The Model Research And Application On Purge Gas Recovery Using Membrane Separation

Methanol is one of the most important chemical raw materials in the chemical industry with extremely wide applications and broadly marketing prospects. The applications of chemical process simulation technology in process optimization make it easier for the controlling and optimizing of operating conditions, and facilitate the progress of craft. To the end, the enterprises can gain much more economic benefits followed by the energy-saving and emission-reduction.Low-pressure method is commonly used for the synthesis of methanol, and Casale technology is used in a very far range because of its axial radial flow. The methanol synthesis loop is the most important part in methanol synthesis department, and it's performance quality directly influences the whole device of methanol production. Many operating parameters can affect the yield of methanol, mainly include temperature, pressure, the flowrate of recycle gas to circulator and the composition of synthesis gas purge gas, etc. Considering the different influences of the above factors, we firstly used the chemical process simulation software PRO/? to establish the methanol synthesis loop based equilibrium module, and then confirmed the optimal operating conditions by analyzing the influence of the simulated conditions for the concentration and yield of the crude methanol in the section.Connected with the influence of the purge-gas-related parameters for the concentration and yield of the crude methanol, we accordingly established a differential mathematical model for the hydrogen recovery membrane separation process. At the same time, we analyzed the factors of purge gas included the feed fraction, feed rate, temperature, pressure and the permeable lateral pressure for the influence of the concentration and yield of the hydrogen, and further analyzed these factors for the influence of the crude methanol.We confirmed the optimal operating conditions by analyzing and optimizing the conditions of the methanol synthesis loop especially analyzing the factors of the purge gas membrane separation and recovery of hydrogen which has a certain guiding significance in the practical production process.