much more costly to build and operate. Most EfW plants opt for
SNCR as this provides adequate performance within current IED limits, however more recent facilities
have incorporated an allowance within their design for conversion to SCR if needed.
The SNCR system proposed would, therefore, appear to be the best choice in terms of meeting
applicable emissions limits. A more costly SCR system is not justified, noting that the Air Quality Impact
Assessment (AQIA) concludes that there would be no/minimal improvement on the environmental
performance of the facility by reducing the NOx emissions to SCR levels.
4.2 Acid gases abatement method (semi-dry vs dry vs wet); Table 2 below presents positive, neutral and negative aspects of commonly available FGT systems. It
can be seen that no single flue gas treatment concept is advantageous under all the evaluation criteria
considered. Therefore, the evaluation criteria need to be weighed against the specifics of the project,
according to site location, the individual priorities and needs of the operator / owner.
Table 2: Assessment of base concepts for dry, semi-dry, combined and wet FGT technology
Evaluation criteria: Dry Semi-
dry Wet
Operational availability
- Performance history of reliable operation + + 0
- Reduced unavailable risk due to less technical
complexity + + 0
Capability
- Ability to handle changes in raw gas composition - 0 +
Flexibility
- Ability to meet more stringent future emission limit - 0 +
Health and safety
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Evaluation criteria: Dry Semi-
dry Wet
- Reduced human contact with hazardous material 0 0 0
Sensitivity to local conditions
- Limited plume visibility + + -
- Discharge of treated wastewater N/A N/A -
Other environmental issues
- Low chemical consumption - 0 +
- Low water consumption + 0 -
- Low electricity consumption + + 0
- Low residue production - 0 +
‘+’= attractive for project, ‘0’= neutral and ‘-‘=negative
When the key assessment criteria are considered, the following conclusions are drawn:
Most attractive concept
A dry or semi-dry FGT system is recommended as being the most attractive option for the Mt. Piper
development. This is due to:
• The system is optimal for EfW plants processing waste where the pollutant content is not
expected to vary significantly in future years.
• Water consumption is low (particularly for a dry system) and there is no production of
wastewater requiring specialist treatment and discharge.
• It is not envisaged that flue gas condensation is beneficial.
• Relatively simple operational requirements.
• Relatively low capital investment requirements.
Alternatives
Wet scrubbing systems are only of interest where:
• Wastewater discharge is an option.
• The waste pollutant load is high.
• There are highly stringent emission requirements and exceptional environmental ambitions.
• Low residue generation is a key factor.
The drawbacks of the system are:
• Increased technical complexity – especially where wastewater treatment is necessary
• Increased plume visibility, particularly in cold climates.
• Higher capital investment requirements.
This would exclude a wet system from consideration for the Mt. Piper development.
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4.3 Acid gases abatement reagent (lime vs sodium bicarbonate)
Table 3 below presents positive, neutral and negative aspects of a dry lime and bicarbonate system
relative to each other. Once again, it can be seen that neither reagent is advantageous under all the
evaluation criteria considered and specific project circumstances need to be taken into account.
Table 3: Assessment of lime and bicarbonate reagents
Evaluation criteria: Lime Bicarbonate Comments
Installation and operation
0 0 Either reagent (in a dry system) has low investment
costs and is relatively simple to install and operate
Performance
0 0
Acid gas removal performance is similar for both reagents.
Efficiency of lime usage may be improved by using a higher grade of lime with improved reactivity. Lime is used in many plants, particularly smaller facilities, hence the wide availability of references and operational experience.
Chemical consumption - +
Bicarbonate consumption is more moderate because approximately 20% excess reagent use is typically required.
Chemical costs and supply
+ - Bicarbonate is relatively expensive to purchase and there is often a limited number of suppliers.
Chemical residues
- +
A significant excess of hydrated lime is required to treat flue gases to levels that comply with emission limits. This is typically 100-200% excess hydrated lime and this results in large quantities of residue generation.
With bicarbonate, the use of an electrostatic precipitator before the main process results in a chemical residue at the bag filter, which can in principle be recycled. This reduces the amount of residues produced when compared to a lime-based flue gas treatment plant.
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5 Review of Proposed ERP against Indicative BAT
5.1 Introduction Although the RDF meets the requirements of some elements of the policy, it is not classified as an
“Eligible Waste Fuel” and therefore the proposed facility has to comply with the requirements of the
policy in terms of its definition of “Energy Recovery Facilities”.
As such it is required that these plants are using current international best practice techniques in the
following key areas:
• Process design and control.
• Emission control equipment design and control.
• Emission monitoring with real-time feedback to the controls of the process.
• Arrangements for the receipt of waste.
• Management of residues from the energy recovery process.
The above parameters are included within the requirements of the BATC (Best Available Techniques
Conclusions) as set out in the revised draft of the Waste Incineration BAT reference document (BREF).
Although these criteria are currently in draft, they are anticipated to be formulated by the end of 2019
and therefore represent the most likely scenario.
Ricardo’s findings against the BATC are identified in Section 6 of this report and we have provided
commentary against each element where they are both relevant and our opinion in relation to the
requirements of BAT.
5.2 Reference Facility Ricardo recognises that within the Australian market there has been little investment in facilities of this
type. However, confidence can be derived from consideration of other facilities worldwide that are able
to meet the same requirements.
