球形氧化铝负载Ni-Co双金属催化剂上沼气重整制氢——制备规模的影响

BIOGAS REFORMING FOR HYDROGEN PRODUCTION OVER Ni-Co BIMETALLIC CATALYST: EFFECT OF PREPARATION SCALE

采用过量浸渍法将沼气重整制氢Ni-Co/La2O3-γ-Al2O3球形催化剂的制备规模分别放大20倍和40倍进行工艺研究,以考察放大效应。以CH4/CO2体积比为1的混合气模拟沼气,考察制备规模对催化剂沼气重整反应性能的影响。采用能量色散X射线荧光光谱仪(EDX)、透射电镜(TEM)、热重-差示扫描量热(TG-DSC)等手段对催化剂进行表征。结果表明,随着制备规模的加大,催化剂的重整活性虽然在前期明显下降,但随着反应的进行会迅速回升。反应9h后,制备规模为100和200g的催化剂的甲烷转化率与制备规模为5g的催化剂相比仅下降约5%;二氧化碳转化率下降不明显;反应后催化剂的表面积炭有所增加,但增加的趋势随制备规模加大趋于平缓;反应前和反应后金属颗粒粒径也有所增大,但未发现明显的团聚和烧结,增大的趋势也随制备规模加大趋于平缓。由此可见采用过量浸渍法放大制备本催化剂基本可行。

In order to survey the effect of preparation scale, the scales of hydrogen prepartion with biogas reforming and spherical Ni-Co/La2O3-γ-Al2O3catalyst were enlarged 20 times and 40 times using excessive dipping method, respectively. The performance of catalysts prepared at different scales was conducted at 850℃under ambient pres- sure and feeding CH4/CO2 molar ratio 1/1, which is similar to the composition presented in biogas streams. The catalysts were characterized by energy dispersive X-ray detector （EDX） transmission electron microscopy （TEM） and thermogravimetry-differential scanning calorimetry （TG-DSC） techniques. The results show that the reforming activity of the catalysts obviously decreases during beginning as the preparation scale rising, however it rises again with processing reaction. The performance of the catalyst, such as the activity and the anti-carbon ability, decrea- ses indistinctly after a reaction with 9h, which suggests that excessive dipping was feasible for scaling of the cata- lyst.