Attempt to yield light hydrocarbons including C₃ fraction by supplying ethene and syngas on Co/SiO₂ catalyst

Abstract

When a 1:2 gas mixture of CO and H₂, namely syngas, was contacted onto Co/SiO₂ catalyst at 513 K with low pressure such as 0.2 kg/cm², G, methanation was preferentially promoted, whereas chain propagation was suppressed. In contrast to this, when 1:3 gas mixture of ethene and syngas was fed onto Co/SiO₂ catalyst under the same conditions, hourly productivity of light hydrocarbons involving C₃ fraction was increased 3.3-fold as much as that in the case flowing syngas alone at that condition. It was deduced that formation of light hydrocarbon like C₃ was caused by capturing methylidene (=CH₂) species by ethene on Co/SiO₂ catalyst on which reverse metathesis (C₂H₄ + 2-C₄H₈ → 2C₃H₆) following the dimerization of ethene was not concerned with C₃ formation. In addition, a small amount of liquefied hydrocarbons was collected despite the low pressure and chain growth probability (α) was presumed 0.73. It might be suggested that co-feeding ethene and syngas onto FT active catalyst like Co/SiO₂ was one of effective methods to obtain light hydrocarbons including C₃ fraction at low pressure.