EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 20141
Andrés Mahecha-Botero, Ph.D., P.Eng., Process Engineer C. Guy Cooper, P. Eng., Director Sulfuric Acid
Kim Nikolaisen, Ph.D., Process Engineer
Mesa RedondaPunta Arenas (53°S)
November 16-20, 2014
NORAM Engineering and Constructors Ltd. Vancouver, Canada
The Suitability of Double Absorption and Scrubbing Technologies to Meet New
Emission Standards
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 20142
NORAM Engineering
Based in Vancouver
Founded in 1988
Approximately 100 employees
Focus on Technology
Own BC Research Laboratories
Own Axton Fabrication Shop
Alliance with Tenova Minerals
Own NORAM International AB (Sweden)
Alliance with Turboscrubber (Osprey/FTL)
Represented by Coppex in Chile
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 20143
• Australia
• Belgium
• Brazil
• Canada
• Chile
• China
• Czech Republic
• France
• Finland
• Germany
• India
• Kazakhstan
• Mexico
• Morocco
• Peru
• Portugal
• Russia
• Tunisia
• Venezuela
• UK
• USA
ClientsABSA/Fertinal
Agrium
Agrogen
ASARCO
Bateman Engineering
Bayer
BHP Copper
Cargill
Cellulose du Maroc
Chemetics
Chevron
Climax Molybdenum
Codelco
Cominco
ConocoPhillips
Duke Energy
DuPont
First Chemical Corp
Glencore
Georgia Pacific
Huntsman Chemicals
Innophos
International Paper
Kennecott Utah Copper
Magma Copper
Marsulex
Mexicana de Cobre
Monsanto
Mosaic
Met Mex Penoles
Mexichem
Newmont Gold
Nexen Chemicals
OCP Maroc
Paradeep Phosphates Ltd.
Pequiven, PDVSA
Port Kembla Copper
Phelps Dodge
PCS Phosphates
Potlatch Corp.
Rhodia
Qajamarquilla, Refineria de Zinc
Quimigal
Rubicon
Sherritt International
Teck Metals
Texas Brine
Tianji
Uniroyal
Vale Inco
Westlake
Weyerhaeser
Xstrata
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201444
Stainless Steel Converter
with Internal Exchanger
Stainless Steel Converter
with Internal Exchanger
RFTM SFTM Preheat Exchanger
RFTM SFTM Gas to Gas
Heat Exchanger
Acid Towers
Acid Coolers
Tel: (604) 681-2030 • Fax: (604) 683-9164 • [email protected]
www.noram-eng.com
HPTM Saddle Packing
SMARTTM Acid Distributor
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 20145
Pre-Summary
• Chilean smelters are set to spend large amounts of money to meet new Chilean emission standards
• Evaluate options carefully taking into account: Risk, CAPEX and OPEX.
• Double Absorption is the proven world standard to reduce emissions.
• NORAM has proven effective equipment to use in double absorption
• Look at the use of low pressure drop packing and low pressure drop, reduced fouling gas exchangers to lower operating costs and increase on-stream time
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 20146
OUTLINE
(1) IntroductionNew Chilean Emission StandardsComparison of New Chilean Emission Standards with Those of Other Countries
(2) Double-Absorption TechnologyOverview
Advantages of Upgrading to Double-AbsorptionRequirements to Convert to Double-AbsorptionDesign Considerations to Reduce SO2 EmissionsNew Equipment
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 20147
OUTLINE (Cont’d)
(3) Tail Gas Scrubbing TechnologyOverviewDifferent Scrubbing TechnologiesNew Equipment
(4) Conclusions
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 20148
(1) INTRODUCTION
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 20149
New Chilean Emission Standards New emission standards require technology upgrades to achieve
higher capture of SO2 and As. Careful selection of technology is required.
