Recovery of alkylation activity in deactivated USY catalyst using supercritical fluids: a comparison of light hydrocarbons

Catalytic cracking of carinata oil for hydrocarbon biofuel over fresh and regenerated Zn/Na-ZSM-5

“…Regenerated Zn/Na-ZSM-5 had a lower peak than that of fresh Zn/Na-ZSM-5, meaning the acid sites of Zn/Na-ZSM-5 decreased after the regeneration. The amount of acid sites on the catalyst is related to its catalytic activity and similar observation was found by Ginosar et al [41] that only 82% of the fresh zeolite catalyst activity was recovered after the regeneration using supercritical isobutene. The FT-IR results support the prior discussion on XRD of catalysts that the MFI structure remained intact after the modification of Zn and Na.…”

Low-temperature test reaction for hydride transfer on solid acid catalysts

“…Indeed, when compared with 25BEA65, the IBU physisorption amount detected on SZ was 23 times lower when normalized to the dry weight, or 9 times lower when normalized to the number of acid sites. It was shown that the dilution of the hydride donor IBU was detrimental to the formation of HT products during solid-acid catalyzed alkylation [2,16]. An argument can be made that a catalyst structure capable of adsorbing an increased amount of IBU in the proximity of the active sites should exhibit enhanced HT from the adsorbed hydride donor.…”

“…During low temperature reactions at which cracking becomes slower than oligomerization, hydride transfer has been found to be responsible for limiting the buildup of carbonaceous deposits that block catalyst active sites [1,2], as well as for determining the catalyst lifetime and product distribution in the solid-acid catalyzed alkylation of isobutane with light olefins (see for e.g. [3][4][5]).…”

Preparation, characterization and catalytic activity towards green reactions of sulfonic functionalized SBA-15

“…In the particular case of the alkylation of isobutane with C 4 olefins, the usual catalysts used at industry are sulfuric acid and fluorhydric acid. Different zeolitebased catalysts have been studied in order to replace the homogeneous catalysts, but deactivation has been the limiting factor for their application at industrial level, being this deactivation mainly attributed to the micropore blockage Ginosar et al 2004). Therefore, it seems that ordered mesoporous silicas or their functionalized derivatives might be a good alternative (Dalla Costa et al 2009), since in this case the larger pore diameter might allow the product to diffuse out of the pores, thus decreasing the coke deposition rate.…”