Product yield, optimization

Product yield optimization is a continuous process. It continues through preclini-cal and clinical development because it ultimately translates into the profit margin of the product when it is approved for marketing. 

First of all, one should note that refining a low cost raw material into low or medium added value products requires extremely delicate optimization. It is out of the question to give them much more than the specifications require thus highlighting the importance of being able to predict the various product yields and qualities that a given crude oil can supply. A profound understanding of crude oils appears therefore indispensable. That is the role of crude oil analysis, an operation traced in part to refining, with the... 

The detergent industry requires process equipment having high operation flexibility, low energy demand, low operation cost, consistent production yield, and, of course, ecological optimization with respect to effluents and air pollution control. To comply with these requirements, the continuous S03/gas sulfonation and double-step neutralization are the basic principles applied in multitube falling film reactor and Neutrex neutralization (Fig. 5). 

The reactions are still most often carried out in batch and semi-batch reactors, which implies that time-dependent, dynamic models are required to obtain a realistic description of the process. Diffusion and reaction in porous catalyst layers play a central role. The ultimate goal of the modehng based on the principles of chemical reaction engineering is the intensification of the process by maximizing the yields and selectivities of the desired products and optimizing the conditions for mass transfer. 

The majority of biocatalytic reactions are thermodynamically controlled. Product yield is thus dependent on the equilibrium position of a reaction. Optimization of the product yield requires knowledge of the equilibrium position in different organic solvents. Several works described and compared models for the prediction of the equilibrium position in two-phase media [6, 28, 29, 33]. 

The synergism of a dual-catalyst system comprising of Pt/ZSM-12 and H-Beta aiming to improve the benzene product purity during transalkylation of aromatics has been studied. Catalyst compositions of the dual-catalyst system were optimized at various reaction temperatures in terms of benzene product purity and premium product yields. Accordingly, a notable improvement in benzene purity at 683 K that meets the industrial specification was achieved using the cascade dual-bed catalyst. 

Another method for preparing pyrrole rings is by Ugi-type three-component condensation (Scheme 6.184). In the protocol published by Tye and Whittaker [345], levulinic acid was reacted with two different isonitriles and four amine building blocks (1.5 equivalents) to provide a set of eight pyrrole derivatives. While the previously published protocol at room temperature required a reaction time of up to 48 h and provided only moderate product yields, the microwave method (100 °C, 30 min) optimized by a Design of Experiments (DoE) approach (see Section 5.3.4), led to high yields of the desired lactams for most of the examples studied. 

A simple, efficient, and high-yielding synthesis of quinazolin-4-ylamines and thieno[3,2-d]pyridin-4-ylamines based on the condensation of appropriately functionalized N -(2-cyanophenyl)-N,N-dimethylformamidines and primary amines has been reported by Han and coworkers (Scheme 6.253) [440]. Optimization of the reaction parameters resulted in the use of acetonitrile/acetic acid as a solvent mixture and of 1.2 equivalents of the requisite amine. In general, microwave heating at 160 °C for 10 min provided excellent product yields. 

The use of a Fischer-Tropsch (FT) process to produce long-chain hydrocarbons is well known in industry, and achieving the desired selectivity from the FT reaction is crucial for the process to make economic sense. It is, however, well known that a one-alpha model does not describe the product spectrum well. From either a chemicals or fuels perspective, hydrocarbon selectivity in the FT process needs to be thoroughly understood in order to manipulate process conditions and allow the optimization of the required product yield to maximize the plant profitability. There are many unanswered questions regarding the selectivity of the iron-based low-temperature Fischer-Tropsch (Fe-LTFT) synthesis. 

The relative product yields can be rationalized in terms of crystal-structural influences (247). In both crystal forms the packing of the nitrile groups is well-suited for optimizing the dipole-dipole attraction between molecules. For the reaction 183 — 185 to occur, one free radical would need to rotate about an axis perpendicular to the plane, thus allowing the nitrile nitrogen to approach... 

Analytical scientists will provide support for many of the activities in a biopharmaceutical company. They are responsible for characterizing the molecules in development, establishing and performing assays that aid in optimization and reproducibility of the purification schemes, and optimizing conditions for fermentation or cell culture to include product yields. Some of the characterization techniques will eventually be used in quality control to establish purity, potency, and identity of the final formulation. The techniques described here should provide the beginning of a palette from which to develop analytical solutions. 

Economic analysis performed for refineries in certain markets have calculated that the benefit of being able to increase kerosene and jet fuel production yield was an improvement of 3-6 cents per barrel over previous operational conditions. On an 180000 barrel per day crude unit this equates to a benefit of 2000000-4000000 per year. Several other refiners are utilizing NMR analyzers on the feed and products of crude units for control and optimization, AGIP has an NMR analyzer for monitoring the feed. 

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