US 8,893,506 B2 · IGCC power plant having flue gas recirculation and flushing gas

Abstract

Disclosed is a method for operating an IGCC power plant, wherein the coal gas from a gasifier, comprising CO and hydrogen, is supplied to at least one shift stage, wherein this is converted primarily into CO2 and hydrogen and the coal gas is subjected to at least one gas cleaning step. The coal gas is conducted over a membrane, which at least partially selectively separates the hydrogen from the coal gas. In order to achieve driving potential in the membrane, a flushing gas is used on the permeate side. The hydrogen depleted retentate is fed to a CO2 conditioning process, while the separated hydrogen is fed together with the flushing gas to a gas turbine as fuel gas. The flushing gas used for the membrane is a component of the waste gas produced in the gas turbine after the waste gas has left the waste heat recovery boiler, which is connected downstream of the gas turbine. In the power plant, the gas turbine also functions as a means for providing the flushing gas. The power plant comprises a line from the waste heat recovery boiler connected downstream of the gas turbine to the permeate side of the membrane.

Claims26

Dependent claims

A method for operating an IGCC power plant, comprising the following steps:

supplying a solid fuel, steam, and oxygen to a gasifier;
supplying the coal gas from the gasifier, comprising CO and steam, to at least one shift stage, where a conversion of the CO with steam primarily into CO2 and hydrogen takes place;
subjecting the coal gas to at least one gas cleaning step, with the gas cleaning step or steps being disposed upstream of, downstream of, or between individual shift stages;
conducting hydrogen- and CO2-containing coal gas over a membrane, which selectively at least partially separates the hydrogen from the coal gas, with a flushing gas being used on the side of the permeate;
supplying the coal gas depleted of hydrogen to a CO2 conditioning step;
and
supplying the separated hydrogen, together with the flushing gas, to a gas turbine having a downstream steam turbine;
and
wherein the flushing gas for the membrane is part of the waste gas produced in the gas turbine;
and
wherein the flushing gas is conducted directly from a heat recovery boiler connected downstream of the gas turbine to a compressor and then to the permeate side of the membrane.

8 more elements

Dependencies are inferred from the claim text.

IGCC power plant having flue gas recirculation and flushing gas

Life of this patent

IGCC power plant having flue gas recirculation and flushing gas

Life of this patent

Abstract

Claims26