Kinetic Process Assessment of H2 Purification over Highly Porous Carbon Sorbents under Multicomponent Feed Conditions

Abstract

As a universal energy carrier, the need for pure H2 is ever increasing due to its ubiquitous role in petrochemical refining, metal reduction, and the up-and-coming fuel cell market. Hydrogen produced from steam methane reforming (SMR) is typically laden with impurities such as CO2, CO, and CH4 and a full efficiency screening for potential H2 purification sorbents requires evaluating the thermodynamic and kinetic behaviors associated with multicomponent pressure swing adsorption (PSA). As such, in this study we assessed three commercially available activated carbons with high surface area and pore volume for the PSA upgrading of H2 from simulated SMR off-gas stream consisting of H2/CO/CH4/CO2 (75/5/5/15 vol%). In addition to high-pressure adsorption isotherms for pure gases, H2 purity and recovery, and H2 productivity were estimated from cyclic PSA experiments, while actual (CO + CH4 + CO2)/H2 selectivity values were estimated from breakthrough experiments. For the best performing material, the results demonstrated H2 purity and recovery of 99.6 and 55.3 %, respectively with a productivity of 18.3 molH2/kg.h and multicomponent (CO + CH4 + CO2)/H2 selectivity of 59.86 %. Moreover, the affinity of the different adsorbates toward the activated carbons presented from the most adsorbed to the least adsorbed gas was in the order of CO2 > CH4 > CO ≫ H2. The H2 purification over these carbon-based adsorbents was found to be an equilibrium-controlled process.

Department(s)

Chemical and Biochemical Engineering

Comments

National Science Foundation, Grant IIP-2044726

Keywords and Phrases

Activated Carbon; H Purification 2; Multicomponent Adsorption; Psa

International Standard Serial Number (ISSN)

1873-3794; 1383-5866

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 Elsevier, All rights reserved.

Publication Date

15 Feb 2023

Link to Full Text

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