Modeling And Optimization Of Internal Thermally Coupled Distillation Columns

The Internal Thermally Coupled Distillation Column (ITCDIC) is the frontier of distillation energy saving research. The researches are mainly in Japan and Institute of Industrial Process Control of Zhejiang University. The research results show that the energy saving percent of ITCDIC is up to 30%~40% and the operation expense saving percent of ITCDIC is close to 30%, compared with the energy consumption and operation expenses of conventional distillation column (CDIC) under the minimum reflux ratio operation respectively.The manipulation of internal thermal coupling is accomplished through heat exchange between the rectifying and the stripping sections. In order to provide the necessary temperature driving force for the heat to be transferred from the rectifying section to the stripping section, the former must be operated at a higher pressure than the latter. For adjusting the pressure, a compressor and a throttling valve are installed between the two sections. Due to the internal thermal coupling, a certain amount of heat is transferred from the rectifying section to the stripping section and brings the downward reflux flow for the rectifying section and the upward vapor flow for the stripping section. As a result, the condenser and reboiler are not required, and energy savings are realized.This research project is China-Japan cooperative project "Research on energy savings and alleviating environmental burden in petroleum enterprises" between Institute of Industrial Process Control of Zhejiang University and National Institute of Material and Chemical Research of Japan, supported by National Environmental Protection Bureau of P. R. China (Huan-Ke-Ke, 1997, No 006, Project 14). The purpose is to research the operational characteristics, dynamic behaviors and control...