Abstract: The methane molecule does not contain specific centers and has high bond strength of C-H, so its activation for subsequent conversion into valuable products requires high temperatures and the presence of homogeneous or heterogeneous catalysts [1]. Technologies of involvement of methane in reactions with participation of other hydrocarbons are of special interest. Such processes carry out either in two stages [2] or in two-section reactors [3.4]. The ideas of physical separation or separate fulfillment of various stages of chemical process are the cornerstone of a way. At the same time, each stage proceeds under optimal conditions. The investigation of the joint methane and ethylene transformation in the two-section reactor with activation of methane on a surface of the FeCrAl alloy spiral was the purpose of this work. Process takes place in the T-shaped reactor. The FeCrAl alloy spiral heated by electric current is located in the bringing tube on a joint with the main section. The spiral, which is heated to 700-1100 oC, are blown by cold gas mixture consisting 15-75 % methane in nitrogen or pure nitrogen. On the border of the first and second sections there is a contact of the stream containing pyrolysis products (including methyl radicals) with ethylene – nitrogen mixture (30 % C2H4). The following facts were established: a significant increase in the conversion of ethylene in contact with the flow of methane-nitrogen mixture which was converted on the FeCrAl spiral, a decrease in the yield of acetylene and trans-butene - the products of ethylene conversion and an increase in the yields of propylene, propadiene and isobutene - the products of the interaction of ethylene with methyl radicals. This facts can be interpreted as evidence of the interaction of methyl radicals with ethylene. Increasing the temperature of the FeCrAl alloy spiral leads to an increase in the yield of the main products, except for propylene. The maximum in the yield of propylene is observed at a temperature of 950-1000 °C. The increase of methane concentration in the mixture leads to an increase in ethylene conversion and increases the yield of isobutene, as well as the yield of trans-butene and acetylene decreases. he maximum propylene yield is achieved at the following conditions: 1) 30% methane concentration in the gas mixture; 2) flow rate of 200 ml/min; 3) temperature of FeCrAl alloy spiral - 900 ° C. The mechanism of the main products formation providing the stage of interaction of ethylene and methyl radicals is offered.

Cite: Sigaeva S.S. , Anoshkina E.A. , Temerev V.L. , Shlyapin D.A.
Interaction of ethylene with methane and its pyrolysis products on a resistive FeCrAl alloy catalyst
XI International Conference “Mechanisms of Catalytic Reactions” 07-11 Oct 2019