Globally successful waste-to-energy technologies that respond to worldwide trends towards renewables were showcased by CST Wastewater Solutions at Ozwater in Sydney.
Environmentally advanced technologies transform waste organic materials and wastewaters from an environmental liability into a profit centre, says CST Wastewater Solutions Managing Director, Mike Bambridge.
One of the technologies, GWE’s Rapid Transformation of Organic Residues(RAPTOR), is a liquid-state anaerobic digestion process that consists of enhanced pre-treatment followed by multi-step biological fermentation.
RAPTOR is suited to both industrial and municipal applications in Australasia, with one of its most recent installations demonstrating its potential for similar applications here, says Bambridge, whose company distributes the technology throughout Australia and New Zealand.
RAPTOR has been used successfully in several projects around the world. One example is an organic-waste-to-energy project in Connecticut USA, which moved into production late last year. It converted up to 40,000 tons of organic waste annually into environmentally green energy and dry bio fertiliser.
The plant also avoided the need to dump the waste into landfill, from where organic wastes can seep into water tables of surrounding urban and rural development.
The Quantum Biopower Plant serving the central Connecticut region incorporates its GWE RAPTOR rapid anaerobic digestion system at the heart of its process that harvests mixed organic wastes for conversion into enough biogas (primarily methane) to generate 1.2 MW of electricity and up to 5.6 tons a day of dry bio fertiliser.
Biogas extracted from the refuse replaces fossil and other fuels typically used to generate electricity for the nearby Town of Southington, CT, reducing its environmental footprint and helping the State meet its renewable energy goal of generating 27 per cent of the state’s electricity from renewable energy resources by 2020.
The Southington plant’s biogas production of more than 420,000Nft3 (about 12,000 Nm3 ) a day @62.5 per cent methane (CH4 ) is equivalent to 8000kg a day of fuel oil, or more than 3000 tons of the fossil fuel a year, projected to be worth over $A10 million in the plant’s first decade of service.
The company responsible for the installation, GW&E (a subsidiary of Global Water Engineering Engineering) has also completed another waste-to-energy plant in Canada and is currently completing another in the Caribbean that converts food waste and a form of grass to energy.
As well as profit and environmental benefits, this technology provides consistent and reliable base load power, which is not always possible with alternative green energy technologies, such as wind and solar. Further expansion of the facility to 80,000 tonnes/yr is planned, with the additional biogas to be converted to renewable natural gas and injected into the local gas pipeline network.
GWE anaerobic technologies have been successfully deployed on diverse organic and agribusiness waste streams produced by industries including food and beverage processing, starch and fermentation industry, pulp & paper and many other type of agro-industry. GWE has successfully built and commissioned scores of biogas utilisation plants for clients worldwide over the past 15 years, while CST Wastewater Technology anaerobic digestion installations in in Australia and New Zealand include meat, dairy, fruit processing and brewery production.
The technologies are also suitable for processing biological waste produced by a wide range of specific user types, including universities, grocery chains, restaurants, food transporters, hospitals, sports arenas, large office complexes, commercial buildings and large residential complexes.