A Study on Modified HZSM-5 Aromatization for FCC Light Gasoline.

In this article, the HZSM-5 type zeolite catalysts modified with zinc nitrate and calcium nitrate are prepared by impregnation method. The FCC gasoline (<75°C fraction) is observed and studied on the modified HZSM-5 type zeolite catalysts. The results are that the Zx-HZSM-5 type zeolite catalysts have a high initial aromatic yield but a rapid deactivation. The Cy-HZSM-5 type zeolite catalysts have a lower aromatic yield and a familiar deactivation comparing to Zx-HZSM-5. The HZSM-5 type zeolite catalysts modified with bimetal zinc nitrate and calcium nitrate have a rather low initial aromatic yield but a long catalyst life; among them, the C3.5Z2.0HZSM-5 has the best performance. And also, the C3.5Z2.0HZSM-5 type zeolite catalyst has demonstrated good regenerated performance. After regenerated three times, the catalyst still has a good stability. The reaction operational conditions are also observed and studied. The results are that the optimal reaction temperature is 450–490°C, the liquid hours space velocity (LHSV) is 1 h-1 and the reaction pressure is 0.1 MPa. [ABSTRACT FROM AUTHOR]