Acetylene and Hydrogen From the Pyrolysis of Methane

Pyrolysis of methane in the temperature range 1000–1700 K

“…On the basis of these experiments, the authors concluded that the initial autoacceleration of the pyrolysis on the soot nuclei, formed in the volume of the reactor and on the surface, is heterogeneous. Many workers suggest the existence of a pathway leading to the direct decomposition of methane into carbon and hydrogen, bypassing the formation of intermediate C2 hydrocarbons, 33 · 41 ' 42 on the surface of the reactor, 42 which might explain the low activation energies for the carbon deposition process on the surfaces of graphite (36.0 kcal mol 1 41 ) and alumina (16.2 kcal mol" 1 33 ) reactors. Similar activation energies (~25 kcal mol" 1 ) have been obtained for the methane decomposition and carbon deposit formation reactions in a tubular graphite reactor with a high ratio S/V = 10 cm" 1 in the temperature range 1573-2473 K, while the temperature dependence of the yield and of the rate constants for the formation of ethylene and acetylene was more marked.…”

“…It may be that the latter process is heterogeneous and takes place when hydrogen interacts with the soot deposits in the system. 33 Yampol'skii et al, 42 who investigated the pyrolysis of methane in a graphite flow reactor for high dilutions with hydrogen (H 2 /CH 4 up to 21) and at high temperatures (2003-2173 K) also concluded that hydrogen inhibits certain heterogeneous processes associated with the pyrolysis of methane.…”

Survey of Recent Methane Pyrolysis Literature

“…Happel and Kramer ( 2 ) reported that methane, either alone or diluted with hydrogen, can be pyrolyzed to give high yields of relatively uncontaminated mixtures of acetylene and hydrogen over the temperature range of 1500"-2000°C (2732"-3632°F).…”

“…All the data of Happel and Kramer (2) have been correlated on the basis of reaction per unit volume of reactor. Nevertheless, these effects are not always incorporated in the discussion of the overall kinetics.…”

Oxidative-Coupling-Assisted Methane Aromatization: A Simulation Study

“…27,28 At temperatures lower than 800 K, CH4 is comparatively more stable compared than other hydrocarbons based on the Gibbs free energy of formation (ΔGf). [29][30][31] This thermodynamic constraint necessitates high temperature operation in order to achieve efficient production of viable chemicals, including C2H2, C2H4, and C6H6 via CH4 pyrolysis. 32 Among the reactions considered for CH4 conversion, the direct aromatization of CH4 is an endothermic process as shown in reaction 4.…”