System and method for sealing a syngas cooler

1. A system, comprising:

a syngas cooler configured to cool a syngas, wherein the syngas cooler comprises a seal configured to block the syngas from a passage between an outer wall of the syngas cooler and a tube cage of the syngas cooler;

a compatible seal gas system configured to supply a compatible seal gas to the seal of the syngas cooler, wherein the compatible seal gas system comprises a hydrogen sulfide absorber;

a syngas treatment system configured to be fluidly coupled to the syngas cooler and the compatible seal gas system, wherein the syngas treatment system is configured to receive the syngas and generate a partially treated syngas, wherein the syngas treatment system comprises an acid gas removal (AGR) system configured to remove an acid gas from the partially treated syngas to generate a treated syngas; and

a flow path extending from the syngas treatment system to the compatible seal gas system, wherein the flow path is configured to supply at least a portion of the partially treated syngas to the hydrogen sulfide absorber of the compatible seal gas system, wherein the hydrogen sulfide absorber is configured to remove hydrogen sulfide from the portion of the partially treated syngas and to generate the compatible seal gas.

2. The system of claim 1 , further comprising:

a gasifier configured to generate the syngas from partial oxidation of a fuel and an oxidant; and

a chemical production system disposed downstream from and fluidly coupled to the syngas treatment system, wherein the chemical production system is configured to generate a chemical product from a chemical reaction with the treated syngas.

3. The system of claim 1 , wherein the syngas treatment system comprises a shift reactor configured to perform a water-gas-shift reaction of the syngas to produce the partially treated syngas comprising a shifted syngas, and wherein the flow path is configured to fluidly couple the shift reactor and the compatible seal gas system such that the compatible seal gas system receives and supplies at least a portion of the shifted syngas as the compatible seal gas to the seal.

4. The system of claim 3 , wherein the compatible seal gas system comprises:

a compressor configured to increase a pressure of the portion of the shifted syngas; and

a heater configured to increase a temperature of the portion of the shifted syngas.

5. The system of claim 1 , wherein the AGR system and the compatible seal gas system are fluidly coupled such that the compatible seal gas system receives and supplies a portion of the treated syngas as the compatible seal gas to the seal, and the compatible seal gas system comprises a compressor configured to increase a pressure of the portion of the treated syngas.

6. The system of claim 1 , wherein the syngas cooler is configured to generate steam from cooling the syngas, and the compatible seal gas system is configured to receive the steam from the syngas cooler via a steam flow path extending between a steam source in the syngas cooler and the compatible seal gas system and to supply the steam as the compatible seal gas to the seal.

7. The system of claim 6 , wherein the compatible seal gas system comprises:

a superheater configured to superheat the steam from the syngas cooler to produce a superheated steam; and

a pressure let-down device configured to decrease a pressure of the superheated steam supplied to the seal as the compatible seal gas.

8. The system of claim 1 , comprising at least one of a boiler, a steam drum, a steam turbine, or a heat recovery steam generator (HRSG), or any combination thereof, configured to generate steam as the compatible seal gas.

9. The system of claim 1 , wherein the syngas treatment system comprises a carbon capture system configured to separate carbon dioxide from the syngas, and wherein the compatible seal gas system is configured to receive and to supply at least a portion of the carbon dioxide as the compatible seal gas to the seal, and the compatible seal gas system comprises a compressor configured to increase a pressure of the portion of the carbon dioxide.

10. The system of claim 1 , comprising:

a controller programmed to control the syngas cooler and the compatible seal gas system, wherein the controller comprises:

one or more tangible, non-transitory, machine-readable media collectively storing one or more sets of instructions; and

one or more processing devices configured to execute the one or more sets of instructions to:

control the syngas cooler to cool the syngas, and to block the syngas from entering the passage between the outer wall of the syngas cooler and the tube cage of the syngas cooler using the seal disposed in the syngas cooler; and

control the compatible seal gas system to supply the compatible seal gas to the seal.

11. The system of claim 1 , wherein the AGR system comprises a carbon capture system configured to generate at least a portion of the compatible seal gas, wherein the portion of the compatible seal gas comprises carbon dioxide.