Design and scale-up of a Cr-free Fe-Al-Cu catalyst for hydrogen production from waste-derived synthesis gas

• Published in: Applied catalysis. B, Environmental Vol. 249; pp. 72 - 81
• Main Authors: Jang, Won-Jun, Shim, Jae-Oh, Jeon, Kyung-Won, Na, Hyun-Suk, Kim, Hak-Min, Lee, Yeol-Lim, Roh, Hyun-Seog, Jeong, Dae-Woon
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.07.2019; Elsevier BV
• Subjects: Aluminum; Catalysis; Catalysts; Chromium; Cobalt; Conversion; Copper; Cr-free; Crystallites; Crystals; Dispersion; Hydrogen; Hydrogen production; Iron oxides; Metal concentrations; Scale-up; Side reactions; Synthesis gas; Waste-derived synthesis gas; Water gas; Water gas shift; Waste-derived synthesis gas; Cr-free; Hydrogen production; Water gas shift; Scale-up
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2019.02.036

[Display omitted] •Fe-Al-Cu catalysts were prepared by homogenous one-step co-precipitation.•Precursor concentrations were systematically varied at optimized composition.•Obtained catalysts promoted the recovery of H2 from waste-derived synthesis gas.•Efficient H2 recovery and high CO conversion were achieved.•Properties of the best catalyst were preserved when production was upscaled. Herein, we have prepared a series of Cr-free Fe-Al-Cu catalysts by the homogeneous one-step co-precipitation method and examined their ability to promote the water gas shift (WGS) reaction and thus facilitate the production of hydrogen from waste-derived synthesis gas. The prepared catalysts are confirmed to possess γ-Fe2O3, which can be more easily transformed into Fe3O4 than α-Fe2O3. The surface area, Fe3O4 crystallite size, reducibility, and Cu dispersion of these catalysts significantly depend on the concentrations of metal precursor. The catalysts effectively promote the WGS reaction without facilitating undesirable side reactions, achieving efficient hydrogen production and high CO conversion. The characteristics of the best-performing sample are preserved when the production is scaled up by a factor of 40 and thus obtained large-scale Fe-Al-Cu catalyst exhibits excellent reducibility and high CO conversion. Both commercial Fe-Cr and large-scale Fe-Al-Cu catalysts achieve close-to-equilibrium CO conversions at a gas hourly space velocity (GHSV) of 3000 mL g−1 h−1, but the latter showed a higher conversion than the former at a GHSV of 40,057 mL g−1 h−1 owing to the promotional effect of Cu on the easier reducibility of Fe species and the formation of additional Cu active sites. Thus, we demonstrate the possibility of finding Cr-free alternatives and show that the reducibility, Fe3O4 crystallite size, and Cu dispersion of the best-performing catalyst could be maintained upon upscaling, which made this catalyst well suited for converting waste-derived synthesis gas into H2.