| As fuels derived from renewable resources take on a | | | | pretreat feedstocks, because acid compounds can |
| greater role on the global energy stage, it is critical | | | | degrade xylose, an essential component in ethanol |
| that researchers continue to design novel ways to | | | | production. To create lignocellulosic feedstocks of |
| generate biofuels to meet this demand. Of those | | | | suitable particle size for ethanol production, the |
| renewable resources, switch grass has many | | | | patented methodology subjects the precursor to |
| advantages as an ethanol source. In fact, a look at | | | | milling techniques that mechanically treat the biomass |
| intellectual property disclosures citing novelties using | | | | material. |
| switch grass for ethanol production shows that | | | | One of DuPont's more recent disclosures (the |
| indeed researchers are examining this abundant | | | | company has three World patent applications |
| source. | | | | published between 2006 and 2007) also address |
| In January, Chemical & Engineering News | | | | treating biomass resources for ethanol formation. |
| reported that researchers from the University of | | | | Published in 2006, World Patent Application |
| Nebraska discovered that a net energy surplus | | | | 2006110900/WO-A2 describes a method of |
| resulted when switch grass was used as a feedstock | | | | pre-treating biomass with ammonia compounds and |
| for ethanol production. Their five-year study found | | | | digesting it with a saccharification enzyme to |
| that 540 percent more renewable energy was | | | | generate fermentable sugars. The fermentable sugar |
| generated as compared to the energy needed to | | | | is then biocatalyzed by adding biocatalysts that |
| grow and harvest the switch grass feedstock. While | | | | include bacteria, filamentous fungi, and yeast to |
| a net energy surplus is one criterion that must be | | | | produce ethanol. The patent describes using switch |
| met to commercialize a feedstock for bioethanol | | | | grass, but the bio-source could also be wastepaper, |
| production, other factors such as increasing the | | | | corn cobs, corn husks, corn stover, wood chips, or |
| extractability of cellulose from the lignin matrix and | | | | animal manure. |
| the ability to ferment the sugars to ethanol must be | | | | Also assigned to DuPont is World Patent Application |
| enhanced for this conversion process to succeed in | | | | 2007149450/WO-A2 published in December 2007. |
| industry. | | | | The patent notes that bacterial growth is a concern |
| Three Companies Dominate Patent Activity | | | | of ethanol fermenters because microbe formation |
| An examination of U.S. and International patents | | | | during the fermentation process can convert sugars |
| found 39 patents filed in the past five years dealing | | | | to non-ethanol products including organic acids. This |
| with ethanol generation from switch grass precursors. | | | | patent describes using chlorine dioxide to prevent |
| While switch grass is noted as a feedstock used in | | | | microbe formation during cellulosic feedstock |
| these inventions, other feedstock materials are | | | | fermentation. It also states that switch grass or |
| claimed as well, including lignocellulosic feedstock | | | | other biomass resources can be used in this process, |
| sources such as wood, and waste agricultural fibers | | | | including potatoes or whey. |
| such as wheat straw and oat hulls. Currently, | | | | Novozymes is also a player, having filed two World |
| researchers are particularly interested in utilizing | | | | patent applications in 2006 involving ethanol formation |
| readily available and renewable biomass starting | | | | from switch grass, focusing on ways to pretreat |
| materials to generate ethanol. Of these, Iogen, EI du | | | | lignocellulosic material before fermentation. Cellulase |
| Pont de Nemours (DuPont) and Novozymes have the | | | | and xylose isomerase can be combined in pretreating |
| most patents disclosing novelties on this technology. | | | | biomass materials to bring an increase in available |
| Iogen has nine patents, only one of which was filed in | | | | five-carbon sugars. These sugars then can be |
| the United States. Most of Iogen's disclosures were | | | | fermented into ethanol using enzymes such as |
| filed as European or World patent applications, an | | | | saccharomyces cerevisciae. The patent states that |
| indication of where the company thinks the market | | | | switch grass as well as office paper, or pine wood |
| will develop. Iogen patents disclose inventions for | | | | can be used as the feedstock resource for this |
| alternative methodologies to pretreat feedstock prior | | | | process. |
| to ethanol formation as described in World Patent | | | | Keep an Eye out for Non-U.S. Patents |
| Application 2005099854/WO-A1. After treating a | | | | Researchers are currently disclosing through patent |
| feedstock such as switch grass with hot | | | | applications ways to pretreat feedstock materials |
| concentrated sulfuric acid steam to reduce the | | | | including switch grass to enhance the availability of |
| material's particle size, a metal sulfate impurity can | | | | cellulosic extractables. Most inventions were not filed |
| form and become entrapped in the chemically treated | | | | in the U.S., so it is important for companies seeking |
| feedstock. This can affect the transformation in fuel | | | | to monitor their competitors to review international |
| ethanol. One of Iogen's patent describes a | | | | disclosures. Companies are most interested in |
| pre-treatment extraction method to recover these | | | | increasing the amount of extractable five-carbon |
| inorganic salts, which can then be used for fertilizers. | | | | sugars as these have been shown to be most |
| Pretreatment Is a Common Focus | | | | effective in fermentation to ethanol. Further |
| Another Iogen invention claims novel ways to | | | | R&D efforts on using switch grass for ethanol |
| pretreat feedstock sources before ethanol formation | | | | production is expected to continue as commercial |
| (European Patent 01364072/EP-B1). This patent is | | | | interest grows in the generation of biofuels using |
| based on reducing the amount of acid needed to | | | | sources that have minimal impact on food production. |