The superior environmental performance and benefits of a plasma gasification facility encompass the following key aspects:
A plasma gasification combined cycle power plant or reciprocating engine plant differs significantly from an incineration plant in terms of emissions. While incineration technology burns MSW to generate energy, the Plasma Gasifier employs extreme heat from its Plasma Torches to break down MSW into its molecular constituents, including hydrogen and carbon monoxide, the two primary components of syngas.
In a combined cycle or reciprocating engine application, syngas from a Plasma Gasifier undergoes cleaning to meet specifications similar to natural gas. It is this clean syngas that is burned in a gas turbine or reciprocating engine to generate power. Emissions from this type of plant are comparable to those of a natural gas-fired power plant.
Lower Greenhouse Gas Footprint
In a report produced by Scientific Certification Systems (“SCS”) in 2010, a comparison was made between the lifecycle greenhouse gas emissions of a plasma gasification combined cycle power plant, a state-of-the-art incineration facility, and a landfill with energy capture facility.
The SCS report concluded:
“The results of this analysis show that the Plasma Gasification Combined Cycle (“PGCC”) system provides the lowest greenhouse gas emissions of the evaluated systems for waste disposal. The SCS study also concluded that the lifecycle greenhouse gas emissions were almost equivalent to those of a state-of-the-art natural gas combined cycle power plant.
Plasma gasification offers reduced emissions, decreased volumes of solid waste requiring landfilling, and diminished greenhouse gas emissions, making it the superior environmental choice in all respects.
Beneficial Byproducts vs. Bottom Ash and Flyash
A Plasma Gasification facility produces vitrified slag as a byproduct, which is inert and safe to use as aggregate or in other applications. This slag poses no risk of contaminating soil or drinking water. Rigorous testing against standards, including JLT-46, NEN-7341, and TCLP analysis, has been conducted by independent laboratories Shimadzu Techno-Research Inc. and ALS Laboratory Group. The results indicate that the slag from the Mihama-Mikata plant falls below test detection limits and is considered non-leaching. All slag from the Mihama Mikata plant is utilized as aggregate for concrete products.
In a Plasma Gasifier, particulate matter is removed from the syngas downstream from the gasifier. However, this particulate can be recycled back into the gasifier for destruction (and further energy recovery) and does not become a byproduct requiring disposal.
In contrast, incineration plants produce bottom ash and flyash, with the latter often being categorized as hazardous waste in many jurisdictions, necessitating special disposal methods.
Assuming that particulate matter is recycled back into the gasifier, less than 2% of the introduced material needs to be sent to a landfill. In comparison, approximately 20% to 30% of waste processed in an incinerator must be consigned to a landfill.