Abstract：
Methane, either as natural gas or as a resource obtained from various bioprocesses (e.g., digestion, landfill) can be converted to carbon and hydrogen according to. CH4(g)→C(s)+2H2(g)ΔH298K=74.8kJ/mol. Previous research has stressed the growing importance of substituting the high-temperature Steam Methane Reforming (SMR) by a moderate temperature Catalytic Methane Decomposition (CMD). The carbon formed is moreover of nanotube nature, in high industrial demand. To avoid the use of an inert support for the active catalyst species, e.g., Al2O3 for Fe, leading to a progressive contamination of the catalyst by support debris and coking of the catalyst, the present research investigates the use of carbon nanotubes (CNTs) as Fe-support. Average CH4 conversions of 75-85% are obtained at 700 °C for a continuous operation of 40 h. The produced CNT from the methane conversion can be continuously removed from the catalyst bed by carry-over due to its bulk density difference (∼120 kg/m3) with the catalyst itself (∼1500 kg/m3). CNT properties are fully specified. No thermal regeneration of the catalyst is required. A tentative process layout and economic analysis demonstrate the scalability of the process and the very competitive production costs of H2 and CNT.
摘要：
甲烷,作为天然气或从各种生物过程中获得的资源(例如，消化，填埋)可以转化为碳和氢。CH4(g)-C(s)+2H2(g)ΔH298K=74.8kJ/mol。先前的研究强调了用中等温度的催化甲烷分解（CMD）代替高温蒸汽甲烷重整（SMR）的重要性。此外，形成的碳具有纳米管性质，高工业需求。为了避免对活性催化剂物种使用惰性载体，例如，Al2O3为Fe，导致载体碎片和催化剂焦化逐渐污染催化剂，本研究调查了使用碳纳米管（CNTs）作为铁载体。在700°C下连续操作40小时，平均CH4转化率为75-85%。甲烷转化产生的CNT由于其与催化剂本身的堆积密度差（~120kg/m3）（~1500kg/m3），可以通过携带从催化剂床中连续去除。CNT性质是完全指定的。不需要催化剂的热再生。初步的工艺布局和经济分析证明了该工艺的可扩展性以及H2和CNT的非常有竞争力的生产成本。
