镍基催化剂对CO-超临界水制氢固碳反应的影响

Effect of Catalyst Ni/ZrO_2-CeO_2-Al_2O_3 on CO-Supercritical WGS Reaction for Hydrogen Production and Carbon Sequestration

利用水热法制备镍基催化剂Ni/ZrO2-CeO2-Al2O3,并采用X-射线衍射仪和X-射线荧光能谱仪对其组分进行表征.在高温高压反应釜中,同时添加镍基催化剂和固碳剂(硅灰石)的条件下进行CO-超临界水气转化(WGS)试验,分别考察温度、压力等因素对CO-超临界水气化反应的影响及探究制氢固碳的可行性.结果表明:添加催化剂Ni/ZrO2-CeO2-Al2O3能同时提高制氢效率和矿化效率,相同工况下添加催化剂时制氢效率最大可提高8%,矿化效率最大可提高8.2%;CO初压为4 MPa、温度为420℃时,添加1 g催化剂和10 g硅灰石,制氢效率可达到16.8%;CO初压为6 MPa、温度为400℃时,添加相同样品的工况下,CO2矿化效率达到38.1%;在存在催化剂Ni/ZrO2-CeO2-Al2O3的WGS反应中,CO初压对CO2矿化影响较大,而温度对制氢效率的影响较大.

Catalyst Ni/ZrO2-CeO2-Al2O3 was synthesized by hydrothermal method,of which the composition was subsequently characterized using X-ray diffraction spectroscopy（XRD） and X-ray fluorescence spectroscopy（XRF）.Taking Ni/ZrO2-CeO2-Al2O3 as the catalyst and wollastonite as the carbon sequestration agent,CO-supercritical water-gas shift（WGS） experiments were carried out in a high-temperature high-pressure autoclave,so as to analyze the influence of temperature and pressure on the WGS reaction,and study the feasibility of hydrogen production and carbon sequestration by WGS reaction.Results indicate that the addition of catalyst Ni/ZrO2-CeO2-Al2O3 can simultaneously raise the efficiency of both hydrogen production and mineral sequestration,respectively by an increase of 8% and 8.2% at most.For an addition of 1 g catalyst and 10 g wollastonite,the hydrogen production rate can reach 16.8%,and the CO2 mineral sequestration rate can achieve 38.1%,at an initial CO pressure of 6 MPa and a reaction temperature of 400 ℃.With existence of Ni/ZrO2-CeO2-Al2O3 catalyst in the reaction system,initial CO pressure influences more on the CO2 sequestration,while temperature impacts more on the hydrogen production.