Although many plants exhibit similar attributes, it is important for this project that a reference plant
closely resembling that of the proposed ERP can be identified and, if required, visited to allow any
concerns to be allayed.
The reference facility selected in discussion with the contractor is the Rudersdorf Facility operated by
STEAG. Ricardo understands the reference facility has been visited by the proponents and they have
provided relevant performance data.
The reference facility differs in that it DOES generate electricity itself, rather than providing steam to a
third party to generate electricity on its behalf. However, in all significant aspects, it exhibits strong
similarities to the proposed ERP.
It is important to note that EfW plants suffer significantly greater maintenance costs at steam
temperatures much in excess of 400°C, despite the use of specialist materials (Inconel etc.) due to ash
fusion and high temperature corrosion mechanisms. A steam temperature of 400°C has, therefore,
become a “standard” temperature for modern EfW plants. Turbines are designed against the pressure
and temperature of the steam generated, with higher pressure units driving towards greater efficiency.
It is proposed that the ERP is operated with a steam temperature of 400°C, with flexibility to operate
between 380°C and 425°C.
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The plant does utilise RDF as a fuel, with an assumed wide range of flexibility in its “firing diagram”
allowing it to operate on fuels of between 6-18MJ/kg, which is wider than the proposed Mt Piper plant.
The plant has been operating since 2009. It is also of a very similar size, having a thermal rating of
110MWth, against the proposed sites 104MWth.
More information is provided within the BATC appraisal, but a summary of key points is noted here:
Table 4. Reference Plant Characteristics Applicable to ERP7
Key Area Commentary
Process design and control. The plant will be controlled by A DCS / SCADA system
that take information from instrumentation plant wide.
Control loops within the program monitor all the
essential parameters and control the process in real
time.
Emission control equipment design and
control.
The emissions control equipment is described
elsewhere in this report, but follows standard principles
to ensure that reagent use is optimised, especially
when using a recirculation system of reagents to
improve the efficiency of use. Monitoring of factors
such as pressure drop across the fabric filter as well as
feedback from the CEMS system are all important to
reduce operational costs.
Emission monitoring with real-time
feedback to the controls of the process.
The CEMS system continuously monitors the
emissions leaving the stack and is a key indicator for
the emissions control equipment. An example would
be the direct link between ammonia injection for NOx
control. The first element for control of NOx is the
combustion control system which operates to make the
combustion process as efficient as possible. However,
the NOx levels will always need monitoring and
additional control implemented. By monitoring the NOx
level from the CEMS it can be identified if reagent
needs to be added to reduce the NOx levels further and
by monitoring other parameters can determine the
optimal level of addition.
Arrangements for the receipt of waste. The arrangements for the receipt of waste for the
reference project have to be in line with European
requirements, ensuring that any received waste,
including RDF, is clearly identified for what it is, who is
the producer and where it is going. The management
of materials on site, from receipt, inspections and
sampling, is noted within the Mt Piper Energy Recovery
Project RDF Feedstock Report by Ricardo.
Management of residues from the energy
recovery process.
Residues from the FGC plant are treated as hazardous
waste and much work has been carried out to identify
whether these can be used in block manufacture as an
example to achieve “End of Waste” status in the EU.
Bottom ash is processed and supplied into the
7 Parameters noted in Table 4 are common to the reference facility and the proposals for the ERP
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aggregates market as an inert material rather than
disposed of as a waste. In Australia we understand that
this market is yet undeveloped but has potential to
recover this material in a similar way.
5.3 Technical Criteria Table 1 below identifies the Technical Criteria from the NSW Energy from Waste Policy and confirms
whether the reference plant meets the requirements of the policy.
Table 5: Technical Criteria
Technical criteria: Proposed Plant Reference Plant
Meet 850°C for at least 2
seconds in the combustion
chamber [equivalent to the
European Waste Incineration
Directive] or 1100°C for 2
seconds if the waste contains
more than 1% of halogenated
organic substances, expressed
as chlorine.
Yes. The proposed plant has
been selected to meet this
requirement.
Yes. The plant achieves this
requirement.
Meet or exceed the Group 6
emission standards in the
POEO Act [Ricardo assumes
that the limits for ‘general
activities and plant’ apply]
(solid particles 50 mg/m3; NOx
350 mg/m3; SOx 100 mg/m3;
H2S 5 mg/m3; HF 50 mg/m3; Cl
200 mg/m3; VOCs 40 mg/m3 or
CO 125 mg/m3; HCL 100
mg/m3; Cd or Hg 0.2 mg/m3;
dioxins or furans 0.1 ng/m3; type
Yes. The proposed plant will be
able to achieve the emissions
limits stated in European
Directive 2010/75/EU, the
Industrial Emissions Directive
which has more stringent
requirements for some
parameters than NSW set limits.
The plant operates to the
requirements of the Waste
Incineration Directive (WID),
the forerunner of the
Industrial Emissions
Directive.
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Technical criteria: Proposed Plant Reference Plant
1 (Sb, As, Cd, Pb, Hg) and type
2 (Be, Cr, Co, Mn, Ni, Se, Sn,
V) substances 1 mg/m3; smoke
Ringelmann 1 or 20% opacity.
Continuous measurements of
NOx, CO, particulates, total
organic compounds, HCL, HF
and SO2 and available in real
time to the EPA, plus
combustion temperature,
pressure and temperature in
stack, oxygen concentration and
water vapour in exhaust gas.
