在流化床反应器内,初步研究了处理方法对活性炭在甲烷裂解制氢过程中催化活性的影响。结果表明,浓硝酸处理后,活性炭表面会生成大量的含氧基团,未处理的活性炭上,850℃和900℃时甲烷的初始转化率在8%和11%左右,浓硝酸处理后,850℃和900℃时初始转化率分别上升到12%和16%,稳定性也明显改善。离子交换法负载微量金属的活性炭比采用浸渍法负载的有更好的活性和稳定性。
Commercial activated carbon (AC) samples were employed as catalysts to produce CO-free hydrogen from decomposition of methane in a fluidized-bed reactor. The primary experimental results show that conversion of methane attains about 8% and 11% at 850 ~C and 900 ~C, respectively. It reaches 12% and 16% at 850 ~C and 900 ~C, respectively, after treating AC in concentrated HNO3 solution. The reason is attributed to formation of lots of highly active sites due to decomposition of oxygen-containing groups on the surface of AC produced during treatment process. The promoting effect of 0.16% Ni loaded on treated AC by ion-exchange process on the activity of AC was clearly better than that by dry impregnation.