Life cycle analysis and power optimization of three typical hydrogen supply chains

With the exhaustion of traditional fossil fuels and environmental protection pressure, clean renewable energy has become a topic of high interest. At present, three hydrogen supply chains run into the mainstream, including conventional coal-based hydrogen production (CTH), methanol-to-hydrogen production (MTH) and ammonia-to-hydrogen production (ATH). In order to comprehensively understand the impact of these three hydrogen supply chains on the environment and select the cleanest hydrogen supply scheme, the hydrogen supply chains were analyzed by CML, Eco-indicator99 method and sensitivity analysis. Besides, through sensitivity analysis to understand the contribution of each phase to the environmental impact. Thus, the optimization direction is found, and beneficial enlightenment is provided for promoting and applying hydrogen energy. The results showed that the comprehensive environmental impact of ATH was much more severe, which 2.8 and 2.4 times that of the other two supply chains. In the ATH, the environmental load of ammonia production phase is the largest, while the methanol pyrolysis phase and coal gasification phase are the main load contributors to MTH and CTH. In addition, the study also found that electricity is the most sensitive parameter. When 100% clean energy is used, the environmental impact of all three supply chains is significantly reduced. Consequently, the objective of clean creation and feasible advancement of hydrogen industry can be accomplished by changing its innovation structure as well as smart utilization of clean energy for the power age. [GRAPHICS]