Fermentation biofuels from

One can envisage the future production of liquid fuels and commodity chemicals in a biorefinery Biomass is first subjected to extraction to remove waxes and essential oils. Various options are possible for conversion of the remaining biofeedstock, which consists primarily of lignocellulose. It can be converted to synthesis gas (CO + H2) by gasification, for example, and subsequently to methanol. Alternatively, it can be subjected to hydrothermal upgrading (HTU), affording liquid biofuels from which known transport fuels and bulk chemicals can be produced. An appealing option is bioconversion to ethanol by fermentation. The ethanol can be used directly as a liquid fuel and/or converted to ethylene as a base chemical. Such a hiorefinery is depicted in Fig. 8.1. 

Producing ethanol as a biofuel from the sugars in corn (glucose) has become a major industry in the grain belt. This process can be summarized as follows, where glucose is fermented to form ethanol and carbon dioxide. Use bond energies to estimate ATT for this reaction. 

More Biochemical Connections Boxes In response to customers demand for more Biochemical Connection boxes, we have added several new boxes to the text, such as Lactic Acid—Not Always the Bad Guy, Biofuels from Fermentation, and Catalysts for Green Chemistry. ... 

Efremenko EN, Nikolskaya AB, Lyagin IV, Senko OV, Makhlis TA, Stepanov NA, Maslova OV, Mamedova F, Varfolomeev SD (2012) Production of biofuels from pretreated microalgae biomass by anaerobic fermentation with immobilized Clostridium acetobutylicum cells. Bioresour Technol 114 342-348... 

Biotechnology for Biofuels. 2007- London BioMed Central Ltd. (1754-6834). Online http // www.biotechnologyforbiofuels.com/. An open access online journal publishing research on advances in the production of biofuels from biomass, including development of plants for biofuels production, plant deconstruction, pretreatment and fractionation, enzyme production and enzymatic conversion, and fermentation and bioconversion. 

Lachke A (2002) Biofuel from D-xylose—the second most abundant sugar. Resonance 7(5) 50-58 Li Z, Xiao H, Jiang W, Jiang Y, Yang S (2013) Improvemoit of solvoit production from xylose mother liquor by engineering the xylose metabolic pathway in Clostridium acetobutylicum EA 2018. Appl Biochem Biotechnol 171(3) 555-568. doi 10.1007/sl2010-013-0414-9 Lin Y, Tanaka S (2006) Ethanol fermentation from biomass resources current state and prospects. Appl Microbiol Biotechnol 69(6) 627-642... 

Biofuel generation from sweet sorghum Fermentative hydrogen production and anaerobic digestion of the remaining biomass. Biores. Technol. 99 (1), 110-119. 

Second-generation biofuel technologies make use of a much wider range of biomass feedstock (e.g., forest residues, biomass waste, wood, woodchips, grasses and short rotation crops, etc.) for the production of ethanol biofuels based on the fermentation of lignocellulosic material, while other routes include thermo-chemical processes such as biomass gasification followed by a transformation from gas to liquid (e.g., synthesis) to obtain synthetic fuels similar to diesel. The conversion processes for these routes have been available for decades, but none of them have yet reached a high scale commercial level. 

Microbial biofuel cells were the earliest biofuel cell technology to be developed, as an alternative to conventional fuel cell technology. The concept and performance of several microbial biofuel cells have been summarized in recent review chapters." The most fuel-efficient way of utilizing complex fuels, such as carbohydrates, is by using microbial biofuel cells where the oxidation process involves a cascade of enzyme-catalyzed reactions. The two classical methods of operating the microbial fuel cells are (1) utilization of the electroactive metabolite produced by the fermentation of the fuel substrate " and (2) use of redox mediators to shuttle electrons from the metabolic pathway of the microorganism to the electrodes. ... 

The first-generation biofuels can be identified as ethanol, which was produced via the alcoholic fermentation of cereals, and hio-oil or biodiesel, which was extracted from seeds such as sunflower, rapeseed, or palm. The use of cereals and sunflowers was rejected by public opinion and some scientific environments, because their use for energy production conflicted with their use as foodstuffs. In fact, the diversion of cereals to the production of ethanol for transport has led to a rise in the price of flour and derived goods, especially in Mexico. The same situation has arisen for some bio-oils, such that the source was shifted to palm-oil which, essentially, is produced in Asian countries such as Malaysia. 

The CASH process was developed by cooperation between Canada, the USA and Sweden. In this method, hydrolysis occurs in two steps with dilute sulfuric acid at a temperature around 200 °C (pressure 8-25 bar) and the fermentation of sugars by yeast to ethanol. It has been shown that by using SO2 and dilute sulfuric acid in two steps, this increases the sugar and ethanol yield, since the amount of inhibitors such as furfural is decreased. The process was developed for raw materials such as sawdust and other residues from trees. The ethanol yield is about 30% of the energy in the raw material and there are also by-products, with up to 40% of the energy content in solid form (lignin), which can be used as biofuel. 

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