Rectification-membrane separation integrated technology is a technology that highly integrates rectification separation and molecular sieve membrane dehydration separation technology to dehydrate and recover organic solvents. There are mainly two cases of rectification-membrane separation integration technology: 1) The rectification equipment is introduced before the molecular sieve membrane equipment, and the solvent vapor at the top of the rectification tower directly enters the membrane separation system in the form of gas phase to realize the coupled operation of rectification and membrane separation , shorten the process, and significantly reduce the energy consumption generated by the secondary evaporation process of molecular sieve membrane equipment. 2) After the molecular sieve membrane equipment is equipped with rectification equipment, the solvent vapor after the dehydration of the molecular sieve membrane equipment is directly introduced into the subsequent refining distillation tower in the form of vapor phase without condensation, so as to realize the coupled operation of membrane separation and rectification, significantly reducing Refining and rectifying column process energy consumption.
In addition, Jiutian Hi-Tech owns the small-scale and pilot-scale experimental equipment of rectification-membrane separation integration technology, carried out related experiments on the separation and dehydration of specific solvent systems, obtained basic data, and independently developed a molecular sieve membrane process technology on this basis Computing software; developed a process control system and equipment for rectification-membrane separation integration technology.
1) By recovering the waste heat of solvent vapor, the energy consumption of the process can be fully saved, and the energy saving is more than 40% compared with conventional distillation and adsorption processes.
2) The high-temperature and high-pressure steam at the top of the rectification tower can directly enter the molecular sieve membrane separation system, which significantly improves the membrane separation efficiency.
3) It is suitable for dehydration of organic solvents with different water content or solvent products with high water content requirements, which broadens the application range of membrane separation and dehydration technology.
4) The automatic control system and equipment optimization of the coupling and separation process improves the stability of the production process, realizes the miniaturization of the coupling device, and reduces the equipment cost and operating cost.
On December 16, 2017, the Sinopec Federation organized an expert group headed by Academician Gao Congjie and Academician Shu Xingtian to appraise the achievements of "Rectification-Molecular Sieve Membrane Coupling Separation Technology for Solvent Recovery in Complex Systems" and concluded that " This technology is of great significance to promote the technological upgrading of related industrial processes and realize the energy saving and emission reduction of traditional industries; the technology has reached the international advanced level."
Currently, rectification-membrane separation integration technology has established 15 sets of rectification-membrane integration industrial equipment in Shandong, Liaoning, Zhejiang and other places, saving energy and reducing consumption, bringing huge economic and social benefits to customers.