Hydride transfer between a phenolic surface pool and reactant paraffins in the catalytic cracking of m-cresol/hexanes mixtures over an HY zeolite

Abstract

The effect of the presence of m-cresol on the monomolecular and bimolecular pathways of paraffin conversion has been studied over the bare surface of an HY zeolite in a micro-pulse reactor. The influence of m-cresol is interpreted in terms of the two types of sites present in pristine HY zeolites pre-treated at high temperatures. These two types of sites are described as normal Brønsted acid sites and synergistic sites. The latter have higher activity and favor the monomolecular path. They are more severely deactivated than the former by the presence of mcresol, especially at low reactant concentrations, where the monomolecular reaction is the dominating path. At higher reactant concentrations, hydride transfer from paraffins becomes important and promotes desorption of the phenolic compounds, which hinders the deactivating effect of m-cresol and the growth of a surface phenolic pool, typically formed by condensation reactions of phenolics. Hydride transfer between the paraffinic feed and the surface carbenium ions is also reduced by the presence of m-cresol.

Perspective on Co-feeding of Phenolic Compounds into Existing Refinery Units

“…Recently, it was shown that small amounts of m-cresol at low reactant concentrations caused fast deactivation of an FCC catalyst [33]. Nevertheless, increasing the paraffin concentration hindered the deactivating effect of m-cresol.…”

Selective Phenol Recovery by Catalytic Cracking of Thermal Decomposition Gas from Epoxy-Based Carbon-Fiber-Reinforced Plastic

“…To overcome these drawbacks, we considered a catalytic process using the exhaust heat from the thermal decomposition to convert the various compounds generated by CFRP thermal decomposition into a single valuable compound. Various processes of catalytic decomposition of exhaust gases have been reported, so it is not difficult to industrially expand the removal system. − Moreover, it is well known that a solid acid catalyst, especially zeolite, is effective for the decomposition of heavy hydrocarbons at temperatures of around 500 °C or lower. − Although much research has been carried out, the application of zeolites for CFRP recycling has not been investigated. If the various compounds generated from CFRP thermal decomposition can be converted to a single compound by catalytic cracking using the exhaust heat, a process capable of recovering valuable materials in addition to removing harmful gases can be established.…”

Model based analysis of the effect of 2-ethylphenol addition to n-decane in fluid catalytic cracking over a series of zeolites

“…Hence, one is forced to resort to generalities rather than details. An option would be to employ feed model compounds [1,4,[10][11][12] and consider the behaviour of groups of components as a unit.…”