Alkylation catalyzed by H2SO4: Promoting effects of ASO on the solubility of isobutane in acid phase

For alkylation catalyzed by H 2 SO 4 , the promotion of solubility of isobutane in H 2 SO 4 is of major importance to the enhancement of quality of alkylates. ASO (acid-soluble oils or conjunct polymers or red oil) are the potential co-catalyst to improve the solubility of isobutane and to optimize the interfacial characteristics of acid/hydrocarbon dispersions. On the basis of the calculation results of COSMO-RS method, we found that the solubility of isobutane in H 2 SO 4 was obviously increased upon the addition of most ASO molecules. Moreover, a better dissolution of isobutane in H 2 SO 4 can be achieved by adding the hydrocarbons like paraffins and cycloparaffins into H 2 SO 4 . On the basis of these findings, two cycloparaffins were selected and used as the co-catalyst (the co-catalysts A and B) to improve the performance of the H 2 SO 4 catalyst. The alkylation results showed that these cycloparaffins enhanced the quality of alkylates. In particular, upon the addition of the co-catalyst B, the RON (research octane number) value, the TMP/DMH (trimethylpentane/dimethylhexane) ratio, and the contents of C8 and TMP (trimethylpentane) were increased significantly from 92.67 and 6.51, 68.25% and 59.10% to 94.38 and 6.97, 74.81% and 65.34%, and the consumption of the H 2 SO 4 catalyst was reduced by 38%.