Continuous monitoring of the flue
gas at the stack is available
within the DCS. Subject to
providing a secure portal this
data will be made available to the
EPA.
Continuous monitoring of the
flue gas by a CEMS system
is in place.
It is not a requirement of the regulator to have online access to these readings, a public website is available with summary data8
Proof of performance trials as
part of the licence conditions to
demonstrate compliance with
emissions limits and
subsequently twice-yearly
measurements of heavy metals,
PAHs, chlorinated dioxins and
furans, and all to be subject to
continuous monitoring if and
when appropriate measurement
techniques are available.
Regular testing will be carried out
and sample points fitted at
appropriate locations on the flue
gas ductwork and stack to
facilitate the taking of those
measurements.
A regular monitoring regime
is required by the regulators
and it is understood that this
takes place at similar
intervals.
Total organic carbon (TOC) or
loss on ignition (LOI) content of
the slag and bottom ashes must
not be greater than 3% or 5%
(dry weight) respectively.
The proposed plant will be
including this as standard within
its design.
No specific information
provided to Ricardo, but this
is a standard parameter that
has been in place across
plants for a long time.
Waste feed interlocks to prevent
feeding when required
temperature has not been
reached.
The proposed plant will be
including this as standard within
its design.
This is a requirement of the
regulations and will be fitted.
This is a common
requirement on Energy from
Waste plants since the
introduction of WID.
Air quality impact assessment
must be undertaken in
accordance with the Approved
Methods for the Modelling and
Assessment of Air Pollutants in
NSW.
An Air quality Impact Assessment
has been carried out for the
facility.
A full air quality impact
assessment in accordance
with local requirements was
undertaken for the facility.
8 https://xn--ikw-rdersdorf-0ob.de/emissionswerte.htm
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Technical criteria: Proposed Plant Reference Plant
Thermal efficiency criteria:
Plants that do not recover
energy are outside the scope of
the Policy.
Not applicable. Not applicable.
At least 25% of energy will be
captured as electricity (or an
equivalent level of recovery for
facilities generating heat alone).
It is anticipated that
approximately 30MWe will be
attributed to the steam provided
by the facility. Performance
modelling of the scheme has
provided an indicative figure of
29% for overall energy recovery,
a significant step above the
Policy threshold level.
Performance figures from
Rudersdorf indicate that the
efficiency of the process is
around 30%.
Any heat must be demonstrated
to be recovered as far as
practicable.
The facility will supply the
recovered heat to the Mt Piper
Unit 2 in the form of superheated
steam for the generation of
electricity.
There is some heat offtake
from the process, supplying
local industrial consumers.
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6 Assessment against BATC
The IED specifies that a BATC review is considered to be a process whereby site-specific BAT is
determined with reference to relevant BATC. A BATC document is defined in the IED as a document
containing the parts of a BREF laying down the conclusions on best available techniques. In basic
terms the BATC will describe the issues to be considered and the expected performance levels of an
installation; it is then for the operator to demonstrate and ensure that the installation can meet these
performance levels.
BATC have a key role in the review process as their publication is the reference for setting permit
conditions.
BAT 1. In order to improve the overall environmental performance, BAT is to elaborate and
implement an environmental management system (EMS).
Compliant due to the following:
The Operator is experienced in the development and implementation of the necessary procedures
under an Environmental Management System (EMS) and have already put in place a certified system
for the existing Mt Piper installation. The nature of the different core activities means that for clarity the
ERP will not be incorporated into the wider Mt Piper EMS, but instead will have its own procedures and
systems in place and will seek to implement a certified ISO14001 EMS as soon as practicable.
The procedures to be put in place to implement the Environmental Policy will be developed as part of
the ongoing review of the operations throughout the design and construction of the project. This will
ensure that a robust and viable set of procedures can developed that are effective and achievable at
an early stage. The ERP has been fully assessed through the Environmental Impact Statement (EIS)
process to identify areas in which there is potential for any environmental risks to be present and these
have been identified for incorporation into the emergency planning for the site.
In operation, the plant will be controlled by a DCS/SCADA based system that will allow monitoring of
all systems ensuring effective and efficient operation of the plant. The system will provide for logging
and monitoring of key process parameters that can be used to seek resolution to any issues that arise
on the plant.
The ERP will be subject to its own safety permitting scheme, ensuring that any operations and
maintenance work is carried out in a safe manner and that “safety from the system” can be achieved
prior to any normal maintenance activity.
Maintenance procedures shall be put in place that will provide for condition monitoring and Planned
Preventative Maintenance (PPM).
In order to ensure that these, and other monitoring requirements are maintained, the Operator will be
subject to a system of both Internal and External audits that will serve to identify any ways in which the
EMS and other systems can be improved.
The EMS will also incorporate procedures that relate to the monitoring of residues and fugitive
emissions generated from the process as well as emissions to air and water, for example bottom ash
and odour.
These will be subject to appropriate plan documents that will be put in place as part of the EMS to
ensure that adequate controls are present and applied to minimise any impact of the plant.
With any facility, it is important that the decommissioning of the plant is covered within the construction
phase, to ensure that the plant can be safely taken out of service at the end of its useful life. As such
a Decommissioning Plan will be included in the EMS, covering key aspects of work that will be required.
Note that at this time this will be a high-level document in accordance with any local requirements.
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BAT 2. BAT is to determine either the gross electrical efficiency, the gross energy efficiency, or
the boiler efficiency of the incineration plant as a whole or of all the relevant parts of the
incineration plant.
