Zero emissions closed rankine cycle power system

Abstract

A fuel combustion power generation system is provided operating as a closed loop Rankine cycle and with zero atmospheric emissions. The fuel is combusted with oxygen in a combustor to generate high temperature products of combustion. The products of combustion are routed to a first side of a heat exchanger. A second side of the heat exchanger has a working fluid of the closed loop Rankine cycle passed therethrough to boil the working fluid into a gas. The working fluid is then expanded, condensed back to a liquid and pumped back to high pressure for return to the heat exchanger. the products of combustion enter a condenser, where gases are collected and liquids recirculated or released. The products of combustion can be expanded upstream of the heat exchanger. The fuel can be a gaseous fuel or a solid or liquid fuel, such as coal or biomass, with gasification before combustion.

1 - A zero emissions closed Rankine cycle power generation system, comprising in combination: 
 a closed Rankine cycle working fluid recirculation loop including a working fluid heater, a working fluid expander, a working fluid condenser and a working fluid pump;    a source of oxidizer, the oxidizer being a majority oxygen;    a source of fuel, the fuel being capable of combustion with oxygen to produce elevated temperature products of combustion;    a combustor having an oxidizer inlet downstream from said source of oxidizer, a fuel inlet downstream from said source of fuel, said combustor adapted to combust the fuel with the oxygen to produce elevated temperature products of combustion, and an outlet adapted to discharge the elevated temperature products of combustion from the combustor; and    a heat exchanger downstream from said combustor outlet, said heat exchanger adapted to transfer heat from said elevated temperature products of combustion to the working fluid of said closed Rankine cycle as at least a portion of said working fluid heater.    
   
   
       2 - The system of  claim 1  wherein said source of fuel includes the element hydrogen.  
   
   
       3 - The system of  claim 1  wherein said source of fuel includes the element carbon.  
   
   
       4 - The system of  claim 3  wherein said source of fuel includes the element hydrogen, such that said source of fuel is a source of hydrocarbon fuel.  
   
   
       5 - The system of  claim 4  wherein said source of fuel includes methane.  
   
   
       6 - The system of  claim 4  wherein said source of fuel includes syngas comprising hydrogen gas and carbon monoxide gas.  
   
   
       7 - The system of  claim 6  wherein said source of fuel includes a gasifier, said gasifier including an inlet for a carbon containing feedstock, and an inlet for oxygen from said source of oxidizer, said gasifier adapted to convert the carbon containing feedstock into syngas, said oxidizer including an outlet for syngas, said outlet upstream of said combustor fuel inlet.  
   
   
       8 - The system of  claim 7  wherein said carbon containing feedstock includes coal.  
   
   
       9 - The system of  claim 7  wherein said carbon containing feedstock includes biomass.  
   
   
       10 - The system of  claim 1  wherein said combustor includes a water inlet, said combustor adapted to combine water from said water inlet with the elevated temperature products of combustion before discharge from said combustor from said outlet.  
   
   
       11 - The system of  claim 10  wherein said source of fuel includes hydrogen, such that at least one of the elevated temperature products of combustion is water, and wherein the water produced within said combustor is at least partially routed to said water inlet, such that the water entering said combustor at said water inlet is at least partially water produced within said combustor previously.  
   
   
       12 - The system of  claim 11  wherein a condenser is located downstream of said outlet of said combustor, said condenser adapted to condense water within the products of combustion from steam to liquid water, said condenser including a liquid water outlet oriented upstream from said water inlet of said combustor; and a water preheater located between said liquid water outlet of said condenser and said water inlet of said combustor, said water preheater adapted to transfer heat from the products of combustion between said outlet of said combustor and said condenser to the water passing from said condenser to said combustor.  
   
   
       13 - The system of  claim 12  wherein said water preheater is adapted to heat the water therein sufficiently to boil the water from liquid water into steam, and wherein the water at said water inlet is steam.  
   
   
       14 - The system of  claim 13  wherein said oxygen from said source of oxidizer is in a gaseous phase.  
   
   
       15 - The system of  claim 14  wherein said oxygen from said source of oxidizer is substantially free of water until said oxygen enters said combustor.  
   
   
       16 - The system of  claim 1  wherein said source of oxidizer includes an air separator, said air separator including an inlet for air and an outlet for oxidizer which is a majority oxygen, said air separator adapted to separate at least a portion of oxygen in the air from nitrogen in the air.  
   
   
       17 - The system of  claim 16  wherein said air separator is adapted to cool the air to a temperature at which at least the nitrogen condenses into a liquid, to facilitate separation of the oxygen from the nitrogen.  
   
   
       18 - The system of  claim 16  wherein said air separator includes at least one ion transfer membrane adapted to separate oxygen from nitrogen in the air.  
   
