Process for obtaining liquid fuel-oil and/or gaseous hydrocarbons from solid carbonaceous feed stocks

• US 4,076,612 A
• Filed: 12/09/1974
• Issued: 02/28/1978
• Est. Priority Date: 12/07/1973
• Status: Expired due to Term

• Current Assignee: Rio Tinto Limited
• Original Assignee: Rio Tinto Limited
• Inventors: Hollaway, John William
• Primary Examiner(s): Gantz, Delbert E.
• Assistant Examiner(s): Hellwege, James W.
• Application Number:
  US05/530,557
• Time in Patent Office: 1,177 Days
• Field of Search: 208/8, 208/10, 48/197 R, 48/210, 252/373, 423/655, 423/650, 260/449 R
• US Class Current: 208/414
• CPC Class Codes: C07C 1/0485 Set-up of reactors or accessories; Multi-step processes
• CPC Class Codes: C10G 1/002 in combination with oil conversion- or refining processes
• CPC Class Codes: C10G 1/006 Combinations of processes provided in groups C10G1/02 - C10G1/08
• CPC Class Codes: C10G 49/007 in the presence of hydrogen from a special source or of a special composition or having been purified by a special treatment
• CPC Class Codes: C10L 1/04 essentially based on blends of hydrocarbons

Abstract

A process for forming a fuel-oil from coal. The coal is treated in a low temperature carbonisation retort to give coke, coal-gas and tar-oil. The coke is converted to water-gas which is then synthesised in a Fischer-Tropsch synthesiser to form fuel-oil. The tar-oil is hydrogenated in a hydro-treater by hydrogen produced from the coal-gas. Hydrogen is produced from coal-gas either in a thermal cracking chamber or by reforming the methane content to hydrogen and passing the resultant hydrogen/carbon monoxide mixture through a water-gas shift reactor and a carbon dioxide scrubber.

Claims

1. In a process of obtaining hydrocarbon fuel-oils from coal, comprising the steps of:

(a) treating the coal by low temperature carbonization at a temperature of 500°

- 1000°

C to form tar-oil, coal-gas and coke;

(b) passing said coke formed at low temperature direct to a water-gas reaction and producing a gas mixture containing hydrogen and carbon monoxide from the coke by said water-gas reaction;

(c) synthesizing the gas mixture into fuel-oil by a Fischer-Tropsch type synthesis;

(d) treating the coal-gas to form hydrogen and carbon monoxide;

(e) generating a hydrogen stream from the gas produced in step (d) by passing the hydrogen and carbon monoxide through a a water-gas shift reactor and a carbon dioxide scrubber.

(f) adding part of the gas from step (e) to step (c); and

(g) hydrogenating the tar-oil with the remainder of the gas from step (e);

the improvement comprising

(h) adding part of the gas produced in one of steps (b) and (d) to the gas produced in the order of steps (b) and (d), the addition being in the direction (b) to (e) when the amount of hydrogen that would otherwise arrive in (c) is less than twice the amount of carbon monoxide and in the direction (d) to (c) when the amount of hydrogen that would otherwise arrive in (c) is more than twice the amount of carbon monoxide, thereby to make maximum use of the hydrogen contained in the coal and consequently minimize carbon loss due to the water-gas shift reaction occurring in (b) and (e), and to maintain a 2;

1 ratio of hydrogen to carbon monoxide in (c).

2. A process according to claim 1 wherein the coal-gas is treated by reforming it with steam in the presence of a catalyst to give a hydrogen/carbon monoxide mixture.

3. A process according to claim 1 wherein the tar-oil is hydrogenated in a hydro-treater at elevated temperature and pressure in the presence of a catalyst.

4. A process as claimed in claim 1 wherein the off-gases from the gas mixture synthesising step are recirculated to the coal treatment step.

5. A process according to claim 1 wherein the off-gases from the tar-oil hydrogenating step are recirculated to the coal treatment step.

6. A process according to claim 1 wherein the off-gases from the gas mixture synthesising step and the off-gases from the tar-oil hydrogenating step are recirculated to the coal treatment step.

7. A process according to claim 1 wherein the off-gases from the gas mixture synthesising step are recirculated to the gas mixture producing step.

8. A process according to claim 1 wherein the off-gases from the tar-oil hydrogenating step are recirculated to the gas mixture producing step.

9. A process according to claim 1 wherein the off-gases from the gas mixture synthesising step and the off-gases from the tar-oil hydrogenating step are recirculated to the gas mixture producing step.

10. A process according to claim 1 wherein the off-gases from the tar-oil hydrogenating step are recirculated to the gas mixture synthesising step.