Reactor for the thermal conversion of methane

An apparatus comprising a reactor of elongated shape, comprising a square or rectangular cross-section and a longitudinal axis, said reactor having a first end, a second end, inlet means at said first end for supplying a gaseous mixture, outlet means at said second end for discharging effluent, and means for supplying a cooling medium,

• said reactor further comprising at least one longitudinal zone between two walls one of refractory material adjacent said first end, at least one of said walls being disposed between outside walls of said reactor wherein said two refractory walls are substantially parallel to each other and substantially parallel to said axis of said reactor, said at least one longitudinal zone comprising a plurality of elements disposed in at least two layers, said layers being substantially parallel to each other, and substantially parallel to said axis of said reactor, wherein said elements in at least one of said layers comprises a series of sheaths inside which are electric heating means, thereby forming a series of heating elements,
• said elements in at least two layers being positioned to define passages for circulation of gas between said elements, between said layers of elements, and/or between said elements and walls, whereby said electric heating means and said sheaths are capable of heating said passages in successive independent sections which are substantially perpendicular to said axis of said reactor, each of said sections comprising at least one transverse row of elements,
• said reactor further comprising means for automatic control and modulation of heating connected to said electric heating means, and
• said reactor further comprising, adjacent said second end, means for cooling effluent connected to said means for supplying cooling medium.