The Simulation And Energy-saving Research Of Producing Isobutylene By MTBE Cracking Device

The most widely used technical way to produce isobutene is through MTBEcracking．The raw materials are easy to get and the scale of production is large, whilethe energy consumption is high in the technology. It is of great significance to studythe energy-saving problem by optimizing the energy using scheme of producingisobutylene by MTBE cracking device.Focusing on the subject and according to thereal situation of a certain project， we studied the rigorous simulation of the producingisobutylene by MTBE cracking device in this paper．Based on the results of thesimulation, utilizing pinch technology, the optimization of the heat exchanger networkand the heat integration between distillation columns and the process system werefinished, which brought about a significant energy-saving effect.The rigorous simulation was established based on the producing isobutylene byMTBE cracking device’s process data. First, the materials of the process were analyzed,and we selected the UNIQ-RK property method for the model’s calculation, and thenbased on the material balance and energy balance,we established the model of themain operating units and regulated the process parameters simultaneously. At last, weselected the streams which need to be broken, selected Wegstein method as theconvergence method, and the convergence accuracy was0.0001. Compared with thedesigned data, we found that the simulation results were in agreement with thedesigned data highly. Therefore,the property method in the simulation was suitableand the the models of the main operating units were accurate and reliable.What’smore,the reliable simulation results could provide significant reference for thefollowing process optimization and energy saving..Secondly, based on the right simulation results of the producing isobutylene byMTBE cracking device, the heat exchanger networks’ energy-saving was researchedusing pinch technology. The device’s process was analyzed and17flow’s physicalproperties data were extracted as the basic data for energy-saving research.. We set theminimum temperature difference at20℃,,the hot and cold composite curve weremade in view of the extracted data, and it could found the minimum cold utility was 1877.09kW, the minimum hot utility was1689.39kW, which determined theenergy-saving target. According to the pinch design principles, we obtained thecomplete MER network theoretically. Finally, the MER network was simulated and thepractical MER network was obtained, and its energy consumption was calculated, theresults of the practical MER network compared with the initial heat exchangernetwork’s data showed that the cold utilities can save the amount of10.38%, while thehot utilities can save the amount of11.41%.We researched the energy integration of the device and carried out the integrationbetween distillation columns and the process system, which led to a significantenergy-saving effect. Specifically, the results of the optimized heat exchanger networkcompared with the initial heat exchanger network’s data showed it can save864.4kwcold utilities and759.27kw hot utilities,that’s to say, the cold utilities can save theamount of41.27%, while the hot utilities can save the amount of39.82%.