Compliant due to the following:
The ERP will be supplying steam into the reheat cycle of the Mt Piper unit and therefore electrical
efficiency is not able to be monitored directly. Boiler Efficiency will therefore be used as an indicator of
the plant’s performance.
The operational efficiency of the plant will be monitored on a continuous basis through the DCS, but a
formal test would be required on a periodic basis to validate this.
A full load test will need to be carried out taking into account the potential variation in Calorific Value of
the RDF, and the net energy supplied to Mt Piper.
It is anticipated that due to the arrangement with Steam being supplied into the existing unit that
correspondingly higher electrical generation per unit of steam can be achieved.
BAT 3. BAT is to monitor key process parameters relevant for emissions to air and water.
Compliant due to the following:
A Continuous Emissions Monitoring System (CEMS) will be installed on the plant located in the stack
or flue gas ductwork.
Sensors within the ductwork will allow the measurement of pressure and temperature and flow rate will
be monitored by using an ultrasonic device.
The parameters will be monitored through the DCS and should there be a significant variation alarms
will be raised to alert the operator.
Any waste water from the plant is normally stored for reuse within the plant and will be monitored for
pH, temperature and production rate.
If there are any other residues, these will also be similarly monitored and treated prior to disposal in
accordance with the relevant discharge consents.
BAT 4. BAT is to monitor channelled emissions to air with at least the frequency given below
and in accordance with EN standards. If EN standards are not available, BAT is to use ISO,
national or other international standards that ensure the provision of data of an equivalent
scientific quality.
Compliant due to the following:
Channelled emissions to air relate to the release of emissions from the stack as the single point source
emission from the ERP.
There is potential for (fugitive) emission from other areas of the plant in the form of noise, odour and
dust, though these are subject to local controls as discussed elsewhere in this document.
Channelled emissions to air shall be monitored through the use of an appropriately certified Continuous
Emissions Monitoring System (CEMS) that will be installed in the stack or flue gas ductwork after all
flue gas treatment operations.
This will provide for regular monitoring in accordance with the Industrial Emissions Directive
(2010/75/EU).
In addition, there are some determinants that are to be monitored on a periodic basis and sampling
ports to meet the requirements of the monitoring agency are to be installed on the plant.
Any sampling point needs to be in a location that can ensure that representative samples can be taken
and that a stable gas flow condition has been achieved.
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BAT 5. BAT is to appropriately monitor channelled emissions to air from the incineration plant
during OTNOC.
Compliant due to the following:
Monitoring of the plant during Other Than Normal Operating Conditions (OTNOC) will be carried out
using the direct CEMS instrumentation.
Emissions during start up and shutdown will be estimated as the start-up conditions will not generally
provide for adequately stable conditions for monitoring.
BAT 6. BAT is to monitor emissions to water from FGC and/or bottom ash treatment with at least
the frequency given below and in accordance with EN standards. If EN standards are not
available, BAT is to use ISO, national or other international standards that ensure the provision
of data of an equivalent scientific quality.
Not Applicable.
Waste water from the processes on site will normally be reused within the site, for example bottom ash
quenching, and therefore there will not be any releases from the site.
Should there be a requirement for waste water to be released from site, it would be carried out under a
defined trade discharge consent or tankered from site for disposal via a facility licensed to receive that
waste.
BAT 7. BAT is to monitor the content of unburnt substances in slags and bottom ashes at the
incineration plant with at least the frequency given below and in accordance with EN standards.
As part of the EMS, the plant will implement monitoring procedures to review the quality of bottom ash
produced.
BAT 8. For the incineration of hazardous waste containing POPs, BAT is to determine the POP
content in the output streams (e.g. slags and bottom ashes, flue-gas, waste water) after the
commissioning of the incineration plant and after each change that may significantly affect the
POP content in the output streams.
Not applicable.
The Mt Piper ERP is not going to be processing Hazardous wastes, and therefore this requirement is
not applicable.
BAT 9. In order to improve the overall environmental performance of the incineration plant by
waste stream management (see BAT 1).
Please also see Mt Piper Energy Recovery Project RDF Feedstock Report - Ricardo
The Plant has been designed to accept an RDF that has bene specifically prepared to meet the
requirements of the combustion plant. The RDF specification is derived from municipal and Industrial /
Commercial (I&C) waste streams with a target CV of and waste (commercial waste which is similar in
composition to municipal waste) with a calorific value of 15MJ/kg. Over time it is likely with changing
lifestyles through regulation it is possible that the CV of the RDF will change, but the operating envelope
(aka “firing diagram”) of the plant allows for operation between 9 – 18MJ/kg giving significant ongoing
flexibility.
Prior to delivery to the plant, the specification for the RDF will be clearly communicated to the providers,
with regular audit and checks carried out to ensure that the RDF is suitable for processing at the plant.
Particular reference will be made to those criteria that are important for the management of
environmental issues on site, such as the fraction size of the RDF (large items may cause blockages in
the feed system or in the ash discharge of the combustion unit) and the component waste streams
being processed (to ensure that the RDF comprises non-hazardous material) to create the RDF.
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Procedures will be in place for material received at the plant. Visual inspections of bulk compacted
loads will take place on arrival against any potential fire risk, and on depositing in the bunker for any
non-compliances in material. Occasional loads will be deposited on the floor for inspection and
sampling prior to pushing into the bunker.
