TRANSALKYLATION OF DIISOPROPYLBENZENE WITH BENZENE IN SUPERCRITICAL CARBON DIOXIDE

摘要

This work was devoted to investigate the main variables affecting the production of cumene by transalkylation of diisopropylbenzene with benzene using supercritical carbon dioxide as solvent and a beta zeolite as catalyst. Pressure did not significantly affect process yield. On the contrary, temperature within the interval of 150-250°C greatly increased reaction rate and catalyst stability. High contact times were also beneficial for enhancing product yield. The process in supercritical carbon dioxide was compared to liquid phase. The comparison was run at different temperatures and several contact times. At all conditions, catalyst activity was pretty similar in both media while the zeolite stability was lower in supercritical conditions. The analysis of the spent catalyst samples revealed a higher and more evolved coke content in the supercritical treated samples. The results were ascribed to the lower solvating capacity for heavy hydrocarbons of the supercritical medium.