Life Cycle Assessment and Water Footprint of Hydrogen Production Methods: From Conventional to Emerging Technologies

TLDR

Sustainable production demands efficient resource use, and life‑cycle impact assessment methods are rapidly evolving to analyze multiple environmental impacts of product and process production. This study aims to develop a streamlined, process‑based life‑cycle analysis of several hydrogen production pathways, including an innovative assessment of water consumption, to guide decisions on technology selection. The authors applied ReCiPe 2016 to evaluate 17 midpoint and 3 endpoint impacts for steam reforming, coal gasification, PEM and SOEC electrolysis, biomass gasification, and dark fermentation, and quantified water scarcity using the AWARE method. The analysis identifies strengths, weaknesses, and key drivers of environmental impact for each pathway, quantifies midpoint and endpoint effects, and provides a theoretical reference for decision‑makers evaluating hydrogen production systems.

Abstract

A common sustainability issue, arising in production systems, is the efficient use of resources for providing goods or services. With the increased interest in a hydrogen (H2) economy, the life-cycle environmental performance of H2 production has special significance for assisting in identifying opportunities to improve environmental performance and to guide challenging decisions and select between technology paths. Life cycle impact assessment methods are rapidly evolving to analyze multiple environmental impacts of the production of products or processes. This study marks the first step in developing process-based streamlined life cycle analysis (LCA) of several H2 production pathways combining life cycle impacts at the midpoint (17 problem-oriented) and endpoint (3 damage-oriented) levels using the state-of-the-art impact assessment method ReCiPe 2016. Steam reforming of natural gas, coal gasification, water electrolysis via proton exchange membrane fuel cell (PEM), solid oxide electrolyzer cell (SOEC), biomass gasification and reforming, and dark fermentation of lignocellulosic biomass were analyzed. An innovative aspect is developed in this study is an analysis of water consumption associated with H2 production pathways by life-cycle stage to provide a better understanding of the life cycle water-related impacts on human health and natural environment. For water-related scope, Water scarcity footprint (WSF) quantified using Available WAter REmaining (AWARE) method was applied as a stand-alone indicator. The paper discusses the strengths and weaknesses of each production pathway, identify the drivers of environmental impact, quantify midpoint environmental impact and its influence on the endpoint environmental performance. The findings of this study could serve as a useful theoretical reference and practical basis to decision-makers of potential environmental impacts of H2 production systems.