Methanol Synthesis from CO/CO2/H2over Cu/ZnO/Al2O3at Differential and Finite Conversions

Methanol Synthesis from Industrial CO2 Sources: A Contribution to Chemical Energy Conversion

“…Liu et al [15] reported the inhibiting effect of water adsorption during CO 2 hydrogenation, which was confirmed by Sahibzada et al [16] When differential conversions are achieved, CO 2 hydrogenation is around 20 times faster than hydrogenation of CO, underlining the role of CO 2 as the main carbon source and showing that there is only a negligible inhibition by CO 2 itself [16]. But when methanol synthesis is performed at finite, higher conversions, there is an order of magnitude difference between finite and differential conversions in methanol synthesis starting from CO 2 [16]. This observation indicates that the product water inhibits the production of methanol.…”

“…This results in inhibition of the CO 2 adsorption. Sahibzada et al [16] showed that a lower methanol production rate is observed with addition of water to the H 2 /CO 2 feed. Another possible reason of catalyst deactivation is crystallization of Cu and ZnO particles [23].…”

“…The blocking species was further proposed to be carbonate or formate species resulting from the reaction of water with CO 2 [16].…”

Activity and deactivation studies for direct dimethyl ether synthesis using CuO–ZnO–Al2O3 with NH4ZSM-5, HZSM-5 or γ-Al2O3

“…The typical composition of the syngas used in the methanol synthesis is H 2 :CO ratio of 2:1 with 1-4% CO 2 (this gas composition was found to give the best results for the present reaction [37]). Therefore after activation the catalyst was exposed to the syngas mixture (BOC gases) which contained (62% H 2 , 31% CO, 4% CO 2 and 3% Ar) [38,39].…”

Artificial Photosynthesis from a Chemical Engineering Perspective

“…Results presented at the table and in photocatalytic carbon dioxide reduction studies in general indicated very low carbon dioxide reduction yields when compared to photosynthetic and even to the catalytic carbon dioxide reduction yields. To illustrate, methanol was reported to be produced with a rate of 220 000 µmol/g cat /h with a Cu/ZnO/Al 2 O 3 catalyst at 45 bar and 250 °C (Sahibzada et al, 1998). For a more proper comparison of catalytic and photocatalytic reduction rates, the results should be evaluated at the same conditions; i.e., at the same temperature and pressure.…”