power generation

GASIFICATION PROJECT - the way of the future.

The City Circle Group runs one of Victoria’s largest Demolition and C&D Waste Recycling operations. The demolition arm of the business generates significant volumes of C&D waste and while the recycling division processes the inert content for re-use in civil construction, the majority of timber waste ended up in landfill.

Un-utilized landfill space is a rapidly depleting environmental resource and each tonne of waste timber dumped in landfill displaces multiple cubic metres of future land filling capacity.

City Circle intends to divert all waste timber generated by its demolition activities for gasification and conversion to green energy. Gasification is an environmentally sustainable means of diverting waste timber from landfill and in this instance replacing fossil-fuelled electricity generation.

The company’s gasification plant at Brooklyn is designed to convert waste timber through pyrolysis (destructive distillation in an oxygen-free atmosphere) to produce gaseous fuel for generation of electricity and power its on-site concrete crushing and recycling operations.

Gasification technology was introduced more than 100 years ago but its potential for use in waste to energy applications has never been properly commercialised.

Unlike combustion, gasification limits fuel conversion and allows producer gas capture for use in sustainable green energy production.The revolutionary downdraft design of this gasifier incorporates numerous environmental refinements and technical improvements including a new biomass feeder design and tar recycling system with higher processing temperatures yielding cleaner gas and no harmful emissions.

The gasifier and 1.0MW electricity generation facility at Brooklyn is housed in shipping containers. The modular plant layout allows flexibilitywith potential to apply the design basics to processing a wider range of organic wastes elsewhere in the State.

A good example would be the agriculture industry where large stockpiles of harvest residue such as fruit stones, nutshells, husks, etc., are available for conversion and generation of electricity, heating, drying for ancillary processing and manufacturing activities.

The two gas engines and 500KW electricity generators are specialised equipment imported specifically for this project.

The gasifier construction complies with all relevant Australian Design Standards, EPA and Energy Safe Victoria and Worksafe regulations. Rated power output of 1.0MW requires less than 260SCMH of methane or 410SCMH of biogas. The SCATA monitoring system controls gas temperature and maintains quality within specified limits designed for optimized engine performance and efficiency.

Gas cleaning involves automatic removal of tar, which is collected and fed into the combustion zone so as not to constitute an environmental hazard. Chemical analysis of the ash content is an integral part of gas testing and monitoring.

The gasification plant has an automatic feed system and the entire facility is designed for unattended operation. Operational procedures and safety features are detailed in the Operational Safety Manual.

PROJECT OUTCOMES

The Brooklyn gasification plant utilizes waste timber from City Circle’s building demolition activities to provide green electrical energy powering the company’s on-site concrete crushing and recycling operations.

Gasification technology provides a solution for industry generally to convert organic waste materials to green energy and effectively diverting it from landfill.

Waste timber creates major waste management issues in many regional areas where economic access to landfills and other disposal options are limited. Gasification technology offers environmentally sound solutions for organic waste disposal as well as a wide range of waste to energy applications in rural communities.

The City Circle gasification plant delivers 1.0MW of electricity currently powering City Circle Group’s C&D waste recycling operations in Brooklyn. It replaces an 800KVA diesel powered generator saving 300,000 litres of diesel fuel annually.  

The process and technology is sufficiently advanced to evaluate other organic wastes for use as RDF. MSW in particular might be a suitable RDF for gasification with potential to generate energy and help achieve ‘zero waste to landfill’ objectives.

The primary stakeholder in the project is City Circle Group. Sustainability Victoria helped provide additional funding assistance in the form of a grant.