Study On Butadiene Extraction Technology And Its Energy Consuming Analysis And Optimization

Since our domestic technical level of butadiene plants is far behind the same technology overseas, and the demand of 1.3-BD both domestic and overseas has been increasing yearly, it is very important to have comparative analysis of the butadiene extraction technology and to conduct the research on energy saving. Two aspects of work have been done in this thesis:1. Three main 1,3-BD extraction process were dicussed in details, and the advantage and disadvantage of each one aspects were pointed out. The DMF process is known as poisonous solvent, complicated technology. The economical value of this process is not very impressive with a lot of waste residue and abundant waste water, and it is not easy to be treatted by biochemical method. Thed advantage of ACN process is that of low cost, compact process and equipments and no needing for compressor, no waste and the low cost solvent . The shortcoming of ACN process is that the solvent is poisonous and corrosive. NMP process is well known as enviorement protection setup, and short process, convenient operation, small volume, very little waste, no-poisonous and non-corrosive solvent . But its shortcoming is that we don't have domestic technology and need to import solvent which turns out to be very high cost. In general , among the three technology of BD extraction, none of them is perfect, although ACN and DMF are very mature technology domestically, ACN is still suitable for us right now. And from the long run, NMP must be very popular because of its enviorment protection.2. Problem schedule method of pinch point technology was applied to decide the pinch point and the minimum energy targets. Pinch point technology was also used for the analysis of the heat exchanger network of a butadiene extraction plant using acetonitrile and it was found that the energy waste results from the heat transfer acrossing the pinch point and the less efficient use of the low temperature heat energy. Based on pinch point analysis, and also considering the existing heat exchanger network of the butadiene extraction plants, the heat exchanger network was optimized by using the optimized technical data. The energies in heating and cooling were reduced respectively by 10.3% and 21.8% after the optimization. These meet the minimum energy targets set by the pinch point technology. By this up to 1.212 million RMB per year can be saved, showing a dramatic effect of energy saving.