Feasible products for reaction with separation
Methods to determine feasible products for combined reaction and distillation processes identify its potential advantages over the conventional configuration of reaction followed by distillation. The aim of this dissertation is to develop an approach that determines design targets for combined reaction and separation without equipment specifications. Using this approach, the critical aspect of generation and screening of feasible alternatives in conceptual design is addressed.
The generation of feasible alternatives involves development of mathematical models, normally consisting of conservation equations such as the mole balances. A general and systematic method is developed to formulate these mole balances for complex chemistries such as those encountered in the production of many pharmaceuticals, specialty chemicals, pesticides, or monomers. The mole balances are independent of the devices involved in a process. This method not only determines the mole balance constraints on systems with simultaneous reaction and separation, but also it simplifies the task of determining raw materials consumption, wastes generation, and consistency of experimental measurements, all of which are important in the conceptual design of processes.
Methods for finding feasible products for combined reaction and separation devices are useful in the generation and screening of alternatives. Systematic methods for batch and continuous systems have been developed. A simple method to determine feasible yields and selectivities for batch reactive distillation devices identifies its potential advantage over the conventional technology. A cross-flow device is used to simplify the determination of feasible products from a continuous counter-current reactive distillation system. A method based on the geometric approach of attainable regions finds feasible product regions for continuous reaction-separation systems, and device configurations that achieve them. The attainable regions approach is based on the fundamental processes and does not assume any device configurations. Useful design targets can therefore be determined without specifying any equipment and allows quick estimation of the process economics. The attainable region (or feasible region) together with the mole balances determine the design targets for combined reaction and separation processes.