Samples will also be taken to check the calorific value, moisture content and other characteristics of the
waste on the basis of individual suppliers to the plant.
As the material is all RDF, there is no need for specific segregation of material and once deposited in
the bunker it will become mixed and blended with other material already in place. This creates a
homogenous mix of material for feed into the combustion, aiding the plants ability to maintain stable
combustion conditions.
Whilst there may be a storage area identified for bales, the preference is that baled material will be
opened and delivered to the bunker as soon as practicable. In the event that storage is required, this
will be managed on a first in / first out basis with clear labelling to identify the bales
BAT 10. In order to improve the overall environmental performance of the bottom ash treatment
plant, BAT is to include output quality management features in the EMS (see BAT 1).
Compliant due to the following:
The bottom ash from the ERP will not have any appreciable metal content as this will have been
extracted as part of the fuel preparation (RDF) process.
The bottom ash will be monitored in order to ensure that the necessary requirements (BAT 7) are met
prior to its transport and storage within a landfill.
Within the UK and Europe, the market for bottom ash as a material is well developed due to the number
of facilities and the volume of material generated. In Australia, this market, and the associated
regulatory environment, is yet undeveloped and so, until such time as it becomes viable to recover it, it
will be stored in a dedicated cell.
BAT 11. In order to improve the overall environmental performance of the incineration plant,
BAT is to monitor the waste deliveries as part of the waste acceptance procedures (see BAT 9
c) including, depending on the risk posed by the incoming waste.
Compliant due to the following:
The ERP will only be receiving RDF that has been processed from Municipal waste and other similar
non-hazardous waste streams. Therefore, only the first category of this section is relevant to this project.
Please see BAT 9 above also. The RDF being delivered to the site will be in either baled or bulk
compacted form and as such will be delivered in different ways.
Bales
Delivery of bales that are being immediately processed will be batch weighed as they are delivered to
site over the weighbridge. Any that are going into storage will be noted to ensure that accurate stock
records can be maintained.
Visual inspection of the bales to ensure their integrity will be carried out, particularly where the bales
are going to be stored. The internal content of bales cannot be checked until it has been passed through
the bale breaker / shredder on feeding into the bunker. However, appropriate quality checks and audits
at the producer sites will be carried out to ensure consistency is achieved.
This will also include periodic sampling and/or the consideration of an analyser within the RDF process
line to confirm the typical energy content and other key composition parameters of the material.
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Bulk Compacted
Bulk compacted material will also be weighed as it enters the site and the producer sites will also be
subject to regular review to ensure that the material is appropriate for processing by the ERP.
A visual inspection of each load prior to tipping may be carried out, though this will only be relatively
cursory for issues such as large items, or serious issues such as a potential hot load (i.e. visible signs
of smouldering).
Periodic samples of the RDF being tipped at the site will be taken on a supplier and load frequency
basis so that key parameters such as energy content can be monitored, thereby ensuring a consistent
feed into the plant.
BAT 12. In order to reduce the environmental risks associated with the reception, handling and
storage of waste.
Compliant due to the following:
RDF coming into the site will either come in bulk compacted or in baled form. Wrapped bales of RDF
are, by their nature, sealed to prevent any release of liquid effluent/leachate and on arrival will be
processed through a large shredder and discharged into a large concrete storage bunker. Use of a
concrete storage bunker is common practice throughout the vast majority of EFW plants worldwide and
provides a sealed unit that prevents leachate from the fuel seeping into the local environment. It also
means that groundwater cannot ingress into the fuel causing combustion problems.
In general, leachate in the fuel is reabsorbed and processed through the plant.
The bunker area is fully enclosed to prevent odour emissions, wind-blown litter and dust emissions from
the site and any excessive bunker leachate is extracted and treated.
The bunker will have a design capacity of 4.5 days, which is based on the requirement to continuously
operate through periods when no deliveries are being accepted at the plant. At this level there is little
risk of spontaneous combustion of the stockpile. For the majority of the time the storage bunker will not
be full (perhaps operating around 50% capacity), and the operators will make reasonable efforts to
process “older” RDF first. There is also the capability to stack RDF further during short term plant
outages for continuity of deliveries.
The plant operator would liaise with waste suppliers to control deliveries as set out in the Operation and
Maintenance plan which would be developed during the plant design and construction phase
BAT 13. In order to reduce the environmental risk associated with the storage and handling of
clinical waste.
Not applicable.
BAT 14. In order to improve the overall environmental performance of the incineration of waste,
to reduce the content of unburnt substances in slags and bottom ashes, and to reduce
emissions to air from the incineration of waste, BAT is to use an appropriate combination of the
techniques given below.
Compliant due to the following:
Use of an RDF fuel provides for some relative consistency in feedstock relative to an unprocessed
Municipal Waste. However, some fluctuations in quality can arise depending on its source and therefore
mixing and blending operations with the bunker crane are a crucial part of the process to ensure good
operation of the plant.
At regular intervals, when the crane is not involved in feeding the hopper, selective mixing of the bunker
material will take place, allowing not only for consistency of feed but also for the operator to spot any
larger items of waste within the RDF that would present a risk to the process.
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The combustion control system incorporated as part of the DCS also provides for online adjustment of
primary and secondary combustion air flows and fuel feed-rate to ensure that the combustion process
is optimised.
