GENERATING POWER FROM A NATURAL GAS WITH CARBON DIOXIDE CAPTURE

摘要

In some implementations, one or more methods can include producing a hydrogen rich fuel gas for a gas turbine ballasted with nitrogen and steam and superheated to a temperature above its dew point. The fuel gas may have a minimal or reduced content of CO2 or fuel components CO and CH4 which contain carbon so that when combusted in a suitable gas turbine there may be minimal or reduced emissions of CO2 to the atmosphere. These example methods may result in a capture of the bulk of the carbon present in the total natural gas feed as CO2 compressed to pipeline delivery pressure for sequestration.

主权项

1. A method for producing fuel gas mixture comprising;
exothermically reacting a first portion of a hydrocarbon feed stream with at least one of steam or an oxidant gas comprising molecular oxygen to produce an exothermically generated syn-gas product; endothermically reforming a second portion of the hydrocarbon feed stream with steam over a catalyst in a heat exchange reformer to produce an endothermically-reformed syn-gas product, wherein at least a portion of heat used in generation of the endothermically-reformed syn-gas product is obtained by recovering heat from the exothermically-generated syn-gas product and the endothermically reformed syn-gas product; cooling the combined syn-gas stream to produce steam in a heat recovery boiler; reducing the pressure of the cooled syn-gas stream in a power producing expansion turbine to the pressure required for a substantially CO2 free fuel gas feed stream to a power producing gas turbine; catalytically reacting a combination of the endothermically-reformed syn-gas product and the exothermically-generated syn-gas product in one or more catalytic carbon monoxide shift reactors to generate a combined stream including additional H2 and CO2; cooling the combined syn-gas stream to near ambient temperature in a multipassage multi stream plate-fin heat exchanger which heats water required for steam production for the syn-gas generation system and preheats fuel gas product and evaporates water for mixing with the fuel gas product; removing CO2 from the combined shifted syn-gas stream above a specified threshold to produce a fuel stream with a minimum content of CO2; generating oxygen in an air separation unit which is supplied with air produced from air compressors driven by a first gas turbine; utilizing at least part of the nitrogen from the air separation unit to be mixed with the CO2 depleted syn-gas plus evaporated water to provide a fuel gas for a second power producing gas turbine; and utilizing at least part of the heat in the first gas turbine exhaust to provide at least part of the heat required for preheating fuel plus oxygen plus steam feeds to the syn-gas generation system.