The Study On Transformation Of Two-step To One-step Rectisol Process Based On One Actual Plant

As the rectisol wash technology continues to progress and updates, it has been applied not only in the ammonia industry to purify the acid gases, but also in many other chemical industries.The rectisol wash process is generally divided into one-step and two-step processes. We adopt the appropriate process depending on the practical condition, because the feed gas components and product demands of each plant unit are different. In order to improve the rectisol wash system to adapt to the changing market environment and industrial demands, this work has proposed the concept to change the two-step process to a new one-step process. It has important significances for the expansion of the actual range of the rectisol wash applications.This work has simulated and analyzed the two-step rectisol wash process of some factory. Then the two physical properties of PSRK and RKSMHV2were screened for this system. By means of calculating and verifying, this work has ultimately determined more accurate PSRK method for global computer calculation. Based on the experience of the simulation of the two-step process, this work has designed a new one-step rectisol wash process which has combined the desulfurization and decarbonization absorber and added a flash and N2stripper tower at the same time, under the condition of maintaining the existing equipment unchanged.This work has used the general simulation software and established realistic and accurate process simulation system according to the process module options. Under the condition of meeting separation requirements and specified indexes, it has designed the process and main towers’operating parameters of the rectisol wash process based on sensitivity analysis and practical applications. This work has adjusted the unit model parameters appropriately in order to match the simulation results with the design data, based on which the whole process simulation was conducted. According to matching the heat exchanger network, it could recover the system heat effectively, reduce the energy loss of the system and lower the utilization of cold ammonia. The success of the new one-step process design has provided more selections and reliable technical supports for the plants. And it could be selected by industrial design.