BAT 15. In order to improve the overall environmental performance of the incineration plant and
to reduce emissions to air, BAT is to set up and implement procedures for the adjustment of the
plant’s settings, e.g. through the advanced control system (see description in Section 2.1), as
and when needed and practicable, based on the characterisation and control of the waste (see
BAT 11).
Compliant due to the following:
The ERP will be controlled via a Distributed Control System (DCS). This allows for the operators to
monitor and control all aspects of the process from the control room. It will incorporate various
automatic control set points for the process that will allow the DCS to monitor and adjust key parameters
such that the overall process efficiency is maintained.
The advanced combustion control system is incorporated within the DCS and therefore meets this
requirement.
BAT 16. In order to improve the overall environmental performance of the incineration plant and
to reduce emissions to air, BAT is to set up and implement operational procedures (e.g.
organisation of the supply chain, continuous rather than batch operation) to limit as far as
practicable shutdown and start-up operations.
Compliant due to the following:
The ERP will maintain strong links with its fuel supply chain, as much as to ensure that the RDF being
received is of a consistent quality as to ensure security and regularity of supply. By incorporating a 4.5
day storage bunker as well as bale storage facility, the plant can continue operating even over some
days of breakdown of the supply chain, allowing any issues arising to be managed. It is standard
practice across Waste to Energy plants of this type to have a bunker sized at this capacity.
The core principle of operation for the ERP, and other energy from waste facilities of this type, is to
operate as “base load”, i.e. to be operating continuously except for periods of planned maintenance.
BAT 17. In order to reduce emissions to air and, where relevant, to water from the incineration
plant, BAT is to ensure that the FGC system and the waste water treatment plant are
appropriately designed (e.g. considering the maximum flow rate and pollutant concentrations),
operated within their design range, and maintained so as to ensure optimal availability.
Compliant due to the following:
At this stage of the design the techniques proposed to control emissions are broadly categorised into
two key areas:
1. Control of NOx.
2. Absorption of Pollutants.
The selection of technologies to be used do not require waste water treatment as a “Dry” FGC system
is proposed rather than ‘Wet’ scrubbing systems which have several processing stages.
NOx control will utilise two key methodologies. Flue Gas Recirculation, where a proportion of the flue
gas is recirculated back into the combustion system, and Selective Non-Catalytic Reaction (SNCR).
The SNCR process entails ammonia water, or urea, injection in the upper part of the combustion
chamber of the furnace where gasses are at a temperature of 850-950°C. These temperatures are
suitable for ammonia to react with nitrogen oxide (NO) and nitrous oxide (NO2).
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There is potential for an emission of ammonia from the stack using SNCR, which is termed “ammonia
Slip”. However, this is a useful parameter as it can be continuously monitored and kept to a minimum
level, therefore allowing the process to operate efficiently.
A dry absorption systems is where the chlorine and sulphur content of the waste leaves the facility as
a dry product, and no wastewater is produced. This system is commonly employed in EfW plants. Lime
is the most commonly used reagent in a dry system, noting that sodium bicarbonate-based systems
are also sometimes specified.
BAT 18. In order to reduce the frequency of the occurrence of OTNOC and to reduce emissions
to air and, where relevant, to water from the incineration plant during OTNOC, BAT is to set up
and implement a risk-based OTNOC management plan as part of the environmental management
system (see BAT 1).
Compliant due to the following:
As part of the design process critical failure items will be identified and, where appropriate, redundancy
included within the design.
The core principle of the ERP will be to maintain the plant effectively to ensure that there are limited
opportunities for OTNOC to apply and procedures will be in place to coordinate and control the
maintenance of the plant. By controlling and monitoring the plant through the DCS, many situations
can be identified early and a shutdown of the plant avoided.
A key component of the design is to ensure that the plant operates to achieve the required post
combustion residence requirements of 850°C for 2 seconds. Should the DCS (or operator) identify that
the operating temperatures are dropping, then the auxiliary start up burners will be initiated to keep the
plant operating at its required temperatures.
Should power to the site be lost for any reason, it is normal that an emergency / standby generator be
employed in order to provide sufficient power that the site can shut down in a controlled fashion.
Through the design phase the potential for secure power supplies to be provided from the existing
network (Mt Piper Power Station) may also be considered as an alternative.
At all times the CEMS system will be operational and will ensure that the emissions to air are monitored
in accordance with the requirements of the EPA.
BAT 19. In order to increase the resource efficiency of the incineration plant, BAT is to use a
heat recovery boiler.
Compliant due to the following:
The ERP will recover energy in the form of steam through a boiler. This steam will be provided to the
Mt Piper Power Station at a pressure and temperature to be introduced into the existing “reheat” steam
circuits. The pressure and temperature of this steam circuit is typical of Energy from Waste boiler
conditions, as being a temperature, at which fouling and corrosion of the boiler can be minimised
providing for economic operation.
BAT 20. In order to increase the energy efficiency of the incineration plant, BAT is to use an
appropriate combination of the techniques given below.
Compliant due to the following:
The ERP will use a variety of techniques in order to maintain high levels of energy efficiency. As is the norm for these plants, the entire combustion system and boiler will be well insulated and
incorporate the use of heat recovery tubes in the membrane walls of the combustion chamber and
immediately adjacent gas path.
Combustion air is carefully controlled through the control system to maintain optimum combustion
conditions and defines the amount of draught required.
