Design and intensification of industrial DADPM process

Process intensification is an essential method for the improvement of energy and material efficiency, waste reduction and simplification of industrial processes. In this research a Process Intensification methodology developed by Lutze, Gani and Woodley at the Computer Aided Process Engineering Center (CAPEC) at DTU in Denmark is used for the intensification of the 4,4′-methylenedianiline (DADPM) process at Huntsman B.V. in the Netherlands. The goal of this research was the extension of the DTU methodology for applicability on running, industrial processes and improvement of the Huntsman process, focus is on reduction of operation costs. We have shown in the DADPM case that an analysis of the performance per section or unit operation and the mutual interactions provide essential additional information that is not being detected by the DTU method. We demonstrated how good engineering practice and heuristics can also reduce the number of process options that have to be modelled in detail. Selection of the optimal process is done based on a quantitative analysis of several intensified process options which all obey all required constraints. Equipment models were built in Excel and integrated in an Aspen Plus process flowsheet containing 27 different process options. A sensitivity analysis is done using Aspen, yielding the optimized and intensified process for DADPM production. Energy costs for the DADPM process are reduced by 24% using a combination of both heuristic and methodology-based intensification. We conclude that the method developed by Lutze et al. is a valuable tool for PI and process analysis and synthesis. The extension developed using heuristics, provides additional insight, traces the process weak points, facilitates implementation of new technology and reduces calculations.