Biochemical catalytic production processing

In terms of biodiesel conversion processes, chemical conversion using alkali and acid-based catalysts is stiU the most favorite approach. Various investigations have been carried out to develop novel catalysts and/or novel processes for efficient conversion of TAG to FAME. This part was reviewed in the chapter Production of biodiesel via catalytic upgrading refining of sustainable oleageneous feedstocks. The chapter Biochemical catalytic production of biodiesel introduced a promising alternative way of biodiesel production via enzyme-catalyzed processes. Recentiy, microalgae... 

With the technical development achieved in the last 30 years, pressure has become a common variable in several chemical and biochemical laboratories. In addition to temperature, concentration, pH, solvent, ionic strength, etc., it helps provide a better understanding of structures and reactions in chemical, biochemical, catalytic-mechanistic studies and industrial applications. Two of the first industrial examples of the effect of pressure on reactions are the Haber process for the synthesis of ammonia and the conversion of carbon to diamond. The production of NH3 and synthetic diamonds illustrate completely different fields of use of high pressures the first application concerns reactions involving pressurized gases and the second deals with the effect of very high hydrostatic pressure on chemical reactions. High pressure analytical techniques have been developed for the majority of the physicochemical methods (spectroscopies e. g. NMR, IR, UV-visible and electrochemistry, flow methods, etc.). 

Biochemical industries are based on the growth of microbes such as bacteria, fungi, molds, yeasts and others. Although some microbes are grown as food, interest here is in the production of chemicals with their aid. A distinction is drawn between steps that involve cells and those that employ isolated catalytic enzymes which are metabolic products of cells. Major characteristics of microbial processes that may be contrasted with those of ordinary chemical processing include the following ... 

The petrochemical industry typically works on a build-up approach where the base oil feedstock is fractionated, and complex materials are built up from simpler ones, producing a wide array of materials in the process, for a range of market outlets. The future exploitation of plant materials is seen in a somewhat similar fashion, although in contrast to the petrochemical industry, there will typically be an initial breaking up of more complex materials into simpler building blocks that can then be utilised and built on with the support of chemical, biochemical and catalytic processes, to produce more complex products synonymous with those produced by today s petrochemical industry. This whole crop approach to industrial use of plant-derived material is typically termed biorefining (see Chapter 1). 

A major aspect of research and development in industrial catalysis is the identification of catalytic materials and reaction conditions that lead to effective catalytic processes. The need for efficient approaches to facilitate the discovery of new solid catalysts is particularly timely in view of the growing need to expand the applications of catalytic technologies beyond the current chemical and petrochemical industries. For example, new catalysts are needed for environmental applications such as treatment of noxious emissions or for pollution prevention. Improved catalysts are needed for new fuel cell applications. The production of high-value specialty chemicals requires the development of new catalytic materials. Furthermore, new catalysts may be combined with biochemical processes for the production of chemicals from renewable resources. The catalysts required for these new applications may be different from those in current use in the chemical and petrochemical industries. 

Finally, for an overall perspective on catalysis of all types, here are a few words about biochemical catalysts, namely, enzymes. In terms of activity, selectivity, and scope, enzymes score very high. A large number of reactions are catalyzed very efficiently, and the selectivity is high. For chiral products enzymes routinely give 100% enantioselectivity. However, large-scale application of enzyme catalysis in the near future is unlikely for many reasons. Isolation of a reasonable quantity of pure enzyme is often very difficult and expensive. Most enzymes are fragile and have poor thermal stability. Separation of the enzyme after the reaction is also a difficult problem. However, in the near future, catalytic processes based on thermostable enzymes may be adopted for selected products. 

Enzymes are catalytically active proteins that are involved in every in vivo transformation. They enhance the rates of biochemical reactions by 10 to 10 2 by reduction of the free energy of activation. Two distinctive properties of enzymes are their high substrate specificity and the narrow range of conditions under which they are effective. They usually catalyze one reaction of a few substrates. Activities are dependent on pH, temperature, the presence of cofactors, as well as concentrations of substrates and products. Enzymes perform specific reactions because they possess cavities in which substrates are oriented white they are transformed (Figure 1). This process involves interaction of the substrate with amino acids of the enzyme. 

Given a fixed, predetermined set of elementary reactions, compose reaction pathways (mechanisms) that satisfy given specifications in the transformation of available raw materials to desired products. This is a problem encountered quite frequently during research and development of chemical and biochemical processes. As in the assembly of a puzzle, the pieces (available reaction steps) must fit with each other (i.e., satisfy a set of constraints imposed by the precursor and successor reactions) and conform with the size and shape of the board (i.e., the specifications on the overall transformation of raw materials to products). This chapter draws from symbolic and quantitative reasoning ideas of AI which allow the systematic synthesis of artifacts through a recursive satisfaction of constraints imposed on the artifact as a whole and on its components. The artifacts in this chapter are mechanisms of catalytic reactions and... 

The most suitable driving force in BI is the reduction of the diffusion path that already operates in transport processes across biological bilayers. Consequently, biocatalyst membranes and specially designed bioreactors, such as jet loop and membrane reactors, are available to intensify biochemical reactions. " " Supported biocatalysts are often employed to enhance catalytic activity and stability and to protect enzymes/ microorganisms from mechanical degradation and deactivation.f Immobilization of the cells is one of the techniques employed to improve the productivity of bioreactors. 

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