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The boiler will incorporate a number of tube bundles as part of the heat recovery system, including
evaporator, superheater and economiser tubing sections and these will be positioned to ensure that
good quality steam can be produced at the same time as ensuring a rapid temperature drop of the flue
gas through critical temperature bands to prevent the reformation of dioxins and furans via de Novo
Synthesis.
The steam conditions have been selected to meet the requirements of the adjacent power station, and
by operating in this steam supply mode allows for a greater electricity yield per unit of ERP steam than
by fitting a dedicated steam turbine.
The use of heat exchangers beyond the economiser within the system, e.g. after the FGC system, is
restricted in many plants as the flue gas temperature at the exhaust of the stack needs to have sufficient
temperature to encourage plume buoyancy and dispersion of the flue gas. In addition, the opportunity
for recovering this heat into the cycle remains very low as other sources of waste heat are already
utilised in order to preheat combustion air, for example.
This is carried out by using the cooling system of the grate to preheat air and, in some circumstances,
feed water. Feedwater will be provided from the Mt Piper power station and therefore the requirement
to preheat raw water is negligible.
The ERP plant design incorporates good practice techniques as can be seen on the reference plant
and will have a high efficiency of energy recovery to steam.
BAT 21. In order to prevent or reduce diffuse emissions from the incineration plant, including
odour emissions.
Compliant due to the following:
Odour from the plant will be managed through the implementation of an Odour Management Plan, to
be included within the EMS.
In general, when the plant is operational air for combustion will be drawn from the area above the waste
storage bunker, bringing that area of the building under a slight negative pressure and therefore
reducing the potential for release of odour. Limiting the openings into the building through door
management procedures also improves this control.
Material in the bunker will be processed in reasonable time frames from receipt and therefore will not
be allowed to remain in the bunker for long periods of time increasing their potential to emit odorous
compounds.
At times when the plant is offline, the bunker area will be closed and a bunker standstill odour extraction
system will mitigate any emission of odours.
Any other waste stored in bales will be sealed preventing any release of odour.
BAT 22. In order to prevent diffuse emissions of volatile compounds from the handling of
gaseous and liquid wastes that are odorous and/or prone to releasing volatile substances at
incineration plants, BAT is to introduce them into the furnace by direct feeding.
Not applicable due to the nature of the acceptable wastes for the ERP.
BAT 23. In order to prevent or reduce diffuse dust emissions to air from the treatment of slags
and bottom ashes, BAT is to include in the environmental management system (see BAT 1).
The bottom ash will be deposited on site in a controlled fashion with water addition to minimise dust
production during transport and placement in the ash repository.
Due to metals being removed from the RDF pre-combustion, no treatment or separation processes are
proposed at this time.
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BAT 24. In order to prevent or reduce diffuse dust emissions to air from the treatment of slags
and bottom ashes, BAT is to use an appropriate combination of the techniques given below.
Not applicable, as bottom ash treatment processes do not form part of this facility – see BAT23.
BAT 25. In order to reduce channelled emissions to air of dust, metals and metalloids from the
incineration of waste.
Compliant due to the following:
A dry system will be used that allows for the injection of hydrated lime and activated carbon for the
control of acid gases and dioxins, mercury and other heavy metals respectively. This will be separated
from the gas steam by means of a bag filter.
BAT 26. In order to reduce channelled dust emissions to air from the enclosed treatment of slags
and bottom ashes with extraction of air, BAT is to treat the extracted air with a bag filter.
Not applicable as bottom ash treatment processes are not part of the ERP.
BAT 27. In order to reduce channelled emissions of HCl, HF and SO2 to air from the incineration
of waste.
Compliant due to the following:
The ERP will incorporate a system for the injection of Hydrated Lime within the gas path. The ERP will
use a dry Sorbent Injection system of hydrated lime and activated carbon for the control of acid gases
and dioxins, mercury and other heavy metals respectively. This will be separated from the gas steam
by means of a bag filter.
BAT 28. In order to reduce channelled peak emissions of HCl, HF and SO2 to air from the
incineration of waste while limiting the consumption of reagents and the amount of residues
generated from dry sorbent injection and semi-wet absorbers
Compliant due to the following:
The FGC system will use online monitoring from the CEMS to control the operation of the fabric filter
and dosing rates.
The fabric filter operates in its most effective mode when it has a collection of material over its service,
decreasing its effective pore size yet also providing increased residence time for acid gas control.
However, the deposition of material also creates an increased pressure drop over the system and
therefore requires cleaning via a reverse pulse air jet.
The system collects the ash in the bottom of the hopper and a proportion of the material is recirculated
back to the injection point in the gas path. This means that the efficiency of FGC using hydrated lime
and activated carbon is increased yet the consumption of the reagents is much lower.
BAT 29. In order to reduce channelled NOx emissions to air while limiting the emissions of CO
and N2O from the incineration of waste and the emissions of NH3 from the use of SNCR and/or
SCR.
Compliant due to the following:
A combination of the techniques will be listed, including:
Optimisation of the incineration process – The plant and its combustion system will be controlled by a
DCS, monitoring the combustion process.
Flue Gas Recirculation – This will be further considered in the detailed design phase for the further
reduction in NOx levels.
Selective non-Catalytic Reduction (SNCR) – This is a preferred option for the control of NOx, providing
easy application in the use of Urea or Ammonium Hydroxide.
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Optimisation of the SNCR System – All the FGC systems will be monitored continuously through the
DCS.
