The production of frictionoffs from renewable sources serves to climate protection – but because of the competition for food production under criticism. Algae offers themselves as an alternative
The fuel production of agricultural products is around the globe plenty of a rough and, thanks to odds and subsidies, profitable business. Six percent of the world’s grain harvests are now no longer processed for human health, but cover our energy needs. Ascending trend. Actually, good news – renewable raw materials do not burden the climate balance in addition. However, since the hunger problem is not dissolved, the fact can not really justify the fact, potential foods such as corn and sugar cane (the main sources of biofuel) through the exhaust faster limousines on German highways. Not only the researchers, even the politicians are therefore urgently looking for an alternative that is not in competition for food production.
How were it with non-edible, cellulose-containing substances, such as in agriculture as residues? This is still missing at the treatment technology: It is too expensive and too inefficient to split the long chain molecules so that they can be processed into ethanol. For biofuel production in question but also algae. Although they end up in some countries already in the cake – but the quantities of quantities weighed are negligible.
At least there are already experience in their cultivation: worldwide, about 15 million tonnes are gained and used for eating and dungung. Brown sea saturations have a lot of advantages as a fuel basis – especially because for their farming neither agricultural efficiency nor dungems nor subassemblies are needed: three factors that also produce a certain competition for food production even with alternative crops.
Photo: Image Courtesy of Bio Architecture Lab, Inc.
Even chemically bring algae a few advantages – for example, it is easier than cellulose-containing fabrics to extract the various sugars. At least 60 percent of the dry matter consists of fermentable carbohydrates! Reports skate that you could win 59 tons of algae (dry weight) per hectare and year. With an ethanol yield of 25.4 mass percent can be in the best case 19.Create 000 liters of organic ethanol per hectare and year. The yield is thus twice as high as sugar cane and funfals as high as in corn. So all the best?
Not quite – there is a small chemical problem. In algae, the three sugar ALGINAT, MANNITOL and GLUCAN come before. The two latter are trouble-free – but for the industrial decomposition of alginate (containing about half of the total energy) is currently no efficient way known. This is particularly involved, because this is also hindered the use of mannitol: only with simultaneous fermentation of Alginat, for the mannitol decomposition are ideal conditions.
A potential solution for this problem now show researchers in a paper in the science magazine science. The scientists have succeeded in finding a gene complex in the Sea Bacterium Vibrio Splendidus, which synthesized for the decomposition of alginate-upsy proteins. This section of the DNA have the researchers in the erbspanz of the well-known pattern bacterium Escherichia Collaubert – actually this is able to be able to digest alginate.
In this way, the researchers do not come to a process scaled on industrial transactions on a yield of good 28% by mass of ethanol – these are about 80 percent of the theoretical maximum.