Biomass conversion into production

Biomass Conversion into Hydrogen with the Production of Carbon Suboxides and Without CO2 Emission... 

This chapter is an overview of architectures adopted for the catalytic/biocatalytic composites used in wide applications like the biomass valorization or fine chemical industry. On this perspective, the chapter updates the reader with the most fresh examples of construction designs and concepts considered for the synthesis of such composites. Their catalytic properties result from the introduction of catalytic functionalities and vary from inorganic metal species e.g., Ru, Ir, Pd, or Rh) to well-organized biochemical structures like enzymes e.g., lipase, peroxidase, (3-galactosidase) or whole cells. Catalytic/biocatalytic procedures for the biomass conversion into platform molecules e.g., glucose, GVL, Me-THF, sorbitol, succinic acid, and glycerol) and their further transformation into value-added products are detailed in order to make understandable the utility of these complex architectures and to associate the composite properties to their performances, versatility, and robustness. 

Not the least, catalytic/biocatalytic systems can be very simple separated and recycled by applying an external magnetic force, avoiding the complications associated with the use of rmit operations as catalyst filtration or centrifugation. Hence, several designs of the magnetical-separated com-posite/biocomposite have been developed and appHed for biomass conversion into platform molecule and further to value-added products. 

Biomass conversion technologies can be divided into direct production technology routes and technologies aimed at the conversion of storable intermediates. Direct routes have the advantage of simplicity. Indirect routes have additional production steps, but have an advantage in that there can be distributed production of the intermediates, minimizing the transportation costs of the biomass. Intermediates can be... 

Bioethanol is the largest biofuel today and is used in low 5%—10% blends with gasoline (E5, E10), but also as E85 in flexible-fuel vehicles. Conventional production is a well known process, based on the enzymatic conversion of starchy biomass (cereals) into sugars, and fermentation of 6-carbon sugars with final distillation of ethanol to fuel grade. 

The need for catalysis in this field is very clear. Molecular conversion technologies of non-food biomass have, so far, only been implemented for fermented cellulose. Even for those products, conversion into energy carriers is not yet very efficient. 

Figure 2.13 did not include all the biomass conversion processes discussed above. It only considered those that produce transportation fuels. The processes that convert bio-feedstock into biocrude or electricity could not be included because their products have a different value than the transportation fuels. Such a comparison can be attempted by displaying the total manufacturing cost of biobased products in a graph that shows typical relationships between the price of crude and that its derivatives, i.e., of fuel oil, transportation fuel and electricity. This has been done in Fig. 2.14 for the lignocellulose conversion processes. 

The production of H2 from some by-products of biomass conversion is also a possible option, which also requires the development of, new, more stable, more efficient catalysts that operate directly in the liquid phase. The catalytic production of hydrogen from more valuable products, such as bioethanol, should be reconsidered with appropriate economic assessments that take into account the alternative possible uses of these products. 

Methanol can be produced from biomass, essentially any primary energy somce. Thus, the choice of fuel in the transportation sector is to some extent determined by the availability of biomass. As regards to the difference between hydrogen and methanol production costs, conversion of natural gas, biomass and coal into hydrogen is generally more energy efficient and less expensive than the conversion into methanol. 

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. 

The enhanced, direct fixation of C02 into fast-growing biomasses might contribute towards reducing its accumulation in the atmosphere, under non-natural conditions. Such an approach could be used for the production of chemicals and energy (e.g., conversion into gaseous and liquid fuels, rather than direct combustion of the solid biomass), with beneficial effects on reducing C02 emissions and accumulation in the atmosphere. The potential of biomass as a possible substitute for fossil fuels in the USA is shown in Figure 1.7. 

Experiments were carried out in batch-type and flow-type supercritical biomass conversion systems. The batch-type reaction system was the same as reported previously (14). In brief, it consisted of a tube reaction vessel (Inconel-625 5 mL in volume) equipped with a thermocouple and a pressure gage. For hydrolysis reaction, 1 mL of rapeseed oil mixed with 4 mL of water was fully charged into the reaction vessel. The reaction vessel was then heated with molten tin preheated at desired temperatures. It took about 12 s to reach the reaction temperature. Subsequently, the vessel was moved into a water bath to quench the reaction. Reaction time was counted from the time a mixture reached the reaction temperature to when it was quenched. The obtained product was then kept for about 30 min until the two phases separated the upper portion is the hydrolyzed product, while the lower is a mixture of water and glycerol. The upper portion was then evaporated in a vacuum evaporator to remove any water. 

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