METHOD AND SYSTEM FOR PRODUCING SYNTHESIS GAS

• US 20070151155A1
• Filed: 12/12/2006
• Published: 07/05/2007
• Est. Priority Date: 12/14/2005
• Status: Active Grant

• Current Assignee: Adobe Systems Incorporated (Adobe Inc.), Air Products and Chemicals Incorporated (Linde Plc)
• Original Assignee: Shell Oil Company (Shell Plc)
• Inventors: Ploeg, Johannes, Scheerman, Jacobus
• Granted Patent: US 8,083,818 B2
• Time in Patent Office: Days
• US Class Current: 48/210
• CPC Class Codes: C10J 2300/093 Coal
• CPC Class Codes: C10J 2300/0956 Air or oxygen enriched air
• CPC Class Codes: C10J 2300/0959 Oxygen
• CPC Class Codes: C10J 2300/1223 by burners
• CPC Class Codes: C10J 2300/1618 Modification of synthesis gas composition, e.g. to meet some criteria
• CPC Class Codes: C10J 2300/1846 Partial oxidation, i.e. injection of air or oxygen only
• CPC Class Codes: C10J 3/00 Production of combustible gases containing carbon monoxide from solid carbonaceous fuels destructive distillation processes C10B
• CPC Class Codes: C10J 3/72 Other features
• CPC Class Codes: C10J 3/723 Controlling or regulating the gasification process
• CPC Class Codes: C10K 1/101 with water only

Abstract

Method and system for producing synthesis gas by partial oxidation of a carbonaceous stream, wherein the partial oxidation is controlled using an oxygen to carbon ratio (O/C ratio). A carbonaceous stream and an oxygen containing stream is fed into a gasification reactor at a selected O/C ratio, where it is at least partially oxidized. A gaseous product stream is thereby obtained, which at least contains synthesis gas, CO₂ and possibly CH₄. The content of CO₂ in the product stream is determined, and compared with a pre-determined content thereby possibly obtaining a difference value between the determined content and the pre-determined content. The O/C ratio in step is adjusted based on the difference value.

Claims

1. A method of producing synthesis gas by partial oxidation of a carbonaceous stream, wherein the partial oxidation is controlled using an oxygen to carbon ratio, the method comprising the steps of:

(a) feeding a carbonaceous stream and an oxygen containing stream into a gasification reactor at a selected oxygen to carbon ratio;

(b) at least partially oxidising the carbonaceous stream in the gasification reactor, thereby obtaining a gaseous product stream at least containing synthesis gas and a content of CO₂;

(c) determining the content of CO₂ in the product stream obtained in step (b);

(d) comparing the content determined in step (c) with a pre-determined content thereby obtaining a difference value between the content of CO₂ determined in step (c) and the pre-determined content of CO₂;

(e) adjusting the oxygen to carbon ratio in step (a) based on the difference value obtained in step (d).

2. The method according to claim 1, wherein the difference value is expressed as a percentage of the absolute difference between the content of CO₂ in the product stream and the pre-determined CO₂ content relative to the pre-determined CO₂ content and wherein step (e) is performed when the difference value exceeds a pre-selected value and wherein the pre-selected value is between 0.5% and 5%.

3. The method according to claim 1, wherein the carbonaceous stream fed in step (a) comprises particulate coal.

4. The method according to claim 1, wherein the oxygen to carbon ratio is adjusted in step (e) by adjusting the flow rate of one of the carbonaceous stream and the oxygen containing stream fed in step (a) or a combination thereof.

5. The method according to claim 4, wherein the oxygen to carbon ratio is adjusted by adjusting the flow rate of the carbonaceous stream, while keeping the oxygen containing stream constant.

6. The method according to claim 1, wherein the gaseous product stream further contains CH₄.

7. A system for producing synthesis gas by partial oxidation of a carbonaceous stream, the system comprising:

a gasification reactor having an inlet for feeding an oxygen containing stream into the gasification reactor, an inlet for feeding a carbonaceous stream into the gasification reactor, and an outlet for discharging a product stream produced in the gasification reactor;

a first flow controller for controlling a feeding rate of the oxygen containing stream into the gasification reactor;

a second flow controller for controlling a feeding rate of the carbonaceous stream into the gasification reactor;

a quality controller for determining the content of CO₂ in the product stream and comparing thereof with a pre-determined content of CO₂, thereby obtaining a difference value;

wherein the quality controller is functionally coupled with the first and second flow controllers and wherein the quality controller can adjust at least one of the feeding rates in the first and second flow controllers, based on the difference value.

8. The system according to claim 7, wherein the quality controller can adjust the oxygen to carbon ratio.

9. The system according to claim 7, wherein the quality controller can adjust the feeding rate in the second flow controller while keeping the feeding rate in the first flow controller constant.

10. The system according to claim 7, wherein the quality controller adjusts the at least one of the feeding rates when the difference value exceeds a pre-selected value of between 0.5% and 5%, when the difference value is expressed as a percentage of the absolute difference between the content of CO₂ in the product stream and the pre-determined CO₂ content relative to the pre-determined CO₂ content.