4E Assessment Of A Novel Electrolysis Approach For Hydrogen Evolution Directly From Native Biomasses On Life Cycle

With the depletion of fossil fuels and increasing greenhouse effect,hydrogen energy,as a clean and efficient energy,has received increased attention.Using a heteropoly acid as a catalyst and charge carrier,the new high-efficiency biomass electrolysis technology for hydrogen production can electrolysis almost all biomass raw materials to obtain hydrogen.This technology is highly efficiency and has low energy consumption.Therefore,it has great application value.This study uses the hydrogen evolution technology directly from native biomasses as the research object,customises and assembles hydrogen production unit modules with different effective reaction areas,builds a biomass electrolysis hydrogen production experimental platform,and conducts experimental research and comprehensive evaluation on the technology.First,glucose was used as a raw material to study the influence of reaction time,biomass raw material concentration and heating-electrolytic hydrogen production cycle on the hydrogen production performance of the system.The research results show that with an increase in the reaction time,the conversion efficiency of biomass and the performance of electrolytic hydrogen production are also improved.The use of an optimal concentration of biomass material optimises the conversion efficiency of biomass.With an increase in the number of heating-electrolytic hydrogen production cycles,the performance of electrolytic hydrogen production of biomass decreases.On a 10mm×10mm small-scale biomass electrolytic hydrogen production device,the organic matter conversion efficiency of the biomass electrolytic hydrogen production reaction process reached 70%.On the basis of the experiment,a prototype of the hydrogen evolution technology directly from native biomasses was developed.The experimental results show that the hydrogen production rate can reach 6.785L/h,and the system can operate safely,continuously and efficiently.Then,other raw materials(e.g.straw,sludge and lignite)were electrolyzed to produce hydrogen,which expanded the hydrogen production materials and allowed to analyze their hydrogen production characteristics.According to the experimental results,it is preferable to use straw as a biomass material to improve the hydrogen production experiment.The scale-up experiment of hydrogen evolution technology directly from native biomasses system was developed.The experiment results show that the hydrogen production rate can reach 2 655.738 mL/h,and the power consumption of hydrogen production is 28.954 kWh/kg.On the basis of the experiment,a hydrogen evolution technology directly from native biomasses with a hydrogen production capacity of 1kg/h was established.On the basis of the whole life cycle theory,the 4E comprehensive assessment model was established to analysis the energy,environment and economy of various stages of hydrogen evolution technology.On the basis of the abovementioned model,the added environmental impact and policy are the two factors that affect the global economic(entirety economic)analysis.The research results show that the biggest advantage of the hydrogen production technology is environmental protection.The power consumption of the electrolysis hydrogen production system is 2.585(kW·h)/m3,which is about 50%of the power consumption of the electrolyzed water.The energy conversion rate of the biomass electrolytic hydrogen production system is 4.77%.In the process of electrolytic hydrogen production from biomass,the maximum energy consumed in the pretreatment stage is 53503.507 J,accounting for 88.88%of the total energy consumption.Its comprehensive impact on the environment is-4.065mPET2000/kgH2,the energy consumption is 427.442MJ/kgH2 and the cost is 395.57yuan/kg H2.After the preliminary scale-up and the reduction of the price of the proton membrane,the cost can reach 176.853 yuan/kg H2.The cost of hydrogen production is still high.Only after a technological breakthrough is achieved,the cost of hydrogen production can be reduced to 34.02yuan/kg H2,which has a certain economic benefit.