Patent GB-844775-A (GB)
Title: Improvements in or relating to the manufacture of combustible gases
Inventor: COATES EDWARD
IPC: C10G9/36
Filed: 1957-04-18
Abstract: 844,775. Combustible gases. POWER-GAS CORPORATION Ltd. April 17, 1958 [April 18, 1957], No. 12637/57. Class 55 (2). The invention relates to cyclic processes for the production of combustible gas from hydrocarbon oils wherein each cycle includes a heating period followed by a make period and which comprises, during a heating period, passing hot products of combustion through first an oil vaporizing zone or zones and then a zone containing heat storage material and thereby heating up said zones, and during a make period passing steam first through the zone containing heat storage material, thereby superheating the steam, and then through the oil vaporizing zone or zones, spraying oil into the superheated steam in the oil vaporizing zone or zones, and thermally and/or thermo catalytically cracking the hydrocarbons in the resultant vaporous mixture of oil and steam, to produce a combustible gas. According to the invention, in a process of the kind defined above, a part of the steam is passed through a heat storage zone and superheated therein and another part of the steam is passed in heat exchange with the super heated part, the other part of the steam being used to cause or assist in the spraying of hydrocarbon oil into the vaporizing zone or zones. As shown in Fig. 1, steam used in the process is supplied through conduit 41, part of the steam passing through conduit 33, regulating valve 38 and connection 34 into conduit 11, which is in communication with the bottom of vessel 1 through connection 10, and part of the steam passing through conduit 32, regulating valve 39 and connection 30 to coil 29. During the heating period of the cycle a steam control valve 36 is closed and a throttle valve 40 is adjusted to allow a trickle of steam to pass through conduit 32 and coil 29 to an oil atomizer 19, a non-return valve 37 preventing escape of steam to conduit 33. Valves 13 and 16 are open. Fuel and air are supplied to a burner 20 and the hot products of combustion therefrom pass into a vaporization zone 4. No oil is supplied to atomizer 19 and the trickle of steam from coil 29 passes through the oil atomizer into zone 4. Air passes through an inlet 14. into the bottom of a vessel 7, through a zone 8 filled with hot heat storage material, the air becoming preheated. The preheated air burns carbonaceous matter deposited in a catalyst zone 9, zone 4 and a passage 6 connecting them. The resultant hot products of combustion together with the hot products of combustion from burner 20, pass through a stack 12 via a restricted opening 5, zone 4 and a space 3 containing coil 29, causing the steam passing through it to become superheated. During the make period of the cycle the steam control valve 36 is open, throttle valve 40 is adjusted as during the heating period and valves 13, 16 are closed. The supply of fuel and air to the burner 20 is stopped and hydrocarbon oil is supplied to atomizer 19. Valves 38, 39 are adjusted to give the desired flows of steam through conduits 33, 32 and hence through coil 29 and atomizer 19. Steam which enters the bottom of vessel 1 through conduit 33 and connection 34 becomes superheated in heat storage zone 2, passes through space 3 and serves to superheat the steam in coil 29. Superheated steam entering zone 4 meets a spray of oil and superheated steam emerging from atomizer 19. Vaporization of the oil in zone 4 is substantially complete, the vaporous mixture passing through passage 6 into catalyst zone 9 where cracking occurs. A hot combustible gas passes through a heat storage zone 8 and outlet 17 to a wash-box. In a modified apparatus (Fig. 2) designed to produce a gas of higher calorific value, the method of operation is similar to that described above during the heating period with the exception that two burners 20a, 20b may consume fuel to preheat various zones. During the make period of the cycle valves 43a, 43b may be opened and adjusted to obtain the desired flows of oil to atomizers 19a, 19b, while valves 42a, 42b control the flows of superheated steam from coil 29 to atomizers 19a, 19b. Steam entering vessel 1 through conduit 33 and connection 34 becomes superheated during its passage through heat storage zone 2a, and in passing through space 3 containing coil 29 serves to superheat the steam passing through said coil. Further superheating of steam occurs in zone 2b. In zone 4a this superheated steam meets a spray of oil from atomizer 19a and vaporization and partial cracking of it result. The vaporous mixture after having passed to zone 4b via passage 6 meets a further spray of oil and superheated steam from oil atomizer 19b and, since this zone has been heated to the required temperature during the cycle, cracking is completed therein. The resulting hot combustible gas passes to a wash-box via outlet 17 and conduit 18.