Aplicação da análise pinch no estudo da integração energética do processo de produção de formol utilizando o software hint

Abstract

Chemical industries have constantly pursued the energy consumption reduction and the decrease of production costs, motivated by several aspects such as process efficiency and environmental and economic sustainability. Heat integration is an advantageous alternative. It takes into consideration the analysis, the reorganization, and the connection among equipment with high energy loads, such as heat exchangers. In this work, a study based on the heat integration of an industrial formaldehyde production plant using the Pinch Method was carried out by using the Hint software. Based on technical and economic feasibility criteria, the minimum temperature difference was determined to design the heat exchanger network with maximum energy recovery. Four heat exchanger networks were developed and studied. In all of them, the number of heat exchangers, the heat exchange area, the utilities consumption (steam and cooling water), the operational cost and the economic investment for their development were determined. The networks were compared in relation to the total annual cost. After defining the best network based on technical and economic aspects, two situations close to the real project implementation were analyzed: in the first one, the chemical process without heat integration was already established and operational; and in the second, the chemical process was in the design phase for later execution. The new process flowchart was developed neglecting energy loops in the heat exchanger network. The acquisition of four new equipment was suggested to adapt the heat exchanger network. The project showed a 45% reduction in utility consumption compared to the original plant. Thus, a saving of US$ 191,405.00 per year was predicted by reducing utility consumption, with a pay-back less than two years.