LCA comparison analysis for two types of H ₂ carriers: Methanol and ammonia

Abstract

This paper presents a comparative life cycle assessment of two types of H 2 carriers, methanol and ammonia, using GaBi 10 software. Two types of H 2 carriers that is, methanol and ammonia are compared from coal, natural gas and renewables, respectively. The full supply chain is considered in the carbon footprint evaluation, which contains production, storage, transportation, and utilization phase. The energy analysis results show that H 2 carrier produced from natural gas has higher energy efficiency than that from renewables, which can be attributed to the high energy consumption during H 2 generation in the latter. Carbon footprint evaluation indicates that solar PV-based ammonia production route has the lowest GWP in all scenarios, with a value of 43.9 g of CO 2 -Equation MJ À1 of ammonia. In addition, electricity has been found as the key factor affecting GHG emissions in the routes of fuels produced from renewable H 2 through sensitivity analysis. By optimizing electricity generation and expanding the carbon capture scale of power plant, the GHG emissions level of CCU-based methanol production route and solar PVbased ammonia production route can be further reduced.

Life Cycle Greenhouse Gas Emission Assessment for Using Alternative Marine Fuels: A Very Large Crude Carrier (VLCC) Case Study

“…Given that green methanol and green ammonia production have not yet been scaled up, grey productions, as transitional pathways, were also considered. It was assumed that the methanol and ammonia production factories were located in northwest China, where coal, natural gas, and solar energy resources were abundant [32]. The systems were thus split into nine subsystems:…”

“…The data on production and transport for pathways S1 and S2 were taken from Sphera's report [7]. The data on production for S3-5 and S7-9 were taken from Zhu's research data [32], in which the emissions from the utilisations of resources, energy, and materials were considered. The data on production for S6 were taken from Nizami's study [34].…”

“…Table 2 presents the main data for WTT calculation. The data for S1 and S2 were taken from the literature [7]; The data for S3-5 and S7-9 were taken from the literature [32]. 2 The data for S6 were based on the literature [34].…”