A new method of removing toxic hydrogen sulfide from biogas could revolutionise the renewable gas industry, says inventor Andrew White. Jim Drury went to meet him.
Andrew White says he's solved the problem of biogas production creating toxic hydrogen sulfide. The Toronto chemical engineer is turning the sulfide into fertiliser. SOUNDBITE (English) PRESIDENT AND CO-FOUNDER OF CHAR TECHNOLOGIES, ANDREW WHITE, SAYING: "One of the unique aspects of what our process does is that it catalytically converts the sulfide into sulphur. Sulphur is a fertiliser product and because the feedstock we're making it out of is a fibre that's almost a compost when we're done with it we're left with a carbon compost that's already in the fertiliser form, so we don't have to do any reprocessing. As soon as we take it out of the tanks where it's been used for gas cleaning we can apply it directly to the fields." Biogas has been called a clean, carbon-neutral alternative to fossil fuels. But the decomposition process is dirty. SOUNDBITE (English) PRESIDENT AND CO-FOUNDER OF CHAR TECHNOLOGIES, ANDREW WHITE, SAYING: "The greatest asset of biogas is that it's capturing methane that would otherwise be going into the atmosphere where it's 22 times worse than carbon dioxide for global warming, so it's a great story, but the same bacteria that make biogas also make hydrogen sulfide which is toxic, corrosive, and causes a lot of maintenance loss in the industry." White says his SulfaCHAR pellets are the only product to avoid toxic waste disposal, and the most profitable. It can be used in large farms, landfills, and wastewater treatment plants. His prototype should produce a tonne of fertiliser daily by next Spring. Twelve months on and that figure could be ten tonnes, something White says will help renewable gas plants world-wide turn a profit.