Comparative Life Cycle Assessment of Conventional Type IV and Additively Manufactured Hydrogen Pressure Vessel

The transportation sector is a major contributor to global greenhouse gas emissions, driving the need for low-carbon energy solutions. Hydrogen is increasingly recognised as a promising option for decarbonising heavy-duty and long-distance transport; however, hydrogen storage systems contribute significant environmental burdens through material production, manufacturing and end-of-life challenges. This study presents a comparative life cycle assessment of a conventional Type IV composite pressure vessel and a novel additively manufactured, internally reinforced titanium alloy pressure vessel concept for heavy-duty vehicle applications. The two pressure vessel designs were compared within the same available packaging volume on a heavy-duty vehicle. A cradle-to-grave system boundary was applied, covering production, manufacturing, transport, use and end-of-life stages. The environmental assessment was limited to cumulative energy demand and CO2 emissions, which were used as the metrics for comparing the two hydrogen storage systems. Across the entire life cycle, the Type IV pressure vessel exhibited approximately 16% lower energy demand and CO2 emissions that the titanium alloy pressure vessel. The use phase dominated both energy demand and environmental impacts, contributing more than 75% of the total life cycle impacts for both pressure vessel designs due to the high energy demand for hydrogen production. For the manufacturing phase, when normalised per kilogram of pressure vessel, the Type IV vessel produced 21.9 kgCO2eq/kg, compared with 80 kgCO2eq/kg for the titanium alloy vessel. Material production dominated the cradle-to-gate impact of the titanium alloy pressure vessel, primarily because of the energy-intensive primary production of titanium. Although the use of recycled titanium was also assessed, it reduced the manufacturing stage impacts by only 9%, and the overall impacts remained higher than those of the composite alternative.