甲烷与二氧化碳重整制取合成气反应的研究ⅢSr(La)NiAl11O19积炭动力学

Study of Methane Reforming with Carbon Dioxide to Synthesis Gas Ⅲ Carbon Deposition Kinetics of Sr(La)NiAl 11 O 19

用热重（ＴＧＡ）方法，研究了ＬａＮｉＡｌ１１Ｏ１９和ＳｒＮｉＡｌ１１Ｏ１９催化剂上甲烷与二氧化碳重整反应的积炭动力学．实验结果表明，甲烷裂解是ＣＨ４＋ＣＯ２反应中主要的积炭反应；甲烷与二氧化碳重整反应的积炭速率随反应温度升高而增大，但其衰减速度也较快；ＣＨ４＋ＣＯ２反应的积炭速率相对甲烷分压的反应级数是１，相对二氧化碳分压的反应级数是－０．５；在ＳｒＮｉＡｌ１１Ｏ１９中掺入Ｌａ３＋离子，提高了催化剂上甲烷裂解反应的活化能，降低了ＣＯ２消炭反应的活化能，从而提高了催化剂的抗积炭能力．

The carbon deposition kinetics of methane reforming with carbon dioxide on LaNiAl 11 O 19 and SrNiAl 11 O 19 were investigated by TGA. The experimental results indicated that carbon deposition in the reforming reaction is chiefly due to the side reaction—methane decomposition, and the initial carbon deposition rate of CH 4+CO 2 reaction on fresh surface of the catalyst increased with the elevation of reaction temperature, but the higher the reaction temperature, the faster attenuates the rate of carbon deposition. Over LaNiAl 11 O 19 reaction orders of carbon deposition are 1 and -0.5 with respect to partical pressures of methane and carbon dioxide in CH 4+CO 2 reaction, respectively. Compared with SrNiAl 11 O 19 , LaNiAl 11 O 19 show higher activation energy for methane decomposition and low activation energy for carbon elimination, so it has higher performance to resist carbon deposition in carbon dioxide reforming of methane.