Synthesis dynamic programming

A general review on distillation synthesis can be found in Westerberg (1985) and Floquet et ai. (1988). The synthesis of simple separation sequences based on heuristics is fairly well developed. Enumeration search methods (dynamic programming, branch-and-bound) have been proposed by Hendry and Hughes (1972) and Gomez-Munoz and Seader (1985), while evolutionary search procedures have been described by Stephanopoulos and Westerberg (1976), Seader and Westerberg (1977) and Nath and Motard (1981). 

Process synthesis using value added as an objective function (Umeda, 2004). This chapter revisits dynamic programming approaches. 

In these circumstances, dynamic programming is likely to have a number of choices at each decision step which increases as the power of the number of variables. The problem of storing the information for comparison at each step adds enormously to the cost of the solution, if it is feasible at all. In the optimum control method, however, the most serious difficulty is this lack of or complication in the analytical relationships that would facilitate the synthesis of the optimum trajectory. 

Unfortunately, until now the MEIS-based dynamic programming method has found application only in the analysis of problems of technical and economic optimization (optimal synthesis) of circuits. This particular application, however, allowed a valuable experience to be accumulated in solving the most important DP problem, namely the search for extremum of the non-additive function. We will exemplify complexities and effectiveness of applying dynamic programming by the scheme in Fig. 3,a that was already used in the MEIS-based analysis of hydraulic circuits. 

Certainly, solving this problem deserves further studies. If they are successful, the dynamic programming method can prove to be an important tool for the analysis of mechanisms. DP application seems to be most effective to search for a mechanism satisfying some subjective criterion of extremality. Such application can be exemplified by the considered algorithm of optimal circuit synthesis that can be treated as a procedure of simultaneous determination of economic and physical components of the whole mechanism of pipeline system construction. In the context of physicochemical problems the optimality criteria may be the maximum yield of useful products of the modeled process or its minimum harmful impact on the environment. 

Kafarov, V. V, Petlyuk, F. B., Groisman, S. A., Belov, M. V. (1975). Synthesis of Optimal Sequences of Multicomponent Distillation Colunms by Method of Dynamic Programming. Theor. Found. Chem. Eng, 9,262-9. 

With a supply route estabhshed (route 2) and supplies of radafaxine available to fund the initial development activities, focus switched to discovering a more efficient synthesis. Environmental considerations were a key consideration, and a dual program of work was initiated to address these concerns. One approach was to investigate the feasibihty of identifying a Dynamic Resolution to avoid the losses associated with the undesired (R,R)-enantiomer, discussed above, while, in parallel, the viability of employing continuous chromatography to separate the enantiomers was examined. 

A drawback of this reaction has recently been addressed. Only very few S-selective nitrilases were known this problem has been solved a systematic screening program yielded a number of S-selective nitrilases that have successfully been employed in this dynamic kinetic resolution (Scheme 5.17) [38]. In an alternative approach, combining the enantioselectivity of an HNL with the hydrolytic power of a not very selective nitrilase that did accept cyanohydrins as substrates, the synthesis of optically enriched a-hydroxy acids starting from alde-... 

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