Waste to Electricity
Pyrolysis is also referred to as a “conversion technology”. Pyrolysis involves the super-heating of a feedstock—be it MSW, tyres, coal, agricultural residues or wood chips, etc.—in an oxygen-controlled environment to avoid combustion. The distinguishing features for pyrolysis are that the primary heat source is self-sustaining from gas already produced, the oxygen level is extremely low, and operating temperature ranges from as low as about 300°C to as high as 700°C depending on the feedstock. In these low-oxygen environments, the production of dioxins and furans from waste can be significantly reduced compared with incineration.
Conversion technologies are further distinguished from conventional MSW incineration by the production of synthesis gas (or syngas) composed mainly of hydrogen and carbon monoxide, a product of the thermal reactions that take place during the processes. The syngas can then be burned in an efficient, natural gas generator (gensets) or refined into other valuable products. These differences make conversion technologies cleaner, more efficient, and more valuable than mass-burn incineration.
The cleaning of contaminants and impurities from syngas produced via conversion technologies is often cost-prohibitive. Pyronex’s manufacturing partner has developed and deployed an affordable solution for syngas cleaning that is included with every system that we deploy. Conversion technologies do have a clear benefit in that they leave behind safer solid residues—and less of it—than burning MSW. Incinerators produce significant amounts of a waste called bottom ash, of which about 40% must be landfilled. The remaining 60% can be further treated to separate metals, which are sold, from inert materials, which are often used as road base.