A Research On Steam Reforming Biomass Hydroxyl Compound For Hydrogen Production

Based on hydrogen production from biomass hydroxyl compounds is to biomass as raw material products and by-products for reforming,get the environmentally friendly and efficient hydrogen energy, solve the secondary development of biomass energy utilization. At present, biomass ethanol,ethylene glycol and biodiesel by-product.glycerol steam reforming is still in the experimental research and development stage, about the research on various aren’t reported.This thesis preliminary studied the hydroxyl compound(ethanol,ethylene glycol and glycerol) steam reforming for hydrogen production. Preparation of Ni-based catalysts used in fixed bed reactor was investigated that types of raw materials, catalyst, reaction temperature and water carbon ratio (raw material concentration) factors on the hydrogen production performance,through characteristics of the catalyst by X-ray diffraction (XRD), thermogravimetric analysis (TG),scanning electron microscopy (SEM),analysis the relationship between the catalyst structure and catalytic properties.The reaction conditions,catalyst type and catalyst preparation methods make the conversion and reaction of steam reforming of different difference is very large. Non-noble metal catalyst on Ni-based has C-C, O-H bond breaking performance, with higher activity, and the price is relatively cheap. Ni/TiO2,Ni/ZnO,Ni/TiO2-ZnO and Ni-Cu/ZnO catalyst prepared by co-precipitation method,the influence of reaction temperature,ethanol concentration and catalyst type on ethanol steam reforming reaction performance are investigated. The results show that,in the four kinds of catalysts,Ni-Cu/ZnO catalyst for hydrogen production from ethanol steam reforming reaction catalytic best perfonnance.In the more than 450℃,the ethanol conversion rate is almost close to 100%;hydrogen selectivity up to 90.75%; the hydrogen yield up to 882.73mL/min.Can be seen that the active component catalyst double superior performance. Active component Ni is good at C-C,O-H bond breaking performance and performance of methane reforming; active component Cu could help the vapor conversion reaction,and improve the selectivity of hydrogen. Characteristics of the catalyst by XRD,TG,SEM also shows that, Ni and Cu synergy, thus enhancing the catalytic properties of catalysts.For the steam reforming of hydroxyl compounds common and the law,ethanol, adopts ethylene glycol,glycerin as raw materials,respectively,application Ni-Cu/ZnO catalyst and MWC-612 nickel-based commercial catalyst for the steam reforming hydrogen reaction.Hydrogen production by steam reforming of ethanol,ethylene glycol and glycerol over Ni-Cu/ZnO catalyst has good performance,hydrogen production Higher than the commercial catalyst MWC-612 hydroxyl compound steam reforming hydrogen production.Also found,the commercial catalyst MWC-612 also applies to the industrialization of low-temperature hydroxyl compounds (ethanol, ethylene glycol and glycerol) steam reforming reaction.The results show that changes material in the concentration of hydrogen on the steam reforming reaction performance less affected,but the reaction temperature of the steam reforming reaction performance have a greater impact.Hydrogen reaction selectivity as temperatures rise basic shows ascendant trend, ethanol conversion and gas with the reaction rate increased by the rise of temperature.Ethanol,ethylene glycol and glycerol steam reforming reaction of three kinds of raw material properties are: ethanol>ethylene glycol>glycerol.This may be due to the molecular structure of ethanol, simple,easy to react and by-products are relatively few.The acidity and alkaline of catalyst on the catalytic performance has great effect.Based on sintering and carbon deposition phenomenon of the catalyst,initial reaction mechanism and the reasons for coke were proposed.Hydroxy compounds on high-performance steam reforming catalyst and the reaction mechanism and a system of law were discussed, yet in-depth.