Saving the world can be a messy business, and brewing biofuels is far from a waste-free endeavor, as Cargill learned today. A lawsuit filed Monday claims that Cargill failed to pre-treat sludge from its Iowa Falls biodiesel plant before sending it to the municipal water treatment plant. When the city refused to accept the sludge, Cargill paid an independent contractor to spread 135,000 gallons of it onto nearby pastures, and some of it leeched into creeks and killed fish, the AP reports. The lesson will cost the agribusiness giant a mere $100,000.
Unfortunately, this is not an isolated incident in the biofuel world. The New York Times published an article on Tuesday entitled “Pollution Is Called a Byproduct of a ‘Clean’ Fuel,” which notes that there have been multiple cases of biodiesel plants illegally dumping glycerin that is often contaminated with hazardous methanol.
Such media attention on the biofuel plants’ pollution is more bad news for new plant construction. With high corn prices, low ethanol prices and growing construction costs, it’s no wonder that so many biofuel plants are being put on hold.
Don Scott, an engineer for the National Biodiesel Board, assured The Times that these environmental oversights were isolated events, the “growing pains” of an industry that has nearly doubled in size over the past year.
Part of the confusion surrounding these spills and dumpings is the assumption that the effluent from biofuel plants is nontoxic. A major byproduct of biodiesel production, a process called transesterification, is glycerin, a nontoxic and salable substance used to make soap. The problem is that very toxic methanol is used to make biodiesel and unreacted methanol winds up in the glycerin byproduct. Biodiesel producers are supposed to “wash” the methanol out of the glycerin before discharge, but it is an energy-intensive process.
Even washed glycerin, which is biodegradable, can wreak environmental damage. Flooding a river system with glycerin will deplete oxygen levels as microbes break the organic compound down, suffocating fish and other organisms.
While large corporations like Cargill can easily settle hundreds of lawsuits a year, biofuel startups should take heed and avoid environmental entanglements with the local constabulary. You want to grab headlines for making a killer breakthrough in the lab, not for killing wildlife outside your plant.