Influence of feed contamination on the conversion of heavy reformate and toluene over a composite hierarchical zeolite catalyst

• Published in: Reaction chemistry & engineering Vol. 9; no. 6; pp. 1433 - 1443
• Main Authors: Ali, Syed A, Qureshi, Ziyauddin S, Tammana, Veera Venkata R. K, Jishi, Ali N, AlAmer, Mohammed, Mohammad, Thamer A
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 28.05.2024
• Subjects: Adsorption; Basicity; Catalysts; Contaminants; Dealkylation; Hydrogen; Indene; Microreactors; Performance tests; Toluene
• ISSN: 2058-9883; 2058-9883
• DOI: 10.1039/d3re00624g

The effect of feed contaminants on the conversion of heavy reformate and toluene mixture over a catalyst containing 4 wt% Mo impregnated on a bifunctional hierarchical composite of mordenite and ZSM-5 is reported. Specifically, the effects of contaminants in the feed (water, 1,2,4,5-tetramethylbenzene (1245-TeMB) and indene) and contaminants in hydrogen (H 2 S and CO) were investigated through catalytic performance tests in a fixed-bed micro-reactor at 350 °C and 20 bar H 2 . The presence of >35 ppm water in the feed caused significant reduction in the dealkylation of methylethylbenzenes (MEBs) due to a decrease in catalyst's acidity. Hence a dried feed (containing 35 ppm water) was used. An increase of 1.2 wt% in the formation of xylenes was observed with the introduction of 10 wt% 1245-TeMB in the feed due to an increase in the methyl/ring ratio. The addition of 1 wt% indene in the feed resulted in a 4 wt% drop in the formation of xylenes due to the preferential adsorption of indene. The tests with 50 ppm H 2 S and 50 ppm CO in hydrogen showed a drop of about 2 wt% in the formation of xylenes. However, the weak basicity of CO exhibited a much lower impact than the adsorption of H 2 S on the dealkylation. The effects of these contaminants are discussed in the light of changes observed in product composition during the introduction of a contaminant (48 h) and after restoring the baseline conditions (48 h). The effect of feed contaminants on the conversion of heavy reformate and toluene mixture over a catalyst containing 4 wt% Mo impregnated on a bifunctional hierarchical composite of mordenite and ZSM-5 is reported.