Patent GB-344443-A (GB)
Title: Process and apparatus for conversion of methane to liquid hydrocarbons by thermal treatment
IPC: C07C2/76
Filed: 1929-11-27
Abstract: In the production of aromatic and other liquid hydrocarbons by thermal treatment of methane, the conversion is effected in apparatus which closely resembles a coke oven, the methane being led into passages provided within the brickwork, the walls of which are heated by contact with gaseous products of combustion in other passages within the brickwork.  In a construction shown in a vertical section in Fig. 1, and in horizontal section in Fig. 2, <PICT:0344443/IV/1> <PICT:0344443/IV/2> the methane to be converted is led to the conduit g and is distributed to the heat-exchanging chambers f1 which are formed as vertical firebrick passages and alternate in regular sequence with the complementary chambers f.  The methane thus preheated then flows into the sections e1 of the conversion chambers b which are divided into twin flues e, e1, and is there highly heated by the chambers a.  Every heating chamber a is provided with horizontal heating flues c, to which the fuel is led alternately from each side at the change over.  If poor fuel such as blast furnace gas or generator gas is used, it is preheated in the same way as the air for combustion in regenerators d.  The methane is exposed to this thermal treatment until it passes from the flues e to the heat-exchanging chambers f.  The final products pass into the conduit h and can be cooled in a condensation apparatus, perhaps by heat exchange with fresh methane.  The unconverted methane may be treated again.  With relatively pure methane, the greatest output of liquid hydrocarbons occurs between 1040 DEG  and 1060 DEG  C., while the maximum yield from lighting gas fed through glowing coke is obtained between 1200 DEG  and 1220 DEG  C.  In the construction of the apparatus, only refractory ceramic materials are used, and this is possible because there is no sensible difference of pressure within the chambers b as the twin flues e, e1 are connected in parallel, and hence there is no flow of gas between these chambers.  Passage of gas in either direction by leakage between the heating chambers a and the conversion chambers b can only be avoided if the pressures in the different heating chambers a are regulated, as proposed in the German Patent 368,084, so as to be the same as those in the adjacent portions of the conversion chambers b.  The process can be carried out in any existing coke-oven by burning the fuel in the former coking chambers while the former heating walls are fed with the methane to be converted. If the heating is effected in heating flues similar to those of a coke oven, the chambers similar to the usual coking chambers are provided with passages lined with refractory bricks.  To obtain uniform heating it is preferable that the passages traverse the oven horizontally, and are arranged in vertical rows. One or two rows of passages are provided between every two heating walls.  If the passages are vertical, care must be taken, by suitably dimensioning the cross-section or by the provision of valves, that in all the passages there is the same velocity of flow through the flues and that there is the same time of exposure for all the gases to be converted.  Apparatus according to the invention may be combined with a coke-oven installation working with bye-products, so that coal is coked in one set of chambers, while another set is lined with refractory bricks and serves for the conversion of the methane obtained in the coking chambers. The hydrogen produced from the methane may be added to that from the other coal distillation products.  The methane may also be converted by leading it, together with steam, into the pipes for introducing steam to a coking chamber of an existing coke oven battery, and is decomposed by contact with the walls and contents of the chamber; the products may be led away with the gases of distillation, or separately.  In a further construction of the apparatus, the working of an existing coke oven is unaltered; passages are provided in the brickwork of the oven in which the methane is introduced and converted, for example under the sole of the chamber or on the sole of the chamber or in the heating walls above the flues.