Study of catalyst bed composition for the direct synthesis of dimethyl ether from CO2-rich syngas

Chemical Engineering Journal Advances

María Retuerto¹  Dalia Liuzzi¹  Miguel A. Peña¹  Cristina Peinado¹  Sergio Rojas¹  Jurriaan Boon² 

[1] Grupo de Energía y Química Sostenibles (EQS), Instituto de Catálisis y Petroleoquímica CSIC. C/Marie Curie 2, 28049 Madrid, Spain;TNO Energy Transition, Westerduinweg 3, 1755 LE Petten, The Netherlands;

关键词: Dimethyl Ether;    Biofuels;    CO2-rich syngas;    SEDMES;    H2O-sorption;   

DOI  :  

来源: DOAJ

【 摘 要 】

In this work, we study the direct synthesis of DME using CO2-rich syngas, with a CO2/CO ratio similar to that obtained from the gasification of biomass, i.e., 1.9. We used catalytic beds consisting of physical mixtures of the benchmark catalysts used for the synthesis of methanol from syngas and for methanol dehydration to DME, namely Cu/ZnO/Al2O3 and γ-Al2O3, respectively. Our results show that the ratio between each catalytic phase determines the productivity and selectivity to DME, as well CO and CO2 conversions. Thus, higher total carbon conversions were obtained with the catalytic bed with the highest content of the Cu/Zn/Al2O3 phase. The presence of γ-Al2O3 allows to exceed the equilibrium conversion of CO for the syngas to methanol synthesis. The highest DME productivity is obtained with the catalytic bed containing equal amounts of both catalytic phases. In addition, we also show that other reaction variables such as temperature, pressure, and contact time also play an important role in terms of DME productivity. The presence of a high fraction of CO2 in the syngas results in a high production of H2O, which after long times on stream result in the deactivation of the Cu/ZnO/Al2O3 catalytic phase due to the sintering of the copper particles. The in situ removal of H2O via the addition of an H2O sorbent, zeolite 3A, into the catalytic bed, results in a significant enhancement of both carbon conversion and DME productivity.

【 授权许可】

Unknown