Case Studies

According to the Knowledge Product (KP)studies commissioned by the Department of Environmental Affairs (DEA), Pyrolysis is the thermal degradation of a substance at high temperatures in the absence of oxygen. It involves the simultaneous change of chemical composition and physical phase, is irreversible and requires a relatively consistent waste stream. Use was made of manual provided by GreenCape and approved by the Western Cape Department of Economic Development and Tourism, ‘Towards integrated municipal waste management: technical guide for technology identification and screening for integrated waste management planning’.

Configuration

Technology restrictions

• Pyrolysis technology is capital intensive. Investment will vary with the scale of the operation.
• Pyrolysis is energy intensive and the parasitic load reduces the gross energy output of plant significantly.
• Metal and inert material require separation before thermal treatment if they are intended for removal.
• In general plants do not scale up well so a modular system using many smaller units is often required.

Main license requirements for pyrolysis CLICK HERE (/CONTENT/TECHNOLOGIES-OVERVIEW-LEGISLATIVE-REQUIREMENTS) Advantages:

• May be used for all types of solid products but feedstock must be homogeneous.
• Can be easily adapted to changes in feedstock composition because it is a batch process.
• Can be integrated to supply fuel to micro turbine, fuel cell or thermophotovoltaic (TPV) systems for power generation.
• Process produces very little greenhouse gas but the combustion of the fuel will produce CO

Disadvantages:

• High capital costs.
• Does not scale up, generally works well with smaller quantities of waste.
• Qualified and experienced personnel needed to operate machinery.
• Not labor intensive.

Case Study

Botrivier Pyrolysis Plant

Read more: (www.grahamtek.com) This plant converts waste plastics and old tyres into a variety of fuels to power engines and furnaces. The plant produces a multi-fuel, chemically similar to diesel, that can be further refined into a petrol equivalent. By-products (depending on the feedstock) include paraffin and LP gas. It also produces a type of clean ‘sweet crude’ with a zero CO₂ content that can be processed in diverse ways. The sulphur content and viscosity levels of the marine bunker oil are below standard industry norms, while the heavy furnace oil (used in high-volume industrial heat fuel applications) is equally impressive. The plant consists of modular units each capable of processing 10 tons/day. It is planned eventually to process 80 tons/day. [caption id="attachment_3118" align="aligncenter" width="937"]

The Botrivier Pyrolysis Plant featuring modular units that can be added to reach the planned process throughput[/caption]