CO2 science turns to alcohol
12 Jan 2011
London – GEA Niro is developing a process to convert CO2 into fuel alcohol, proteins for animal feed and fertilizer for agricultural purposes.
The process involves feeding the CO2 to algae and transforming the algae to alcohol by fermentation and the residual bio matter to fertiliser. The exhausted yeast cells are then spray dried into protein powder for animal feed.
According to the company, while the principle is simple, process implementation is difficult due to the very large installations and large mass flows involved.
CO2 is scrubbed from processes with high CO2 concentrations such as rotary ovens of cement plants. The CO2 is then introduced to basins that contain large volumes of algae which consume the CO2 gas.
As algaes are polysaccharides containing fermentable sugars, these are easily converted to alcohol through fermentation. The alcohol can then be recovered for use as fuel, leaving the remaining algae bio mass and yeast cream for drying into useful fertiliser and animal feed respectively.
The, as yet, experimental process would be ideal for industries with a large carbon dioxide footprint that are interested in savings from CO2 reduction of production processes, said GEA.
The company, however, acknowledged that the payback period for such a CO2-transformation installation is, as yet, uncertain: the return on investmentwill be determined largely by the tax rates and other penalties governments impose on CO2 emissions.
Nevertheless, Robert Djernaes, food sales group manager of GEA Niro, believes the cost savings will be significant: “The payback time on a process like this depends largely on how much the plant is paying in emissions taxes and to a lesser extent on the sales price of the produced fertilizer, alcohol and protein for animal feed.
Ultimately though, reducing the cost for the plant will reduce the cost for the client and therefore the product’s consumer,” he said.
Currently there are extended tests running in Spain for growing algaes in connection with a cement plant. Preliminary analysis suggests that it is a successful process for reducing CO2 emissions, said GEA.
