Study On The Energy-Saving Technology In Styrene Process

The styrene production process has been developed by China independently. It is clean, without pollution and corrosion, but consumes substantial amount of energy. It is of great significance to study the energy-saving problem by optimizing the energy using scheme of styrene production process.Focusing on the subject and according to the real situation of a certain styrene plant, the energy saving technology of the styrene production process was studied in this paper.Based on the mathematical simulation, the energy consumption of each section was analyzed comparatively. The results show that the energy consumption arising was demonstrated by the high-pressure steam volume increasing. It was caused by the increased benzene recycling amount. Both the catalyst with high molar ratio of benzene to ethylene and process route composed of separating and then trans-alkylation's reaction could cause high benzene recycling amount.The heat exchanger network of the ethyl-benzene section was studied, and the detailed reconstruction was put forward. Only the process pipe is changed, no more heat exchanger need to be added in this reconstruction. The calculation results showed that the ethylene-benzene section could save 81.7t/h cooling water and 1.6t/h low-pressure steam.The heat exchanger network of the styrene section was studied. A retrofit plan with only two more heat exchanger added was presented in this paper. The calculation results showed that the styrene section could save 128.5t/h cooling water and 2.5t/h middle-pressure steam.Energy diagnosis on styrene process was done by using pinch technology. Results showed that the energy recovery through generating low-pressure steam in waste heat boiler needs to be discussed. These heat streams could be used to heat the high temperature cold streams, so the high-quality heat utility could be saved.