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US 8,769,961 B2Granted
Generating power from natural gas with carbon dioxide capture
AssigneeGTLpetrol LLC
InventorRodney J. Allam
Life of this patent
Estimating the term…
Abstract
Methods 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 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.
Claims26
A method for producing fuel gas mixture comprising;
- exothermically reacting a first portion of a hydrocarbon feed stream with steam, an oxidant gas comprising molecular oxygen to produce an exothermically generated syn-gas product, or a combination of the steam and the oxidant gas;
- 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 a combination of the endothermically-reformed syn-gas product and the exothermically-generated syn-gas product to generate a cooled syn-gas stream;
- reducing a pressure of the cooled syn-gas stream in a power producing expansion turbine to the to generate a lower-pressure stream having a pressure for a power producing gas turbine;
- catalytically reacting the lower-pressure syngas in one or more catalytic carbon monoxide shift reactors to generate a combined stream including additional hydrogen (H2) and carbon dioxide (CO2);
- cooling the combined stream to near ambient temperature in a multipassage multi stream plate-fin heat exchanger which heats water 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 stream to generate a CO2-depleted syn-gas having a CO2 concentration below a specified threshold;
- generating oxygen and nitrogen in an air separation unit which is supplied with air produced from air compressors driven by a first gas turbine;
- mixing at least part of the nitrogen from the air separation unit 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, preheating fuel plus oxygen plus steam feeds to the syn-gas generation system.
8 more elements
A method for producing power, comprising;
- exothermically reacting a first portion of a hydrocarbon feed stream with steam, an oxidant gas comprising molecular oxygen to produce an exothermically generated syn-gas product, or a combination of the steam and the oxidant gas;
- 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;
- reducing a pressure of a combination of the endothermically-reformed syn-gas product and the exothermically-generated syn-gas product in a power producing expansion turbine to generate a lower-pressure stream having a pressure for a power producing as turbine;
- reacting the lower pressure stream to generate a combined stream including additional H2 and CO2;
- removing CO2 from the combined stream to generate a fuel stream having a CO2 concentration below a specified threshold;
- sequestering the removed CO2;
- combusting a first part of the fuel stream to generate power for an air separation unit;
- combusting a second part of the fuel stream to generate additional power for downstream consumption;
- and
- heating, using the combusted first part and the combusted second part of the fuel stream, the hydrocarbon feed stream and water feeds to provide pre-heat feeds to a syn-gas generation system.
7 more elements
A system for producing hydrogen, comprising;
- a partial oxidation reactor (POX) or an autothermal reforming reactor (ATR) that exothermically reacts a first portion of a hydrocarbon feed stream with steam, an oxidant gas comprising molecular oxygen to produce an exothermically generated syn-gas product, or a combination of the steam and the oxidant gas;
- a gas-heated catalytic reformer (GHR) that endothermically reforms 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;
- a waste heat boiler that cooling a combination of the endothermically-reformed syn-gas product and the exothermically-generated syn-gas product to generate a cooled syn-gas stream
- a power producing expansion turbine that reduces a pressure of the cooled syn-gas stream to generate a lower-pressure stream having a pressure for a power producing as turbine;
- one or more shift conversion reactors that reacts the lower-pressure syngas to generate a combined stream including additional H2 and CO2;
- a scrubber that removes CO2 from the combined stream to generate a fuel stream having a CO2 concentration below a specified threshold;
- a storage volume that sequesters the removed CO2;
- a first gas turbine that combusts a first part of the fuel stream to generate power for an air separation unit;
- a second gas turbine that combusts a second part of the fuel stream to generate additional power for downstream consumption;
- and
- a multi-channel heat exchanger that heats, using the combusted first part and the combusted second part of the fuel stream, the hydrocarbon feed stream and water feeds to provide pre-heat feeds to a syn-gas generation system.
8 more elements
Dependencies are inferred from the claim text.