Manufacturers of simulation calculations for low-temperature methanol washing
Thread Content
In current purification processes, especially those used in large-scale coal chemical gas purification, low-temperature methanol washing is widely employed. Below are some of the three companies that have made outstanding contributions to the simulation calculations related to low-temperature methanol washing, as collected by me: 1. Since 1980, the Shanghai Institute of Chemical Technology has been conducting systematic research on the phase equilibrium involved in low-temperature methanol washing processes. By using models and data developed by itself, as well as phase equilibrium models and physicochemical data provided by foreign sources, and by employing the SRK-Wilson phase equilibrium model, it has developed simulation software suitable for the Linde process at inlet pressures ranging from 20 to 80 kg/cm2. 2. Sun Jinsheng and others from Tianjin University used the Aspen Plus software to carry out simulation calculations on the methanol scrubber in the low-temperature methanol washing system. By employing the RKSWS thermodynamic model and modifying the parameters for binary interactions, the simulation analysis showed that the errors related to temperature and flow rate were very small. 3. The School of Chemical Engineering at Dalian University of Technology has been engaged in research on the simulation, analysis, and optimization of low-temperature methanol washing units since 1983. It developed the Rectisol Process Simulator (RPS) software for simulating methanol washing processes; the purpose of developing RPS was to provide engineers with a powerful tool for carrying out simulation calculations related to these processes. This software was used to conduct simulation analyses on multiple low-temperature methanol washing units, resulting in a series of recommendations for improving operations and modifying the units. After being adopted by manufacturers, satisfactory results were achieved.
There has been some interaction with Dalian; last time, in the northwest, a modification of a processing unit’s raw materials was carried out using this material, and the results were good. At present, the methanol washing unit at that factory is operating well.
Frustrated! Does anyone know that the process package for Dalian is just a calculation sheet? The engineers at the design institute get so exhausted from this that they’re on the verge of collapsing. Who else can tell me what the differences are between Dalian’s process packages and those used abroad?
There is a significant difference in depth between domestic process packages and those abroad; the former are basically only concerned with mass and heat balance (with considerable deviations). Abroad, aspects such as processes, equipment, instrumentation, electrical systems, safety measures, piping, layout, analysis and testing, as well as operation guidelines, are all detailed, and oversight is also provided for the detailed design. It can be said that there is a substantial gap between the two from an engineering perspective； Of course, the cost difference is basically at the level of exchange rates. If a domestic process package is to be used, it is best to find a design institute that has experience with similar installations, as they can improve the process package in various ways.
Dalian’s process packages are basically copied from Linde’s, and even after copying them, no real understanding or absorption of those technologies was achieved. Many detailed aspects are unclear, but it still looks like the original design; choosing Dalian’s process package means that the workload for the engineering team is extremely large. .
The Second Chemical Engineering Institute is now capable of independently developing the entire set of equipment for low-temperature methanol washing, and this has become proprietary technology!
I agree; personally, I think those from Dalian aren’t very good
To use the process packages from Dalian, it’s necessary to find a good design institute; otherwise, even if the design looks good, one’s own understanding will be limited.
For process technologies such as low-temperature methanol washing, large domestic engineering companies have basically mastered them; what is lacking are only the process property data and the related process flow calculations. The calculations developed by Dalian University of Technology are based on long-term research into the low-temperature methanol washing process; therefore, it is unreasonable to expect them to be on par with foreign process software packages. The combination of this seemingly simple process software package with the engineering experience of experienced domestic companies makes it the most suitable and cost-effective solution, enabling domestic enterprises to save substantial amounts of investment. The specialization of Dalian University of Technology in the research of process and physical property data should serve as a development direction for universities and research institutes in China. For such institutions to reach the level of software packages used by foreign companies, it is impossible to do so without the cooperation of engineering firms. Regarding the first two technologies for low-temperature methanol washing, no records of their actual application have been seen yet, so it’s better to be cautious. Domestic engineering companies specializing in coal chemical engineering, such as Tianchen, Hualu, Donghua, and Wuhuan, are all capable of undertaking the engineering design for low-temperature methanol washing independently.
I used that process package for a while – it was just a thin booklet; designing with it was tedious. Later, there were ongoing problems with its operation, so another modification project was initiated, which took several months to complete. I’ll never use it again. I was fortunate enough to work with the Linde process; the two processes cannot be compared. In terms of the operation of the fully operational plants, the Linde process performs much better, with basically no issues. The two process packages are extremely similar; it’s not clear whether Linde referred to Dalian University of Technology. Dalian University of Technology still refers to Linde. It seems that Shanghai Huajian now offers the RECTISOL process package, and I hear it performs well.
I used to think that Dalian’s process packages were of poor quality, and after working with Luchi’s process packages, I found that their service wasn’t much better either; overall, Dalian offers the best value for money.