Economic Evaluation for the Retrofit of Chemical Processes through Waste Minimization and Process Integration

Abstract

This research involves the development of an economic-based methodology for waste minimization and reduction of energy consumption in the chemical industry by modifying existing processes. The methodology consists of identifying waste minimization options through a sensitivity analysis and flowsheet configurations through a hierarchical procedure. The alternatives identified together with the heat-exchanger network were used to construct a superstructure that was formulated as an MINLP problem. The superstructure was evaluated and optimized with ASPEN PLUS. An economic model based on the net present value method that incorporates both manufacturing and capital costs was used to select the most profitable configuration. The production of methyl chloride was used to evaluate the methodology. Results obtained identified the optimized base case as the best process. When considering byproducts as wastes, the hydrochlorination of methanol using an adiabatic plug flow reactor was identified as the best process.