Enhancing Methanol Yield of CO2 Hydrogenation with the Use of Bifunctional Catalyst/Adsorbent Formulations
- Type: Conference Presentation
- Conference Type: AIChE Annual Meeting
- Presentation Date: November 7, 2021
- Duration: 18 minutes
- Skill Level: Intermediate
- PDHs: 0.50
In contrast to conventional methanol synthesis using syngas (COand H2), the use of CO2 necessitates C=O scission and, consequently, H2O is formed as a byproduct, which can inhibit the rate of methanol synthesis. Thus, abstraction of H2O during catalysis enhances rate of methanol synthesis in CO2 hydrogenation both by alleviating equilibrium constraints and by eliminating HÂ2O inhibition. Steady-state CO2 hydrogenation on commercial Cu/ZnO/Al2O3 formulations (1080 Î¼molsurface-Cu/gcat) with H2O co-feed (30 bar total pressure; CO2 (4.4 bar) + H2 (13 bar) + Ar (12 bar) + H2O (0-0.60 bar) + He balance; 523 K) confirmed the inhibitory effect of H2O observable even at partial pressures below 10% of the inlet CO2 partial pressure. Conversely, co-processing of methanol (30 bar total pressure; CO2 (4.4 bar) + H2 (13 bar) + Ar (12 bar) + methanol (0-0.19 bar) + He balance; 523 K) did not indicate any inhibitory or promotional effect. Transients in rate during CO2 hydrogenation (60 bar; CO2:H2:Ar = 1:3.5:2.7; 503 K) on an interpellet mixture of Cu catalyst and molecular sieve 3A water adsorbent (1:10 by wt.) resulted in ~30% higher methanol synthesis rates attributable to H2O abstraction as evidenced by a delay in H2O evolution with respect to methanol evolution. Regeneration of molecular sieve 3A was also possible with temperature treatment at 523 K under ambient pressure, which did not negatively impact the activity of the catalyst. The presented work highlights the cooperation of reaction and transport phenomena during bifunctional catalysis to modulate methanol yield of CO2 hydrogenation through H2O abstraction.
Once the content has been viewed and you have attested to it, you will be able to download and print a certificate for PDH credits. If you have already viewed this content, please click here to login.
|AIChE Member Credits||0.5|
|AIChE Graduate Student Members||Free|
|AIChE Undergraduate Student Members||Free|