化学循环重整甲烷制合成气LaBO3钙钛矿型氧载体研究

采用溶胶-凝胶法制备了不同B位可变价离子的La-B-O复合氧载体(B=Cr、Ni),采用XRD、BET、FT-IR、H2-TPR及CH4-TPSR等进行了表征,并用于化学循环重整(CLR)CH4反应中.结果表明,LaNiO3氧化物更易于与CH4发生深度氧化和选择氧化,LaCrO3氧化物则利于CH4裂解,其氧物种氧化CH4的能力较弱.在连续流动CLR反应中,LaNiO3具有较高的供氧量和持续供氧能力,能将CH4选择氧化为H2/CO=1.45的合成气,其CH4转化率和CO选择性分别达到23.4%和86.9%,且其结构保持了较高的稳定性.

LaBO3 perovskite oxygen carrier for synthesis gas generation by chemical-looping reforming

Chemical Looping Reforming (CLR) is a new technology that can be used for syngas production (CO+H2), which demands less energy than normal endothermic steam methane reforming (SMR) processes. CLR for syngas production avoids separation problems since the gasses are taken out separately from fuel reactor and air reactor. One key issue with the CLR concept that is being widely studied is the oxidation-reduction performance of potential oxygen-carrier materials. Two compound oxides (La-Cr-O and La-Ni-O) were prepared by sol-gel method, and characterized by XRD, BET, FT-IR, H2-TPR and CH4-TPSR. The catalytic performance of the prepared samples for CLR of CH4 to syngas was investigated. The results indicated that LaNiO3 should provide the oxygen species for the total oxidation and partial oxidation with CH4, whereas cracking reaction of CH4 to H2 is favourable on LaCrO3 oxide. Among them, LaNiO3 oxide has higher oxygen amount and continuous oxygen supply for CLR for CH4 to syngas with H2/CO=1.45 in continuous flow reaction. The CH4 conversion and CO selectivity are 23.4% and 86.9%.