Tobacco Farmers Make Ethanol from Sweet Potatoes
Tyler Hamilton of Clean Break writes in the Toronto Star: Corn prices are spiking and the US agriculture department is warning of shortages, all because of ethanol. Up in Canada's tobacco belt, they have a better idea: sweet potatoes. There used to be 4,000 farmers here, but the decline in smoking and the import of cheaper foreign tobacco has slashed the number to a few hundred. farmer Berry Murray went back to school for an MBA. His master's thesis was on alternative crops for ethanol production, a sensible focus given the controversy surrounding corn-based ethanol and the energy-intensive processes required to make it. He looked for the best crop for local conditions: "All of these crops we've chosen will do very well in the sandy soil and provide alternatives for the tobacco farmers," he says, adding that they also require little irrigation, one of the biggest criticisms of farming corn for fuel.
Murray's plan of building a 150-million-litre ethanol plant in Tillsonburg also includes construction of an anaerobic digester, which will accept residual biomass from the ethanol plant and turn it into biogas (mostly methane) using fermentation.
Typically, this biomass – known as distiller's grain – is dried and turned into animal feed, but the market for this feed can be volatile. Murray figured it would be better to turn the biomass into biogas, and then generate electricity by burning it in a gas turbine. He could then sell the power to the local utility.
"It's a fossil-fuel free, energy-independent complex," says Murray. "We're buying one crop for one purpose: to make ethanol. But after we extract that, we take the biomass we've already purchased and drop it down to extract even more energy by harvesting the methane."
He says getting this project up and running is important, not just for the farmers in Norfolk County but for other parts of Ontario.
"It's a model that could be repeated, in terms of localizing the production of energy," he says. "For example, you could put one of these in the Holland Marsh (about 50 kilometres north of Toronto) and use the waste from vegetables that don't go to market.
"We have the ability, through small complexes in rural Ontario, to produce 50 per cent of our electricity requirements at a tenth the cost of a centralized (power) plant ... That's what they did in Europe. We've just got to think outside of the box with these things." ::Tyler Hamilton in The Star