   
       19 - The system of  claim 1  wherein an expander is located downstream of said outlet of said combustor, said expander adapted to expand flow discharged from said combustor, said expander including a discharge.  
   
   
       20 - The system of  claim 19  wherein said expander is adapted to output power from the system.  
   
   
       21 - The system of  claim 20  wherein said expander includes at least one turbine.  
   
   
       22 - The system of  claim 21  wherein said expander includes a non-condensing gas turbine.  
   
   
       23 - The system of  claim 21  wherein said turbine is integrated with said air separator by providing an air compressor downstream of said air inlet of said air separator and driving said air compressor with said turbine, such that an efficiency with which oxygen is separated from nitrogen in the air is enhanced.  
   
   
       24 - The system of  claim 19  wherein said expander is located upstream of said heat exchanger.  
   
   
       25 - The system of  claim 1  wherein the working fluid of said closed Rankine cycle recirculating loop is water.  
   
   
       26 - The system of  claim 1  wherein the fuel from said source of fuel at least partially includes the element carbon, the combustor adapted to combust the carbon containing fuel into products of combustion including CO2, the system including a separator for the products of combustion, said separator including an outlet for primarily CO2.  
   
   
       27 - The system of  claim 26  wherein said products of combustion include both CO2 and water, said separator including a condenser for the water, and said outlet for primarily CO2 being an outlet for gases not condensing within the condenser.  
   
   
       28 - The system of  claim 26  wherein said outlet for primarily CO2 includes at least one pump to pressurize the CO2 to a pressure at least as great as a pressure within a terrestrial formation, and wherein said outlet for primarily CO2 is coupled to a feed well adapted to deliver the CO2 into the terrestrial formation.  
   
   
       29 - The system of  claim 27  wherein said terrestrial formation includes a natural gas pocket.  
   
   
       30 - The system of  claim 29  wherein said source of fuel includes natural gas from said natural gas pocket to which said outlet for primarily CO2 is coupled.  
   
   
       31 - The system of  claim 1  wherein said source of fuel includes both natural gas and CO2, at least a portion of the CO2 in said source of fuel being CO2 formed as a product of combustion of the natural gas with oxygen within said combustor.  
   
   
       32 - A zero emissions coal or biomass power generation system with external heating of a working fluid, comprising in combination: 
 an air separation unit including an air inlet and an outlet for oxygen enriched air;    a gasifier including an oxygen inlet coupled to said oxygen enriched air outlet of said air separation unit, a carbon containing feedstock inlet and a syngas outlet;    a gas generator including an oxygen inlet downstream from said oxygen enriched air outlet of said air separation unit, a syngas inlet downstream from said syngas outlet of said gasifier, and a water inlet, said gas generator adapted to combust the oxygen from the oxygen inlet with syngas from the syngas inlet to produce products of combustion including steam and carbon dioxide, said gas generator adapted to mix water from the water inlet with the combustion products to produce a combined stream of carbon dioxide and steam; and    a closed loop Rankine cycle steam power generation system including a boiler and an expander, said boiler adapted to boil water into high pressure high temperature steam utilizing heat from the products of combustion discharged from said gas generator, and said expander adapted to output power from the system.    
   
   
       33 - The system of  claim 32  wherein said carbon containing feedstock includes coal.  
   
   
       34 - The system of  claim 32  wherein said carbon containing feedstock includes biomass material.  
   
   
       35 - The system of  claim 32  wherein at least one of the elevated temperature products of combustion is water, and wherein the water produced within said gas generator is at least partially routed to said water inlet, such that the water entering said gas generator at said water inlet is at least partially water produced within said gas generator previously.  
   
   
       36 - The system of  claim 35  wherein a condenser is located downstream of said outlet of said gas generator, said condenser adapted to condense water within the products of combustion from steam to liquid water, said condenser including a liquid water outlet oriented upstream from said water inlet of said gas generator; and a water preheater located between said liquid water outlet of said condenser and said water inlet of said gas generator, said water preheater adapted to transfer heat from the products of combustion between said outlet of said gas generator and said condenser to the water passing from said condenser to said gas generator.  
   
   
       37 - The system of  claim 36  wherein said water preheater is adapted to heat the water therein sufficiently to boil the water from liquid water into steam, and wherein the water at said water inlet is steam.  
   
   
       38 - The system of  claim 37  wherein said oxygen from said source of oxidizer is in a gaseous phase.  
   
   
       39 - The system of  claim 32  wherein an expander is located downstream of an outlet of said gas generator, said expander adapted to expand flow discharged from said gas generator, said expander including a discharge.  
   
   
       40 - The system of  claim 39  wherein said expander is adapted to output power from the system.  
   
   
       41 - The system of  claim 40  wherein said expander includes at least one turbine.  
   
   
       42 - The system of  claim 41  wherein said expander includes a non-condensing gas turbine.  
   
