Advanced Plasma Power (APP) is a world leader in advanced waste to energy and fuels technology. APP has developed the Gasplasma® process, a clean, modular and scalable technology which delivers high efficiencies whilst minimising visual and environmental impact.
The core Gasplasma® process is a unique internationally patented two-stage Advanced Conversion Technology (ACT) which uses an innovative combination of two long standing and well-proven technologies (gasification and plasma conversion) in a new, original configuration to convert residual municipal and commercial waste into a clean, hydrogen-rich synthesis gas (syngas) and a solid, vitrified product (Plasmarok®) each with multiple applications.
This is achieved in a number of stages. Firstly, all recyclable material is removed from the residual waste stream to ensure that maximum value is extracted from the waste. Secondly, non-recyclable waste is converted into a gas in a Fluidised Bed Gasifier, producing a crude synthesis gas (“syngas”), which at this stage still contains tars, soot and ashes. The third stage employs the key to the Gasplasma® process: a separate plasma converter to crack the impurities in the syngas and ‘polish’ it whilst simultaneously vitrifying the ash and inorganic fraction from the gasifier to form Plasmarok®. Finally, the resulting clean syngas is used directly in a power island, consisting of reciprocating gas engines or a gas turbine, to generate clean, local heat and power. Rather than generating power onsite there is also the potential to create renewable fuels such as substitute natural gas or other gaseous or liquid transport fuels from the syngas.
The Gasplasma® process combines two well-proven technologies (gasification and plasma conversion) both of which have years of proven commercial operation at considerable scale. APP’s sister company, Tetronics International, is a world leader in plasma technology and has a long and successful history deploying its patented plasma technology – which is a key component in APP’s Gasplasma® process – in over 80 installations around the world. Tetronics’ plasma technology has been used for a range of applications including hazardous waste treatment and metal recovery.
The Fluidised Bed Gasifier which transforms the organic materials in the Refuse Derived Fuel into a crude syngas, a core stage of the Gasplasma® process, has been successfully proven by APP’s supplier in more than 100 fluidised bed energy systems providing over five million hours of operating experience.
It offers a cleaner, smaller scale, more efficient, community focused waste to energy process than has been previously been available. Gasplasma® enables highly efficient and effective management of waste and resources by converting municipal, commercial and industrial waste into two usable products: a clean fuel gas and an environmentally inert material with a variety of high value end uses.
The process is fully scalable. A typical Gasplasma® plant handling 100,000 tonnes per year of Refuse Derived Fuel (RDF) is around 15 metres high, meaning that it can fit into a standard warehouse similar to those seen in edge-of-town business parks. A plant can therefore be located unobtrusively close to centres of population. Several Gasplasma® units can be used at the same location to process higher volumes of waste.
A standard Gasplasma® facility accepts 170,000 tonnes of residual municipal solid or commercial & industrial waste a year, enough to produce around 100,000 tonnes per annum of Refuse Derived Fuel (RDF). This is enough to generate 20MW of renewable power.
The syngas produced by Gasplasma® process is able to be used directly in gas engines because the plasma conversion stage of the process ‘cracks’ long-chain hydrocarbons in the raw syngas which would otherwise cause the engines to fail. This dramatically improves energy conversion efficiency and maximises electrical output. The electrical conversion efficiency of gas engines and turbines range from around 40 to 50% whilst steam turbines, used in conventional thermal processes, are typically less than 25% efficient.
The Gasplasma® process presents a means of managing waste and producing energy with minimal impact on the environment. The Gasplasma® process enables almost complete landfill diversion and is complementary to recycling. It can be used in conjunction with existing recycling schemes, as it takes waste that cannot be recycled and uses it to produce a clean, renewable energy source. The process produces a high value construction material called Plasmarok® that is recognised by the UK’s Environment Agency as a product not a waste. This removes any environmental, regulatory and commercial risk stemming from concerns over the eco-toxicity of bottom ash produced by incinerators and other thermal processes.
Emissions from the process are minimal and well within the European Union Industrial Emissions Directive (IED). When producing gaseous or liquid biofuels, there are negligible local emissions to atmosphere.
APP has a demonstration Gasplasma® plant operating in Swindon, UK, where a significant variety of feedstocks have been tested. A gas engine has been operating on waste derived syngas produced by the plant since 2008. APP currently has around 10 projects in the pipeline at various stages of the development process.
The potential for the Gasplasma® process as a gateway technology is enormous. APP is working on a project with National Grid to develop and demonstrate an end-to-end process that will use Gasplasma® technology to convert waste to bio-substitute natural gas (bio-SNG) for injection into the national gas grid. Another key area for development is the use of fuel cells to produce electricity either directly from the syngas produced by the Gasplasma® process or from hydrogen (or bio-SNG) derived from the syngas. APP is working with a number of partners to demonstrate these alternative uses to potentially achieve even greater electrical conversion efficiency.
Unlike incineration, Gasplasma® does not burn (combust) the waste, but converts it to a high quality fuel gas. In addition, Gasplasma® converts nearly all the remaining solid raw material into Plasmarok®, which is environmentally inert and non-leaching and can be used as a high-value construction material, making it an almost zero waste technology. In contrast, incinerators produce around 20 to 25% bottom ash which requires transport, processing and disposal thus further impacting the cost and carbon footprint. A Gasplasma® plant has a significantly lower visual and environmental impact than an incinerator. It fits into a much more compact building and has a stack height of less than a third of that of an incinerator with the same treatment capacity.