Carbon‐negative hydrogen from ethanol via catalytic oxidative reforming

Journal Article · Fri Mar 28 00:00:00 UTC 2025 · Biofuels, Bioproducts & Biorefining

DOI: https://doi.org/10.1002/bbb.2760 · OSTI ID:2543128

Tan, Eric C. D.  ^[1]; Davis, Ryan ^[1]; Harrison, Jeffrey ^[2]; Fogarty, Timothy ^[2]

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1. Catalytic Carbon Transformation and Scale‐up Center National Renewable Energy Laboratory Golden CO USA
2. PCC Hydrogen Inc. Louisville KY USA

Abstract This study evaluated a commercial technology for producing low‐ or negative‐carbon hydrogen through ethanol catalytic oxidative reforming, focusing on the life cycle greenhouse gas emissions, or carbon intensity (CI). Various scenarios were analyzed: (a) comparing corn ethanol (first‐generation or Gen1 ethanol) and cellulosic ethanol (second‐generation or Gen2 ethanol) as feedstocks; (b) assessing carbon capture and sequestration (CCS) for CO ₂ from upstream fermentation; and (c) evaluating oxygen sourcing via air separation units vs. on‐site or off‐site water electrolysis using a proton exchange membrane. Findings indicate that the CI for hydrogen production using Gen2 ethanol from corn stover is lower than that of Gen1 corn ethanol. Additionally, using proton exchange membrane‐generated oxygen results in a lower CI than air separation unit‐generated oxygen, regardless of the sourcing method. Implementing CCS for the hydrogen production plant's evolved CO ₂ is essential for achieving a net‐negative CI for hydrogen from Gen1 ethanol. All examined scenarios, including both ethanol generations, oxygen sources, and CCS applications, demonstrated a net‐negative carbon intensity, surpassing the life cycle greenhouse gas emissions threshold of 0.45 kg CO ₂ e/kg to enable policy credits as outlined in the Inflation Reduction Act §45V. In comparison, the CI for hydrogen from steam methane reforming stands at 3.4 kg CO ₂ e/kg with CCS and 9.4 kg CO ₂ e/kg without CCS.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE; USDOE National Renewable Energy Laboratory (NREL)
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 2543128
• Report Number(s): NREL/JA-5100-92774; bbb.2760
• Journal Information: Biofuels, Bioproducts & Biorefining, Journal Name: Biofuels, Bioproducts & Biorefining; ISSN 1932-104X
• Publisher: Wiley Blackwell (John Wiley & Sons)Copyright Statement
• Country of Publication: United Kingdom
• Language: English