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

TL;DR

Adding SAPO-34 and ZnCrOX to a catalyst improves the production of light aromatics from CO by enhancing CO conversion and selectivity.

Contribution

A tri-component catalyst combining SAPO-34, 6Mn4Zr/H-ZSM-5, and ZnCrOX is proposed to boost BTX space time yield.

Findings

Adding SAPO-34 increased BTX selectivity by inhibiting methylation of methanol and DME.

ZnCrOX enhanced CO conversion due to its high activity in methanol and DME synthesis.

The optimized catalyst achieved a BTX space-time yield of 105.90 mg gcat−1 h−1 with good stability over 100 hours.

Abstract

In this research, SAPO-34 were added into 6Mn4Zr/H-ZSM-5 catalyst and the tri-components catalyst was then granule mixed with ZnCrOX, 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 ZnXCr 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 ZnXCr 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 gcat−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 gcat−1 h−1.

SAPO-34 were added into 6Mn4Zr/H-ZSM-5 catalyst and the tri-components catalyst was then granule mixed with methanol synthesis component ZnCrOX. Addition of SAPO-34 increased selectivity of BTX, and addition of ZnCrOX promoted CO conversion.

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