As fuels derived from renewable resources take on a greater role on the global energy stage, it is vital that researchers continue to design novel approaches to produce biofuels to meet this demand. Of those renewable resources, switch grass has a large number of benefits as an ethanol source. In reality, a look at intellectual property disclosures citing novelties applying switch grass for ethanol production shows that indeed researchers are examining this abundant source.
In January, Chemical & Engineering News reported that researchers from the University of Nebraska found that a net power surplus resulted when switch grass was employed as a feedstock for ethanol production. Their five-year study discovered that 540 percent extra renewable power was generated as compared to the power required to grow and harvest the switch grass feedstock. While a net energy surplus is 1 criterion that need to be met to commercialize a feedstock for bioethanol production, other elements such as increasing the extractability of cellulose from the lignin matrix and the capability to ferment the sugars to ethanol have to be enhanced for this conversion method to succeed in market.
3 Businesses Dominate Patent Activity
An examination of U.S. and International patents identified 39 patents filed in the past 5 years dealing with ethanol generation from switch grass precursors. Whilst switch grass is noted as a feedstock employed in these inventions, other feedstock supplies are claimed as well, such as lignocellulosic feedstock sources such as wood, and waste agricultural fibers such as wheat straw and oat hulls. At present, researchers are particularly interested in utilizing readily out there and renewable biomass starting supplies to generate ethanol. Of these, Iogen, EI du Pont de Nemours (DuPont) and Novozymes have the most patents disclosing novelties on this technologies.
Iogen has nine patents, only 1 of which was filed in the United States. Most of Iogen's disclosures had been filed as European or Globe patent applications, an indication of where the enterprise thinks the market place will create. Iogen patents disclose inventions for alternative methodologies to pretreat feedstock prior to ethanol formation as described in Globe Patent Application 2005099854/WO-A1. Immediately after treating a feedstock such as switch grass with hot concentrated sulfuric acid steam to lower the material's particle size, a metal sulfate impurity can form and come to be entrapped in the chemically treated feedstock. This can have an effect on the transformation in fuel ethanol. 1 of Iogen's patent describes a pre-therapy extraction strategy to recover these inorganic salts, which can then be made use of for fertilizers.
Pretreatment Is a Prevalent Focus
An additional Iogen invention claims novel techniques to pretreat feedstock sources before ethanol formation (European Patent 01364072/EP-B1). This patent is based on lowering the amount of acid necessary to pretreat feedstocks, mainly because acid compounds can degrade xylose, an crucial component in ethanol production. To build lignocellulosic feedstocks of appropriate particle size for ethanol production, the patented methodology subjects the precursor to milling techniques that mechanically treat the biomass material.
One of DuPont's significantly more recent disclosures (the corporation has three Globe patent applications published between 2006 and 2007) also address treating biomass resources for ethanol formation. Published in 2006, Globe Patent Application 2006110900/WO-A2 describes a strategy of pre-treating biomass with ammonia compounds and digesting it with a saccharification enzyme to create fermentable sugars. The fermentable sugar is then biocatalyzed by adding biocatalysts that include bacteria, filamentous fungi, and yeast to generate ethanol. The patent describes making use of switch grass, but the bio-source could also be wastepaper, corn cobs, corn husks, corn stover, wood chips, or animal manure.
Also assigned to DuPont is World Patent Application 2007149450/WO-A2 published in December 2007. The patent notes that bacterial growth is a concern of ethanol fermenters because microbe formation throughout the fermentation method can convert sugars to non-ethanol merchandise which includes organic acids. This patent describes using chlorine dioxide to prevent microbe formation in the course of cellulosic feedstock fermentation. It also states that switch grass or other biomass resources can be made use of in this approach, such as potatoes or whey.
Novozymes is also a player, having filed two Globe patent applications in 2006 involving ethanol formation from switch grass, focusing on ways to pretreat lignocellulosic material just before fermentation. Cellulase and xylose isomerase can be combined in pretreating biomass materials to bring an boost in offered five-carbon sugars. These sugars then can be fermented into ethanol using enzymes such as saccharomyces cerevisciae. The patent states that switch grass as well as office paper, or pine wood can be made use of as the feedstock resource for this process.
Maintain an Eye out for Non-U.S. Patents
Researchers are at the moment disclosing via patent applications approaches to pretreat feedstock supplies which includes switch grass to improve the availability of cellulosic extractables. Most inventions were not filed in the U.S., so it is critical for providers looking for to monitor their competitors to assessment international disclosures. Companies are most interested in growing the quantity of extractable 5-carbon sugars as these have been shown to be most helpful in fermentation to ethanol. Further R&D efforts on making use of switch grass for ethanol production is expected to continue as commercial interest grows in the generation of biofuels making use of sources that have minimal impact on food production.