   
       43 - The system of  claim 39  wherein said expander is located upstream of said heat exchanger.  
   
   
       44 - The system of  claim 32  wherein a condenser is located downstream of said gas generator, said condenser adapted to cool the products of combustion sufficiently to condense the steam in the products of combustion into liquid water, said condense including a gas outlet, said gas outlet discharging primarily CO2 and other gases not condensing within said condenser.  
   
   
       45 - The system of  claim 44  wherein said gas outlet includes at least one pump to pressurize the CO2 to a pressure at least as great as a pressure within a terrestrial formation, and wherein said gas outlet is coupled to a feed well adapted to deliver the CO2 into the terrestrial formation.  
   
   
       46 - A zero emissions power generation system featuring both a closed Rankine cycle and an at least partially open direct heating Rankine cycle, comprising in combination: 
 a closed Rankine cycle working fluid recirculation loop including a working fluid heater, a working fluid expander, a working fluid condenser and a working fluid pump;    a source of oxidizer, the oxidizer being a majority oxygen;    a source of fuel, the fuel being capable of combustion with oxygen to produce elevated temperature products of combustion;    a combustor having an oxidizer inlet downstream from said source of oxidizer, a fuel inlet downstream from said source of fuel, said combustor adapted to combust the fuel with the oxygen to produce elevated temperature products of combustion, and an outlet adapted to release the elevated temperature products of combustion from the combustor;    an expander located downstream from said combustor outlet, said expander adapted to expand the products of combustion, and having a discharge; and    a heat exchanger downstream from said discharge, said heat exchanger adapted to transfer heat from said products of combustion to the working fluid of said closed Rankine cycle as at least a portion of said working fluid heater.    
   
   
       47 - The system of  claim 46  wherein said source of fuel includes the element hydrogen and the element carbon, such that said source of fuel is a source of hydrocarbon fuel.  
   
   
       48 - The system of  claim 47  wherein said source of fuel includes methane.  
   
   
       49 - The system of  claim 47  wherein said source of fuel includes syngas comprising hydrogen gas and carbon monoxide gas.  
   
   
       50 - The system of  claim 49  wherein said source of fuel includes a gasifier, said gasifier including an inlet for a carbon containing feedstock, and an inlet for oxygen from said source of oxidizer, said gasifier adapted to convert the carbon containing feedstock into syngas, said oxidizer including an outlet for syngas, said outlet upstream of said combustor fuel inlet.  
   
   
       51 - The system of  claim 46  wherein said combustor includes a water inlet, said combustor adapted to combine water from said water inlet with the elevated temperature products of combustion before discharge from said combustor from said outlet.  
   
   
       52 - The system of claim  511  wherein at least one of the elevated temperature products of combustion is water, and wherein the water produced within said combustor is at least partially routed to said water inlet, such that the water entering said combustor at said water inlet is at least partially water produced within said combustor previously and said water acts as at least a portion of an at least partially open direct heating Rankine cycle.  
   
   
       53 - The system of  claim 52  wherein a condenser is located downstream of said outlet of said combustor, said condenser adapted to condense water within the products of combustion from steam to liquid water, said condenser including a liquid water outlet oriented upstream from said water inlet of said combustor; and a water preheater located between said liquid water outlet of said condenser and said water inlet of said combustor, said water preheater adapted to transfer heat from the products of combustion between said outlet of said combustor and said condenser to the water passing from said condenser to said combustor.  
   
   
       54 - The system of  claim 46  wherein said source of oxidizer includes an air separator, said air separator including an inlet for air and an outlet for oxidizer which is a majority oxygen, said air separator adapted to separate at least a portion of oxygen in the air from nitrogen in the air; wherein said air separator is adapted to cool the air to a temperature at which at least the nitrogen condenses into a liquid, to facilitate separation of the oxygen from the nitrogen; and wherein said expander is integrated with said air separator by providing an air compressor downstream of said air inlet of said air separator and driving said air compressor with said expander, such that an efficiency with which oxygen is separated from nitrogen in the air is enhanced.  
   
   
       55 - The system of  claim 46  wherein said expander includes a non-condensing gas turbine.  
   
   
       56 - The system of  claim 46  wherein the fuel from said source of fuel at least partially includes the element carbon, the combustor adapted to combust the carbon containing fuel into products of combustion including CO2, the system including a separator for the products of combustion, said separator including an outlet for primarily CO2; wherein said products of combustion include both CO2 and water, said separator including a condenser for the water, and said outlet for primarily CO2 being an outlet for gases not condensing within the condenser; and wherein said outlet for primarily CO2 includes at least one pump to pressurize the CO2 to a pressure at least as great as a pressure within a terrestrial formation, and wherein said outlet for primarily CO2 is coupled to a feed well adapted to deliver the CO2 into the terrestrial formation.