Development of heat-integrated evaporation and crystallization networks for ternary wastewater systems. 2. Interception task identification for the separation and allocation network

This work introduces the problem of simultaneous allocation and recovery vi a crystallization and evaporation for ternary wastewater systems and is a c ontinuation of work proposed in part 1. The problem at hand is solved withi n the framework of mass integration. Different sources and sinks are identi fied. Varying sink inlet flow and composition constraints necessitate the u se of the path equations for global tracking of all species of interest. Co nstraint propagation is invoked to determine bounds on allowable sink flow- rate and composition constraints. A two-step solution procedure is proposed to solve the problem. The first step consists of interception task identif ication for a given stream in the process. This is useful because it enable s elimination of infeasible nodes prior to detailed design, thus leading to computational efficiency. The second step consists of the design of a sepa ration network for an identified separation task. This step has been previo usly described in part 1. Part 2 couples the separation task via evaporatio n and crystallization to the allocation requirements of various sinks. A ca se study dealing with the ammonium nitrate manufacturing process is include d to demonstrate the broad applicability and value of this work.