Unified approach for synthesizing crystallization-based separation processes

A procedure for synthesizing crystallization-based separation processes is presented. In an evolutionary manner and without being restricted to a part icular crystallization technique, flowsheet alternatives are generated to m eet the separation objectives for a given system. This is achieved by recog nizing the fact that four basic crystallization-related movements in compos ition space are sufficient to represent a variety of crystallization proces ses. Suitable movements are selected based on relevant features of the phas e diagram to construct feasible flowsheets. The procedure consists of six s teps. First, separation objectives are defined. Second, a separation core s tructure is generated. Third, the separation sequence and unit operations a re selected, followed by adding other units to the structure for proper pla nt operations. Fifth, appropriate crystallizer type is selected. Finally, e conomic evaluation and feasibility checks are performed for the generated a lternatives. Rules are provided to aid decision-making at each step. The pr ocedure is illustrated with various examples including separation of amino acids, p- and m-cresols, chlorobenzoic acids, calcium carbonate and magnesi um oxide from dolomite, and the production of salt.