The Simulation And Thermodynamic Optimization Of Rectisol

In the middle of last century, Lurgi and Linde which are both Germany company worked together developing a process called rectisol. Rectisol is a process which is a new gas purification. After the last1960s, along with the development of large-scale ammonia plant which is using coal, residue and other heavy carbonaceous fuels as feedstock, rectisol is more and more widely used in the world wide.Rectisol process is a physical adsorption method which is using the methanol as the acid gas absorbent. Generally, the operating pressure is2.4～8MPa. The mole fraction of CO2in the synthesis gas is less than lOppm and the mole fraction of total sulfur even less than O.lppm, when the feed gas through the rectisol process.The absorb tower in the rectisol is special because of its low-temperature and high pressure which leads to relatively a large degree of deviation from the ideal property, which is leading to increase a lot of difficulty to the accuracy of rectisol simulation. At the same time, the absorption and desorption of CO2also bring a great challenge to accurate calculation of temperature. For this characteristic of rectisol process, this paper uses the PSRK EOS recommended by the property method tree. After comparing the simulation results with the plant data, it found large errors. In order to improve the simulation accuracy, this paper chose PC-SAFT EOS and revise the pure component parameters and binary parameters. Then all those rivised parameters used in the simulation of absorb tower, CO2reabsorber tower, H2S Concentrating tower, CH3OH and H2O separation tower and the results of simulation are comparing with the actual values of the plant, proving that the improved PC-SAFT EOS is valid. The established model can well applied to simulate the rectisol process.