Conversion of natural gas to liquids via acetylene as an intermediate

This paper describes an experimental investigation of the conversion of natural gas to liquid transportation fuels through acetylene as an intermediate. The first step is the direct thermal conversion of methane to acetylene utilizing a thermal plasma heat source to dissociate the methane. The dissociation products react to form a mixture of acetylene and hydrogen. Significant improvements over the prior art were observed; these improvements may be attributed to an improved methane injection configuration and minimization of radial temperature gradients. Conversion efficiencies (percent methane converted) approached 100% and acetylene yields in the 90–95% range with 2–4% solid carbon production were obtained. A variety of methods were examined for the second step, the conversion of acetylene to liquid products. The most promising technology was the reaction of acetylene with hydrogen over a shape-selective zeolite to form C3–C5+ aliphatics.