The new targets are achievable with existing technologies.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201410
SO2
Limit
%
Decrease
in
Emissions
Required
SO2
Limit
%
Decrease
in
Emissions
Required
Date of Start
of
Enforcement
1 Caletones Codelco 1922 2 01560 MTPD &
2390 MTPD128,468 32.7% 88.0% 80,000 38% 47,680 63% 12-Dec-2018
2 Chuquicamata Codelco 1952 3 03 x 2040
MTPD108,214 27.5% 91.0% 96,500 11% 49,700 54% 12-Dec-2018
3 Potrerillos Codelco 1927 1 0 1500 MTPD 65,280 16.6% 83.5% 89,500 None 24,400 63% 12-Dec-2018
4 Altonorte Xtrata 1993 2 12 x 2040
MTPD39,958 10.2% 93.7% - - 24,000 40% 12-Dec-2016
5Hernan Videla
Lira / PaipoteEnami 1952 2 0
280 MTPD &
560 MTPD21,344 5.4% 89.4% 24,500 None 12,880 40% 12-Dec-2018
6 Ventanas Codelco 1965 1 1 1637 MTPD 15,590 4.0% 93.8% 16,500 None 14,650 6% 12-Dec-2016
7 Chagres AngloAmerican 1960 1 1 1885 MTPD 13,944 3.5% 95.7% 13,950 None 14,400 None 12-Dec-2016
392,798 187,710
9 52.2%
New Total Allowable SO2 Emissions
Total Reduction of SO2 Emissions as
Compared to 2010
Capacity of
Acid Plants
Total SO2 Emissions (2010)
Total Potential Plants to Convert to Double Absorption
CHILEAN METALLURGICAL ACID PLANTS SPECIFICALLY MENTIONED IN THE NEW EMISSIONS REDUCTION LEGISLATION
#
# of Double
Absorption
Acid Plants
Total
Number of
Acid Plants
Average
Capture91%
Temporary Limit
for Transition
Period
New Limit for Existing Plants
%
Capture
S
%
contribution
to total
Chilean
smelter
emissions
SO2
Emissions
(2010)
Start-up
dateOwnerPlant
New Chilean Emission Standards
Acid plant target of 600 ppm is less stringent than in most countries. Typical world scale acid plant can easily achieve 250 ppm with double absorption only.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201411
Comparison of New Chilean Emission Standards with Other Countries
The limit of SO2 emissions from the stack in North America is: 2 kg of SO2 per metric ton of H2SO4 produced.
For a plant operating with 12% SO2 to bed #1, this corresponds to about 360 ppm stack SO2 concentration and 99.7% capture of SO2.
In practice, typical double-absorption plant emissions in the USA range between 0.5 and 2 kg SO2/MT H2SO4 (corresponding to about 90 to 360 ppm stack SO2 concentration and 99.7 to 99.92% capture of SO2).
70 ppm stack SO2 is achievable with double absorption only.
Emissions of 10 to 50 ppm require tail gas scrubbing.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201412
(2) DOUBLE ABSORPTION TECHNOLOGY
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201413
Overview
Smelter gases contain a long list of chemical species including SO2,SO3, H2SO4, As, Se, F, Cl, Pb, Cd, Cu, Bi, dust, etc. Currently, the smelter gases are processed in a gas cleaning plant followed by a sulphuric acid plant. The smelter acid plant design intent is to:
Reduce emissions of SO2, SO3 and H2SO4 to the environment by 97 to 99.95% (depending on plant design).
Produce commercial sulphuric acid for sale, or for internal use.
The heart of the pollution control system of the metallurgical site is the sulphuric acid plant.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201414
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201415
Single Absorption Acid Plants
Single-absorption sulphuric acidplants were common prior to the1970’s.
Stack emissions in the range of 2000to 10,000 ppm, and SO2 capture ratesof > 97%.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201416
Typical Single Absorption Gas System
Typical converter has 3 catalyst beds.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201417
Double Absorption Gas System (3/1 configuration)
New gas equipment: Final acid tower, 4th pass and gas exchangers
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201418
Single Absorption Acid System
Typical acid system has 2 to 3 towers.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201419
Double Absorption Acid System
New acid equipment: Final acid system
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201420
Double Absorption Acid Plants
Double-absorption allows for higher SO2 capture by shifting thechemical equilibrium of SO2 oxidation by removing the SO3product.
Converting an existing single-absorption plant into double-absorption can increase the production rate of sulphuric aciddue to increased SO2 capture (by 2 to 10%), and due to theability to increase process gas concentrations (by 10 to 30%).
The benefits of conversion to double absorption are maximizedif the plant upgrade is carried out together with adebottlenecking and capacity increase project.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201421
Double Absorption Acid PlantsNew double-absorption acid plants use one of the followingconfigurations:
2/2 Configuration: Usually not used for new designs, since it requires larger heat exchange equipment and higher catalyst volumes.
3/1 Configuration: This has become the standard for modern contact sulphuric acid plants. Conversions of 99.7 to 99.8+% can be achieved (corresponding to about 240 to 360 ppm of SO2 in the stack).
Enhanced Configurations using Cesium Catalyst, Enriched Air or additional conversion stages: Can achieve 99.95% recovery (corresponding to as little as 70 ppm of SO2 in the stack).
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201422
600 PPM in the Stack?If a double absorption plant cannot meet 600 ppm, it is likely due to:
Gas Leaks in the Division Plates of The Converter: These leaks would reduce the conversion considerably. Not only SO2 is bypassed, but SO3 can affect chemical equilibrium.
Gas Leaks in the Gas Exchangers: Asarco East Helena, Montana, USA. Fixing gas leaks in the cold exchanger reduced emissions 600 ppm to 300 ppm.
Low Catalyst Activity and Catalyst Fouling: Review of catalyst performance is required.
