Fractionation biorefinery

Valorization, retreatment or disposal of co-products and wastes from biorefinery by catalytic treatments. This includes the utilization of plant and biomass fractions that are residual after the production of, for example, bioethanol and from other production chains (e.g., production of methane). 

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). 

Many improvements are still needed to make really effective use of renewable raw materials in biorefineries. Full utilization of the plants is needed instead of the current under utilization, as well as the development of processes to add value to all fractions of the plant and to valorize the by-products of other industrial... 

Biorefinery includes fractionation for separation of primary refinery products. The fractionation refers to the conversion of wood into its constituent components (cellulose, hemicelluloses and lignin). Processes include steam explosion, aqueous separation and hot water systems. Commercial products of biomass fractionation include levulinic acid, xylitol and alcohols. Figure 3.3 shows the fractionation of wood and chemicals from wood. 

Conversion efficiency and robust fermentation of mixed-sugar lignocellulose-derived hydrolysates are critical for producing ethanol at low cost to realize a commercially viable biorefinery. Biomass sugars are typically released by thermochemical pretreatment followed by enzymatic hydrolysis of chopped or milled biomass. The pretreated soluble fraction of biomass is called the hydrolysate and the hydrolysate containing the insoluble... 

Air-dried com stover provided by the Agricultural Utilization Research Institute was milled and then screened, and only the fraction less than 2-mm sieve was used in this research. Aspen pulping wood chips (Populus tremuloides) with a pretreatment, which were the intermediates of a biorefinery process, were provided by the Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, Minnesota. Aspen wood chips that passed through a 1 -in. sieve but not through a 0.5-inch sieve were used. Aspen wood chips were pretreated with dilute sulfuric acid to remove partial hemicellulose. 

A possible cheap production approach for SCP and YE is the management of yeast biomass derived or produced within the biorefinery fiamework, namely, Irom the upgrading of the hemicellulosic fraction stream. 

Successful integration of carbohydrate chemistry in a biorefinery will greatly depend on the availability and price of the lignoceUulosic feedstock and its fractionation cost. Since the collection of biomass is Umited by its volume and density, biorefineries are likely to be smaller and more highly distributed than petroleum refineries. In order to produce meaningful volumes of products, a biorefinery should focus on a specific set of platform chemicals rather than attempting to provide an extended portfolio of products. There are two technological obstacles to the delivery of such a biorefinery, and effort is required to overcome them. First, the... 

Nowadays, the bulk of succinic acid (SA) is produced at a rate of 25,000 tons per year from maleic anhydride obtained by oxidation of the C4 fraction (n-butane or butadiene) of crude oil [321]. However, the biotechnological production of SA by fermentation of carbohydrates has attracted more recent attention (http // www.dsm.com/en US/downloads/media/12e 09 dsm and roquette connmercialize bio based succinic acid.pdf, http //www.bio-amber.com/press releases.php, [322-326]). The economic and environmental analysis of a biorefinery producing SA indicated that bio-SA is a promising intermediate provided that its production cost could be lowered further [322]. 

Bozell JJ, Black SK, Myers M, Cahill D, Miller WP, Park S (2011) Solvent fractionation of renewable woody feedstocks organosolv generation of biorefinery process streams for the production of biobased chemicals. Biomass Bioenergy 35 4197... 

Bozell JJ, O Lenick CJ, Warwick S (2011) Biomass fractionation for the biorefinery heteronuclear multiple quantum coherence-nuclear magnetic resonance investigation of lignin isolated from solvent fractionation of switchgrass. J Agric Food Chem 59 9232... 

In the last decade, increasing efforts have been dedicated worldwide to realizing the implementation of biorefinery plants for the eonversion of lignocellulosic and cellulosic waste to starting materials for the biotechnological production of bioethanol, biopolymers and a range of fine chemicals. Whereas the material recovery from the lignin fraction is limited to the production of adhesives, sulphur-free fuels and some aromatics, cellulose and hemicellulose provide a rich source of... 

Sustainable usage of lignin for material production is stiU to be established Simultaneous fermentation of C6 and C5 sugars from the hemicellulose fraction is StiU to be optimized Embedding product streams of the biorefinery into the chemical industry is StiU to be estabUshed... 

A biorefinery is the integral upstream, midstream, and downstream processing of biomass into a range of produas. In the classification system lEA Bioenergy Task 42 (described in the next chapter) has differentiated between mechanical pretreatments (extraction, fractionation, separation), thermochemical conversions, chemical conversions, enzymatic conversions, and microbial (fermentation both aerobic, anaerobic) conversions. 

Conventional biorefineries Starch (corn, wheat, cassava) and sugar crops (sugarcane, sugar beet), wood Pretreatment, chemical and enzymatic hydrolysis, catalysis, fermentation, fractionation, separation Commercial Sugar, starch, oil, dietary fibers, pulp and paper... 

Oleochemical biorefineries Oil crops Pretreatment, chemical catalysis, fractionation, separation Pilot plant. Demo, commercial Oil, glycerin, cattle feed... 

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