Xylene isomerization in an extractor type catalytic membrane reactor

Abstract

A zeolite / alumina pore plugging membrane was used to successfully separate xylene isomers. It was then applied as a selective membrane in an extractor type Catalytic Membrane Reactor (CMR), used to enhance the xylene isomerization reaction selectivity towards para-xylene. The results of the CMR in different configurations (permeate-only and combined permeate-&-retentate mode) were compared to conventional fixed-bed reactor results. In both cases, the selectivity was significantly enhanced (up to 100% in permeate-only mode). In the combined mode, the CMR also provided a net increase in productivity over the conventional reactor.

Potential Applications of Zeolite Membranes in Reaction Coupling Separation Processes

“…Synthesis of para-xylene (PX), one of the petrochemical products that is almost exclusively used as raw material in the production of terephthalic acid (TPA) and dimethyl terephthalate (DMT) has been demonstrated in e-IZCMRs/e-ZCMR [83,84,99,109,110,111,112,113,114]. PX is always reacted with ethyleneglycol to form polyethylene terephthalate (PET), the raw material for polyester resin.…”

Process optimization studies of p-xylene separation from binary xylene mixture over silicalite-1 membrane using response surface methodology

“…Therefore, these membranes can be used in the separation of organic compounds with kinetic diameters close to their pores. Moreover, zeolite membrane might offer significant advantage compared to existing technology for the separation of close-boiling point hydrocarbons [1,[18][19][20][21]. MFI zeolite membranes are potentially more energy-efficient for xylene separation process.…”

Zeolite Catalysis

“…Higher isomerization activity was obtained with the arenesulfonic acid-functionalized membrane mainly ascribed to its higher acidity and more effective continuous removal of p-xylene. According to the results gained in this study, the acid-modified membranes turned out to be more effective in terms of m-xylene conversion and p-xylene productivity improvement compared with the membranes reported in early studies [158][159][160][161]. Moreover, the kinetic parameters reported in this study offer useful platform for further optimization of the catalytic membrane reactor design.…”

“…However, already with the intention to overcome the drawbacks of the supported zeolite films typically suffering from defects occurred during thermal stress causing diminished selectivity, van Dyk et al [158] used a zeolite/alumina nanocomposite membrane of the pore-plugging type (zeolite crystals grown as film inside the pores of the porous tubular support) for the m-xylene isomerization in an extractor type zeolite membrane reactor. The tubular membrane used was equipped with the commercial xylene isomerization Pt catalyst, ISOXYL.…”

“…Overview of the application of permselective inert or catalytic active zeolite membranes in membrane reactor configurations for different processes reported in the literature. [158] Xylene isomerization CMR pure m-xylene;…”