Thermal Conversion of Methane to Acetylene

Abstract

This report describes the experimental demonstration of a process for the direct thermal conversion of methane to acetylene. The process utilizes a thermal plasma heat source to dissociate methane. The dissociation products react to form a mixture of acetylene and hydrogen. The use of a supersonic expansion of the hot gas is investigated as a method of rapidly cooling (quenching) the product stream to prevent further reaction or thermal decomposition of the acetylene which can lower the overall efficiency of the process.

Process Development and Reactor Analysis of Coal Pyrolysis to Acetylene in Hydrogen Plasma Reactor

“…And the mixing process provides the necessary heat to convert the volatile into final products. This is reasonable for the process at such high temperatures, while the time scale of gaseous reactions is at the level of 10 −1 ms (Fincke et al, 2002;Slovetskii et al, 2002). With respect to the mixture fraction approach, masses released from coal and the hot hydrogen are identified as the primary and secondary streams, respectively.…”

Cross Sections for Electron Collisions with Acetylene

“…At 6 eV, another 2 S g 1 resonant state was observed. 26 In the TCS, this latter resonance appears as a broad maximum, with a somewhat similar amplitude (about 27 3 10 216 cm 2 ) and position (about 8 eV) to that in CH 4 , see Song et al 23 A number of theoretical studies have also characterized these resonances [27][28][29][30][31] generally via consideration of elastic scattering. These studies will be considered as appropriate below.…”

“…As was discussed in detail for CH 4 , 69 the observed discrepancies between the model and measured cross sections are rather to be attributed to misunderstandings in analyzing the experimental data rather than to the BEB model. Namely, for atoms it is easy to deconvolute the double ionization events, and it is not so in the case of molecules, for which almost all doubly charged ions dissociate into pairs of singly charged ions.…”

“…For example, plasma can be used to make HCCH from coal, 1 natural gas, 2 and methane. 3,4 Conversely acetylene plasmas are used for a variety of chemistries; 5 they are used to make C 2 , 6 CH*, 7 fullerenes, 8 diamonds, 9 carbon nanoparticles, 10 hydrocarbon nanoparticles, 11 nanotubes, 12,13 and polymers, 14 as well as other chemical processes. 15,16 Acetylene plasmas are used to provide a variety of different coatings.…”

Production of hydrogen and carbon black by methane decomposition using DC-RF hybrid thermal plasmas

“…Runge-Kutta method is employed to solve a set of stiff differential equations describing chemical reactions. In this chemical kinetic simula-tion, 29 species and 89 chemical reaction mechanisms are considered with a complete set of their chemical reactions and corresponding rate coefficients given by Fincke et al [9], [23] along with the following governing equations:…”