PROCESS AND APPARATUS FOR THE ENDOTHERMIC GASIFICATION OF CARBON

• US 20070163176A1
• Filed: 07/27/2006
• Published: 07/19/2007
• Est. Priority Date: 07/28/2005
• Status: Active Grant

• Current Assignee: Linde AG (Linde Plc)
• Original Assignee: Choren Industries GmbH
• Inventors: Schulze, Olaf, Ruger, Dietmar, Wolf, Bodo, Moller, Burkhard, Kappeller, Jonas
• Granted Patent: US 7,776,114 B2
• Time in Patent Office: Days
• US Class Current: 48/210
• CPC Class Codes: C10J 2200/158 Screws
• CPC Class Codes: C10J 2300/1609 Post-reduction, e.g. on a red-white-hot coke or coal bed
• CPC Class Codes: C10J 3/487 Swirling or cyclonic gasifiers
• CPC Class Codes: C10J 3/526 for entrained flow gasifiers
• CPC Class Codes: C10J 3/64 with decomposition of the distillation products
• CPC Class Codes: C10J 3/84 with means for removing dust or tar from the gas

Abstract

A process for the endothermic gasification of solid carbon in an entrained bed facility comprises partial oxidation of fuel(s) and endothermic gasification of solid carbon, preferably preceded by low temperature carbonization such that the carbonization gas is passed to the partial oxidation and the carbonization coke is passed to the endothermic gasification. The hot gas streaming downwardly from the combustion chamber is deflected to produce separation of the liquid slag and is then passed to the endothermic gasification that operates with a rising gas stream and with addition of solid carbon having a grain diameter of up to 20 mm. The speed of the gas at the carbon inlet is higher than, and the speed of the gas at the end of the endothermic gasification is lower than, the suspension rate of the reactive carbon particles, to produce an increase of the relative speed difference between the gas and the carbon particles. Apparatus is also disclosed for carrying out the process.

Claims

1. A process for the endothermic gasification of solid carbon, comprising:

conducting a partial oxidation of a fuel to produce a partial oxidation gas that contains CO₂ and H₂O and liquid slag droplets;

separating liquid slag droplets from an exit gas stream of the partial oxidation gas; and

conducting an endothermic gasification by reacting the separated exit gas stream in an entrained bed with an addition of solid reactive carbon particles having a grain diameter of up to 20 mm, while creating a greater relative difference in the speed of the reactive carbon particles with respect to the speed of the gas stream at the exit end of the entrained bed than at a point at which the reactive carbon particles are added.

2. A process as defined in claim 1, wherein the entrained bed is operated under conditions of a rising gas stream, and the creation of a greater relative speed difference comprises maintaining the speed of the rising gas at an inlet point where the carbon is added higher than the suspension rate of the reactive carbon particles and maintaining the speed of the rising gas at the exit end of the entrained bed lower than the suspension rate of the reactive carbon particles.

3. A process as defined in claim 1, wherein the separation of liquid slag droplets comprises deflecting the exit gas stream of the partial oxidation gas.

4. A process as defined in claim 1, wherein the solid reactive carbon comprises coke carbon.

5. A process as defined in claim 1, the fuel of the partial oxidation step comprises a carbonization gas from a low temperature carbonization of a carbon source selected from the group consisting of a renewable or fossil fuel, a biomass, refuse, sludge and a mixture thereof.

6. A process as defined in claim 5, wherein the reactive carbon added during the endothermic gasification step comprises carbonization coke from said low temperature carbonization.

7. A process as defined in claim 2, wherein the speed of the rising gas is maintained by using an entrained bed having a smaller flow cross-section at a lower portion than at its exit end.

8. An apparatus for the endothermic gasification of solid carbon, comprising:

a combustion reactor, having an inlet and an outlet, for conducting a partial oxidation of a fuel to produce a partial oxidation gas that contains CO₂ and H₂O and liquid slag droplets;

a device, positioned subsequent to the outlet of the reactor, for separating liquid slag droplets from an exit gas stream of the partial oxidation gas;

an entrained bed reactor for conducting an endothermic gasification by reacting the separated exit gas stream with an addition of solid reactive carbon particles having a grain diameter of up to 20 mm; and

a feeding device for adding the solid reactive carbon to the entrained bed reactor,

wherein the entrained bed reactor is configured to create a greater relative difference in the speed of the reactive carbon particles with respect to the speed of the gas stream at the exit end of the entrained bed than at a point at which the reactive carbon particles are added.

9. An apparatus as defined in claim 8, wherein the separating device for liquid slag droplets comprises a passageway configured to deflect the exit gas stream of the partial oxidation gas.

10. An apparatus as defined in claim 8, wherein the entrained bed reactor is oriented for operation under conditions of a rising gas stream, and the entrained bed reactor is configured to maintain the speed of the rising gas at an inlet point where the carbon is added higher than the suspension rate of the reactive carbon particles and to maintain the speed of the rising gas at the exit end of the entrained bed lower than the suspension rate of the reactive carbon particles.

11. An apparatus as defined in claim 10, wherein the entrained bed reactor has a smaller flow cross-section at a lower portion than at its exit end.