Second generation biofuel, or cellulosic biofuel, is made of non-food feedstocks such as straw and sugarcane bagasse. The technology is difficult and producing it on large scale is not easy, although Denmark has been spearheading second-generation biofuel application by offering it at Danish gas pumps. Elsewhere, researchers are busy at work developing enzymes that can break down the cellulose that envelopes biomass that can be used for this type of fuel.
Denmark has become a second generation biofuel hub, according to an in-depth report recently broadcast on Public Radio International. The article focused on the efforts by Inbicon, a spin-off of the country’s national energy company DONG energy near the capital city of Copenhagen.
The idea to produce second generation biofuel goes back to the mid-1990s when Denmark told its coal-fired power plants that they should burn straw as well, an initiative designed to make use of farm waste and reduce demand for fossil fuels. But the straw harmed furnaces so they devised ways to treat it, which led researchers to find natural enzymes that break down the rough fibers in the straw. This inspired the idea to make fuel from this type of plant matter.
So, how is it done?
First straw is soaked in water and the cooked at around 400 degrees Fahreinheit. The resulting mash is fed into a large, cylindrical tank. The enzymes are added, and after about six hours, the mixture is mostly liquid.The liquid if full of sugars which can be fermented using yeast. After fermentation, the liquid is distilled into ethanol that is then added to gasoline.
Inbicon said that a proper commercial plant would need to be ten times the size of the demonstration site that IPR visited. The company started started making licencing deals to sell the technology worldwide.
Criticism
It all sounds wonderful, right? Not everyone is convinced, though. Jan-Erik Petersen, a bio-energy specialist with the European Environmental Agency in Copenhagen says it will be very difficult to scale up second generation biofuel production by 2020. He blames biological and transportation difficulties as two main obstables.
He also points out that the amount of energy per unit is small and it would be difficult to gather all material in one plant to have an efficient process.
Elsewhere, Bob Howarth at Cornell University says he and his colleagues don’t understand why society is focused on ethanol and that second generation is not a good fuel. He believes it’s better to just burn feedstock material to co-generate heat and electricity.
But Inbicon is convinced that the technology, that could also use garbage as feedstock, can be made viable both financially and environmentally. Humanity needs to steer itself away from fossil fuels, therefore the real question is: can we afford not to try out new methods of producing fuel and energy? What do you think? Does second-generation biofuel appear to be a good solution?
