Regional Hydrogen Energy Planning:Comparison Of Hydrogen Production Methods And Network Optimization

With increasing energy demands and increasingly serious ecological problems,China is facing an urgent need for energy transformation.Hydrogen is regarded as one of the most promising energy sources that will play an important role in future energy transformation.Therefore,research on optimization of hydrogen energy network is imminent.This paper mainly studies the hydrogen production stage and the site selection stage of the hydrogen refueling station network in the regional hydrogen energy network.Optimize the regional hydrogen energy network through these two aspects.First,life cycle assessment model was established for the four hydrogen production methods of chemical hydrogen production（hydrogen production by coal gasification,hydrogen production by methanol steam reforming,hydrogen production by natural gas steam reforming）and hydrogen production by photovoltaic power generation electrolysis of water.A calculation model for the total energy consumption and total pollutant（GHG）emissions during the entire life cycle of the hydrogen production process was constructed,and the total energy consumption and GHG emissions during the entire life cycle of the four hydrogen production processes were calculated.Through the total energy consumption and total GHG emissions comparison and analysis.It was found that the energy consumption and GHG emissions of the hydrogen production method from photovoltaic power generation electrolysis of water in the whole life cycle are the lowest,and the energy consumption and GHG emissions of the hydrogen production method of natural gas reforming in the whole life cycle are higher than those of photovoltaic electrolysis water hydrogen production;the energy consumption and GHG emissions of coal gasification hydrogen production in the whole life cycle are:327039MJ/1004.5kg H₂and 28241.47kg/1004.5kg H₂,second only to methanol steam reforming hydrogen production technology.Secondly,based on the calculation model of energy consumption and pollutant emission,the energy consumption and GHG emissions of the five hydrogen production sub-stages of the four hydrogen production processes:raw material mining and processing,raw material transportation,hydrogen production,hydrogen compression,and hydrogen transportation are compared and analyzed;the energy consumption and GHG emissions of the hydrogen transportation sub-stages of four different hydrogen production methods are analyzed when the hydrogen transportation distance is different.The results show that the main energy input and GHG emission sub-stages of the chemical hydrogen production process are raw material mining and processing,and hydrogen production;the raw material mining and processing stage is the main sub-stage of energy consumption input and GHG emission in the hydrogen production process of electrolyzed water.Energy saving and emission reduction in the hydrogen production process can be started from the main sub-stages of energy consumption input and GHG emission;the energy consumption and GHG emissions of the hydrogen transportation sub-process increase with the increase of the transportation distance,that is,the total energy consumption and the total GHG emissions of the hydrogen production process throughout the life cycle are positively correlated with the transportation distance.Finally,based on the nuclear density analysis and the shortest path analysis method,an optimization model for the location of the regional hydrogen refueling station network is constructed.Taking the site selection of a hydrogen refueling station network in a certain area of Shanghai as an example,conduct a nuclear density analysis of the total annual hydrogen demand of hydrogen demand points in the area;with the goal of total energy consumption and total pollutant emissions throughout the life cycle of the hydrogen energy network,establish a network topology map of the research area to optimize the path network between alternative hydrogen refueling stations and hydrogen source points in the area.Obtained the total annual hydrogen demand nuclear density points of the four hydrogen demand points in the region（optional hydrogen refueling stations）,and the position coordinates are:（24.5,35.01）,（15.12,32.21）,（16.9,24.96）,（34.93,19.84）;the location of the optimal hydrogen refueling station in the area,the coordinates are:（24.5,35.01）,（34.93,19.84）.