Products, of biorefinery

Sedlmeyer, F. B. (2011). Xylan as by-product of biorefineries Characteristics and potential use for food applications. Food Hydrocolloids, Vol. In Press, Corrected Proof, pp. ISSN 0268-005X... 

It is beheved that such a diversity of substrates and products of biorefinery will greatly improve the economical competitiveness of producing chemicals from biotechnology. 

EXTENSIVE LAND USE FOR THE PRODUCTION OF BIOREFINERY FEEDSTOCK AND DEFORESTATION... 

Biomass is a renewable resource from which various useful chemicals and fuels can be produced. Glycerol, obtained as a co-product of the transesterification of vegetable oils to produce biodiesel, is a potential building block to be processed in biorefineries (1,2). Attention has been recently paid to the conversion of glycerol to chemicals, such as propanediols (3, 4), acrolein (5, 6), or glyceric acid (7, 8). 

Huber, G. W. Dumesic, J. A., An overview of aqueous-phase catalytic processes for production of hydrogen and alkanes in a biorefinery. Catalysis Today 2006, 111, 119. 

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-... 

As shown in Fig. 9.7, bioethanol may be also used in a biorefinery for the production of higher-alcohols, to integrate ethanol and methanol (produced via fermen-... 

The expansion of the market, however, will depend considerably on the possibility of an efficient use of other biomass sources, particularly lignocellulosic-based materials, fast growing dedicated crops, and waste resources. Effective integration of bioethanol production into biorefineries will also be a key aspect in decreasing the price by a better use of all the components of biomass. 

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] ... 

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). 

Figure 4 gives an alternative scheme of possible biomass conversion pathways. Depending on the type of available biomasses and the objective products, each biorefinery will implement a different production and conversion scheme. 

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). 

Table 2 reports the expected market development of major RRM-based products [7] notably, the potential market may significantly enlarge if the progressive introduction of biorefineries decreases the production costs, on one side, and increases the number of biomass-based products on the other side. 

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... 

A biorefinery is a facility that integrates biomass conversion processes and eqtrip-ment to produce fuels, power, and value-added chemicals from biomass. Biorefinery is the co-production of a spectram of bio-based products and energy from biomass. The biorefinery concept is analogous to today s crude oil refinery. Biorefinery is a relatively new term referring to the conversion of biomass feedstock into a host of valuable chemicals and energy with minimal waste and emissions. 

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. 

There are four main biorefineries biosyngas-based refinery, pyrolysis-based refinery, hydrothermal upgrading-based refinery, and fermentation-based refinery. Biosyngas is a mrrltifimctional intermediate for the production of materials, chemicals, transportation fuels, power and/or heat from biomass. Figrrre 3.4 shows the gasification-based thermochemical biorefinery. 

The concept biorefinery is discussed in the US National Research Council Report Biobased Industrial Products [4] and by Lynd et al. [7] in much detail. The basic idea is the processing of multiple renewable resources and the production of multiple products in a production complex. Another characteristic of biorefinery is the integration of thermal, chemical, biological and/or cataly-tical processes for an efficient and optimal processing and utilization of the raw materials. Technological, ecological and economic analysis and system design should be implemented to ensure an overall optimization of raw material conversion and product formation in a similar way as for oil refineries. 

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