Life Cycle Assessment of Hydrogen Production Pathways Across Canada: Evaluating Methane Pyrolysis as a Transitional Low-Carbon Solution

Abstract

Hydrogen is increasingly viewed as a central component of Canada’s long‑term decarbonization strategy, especially in sectors where direct electrification remains challenging. As provinces work to cut emissions while maintaining reliable energy systems, understanding the life‑cycle impacts of emerging hydrogen pathways has become essential. This study applies an ISO 14040/14044‑aligned, cradle‑to‑gate life cycle assessment (LCA) to compare methane pyrolysis with electrolysis and steam methane reforming with carbon capture and storage (SMR-CCS). Three methane pyrolysis configurations, molten‑metal gas‑fired, molten‑metal hydrogen‑fired, and plasma‑based, are evaluated using provincial electricity grid data, upstream natural gas emissions, and established LCA databases.

Results show that molten‑metal hydrogen‑fired pyrolysis and electrolysis generally achieve the lowest greenhouse gas (GHG) emissions in provinces with clean electricity. Plasma‑based pyrolysis performs well only under very low‑carbon grids due to its high electricity demand. Water use also varies, molten‑metal gas‑fired pyrolysis has the lowest national water footprint, while electrolysis and plasma systems show higher water use in fossil‑intensive regions.

A key distinction of methane pyrolysis is its production of solid carbon rather than CO₂, creating potential revenue streams. Plasma systems typically yield carbon black, while molten‑metal reactors can produce higher‑value graphitic carbon. However, long‑term feasibility depends on the development of stable carbon markets.