With the selection of the above processes, there is no requirement to use SCR, Catalytic Filter Bags or
Wet Scrubber.
BAT 30. In order to reduce channelled emissions to air of organic compounds including PCDD/F
(dioxins and furans) and PCBs from the incineration of waste.
Compliant due to the following:
Optimisation of the incineration process – The plant and its combustion system will be controlled by a
DCS, monitoring the combustion process and thereby ensuring that the time / temperature requirements
(2 seconds at 850°C) for ensuring destruction of compounds are met.
In order to keep the boiler and its associated gas passes clear of significant build-up of dust, and to
ensure that it operates efficiently as a heat transfer surface, the ERP will be equipped with online
cleaning sprays and soot blowers at different points in the gas path. These online measures have been
employed on many plants and reduce the requirement to come offline for cleaning.
The boiler will incorporate a number of tube bundles as part of the heat recovery system, including
evaporator, superheater and economiser tubing sections and these will be positioned to ensure that
good quality steam can be produced at the same time as ensuring a rapid temperature drop of the flue
gas through critical temperature bands to prevent the reformation of dioxins and furans via de Novo
synthesis.
By ensuring the destruction and reducing the potential for reforming of dioxins and furans compounds
the residual quantities are controlled by the injection of sorbents into the gas stream.
The ERP will use a dry Sorbent Injection system of hydrated lime and activated carbon for the control
of acid gases and dioxins, mercury and other heavy metals respectively. This will be separated from
the gas steam by means of a bag filter.
BAT 31. In order to reduce channelled mercury emissions to air (including mercury emission
peaks) from the incineration of waste.
Compliant for the following reasons:
The ERP will use a dry Sorbent Injection system of hydrated lime and activated carbon for the control
of acid gases and dioxins, mercury and other heavy metals respectively. This will be separated from
the gas steam by means of a bag filter.
BAT 32. In order to prevent the contamination of uncontaminated water, to reduce emissions to
water, and to increase resource efficiency, BAT is to segregate waste water streams and to treat
them separately, depending on their characteristics.
Not applicable as there are no waste water streams from the plant.
BAT 33. In order to reduce water usage and to prevent or reduce the generation of waste water
from the incineration plant, BAT is to use one or a combination of the techniques given below.
Compliant due to the following:
The FGC equipment is a dry sorbent injection process and therefore does not generate an aqueous
effluent. Any process derived liquids are reused on site, for example in the bottom ash quench, and the
process overall is a net consumer of water.
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BAT 34. In order to reduce emissions to water from FGC and/or from the storage and treatment
of slags and bottom ashes, BAT is to use an appropriate combination of the techniques given
below, and to use secondary techniques as close as possible to the source in order to avoid
dilution.
Compliant due to the following:
The FGC equipment is a dry sorbent injection process and therefore does not generate an aqueous
effluent. Any process derived liquids are reused on site, for example in the bottom ash quench, and
the process overall is a net consumer of water.
BAT 35. In order to increase resource efficiency, BAT is to handle and treat bottom ashes
separately from FGC residues
Compliant as both streams will be handled separately.
BAT 36. In order to increase resource efficiency for the treatment of slags and bottom ashes,
BAT is to use an appropriate combination of the techniques given below based on a risk
assessment depending on the hazardous properties of the slags and bottom ashes.
Not applicable, as bottom ash treatment processes do not form part of this facility.
BAT 37. In order to prevent or, where that is not practicable, to reduce noise emissions, BAT is
to use one or a combination of the techniques given below.
The detailed design phase will identify areas in which there are noise generating plant and seek to
enclose them where necessary. The majority of plant will be enclosed within the building, and therefore
any noise generated is attenuated by the building.
On the site of the ERP, with the close proximity of the Mt Piper Power Station, the noise levels for the
plant are not believed to be critical contributors to the surrounding environment.
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7 Commentary and Conclusions
Following the review and assessment of the technology proposals provided, Ricardo concludes that the
technology proposed for the Mt Piper Energy Recovery Project represents the Best Available Technique
in accordance with the EU Reference Document9.
In reviewing the technology proposals Ricardo has also reviewed information pertaining to an existing
power plant at Rudersdorf. This EfW plant has many similarities to the proposed scheme, including
similar steam temperature (Rudersdorf is a higher-pressure boiler but it generates steam at 400°C as
proposed at the ERP), FGC train and, most importantly, operates on an RDF feedstock. The plant has
operated for many years on RDF and through its high efficiency of operation meets the requirements
of an R1 “Recovery” process.
Whilst this reference facility is important due to its many similarities, the technologies proposed at all
stages of the ERP have many references. The technologies proposed for the ERP are not novel and
have been applied on many projects worldwide and operate effectively on different types of fuel that
exhibit much more variability than the RDF fuel proposed to be fed to the ERP.
Ricardo concludes that the selected technology and techniques are capable of handling and processing
the RDF, along with its inherent variability.
In relation to heat recovery, the performance of the plant and use of the steam within the existing power
plant represents the option to gain most efficiency from the steam produced. On this basis Ricardo
considers that the conceptual design includes heat recovery to the extent practicable.
9 Best Available Techniques Reference Document for Waste Incineration, European Commission Joint Research
Centre Directorate B European IPPC Bureau, December 2018,
http://eippcb.jrc.ec.europa.eu/reference/BREF/WI/WI_BREF_FD_Black_Watermark.pdf, (accessed July 2019)
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