Inadequate Converter Inlet Temperature Control: Control strategy and design of gas dampers to be reviewed.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201423
600 PPM in the Stack?
Inadequate Performance of Interpass Tower: Carryover of acid mist or SO3 would reduce converter performance.
Final Acid Pumping Loop not Independent: A separate final acid pumping loop can reduce the emissions of SO2 to the stack by up to 100 ppm without requiring any changes to the converter.
Other issues with plant design, equipment performance and operation.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201424
Advantages of Upgrading to Double-Absorption
Capability: can achieve the new emission standards.
Water conservation: Zero losses of water from the plant stack.
No production of byproducts or waste: Other technologies produce a scrubbing waste, which is proportional to the plant rate and inlet concentration of SO2, SO3 and H2SO4.
No consumption of chemicals: Examples of these chemicals are caustic, ammonia, hydrogen peroxide, milk of lime, limestone, etc.
No steam consumption: In contrast, regenerative scrubbing requires a constant feed of steam to regenerate the absorbent chemicals.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201425
Advantages of Upgrading to Double-Absorption
Produces concentrated H2SO4 for sale
Familiar technology: Commonality of controls and spares.
Proven technology: Lower technical risk of having unplanned shut-downs.
Known technology: Technology is well known to plant engineers and operators. Little training to existing personnel is required.
Simple logistics: No requirement of: new storage tanks for chemicals, logistics and infrastructure to supply and handle new chemicals, effort to handle and dispose of byproducts.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201426
Advantages of Upgrading to Double-Absorption
Public perception: No visible plume from the stack.
Low operating costs.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201427
Disadvantages of Double-Absorption
Layout and hydraulic considerations
Initial capital investment
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201428
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201429
NORAM Split Flow Gas Exchanger
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201430
New Equipment (cont’d)
Review of Converter Capacity
The SO2 conversion capabilitymust be reviewed under theupgraded conditions. Increasedcatalyst volumes are required toachieve the new emissiontargets.
In many cases, the existingconverter has enough sparevolume to accommodate theadditional catalyst loads. If theconverter is undersized, it canbe modified for the new service.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201431
(3) TAIL GAS SCRUBBING
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201432
Overview
The selection of the scrubbing chemistry depends on:
Potential use for byproducts.
Handling and disposal of byproducts.
Local availability of chemical.
Local price of chemical taking into account delivery and handling.
Familiarity of the plant site with the scrubbing chemical.
Losses of scrubbing chemical due to upstream problems: For regenerative scrubbing: One client in USA spends $0.5 million per year on amine chemicals due to acid mist issues at the inlet.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201433
Different Scrubbing Technologies
A number of technologies can be used to contact the process gas with the scrubbing chemical.
Packed Beds: Uses static packing inside a counter-current contacting tower.
Reverse Jets: Uses large liquid flow in contact with the gas in a froth-zone.
Venturis: Use a flow restriction to allow for co-current contact between the liquid and the gas.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201434
Different Scrubbing Technologies(cont’d)
Spray Towers: Produces fine liquid droplets in atomization nozzles. They can be co-current or counter-current.
Fluidized-Beds: Gas and liquid are contacted over a moving bed. Gas and liquid are counter-current.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201435
New Equipment
New Scrubbing System
New Scrubbing Tower: The tower can be made of steel, FRP, or other materials of construction.
New Scrubber Cooler: A cooler may be required to reject the heat from the process gas.
New Scrubber Pump: Depending on the design of the new scrubbing tower, a new pump-tank may be required.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201436
New Equipment (cont’d)
New Scrubbing Ancillaries
New Byproduct Storage Tank
New Scrubbing Chemicals Tank
New Ancillary Pumps: To handle scrubbing and waste liquids.
Review of Stack: Scrubbing systems saturate the process gas with water. For this reason it is sometimes recommended to review the materials of construction of the stack.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201437
Fluidized Bed Scrubber Installations (NORAM’s TurboScrubber®)Left: SO2, fine particulate abatement, and heat recovery. Right: SO2
and fine particulate abatement
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201438
(4) CONCLUSIONS
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201439
Conclusions
Double-absorption technology can be used to meet the new Chilean regulations in a cost-effective, technically sound and sustainable manner.
Consider debottlenecking, energy recovery and capacity increase at the same time of emissions reduction.
Take advantage of the oportunity to improve your plant process design, equipment performance and materials of construction. Do not replace equipment “in kind”.
Scrubbing technologies are also available to meet the new standards.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201440
Conclusions
Advantages, disadvantages and equipment requirements have been discussed for both options to reduce emissions.
The implementation technology upgrades requires careful evaluation of the existing plant to identify upgrade opportunities from the process engineering and mechanical layout points of view.
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201441
MUCHAS GRACIAS A TODOS!
EMISSIONS REDUCTION
Mahecha-Botero, Cooper, Nikolaisen, 201442