Synthesis of Mass Integrated Processes

A hierarchical decision procedure is proposed for the synthesis of processes, mass integrated to an existing industrial environment. The procedure takes as input the information about the processes already installed, so that the decisions required to complete the design of the new process, are made considering this environment. The procedure decides among alternative technologies for producing the new product, the utilization of output streams from the environment as inputs to the new process and vice versa. Also decides if this utilization should be done through new processing facilities to condition these streams. The hierarchical decision procedure described by Douglas was adapted to include these mass integration decisions, as well as to resort to Mass Exchange Network Synthesis and Source Sink Assignment procedures at the appropriate level of the hierarchy. The procedure is illustrated designing a new biodiesel process, integrated to the agro industrial network already existing in the neighborhood of the city of Reconquista. The paper discusses the tradeoff between implementing mass exchangers or separation processes in the case of methanol added in excess and alkali added as a catalyst in the reaction step, the adaptation of the standard source sink assignment approach adding diet problem constraints and the order of the decisions in the hierarchy. Analysis of the results shows that both the economic and environmental performance of the biodiesel process is significantly improved when taking into account the local industrial environment to integrate the new plant to it.