CAJ | 학술논문

制备了一组高催化活性的NiO-CaO/Al2O3复合催化剂并将其应用于反应吸附强化甲烷水蒸气重整制氢(ReSER)过程中。采用水热沉淀法制备了具有层状复合金属氢氧化物结构(NiAl-LDHs)的复合催化剂前驱体，高温焙烧后得到NiO-CaO/Al2O3复合催化剂hd-cat。通过传统浸渍法制备了另一组相同组分含量的NiO-CaO/Al2O3复合催化剂ci-cat作为对比。BET测得催化剂hd-cat比表面积为134.4 m2?g-1，H2-TPD测得其Ni金属分散度为9.25%，分别为催化剂ci-cat的3.8倍和1.3倍。CO2反应吸附性能(TGA)测试结果表明hd-cat吸附容量和吸附速率分别是ci-cat的1.8倍和2.7倍。在固定床反应器上，反应压力0.1 MPa、温度600℃、H2O/CH4摩尔比4：1条件下，评价了不同体积空速下复合催化剂ReSER制氢效果。hd-cat能达到的最大体积空速为2376 h-1，在此条件下能得到94.4%浓度的H2和98.4%的CH4转化率，十次反应-再生循环中，H2浓度和CH4转化率均保持在90%以上。相同反应条件下，复合催化剂ci-cat在体积空速1188 h-1时便失去制氢活性。实验结果证明水热沉淀法制备的高活性的复合催化剂hd-cat能适于高空速下的ReSER循环制氢要求。
제비료일조고최화활성적NiO-CaO/Al2O3복합최화제병장기응용우반응흡부강화갑완수증기중정제경(ReSER)과정중。채용수열침정법제비료구유층상복합금속경양화물결구(NiAl-LDHs)적복합최화제전구체，고온배소후득도NiO-CaO/Al2O3복합최화제hd-cat。통과전통침지법제비료령일조상동조분함량적NiO-CaO/Al2O3복합최화제ci-cat작위대비。BET측득최화제hd-cat비표면적위134.4 m2?g-1，H2-TPD측득기Ni금속분산도위9.25%，분별위최화제ci-cat적3.8배화1.3배。CO2반응흡부성능(TGA)측시결과표명hd-cat흡부용량화흡부속솔분별시ci-cat적1.8배화2.7배。재고정상반응기상，반응압력0.1 MPa、온도600℃、H2O/CH4마이비4：1조건하，평개료불동체적공속하복합최화제ReSER제경효과。hd-cat능체도적최대체적공속위2376 h-1，재차조건하능득도94.4%농도적H2화98.4%적CH4전화솔，십차반응-재생순배중，H2농도화CH4전화솔균보지재90%이상。상동반응조건하，복합최화제ci-cat재체적공속1188 h-1시편실거제경활성。실험결과증명수열침정법제비적고활성적복합최화제hd-cat능괄우고공속하적ReSER순배제경요구。
A NiO-CaO/Al2O3 sorption complex catalyst with highly catalytic activity was prepared and applied in reactive sorption enhanced reforming (ReSER) process. A layer-structured double hydroxide precursor (NiAl-LDHs) was prepared by hydrothermal precipitation method. The precursor was then calcined to NiO-CaO/Al2O3 composite catalyst hd-cat. Another NiO-CaO/Al2O3 composite catalyst ci-cat was prepared by impregnation method for comparison. The catalyst hd-cat was observed to have a surface area of 134.4 m2?g-1 by BET testing and a Ni dispersion of 9.25%in H2-TPD testing, which were 3.8 times and 1.3 times as much as those of ci-cat, respectively. TGA testing indicated that the sorption capacity and the sorption rate of hd-cat were 1.8 times and 2.7 times as much as those of ci-cat. The catalysts were evaluated in ReSER process in a fixed-bed reactor system at 0.1 MPa and 600℃ with a H2O/CH4 molar ratio of 4:1. The hydrogen production performances under different volumetric space velocities were studied. A H2 concentration of 94.4%and a CH4 conversion of 98.4%were achieved at a space velocity of 2376 h-1 using the hd-cat catalyst. And during 10 times reaction-regeneration cycles, both H2 concentration and CH4 conversion exceeded 90%. However, the ci-cat catalyst lost its activity under a space velocity of 1188 h-1. These results demonstrate that composite catalyst prepared by hydrothermal precipitation method can perform well under high space velocity in ReSER process.