Shaft stability is enhanced and reliability is improved. In a gas turbine power generation system of an embodiment, a pressurizing unit, a rotation control unit, a diaphragm coupling, a turbine, and a generator are disposed to line up sequentially on the same shaft. A thrust bearing is provided between the turbine and the generator. The turbine is configured such that a working medium flows from the diaphragm coupling side toward the rotation control unit side.

An enhanced oil recovery method in which carbon dioxide is injected into a well to pressure the well or add lift a production flow from the well recaptures the injected carbon dioxide for reinjection into the well for lift or into another well in a group of for pressuring the well or adding lift to the production flow from the well. Geothermal energy in the production stream can be converted to electrical power for use in the recapturing of the carbon dioxide or other operations at the well site.

The present process invention in continuation to the U.S. Ser. No. 14/392,066 appertains to Advanced Combustion in post-combustion carbon capture, wherein the CO.sub.2-containing flue gas, said CO2-Stream, is cleaned from harmful constituents, recirculated, oxygenized and employed for combustion for the fossil fuels, referred to Flue Gas Oxy-Fueling in order to obtain a CO.sub.2-rich gas upstream to CO2-CC with significantly less gas flow rate subject to further processing. This continuation process patent also presents processing to prepare a CO.sub.2-rich CO2-Stream for the pre-combustion carbon capture downstream of gasification and gas cleaning process; or from the secondary CO2-Stream that stems from the cathodic syngas [CO/2H.sub.2] downstream of HPLTE-SG of patent parent, then downstream of the HP/IP-water shift converters in [CO.sub.2/3H.sub.2] composition, whereas the CO.sub.2-rich CO2-Stream from either pre-combustion process is routed to the CO2-CC for CO.sub.2 cooling and condensation section of the U.S. Ser. No. 14/392,066 to obtain liquid carbon dioxide for re-use as new fossil energy resource.

A method for utilizing the inner energy of an aquifer fluid includes geothermal thermal water mixed with gas and optionally crude oil in a closed cycle to obtain an environmentally-neutral, carbon-dioxide-free utilization of the aquifer fluid and an environmentally-friendly supply of electric and thermal energy. An aquifer fluid is removed from an aquifer by means of a removal device, gas is separated by degassing the aquifer fluid in a gas-separation device, optionally crude oil is separated if necessary, the heat energy of the thermal water is utilized in at least one system for utilizing the thermal energy, the extracted gas and the optionally separated crude oil is com busted in at least one combustion device and the inner energy of the gas is utilized by operating a generator, the CO.sub.2 being removed from the waste gas and recycled into the aquifer.

In a gas turbine system including a first gas turbine generator, a heat recovery steam generator and a steam turbine generator heat rejection system, the present invention relates to a method for CO.sub.2 capture from flue gas in said system, said method including: (a) diverting an amount of heat recovery steam generator flue gas from the CO.sub.2 capture plant; and (b) mixing the diverted heat recovery steam generator flue gas with an air stream, forming a combined gas stream, wherein (1) the combined gas stream is fed to a second gas turbine generator; (2) exhaust gas from the second gas turbine generator is mixed with exhaust gas from the first gas turbine generator, forming a combined exhaust gas stream; and (3) the combined exhaust gas stream enters the heat recovery steam generator, with the CO.sub.2 content of the combined exhaust gas stream increased through supplementary firing in the heat recovery steam generator.

A fuel, an oxidant, and a diluent can be introduced to a combustion zone, wherein the oxidant comprises air, oxygen-enriched air, or oxygen-lean air. At least a portion of the fuel can be combusted to produce an exhaust gas comprising, nitrogen, nitrogen oxides, and carbon monoxide. The exhaust gas can be expanded to produce mechanical power and an expanded exhaust gas. A concentration of at least one of oxygen, hydrogen, nitrogen oxides and carbon monoxide, in the exhaust gas or the expanded exhaust gas or both can be determined, and an amount of the oxidant or the fuel introduced to the combustion zone, or both, can be adjusted based on the determined concentration to produce an exhaust gas containing a combined amount of oxygen and carbon monoxide of less than about 2 mol % and a nitrogen concentration ranging from 20 mol % to 75 mol %. The diluent to the combustion zone can include at least a portion of the exhaust gas containing a combined amount of oxygen and carbon monoxide of less than 2 mol % and a nitrogen concentration ranging from 20 mol % to 75 mol %.

The present disclosure relates to systems and methods that provide a low pressure liquid CO.sub.2 stream. In particular, the present disclosure provides systems and methods wherein a high pressure CO.sub.2 stream, such as a recycle CO.sub.2 stream from a power production process using predominately CO.sub.2 as a working fluid, can be divided such that a portion thereof can be expanded and used as a cooling stream in a heat exchanger to cool the remaining portion of the high pressure CO.sub.2 stream, which can then be expanded to form a low pressure CO.sub.2 stream, which may be in a mixed form with CO.sub.2 vapor. The systems and methods can be utilized to provide net CO.sub.2 from combustion in a liquid form that is easily transportable.

Offshore systems and methods may be configured for offshore power generation and carbon dioxide injection for enhanced gas recovery for gas reservoirs. For example, a method may include: providing an offshore facility including a gas turbine, and a gas separator; producing a produced gas from a gas reservoir to the offshore facility; combusting the produced gas in a gas turbine to produce power and a flue gas; at least partially removing nitrogen from the flue gas in a gas separator to produce a carbon dioxide-enriched flue gas and a nitrogen-enriched flue gas; compressing the carbon dioxide-enriched flue gas in a gas compressor to produce a compressed gas; and injecting the compressed gas from the gas compressor into the gas reservoir, wherein 80 mol % or more of hydrocarbon in the produced gas is combusted and/or injected into the gas reservoir.

There are disclosed systems and methods for generating electrical power from oxy-fuel combustion in a turbine system. The turbine system makes use of recycled steam as a components of the turbine working fluid. Also disclosed is an integrated recuperator and separator, which may be used with the turbine system, configured to separate water and carbon dioxide from exhaust fluids from the turbine system, heat from the exhaust fluids being used to generate steam from the separated water for recycling to the turbine system. Carbon dioxide separated from the exhaust fluids is condensed to a liquid or supercritical phase and sequestered in a subsurface natural gas reservoir from which natural gas fuel for the turbine system is extracted.

A system for offshore, direct carbon dioxide sequestration includes an offshore marine platform fixed to the ocean floor above an offshore, subsea storage reservoir. A carbon dioxide floating storage unit moored adjacent the marine platform gathers and stores carbon dioxide delivered in discreet amounts from carbon dioxide sources. Carbon dioxide sources may include carbon dioxide delivery vessels and a carbon dioxide capture system mounted on the marine platform. Once a desired volume of carbon dioxide has been gathered in the carbon dioxide floating storage unit, compressors in fluid communication with the carbon dioxide floating storage unit may be utilized to increase the pressure of the gathered carbon dioxide to a desired injection pressure, after which the pressurized carbon dioxide is pumped directly from the fixed marine platform into the subsea storage reservoir.