Increase of light aromatics space time yield by addition of SAPO-34 into multifunctional catalyst

Abstract

In this research, SAPO-34 were added into 6Mn4Zr/H-ZSM-5 catalyst and the tri-components catalyst was then granule mixed with ZnCrO_X, which is regarded as methanol synthesis component. The introduction of SAPO-34 could facilitate the accumulation of HCPs and promote conversion of CO. As methanol & DME were preferentially consumed over HCPs in SAPO-34, the selectivity of light aromatics benzene, toluene and xylene (BTX) increased by inhibiting further methylation. The addition of Zn_XCr could further remarkably enhance the conversion of CO because of it high activity in methanol & DME synthesis, and thus increase the space time yield of BTX components. The influence of Zn_XCr composition, amount of SAPO-34 and 6Mn4Zr on catalyst performance were investigated. The reaction conditions were further optimized to achieve both high CO conversion (41.51%) and BTX selectivity (31.37%). The space-time yield of BTX could achieve 105.90 mg g_cat⁻¹ h⁻¹. The stability of optimized catalyst under optimal reaction condition were evaluated, after 100 h reaction, CO conversion could still reach 36.49% with BTX space time yield of 76.36 mg g_cat⁻¹ h⁻¹.