Amorphous, turbostratic and crystalline carbon membranes with hydrogen selectivity
Amorphous, turbostratic and crystalline carbon membranes with hydrogen selectivity
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DOI：
10.1016/j.carbon.2016.04.062
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发表时间：
2016-09
期刊：
影响因子：
10.9
通讯作者：
A. Wollbrink;K. Volgmann;J. Koch;Karthiga Kanthasamy;C. Tegenkamp;Yanshuo Li;H. Richter;Susanne Kämnitz;F. Steinbach;A. Feldhoff;J. Caro
中科院分区：
文献类型：
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作者：
A. Wollbrink;K. Volgmann;J. Koch;Karthiga Kanthasamy;C. Tegenkamp;Yanshuo Li;H. Richter;Susanne Kämnitz;F. Steinbach;A. Feldhoff;J. Caro
通过生物甲烷或生物乙醇等可再生碳氢化合物的催化蒸汽重整生产氢气已成为可持续化学的一个有吸引力的目标。乙醇蒸汽重整中的副反应降低了氢气的选择性。带有氢选择性膜的低温催化膜反应器有望解决这个问题。研究了三种不同的碳膜从二元和三元反应混合物（H2/CO2）、（H2/CO2/H2O）和（H2/乙醇）中选择性提取氢气的性能，作为生物乙醇蒸汽重整的模型系统。正在研究的三种碳膜是（i）通过使用碳纤维纱在多孔氧化铝载体上物理气相沉积（PVD）碳而制备的无定形碳层，（ii）通过热解作为前体的负载有机聚合物共混物获得的乱层碳层，以及（iii）通过将石墨片压制成自支撑盘而制备的结晶碳。对于等摩尔二元进料混合物（H2/CO2），所有碳膜均被发现具有氢选择性。对于三元进料混合物（41vol.-% H2/41vol.-% CO2/18vol.-% H2O），在无定形和结晶碳膜的情况下，氢选择性在蒸汽存在下也保持不变。乱层碳膜优先从三元进料混合物（H2/CO2/H2O）中分离蒸汽（H2O）。
Hydrogen production by catalytic steam reforming of renewable hydrocarbons like bio-methane or bio-ethanol has become an attractive goal of sustainable chemistry. Side reactions as in ethanol steam reforming decrease the hydrogen selectivity. A low-temperature catalytic membrane reactor with a hydrogen-selective membrane is expected to solve this problem. Three different carbon membranes are investigated with respect to their performance to extract hydrogen selectively from the binary and ternary reaction mixtures (H2/CO2), (H2/CO2/H2O), and (H2/ethanol) as model systems for bio-ethanol steam reforming. The three carbon membranes under study are (i) an amorphous carbon layer prepared by physical vapour deposition (PVD) of carbon on an porous alumina support using a carbon fibre yarn, (ii) a turbostratic carbon layer obtained by pyrolysis of a supported organic polymer blend as precursor, and (iii) a crystalline carbon prepared by pressing of graphite flakes into a self-supporting disc. For the equimolar binary feed mixture (H2/CO2) all carbon membranes were found to be hydrogen selective. For the ternary feed mixture (41vol.-% H2/41vol.-% CO2/18vol.-% H2O), in the case of the amorphous and crystalline carbon membrane, the hydrogen selectivity remains also in the presence of steam. The turbostratic carbon membrane separates preferentially steam (H2O) from the ternary feed mixture (H2/CO2/H2O).