Development Of A Self-heated Methanol Steam Reforming Reactor For PEMFC

In 21st century,energy crises and environmental issues are forcing humans to develop clean and renewable new energy sources.Among them,hydrogen energy has drawn great public attention with the advantages of high calorific value,low pollution and renewable production.However,the current commercialization of hydrogen energy is subject to the hydrogen storage technologies for mobile applications.Existing hydrogen storage technologies still have some shortcomings in terms of energy density,safety,cost,etc.Instead of direct hydrogen storage,methanol steam reforming is a promising method for mobile hydrogen supply.Therefore,this dissertation proposed and tested a self-heated methanol steam reforming reactor with the CO removal unit to generate hydrogen for PEMFC(proton-exchange membrane fuel cells)mobile applications.Firstly,a self-heated methanol steam reforming laminated micro-reactor with micro-pin-fin arrays was designed and fabricated for feasibility verification.Then,the heat and mass transfer characteristics of the micro-reactor were analyzed by numerical simulation.After that,the CO removal method and layer arrangement for laminated methanol steam reforming reactor were investigated.Finally,a self-heated methanol steam reforming reactor with the CO removal unit for PEMFC was developed and integrated with a PEMFC.This work was supported by Natural Science Foundation of China under Grant U1809220 and Natural Science Foundation of Zhejiang Province under Grant LR14E050002.In Chapter 1,the research background and significance of this dissertation were introduced.And the development trend and current research of the methanol reforming for hydrogen production,design of methanol steam reformers,and methods of CO removal for methanol reforming were reviewed.Then the research content of this dissertation was proposed.In Chapter 2,the principle of self-heated methanol steam reforming reactor was introduced.Then,a self-heated methanol steam reforming micro-reactor with micro-pin-fin arrays was designed and fabricated for feasibility verification.The micro-reactor could start start at room temperature and keep working under 220-280 ?.In Chapter 3,a numerical model was developed to investigate the heat and mass transfer characteristics of the self-heated methanol steam reforming micro-reactor.The distribution of velocity,temperature,reactant concentration was analyzed and the results could provide guidance for the design of methanol steam reforming reactors.In Chapter 4,the CO removal method for methanol steam reforming was investigated and the selective CO methanation was chosen.A Ni(Cl0.1)/ZrO2 catalyst was prepared and could remove CO to the level below 10 ppm.Then layer arrangement for the laminated reactor was investigated and a self-heated methanol steam reforming reactor with the CO removal unit for PEMFC was proposed.In Chapter 5,the performance of the self-heated methanol steam reforming reactor for PEMFC was investigated.The influence of steam/carbon ratio,working temperature and reactant flow rate was studied.Finally,the self-heated methanol steam reforming reactor was integrated with a PEMFC and the system had 100 W output of electricity.In Chapter 6,the chief work of dissertation was summarized,and the further research subjects were proposed.