Apparatus for the thermal conversion of methane

In an apparatus suitable for thermally converting a gas mixture containing methane into an effluent containing higher molecular weight hydrocarbons, said system in combination comprising:

• a reactor (1) of elongated shape along an elongated axis,
• means for supplying a gas mixture at a first end of said reactor,
• means for discharging an effluent produced at the opposite end of said reactor, and
• means for supplying cooling fluid between the two ends thereof,
• said reactor comprising in a first part towards the first end:
• a plurality of elongated electric heating means (3) surrounded by sheaths (4), said heating means being substantially parallel and arranged in substantially parallel rows perpendicular to the elongated axis of the reactor so as to define passages for the circulation of gases, said heating means and said sheaths being adapted to heat said passages, and
• heat control and heat modulating means connected to said heating means,
• said reactor comprising in a second part (8) towards said opposite end:
• means (9) for cooling effluent connected to said means for supplying cooling fluid,
• the improvement wherein said apparatus further comprises means for introducing a gas containing hydrogen into the sheaths (4), wherein said sheaths have an open porosity of at least about 1% by volume, and means to establish a higher hydrogen pressure inside said sheaths than outside the sheaths so as to provide a hydrogen pressure gradient enabling at least part of the hydrogen to be diffused from the inside of said sheaths to the outside, at least at certain points.