Biogas - produced by the fermentation of organic matter - is being used by a Canadian chemical engineer Andrew White, as a product to produce fertilizer.
White's SulfaCHAR system eliminates chemical waste from the biogas process, while increasing renewable gas plants' profitability and stopping the degradation to gas engines caused by hydrogen sulfide (H2S).
CHAR Technologies, a University of Toronto research spinoff of White. He says SulfaCHAR is the only product that effectively converts hydrogen sulfide into a fertilizer supplement rather than waste requiring disposal. With a $570,000 USD grant by Sustainable Development Technology Canada, White can improve production dramatically.
According to White, "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 a great story, but the same bacteria that make biogas also make hydrogen sulfide which is toxic, corrosive, and causes a lot of maintenance cost in the industry. So we really need to get it out of the gas so that gas can be used."
White says SulfaCHAR is unique and said, "One of the unique aspects of what our process does is that it catalytically converts the sulfide into sulphur. Sulphur is a fertilizer product and because the feedstock we're making it out of is a fiber that's almost a compost when we're done with it we're left with a carbon compost that's already in the fertilizer form, so we don't have to 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."
There are a number of benefits of the product, per White, such as being used in anaerobic digesters in large-scale animal farming, municipal landfills, and wastewater treatment plants.
Based on cost per kilogram of H2S removed, white says his is the most cost-effective biogas product on the market, "It's the most cost competitive in terms of dollars spent per contaminant removed and that's simply because we've been able to generate such a high capacity for this toxic hydrogen sulfide," he said. "The other end that the customer really likes is that the other solid products that are out there are responsible for sending to landfill to get rid of, whereas with SufaCHAR we take it back and we redistribute it as an agricultural product, so it's cheaper and it has this great beneficial end use."
While the decomposition process generates carbon dioxide as well as other dangerous unpleasant smelling gases which causes an annual global clean-up bill of $1.2 billion - biogas can help create electricity or be used as a replacement for natural gas and is often cited as a clean, carbon-neutral alternative to fossil fuels.
Contributed by Millennium Traders