thin film distillation

Membrane technology for various separation process provides an efficient and cost-effective way. Membrane not only had the potential to practical application in industry related to high pressure and corrosive conditions with high permeability and selectivity and manufacturing processes in a large scale and stable way. In this article, king abdullah university of science and technology, Mohamed professor Eddaoudi, task group developed a universal electrochemical directional assembly strategy, successful preparation of polycrystalline metal - organic skeleton membrane distillation, and its used thin film distillation for highly efficient separation of hydrocarbons. The authors prepared a series of face-centered cubic metal - organic skeleton membrane distillation, the membrane distillation is based on 12 connection of rare earth or zirconium six nuclear cluster compound with different ligands. In particular, the synthesis of fumaric acid base membrane distillation contained in the contraction of the triangular hole, which can realize the mixture of propylene/propane and butane isobutane of molecular sieve and efficient separation. To increase the feed pressure to 7 ATM industrial practical value, can further enhance the total flux and separation selectivity. Process design analysis showed that compared with the traditional single distillation process, which USES face-centered cubic zirconium fumaric acid metal - organic skeleton membrane distillation hybrid membrane distillation system in propylene/propane separation process, the energy input can be reduced almost 90%.

Hydrocarbon efficient separation, especially the wiped film evaporator olefin/paraffin separation between and paraffin isomers, is the core of the sustainable oil chemical development requirements. In the field, molecular sieve membrane distillation due to the advantages of high separation selectivity and low energy input, an energy intensive conventional cryogenic distillation technology is a promising alternative materials. For important propylene/propane (C3H6 / C3H8) separation process, from the distillation process to blend membrane wiped film distillation distillation process save energy about 25%. In order to make the method practical success, membrane distillation must be on the high feed pressure (~ 7 ATM, for example), the lowest selectivity for ~ 50, and sometimes with high stability to resist contain traces of corrosive gases such as H2S upstream feed. However, the current polymer membrane or mixed matrix (MMMs) lack the required permeation selectivity, and besides some fluoropolymer, membrane distillation under high plasticizing, mostly so you need to constantly explore new materials as practical membrane separation of hydrocarbon potential.

Based on periodic polycrystalline thin film distillation of porous material, metal organic skeleton (MOFs) - namely, because of its precise control of aperture size and not susceptible to the influence of plasticizing, become the ideal candidate materials of this kind of separation process. So far, only polycrystalline zeolite imidazole salt skeleton (ZIFs), namely, ZIF - 8 and ZIF - 67 membrane distillation, shows that under the atmospheric pressure separation of hydrocarbons (C3H6 / C3H8, for example). However, in addition to the steam process were special ZIF - 8 membrane distillation, membrane distillation in other ZIF containing H2S environment has the structure of the instability, and the high selectivity of severe lower feed pressure, in the large-scale application of industrial conditions are severely restricted.