Biorefineries biofuels

M. Roehr, ed.. The Biotechnology of Ethanol, Wiley-VCH, Weinheim, 2001 J. Goettemoeller and A. Goettemoeller, Sustainable Ethanol Biofuels, Biorefineries, Cellulosic Biomass, Flex-fuel Vehicles, and Sustainable Farming for Energy Independence, Prairie Oak Pub., Maryville, 2007 L. Olsson, Biofuels, Springer, Berlin, 2007 W. Soetaert, E.J. Vandamme, ed.. Biofuels, John Wiley Sons, Chichester, 2009. 

The Department of Energy (DOE) is helping six firms build cellulosic biorefineries with grants totaling about 385 million. When fully operational, the six plants will produce more than 130 million gallons of cellulosic ethanol a year. DOE is also investing 375 million into three new Bioenergy Research Centers to speed up the development of cellulosic ethanol and other biofuels. 

The additional interesting part of Fig. 1.12 is the biorefinery, which uses biomass and waste, produces waste products C02 and ash, both to be recycled for the production of biofuels, heat and electricity and biomaterials. These biomaterials are highly oxygen functionalized for products such as alcohols, carboxylic acids and esters. A currently produced bioplastic is poly(lactic acid). A main cost factor is separation. 

The biorefinery scheme was developed initially for carbohydrate-containing feedstocks. Large biorefineries are currently operating in the USA (e.g., Cargill at Blair, Nebraska) and in Europe (e.g., Roquette Frs. at Lestrem, France). The concept can be extended to produce chemicals from other renewable feedstocks. An integrated production of oleochemicals and biofuels can be achieved in biorefineries using vegetables oils as main feedstock to produce versatile platform mole-... 

A biorefinery maximizes the value derived from the complex biomass feedstock by (a) optimal use and valorization of feedstock, (b) optimization and integration of processes for better efficiency, and (c) optimization of inputs (water, energy, etc.) and waste recycling/treatment. Integrated production of bioproducts, especially for bulk chemicals, biofuels, biolubricants and polymers, can improve their competitiveness and eco-efficiency. However, although a few examples of biorefineries already exist (Chapters 3 and 6), many improvements are still needed to enhance the process [5] ... 

The valorization of by-products in biomass conversion is a key factor for introducing a biomass based energy and chemistry. There is the need to develop new (catalytic) solutions for the utilization of plant and biomass fractions that are residual after the production of bioethanol and other biofuels or production chains. Valorization, retreatment or disposal of co-products and wastes from a biorefinery is also an important consideration in the overall bioreftnery system, because, for example, the production of waste water will be much larger than in oil-based refineries. A typical oil-based refinery treats about 25 000 t d-1 and produces about 15 000 t d 1 of waste water. The relative amount of waste water may increase by a factor 10 or more, depending on the type of feed and production, in a biorefinery. Evidently, new solutions are needed, including improved catalytic methods to eliminate some of the toxic chemicals present in the waste water (e.g., phenols). 

Byproducts of biofuel production are glycerin and lignin. The production of each gallon of biodiesel also produces a pound of glycerin. These materials can be used to replace oil-based products with bio-based ones. It is expected that in the decades to come, the development of the biofuel industry will result in the building of multiproduct biorefineries. 

Wright, M. and R.C. Brown, Comparative Economics of Biorefineries Based on the Biochemical and Thermochemical Platforms, Biofuels, Bioprod. Bioref, 1, 49-56 (2007a). 

Clark JH, Deswarte FEI, Farmer TJ. The integration of green chemistry into future biorefineries. Biofuels Bioprod Biorefin. 2009 3(l) 72-90. 

Recent attempts aim at the controlled transformation of cellulose, hemicellulose, and lignin to platform molecules for a potential future biorefinery scenario. In this regard, the U.S. Department of Energy has published studies on potential future platform molecules that could be derived from renewable resources [35, 36]. Tailored transformation of biomass to these platform chemicals could serve as a starting point for biofuel production. This would allow the development of comprehensive biorefinery approaches that incorporate both the production of biofuels and chemicals. The... 

Metabolic pathway engineering [125] is used to optimise the production of the required product based on the amount of substrate (usually biomass-derived) consumed. A so-called biobased economy is envisaged in which commodity chemicals (including biofuels), specialty chemicals such as vitamins, flavors and fragrances and industrial monomers will be produced in biorefineries (see Chapter 8 for a more detailed discussion). 

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. 

SneU KD, Peoples OP (2009) PHA bioplastic A value-added coproduct for biomass biorefineries. Biofuels, Bioprod Biorefining 3 456 67... 

S. cerevisiae and other yeasts are valuable platform hosts for biorefinery apph-cations where sugar, starch, or lignocellulose are converted to biofuels or value-added chemicals [15]. Beside bioethanol, biologically produced hpids represent... 

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