Sasol Biosludge Composting Projectsawic.environment.gov.za/documents/3939.pdf · 2015. 3. 18. · • Sasol and Sola Fidei Manufacturing (SFM) have developed a composting process

A new era for Sasol

Sasol Biosludge Composting Project

10 March 2015

A new era for Sasol

Copyright ©, 2014, Sasol

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• Compost is organic matter that has been decomposed and can be recycled as a fertiliser

• How is compost typically made?

• Aerobic (using oxygen) or Anaerobic (not using oxygen) process

• Utilizes garden or other organic waste

• Several weeks of biodegradation and conversion

• What do the micro-organisms do?

• Converts the components present into organic compounds that act as fertiliser for plants

• What are these micro-organisms?

• A variety of bacteria and fungi

• They are specialized in converting the waste product into compost

What is compost and how do you make it?

Example: Bacillus (gram positive)

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• In 2011 Sasol started investigating the technical feasibility of composting sludge streams from

the refinery

• Sasol and Sola Fidei Manufacturing (SFM) have developed a composting process that not

only greatly reduces the quantity of waste to be disposed of but also produces a usable

product

• Composting of domestic sludges is widely practiced world-wide, but the composting of petro-

chemically derived waste sludges has never been done anywhere in the world on this

scale before.

• Composting is an environmentally sustainable and cost-effective alternative for the treatment

of selected waste sludges

Composting as a Technology Alternative for industrial waste stream management

100 tons

sludge

100 tons

biomass

40 tons

compost

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Amid multiple new environmental regulations, Sasol’s technology division is driving

investigations for integrated environmental solutions delivering benefits across all

environmental media

Why is Sasol doing this?

Advantages Composting

waste

Incineration of

waste

Landfill of

waste

Overall cost (NPV) ++ +++ +++

Job creation +++ + +

Plot space requirements ++ + +++

Usable product generated +++ - -

Overall Environmental

sustainability

+++ - -

Energy consumption + ++ +

Hazardous waste Transport

over long distances

+ - +++

Greenhouse Gas abatement + - -

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A small proof of concept trial was conducted on 30 t of waste streams

Map of Area in 2013

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An expanded trial was conducted from 2013, on a total 2,000 tons of these streams

(1% of the final scale)

Map of Area in 2014

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Final land area for 200,000 tpa of sludges = 2000 hectares = 20 square kilometres

Map of Area in 2016

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Origin of Sludge Feed Streams at the Secunda site

Sludge Current disposal methods Proposed feed to

composting process

1 Biosludge Incinerated on-site80 000 t/a (8 trucks per

day)

2Process water dam

sludge

Not yet disposed of (sludge

building up in dams)20 000 t/a

3 API-dam sludge Ash blended and disposed of

on coarse ash heaps on-site40 000 t/a

4Process Cooling

Tower sludgeThird party disposal (landfill) 20 000 t/a

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Waste Recycling

Facility (WRF)

biosludge

Third party disposal (landfill) 5 500 t/a

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Composting Process

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Bulking agent – Sugar Graze

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Harvesting of Biomass for the Project

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Pad preparation

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Sludge collection

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Windrows

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Windrow Turning

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Compost Product

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Moving up the Waste hierarchy

Benefits of Composting

Reduce

Re-use

Recycle

Recover

Disposal

Sludge composting

Incineration

Landfill disposal

• 100 ton sludge reduced to 40 ton compost

• Nutrient re-use

• Recycle waste sludge to compost product

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• The composting trials in the last year have resulted in the employment of 25 people from the

surrounding community, who have been skilled in the composting process as well as the

farming activity. If taken to 200,000 tpa, the full-scale process is set to employ as many as

150 people from the surrounding community.

• There would be a net decrease in GHG emissions as a result of this project

• By having the option of composting close to the Sasol Secunda complex, transport of sludges

over long distances is minimised

• Composting, as a technology is less expensive than landfill or incineration

Employment, GHG emissions, Transport, Cost

Benefits of Composting

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• Although the compost product is re-used in the process to grow biomass, the project is currently

undergoing a process to get registration of the compost as a product

• The following environmental approvals and decisions must be obtained:

• EIA and WML approval – under way

• Recognition for composting as an alternative compliance solution for our biosludge

incinerators. Half of the proposed feed to the composting project originates from

incinerators which are the subject of postponement applications. The viability of

composting biosludge is limited to the duration of postponements granted

With support from various approvals and decisions from the DEA, the composting

project will be taken to scale by mid 2016

Project Plans

A new era for Sasol

Documents

Sasol Biosludge Composting Projectsawic.environment.gov.za/documents/3939.pdf · 2015. 3. 18. · • Sasol and Sola Fidei Manufacturing (SFM) have developed a composting process