Design space thermodynamic

Each suboptimization reflects the optimum thermodynamic system configuration for a given set of market conditions. The net result of this approach is the reduction from an eight-dimension to a three-dimension design space. This makes the task of choosing the optimal design substantially easier. 

The strategy of design, illustrated in Figure 8.1, consists of an evolutionary search of the feasible design space by means of a systematic combination of thermodynamic analysis, computer simulation and only limited experiments. The approach is generic for developing a RD process, at least for similar systems. The first element of similarity is the existence of an equilibrium reaction with water as product This raises the problem of possible aqueous-phase segregation. The second element is the similarity of thermodynamics properties over a class of substrates. However, while the fatty acids and fatty esters manifest a certain... 

Fig. 6.3 Conceptual design space for an amorphous solid dispersion manufactured by hot-melt extrusion, where failure modes are depicted with respect to thermodynamic and kinetic variables...

To tackle these problems successfully, new concepts will be required for developing systematic modeling techniques that can describe parts of the chemical supply chain at different levels of abstraction. A specific example is the integration of molecular thermodynamics in process simulation computations. This would fulfill the objective of predicting the properties of new chemical products when designing a new manufacturing plant. However, such computations remain unachievable at the present time and probably will remain so for the next decade. The challenge is how to abstract the details and description of a complex system into a reduced dimensional space. 

Let us consider instead the possibility of a geometry-based description. In this framework, a thermodynamic variable is identified with a vector of the geometrical space, designated Ms, describing the equilibrium state S of interest. To distinguish this vector aspect notationally, we employ the Dirac ket symbol F) to denote the abstract geometrical vector that corresponds to (double-headed arrow) the calculus-based descriptors of the variable,... 

The scope definition is similar to the definition of the control volume in the thermodynamic analysis or the battery limits in process design, and for the LCA in terms of space and time (e.g., we follow the use of product X in the process from the raw materials to the time it is disposed by the consumer. Throughout the lifetime of the product, we analyze the environmental burden). The reasons for the study are also clearly defined (e.g., is the study necessary to make a decision about a process ), as well as an answer must be given as to who is performing the study and for whom. Consider the following hypothetical example ... 

The measurement of ion activities assumes chemical equilibrium between the PVC membrane and the electrolyte bearing solutions. The time domain chemical and dielectric space charge changes that occur are minimized by membrane composition and sensor design and are considered negligible during the measurement period. Hence, the potential dependence of the ion activity is characterized by the Nemst equation. The following thermodynamic expressions describe the potentials of the... 

Some options for achieving a thermodynamic optimum are to improve an existing design so the operation will be less irreversible and to distribute the irreversibilities uniformly over space and time. This approach relates the distribution of irreversibilities to the minimization of entropy production based on linear nonequilibrium thermodynamics. For a transport of single substance, the local rate of entropy production is... 

Materials and Chemistry. The assessed database has been designed for use within the composition space associated with the SoG-Si materials. Among the 35 binary silicon-containing systems, the Si-Al, Si-As, Si-B, Si-C, Si-Fe, Si-N, Si-O, Si-P, Si-S, Si-Sb, and Si-Te systems have thermodynamically been reoptimized, primarily based on the assessed experimental information. Since thermodynamic calculations for the impurities in SoG-Si feedstock are normally multidimensional in nature, Gibbs energies of other 36 binary systems have also included in the database. 

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