A PROCESS AND AN APPARATUS FOR UTILIZING FOSSIL ENERGY WITH LOW CARBON EMISSIONS

Abstract

The present invention relates to a process and an apparatus for utilizing fossil energy with low carbon emissions, which belongs to a technical field of clean energy and climate mitigation. The present invention is applicable for utilizing fossil, biomass and other carbon-containing fuels in coastal and marine areas to produce clean energy with low carbon emissions to atmosphere and low cost. The process comprises the main steps of carrying out the oxygen enriched combustion and using seawater to scrub the flue gas once to realize carbon capture, and the scrubbing water is recovered to a water quality in accordance with legal requirements and then is discharged into the ocean to realize carbon storage of ocean natural alkalinity, so that the resources of carbon sink and carbon pool in natural ocean are used to reduce greenhouse gases in the atmosphere in a safe and environment-friendly form.

Claims

1. A process for utilizing fossil energy with low carbon emissions, comprising steps of: 1) oxygen enriched combustion including: increasing the oxygen concentration in air for fossil fuel combustion to increase the concentration of carbon dioxide in flue gas in the course of combustion for producing heat energy; 2) carbon capture of seawater scrubbing including: scrubbing the flue gas generated in the course of oxygen enriched combustion in step 1) with seawater so that the carbon dioxide in the flue gas is dissolved into the seawater to realize carbon capture, and generating clean decarburized flue gas and acid scrubbing water containing carbon dioxide of the flue gas; 3) water quality restoration including: diluting the acid scrubbing water generated in step 2) with new seawater, so that a pH value of the acid scrubbing water is recovered to a legal value allowed to be discharged into the ocean, and scrubbing seawater discharges are generated; 4) ocean carbon storage including: injecting the scrubbing seawater discharges generated in step 3) into the ocean to realize ocean carbon storage which is long-term, safe and environment-friendly on marine ecology; 5) low carbon emission to atmosphere including: discharging the decarburized flue gas generated in step 2) into atmosphere; and 6) energy outputting including: converting the heat energy generated in the oxygen enriched combustion in step 1) into applied energy and outputting the applied energy.

2. The process according to claim 1, wherein in the procedure that the carbon dioxide in the flue gas is dissolved into the seawater to realize carbon capture in step 2), 3%-99% of the carbon dioxide in the flue gas is dissolved into the seawater to realize carbon capture.

3. The process according to claim 1, wherein in the course of increasing the oxygen concentration in air for fossil fuel combustion in step 1), the increased oxygen is obtained from an oxygen-producing procedure including a cryogenic liquefied air method, and/or a pressure swing adsorption method and/or a membrane separation method.

4. The process according to claim 1, wherein in the course of injecting the scrubbing seawater discharges into the ocean in step 4), the scrubbing seawater discharges are injected under atmospheric pressure through a pipe into the ocean at a location which is near the water quality restoration location in step 3).

5. The process according claim 1, wherein in the course of converting the heat energy generated in oxygen enriched combustion into applied energy and outputting the applied energy in step 6), the heat energy is converted into the applied energy selected from a group consisted of electric energy, kinetic energy, thermal energy medium and the combination thereof.

6. The process according to claim 3, wherein in the oxygen-producing procedure, nitrogen is recycled as by-product.

7. An apparatus for utilizing fossil energy with low carbon emissions and carrying out the process of claim 1, comprising a device for increasing oxygen, a burner and a carbon capturer, wherein: the device for increasing oxygen, which is configured for increasing the oxygen concentration, includes an intake passageway, a passageway for supplying oxygen enriched air and a passageway for discharging nitrogen, wherein the intake passageway is communicated with the atmosphere, and the passageway for supplying oxygen enriched air is communicated with the burner; the burner includes a device for supplying fuel, a passageway for discharging flue gas and a device for converting and outputting energy, wherein the passageway for discharging flue gas is connected to the carbon capturer; and the carbon capturer includes a passageway for entering of scrubbing water, a device for pumping seawater and a passageway for discharging decarbonized flue gas, wherein: the passageway for entering of scrubbing water is connected to the device for pumping seawater; the passageway for discharging decarbonized flue gas is communicated with atmosphere through an exhaust funnel; a seawater outlet is connected to a pipe for discharging seawater through a device for restoring water quality; and an outlet of the pipe for discharging seawater is communicated with the ocean.

8. The apparatus according to claim 7, wherein the device for increasing oxygen includes a separation device of cryogenic liquefied air, and/or a device of pressure swing adsorption, and/or a device of membrane separation.

9. The apparatus according to claim 7, wherein the device for increasing oxygen is an oxygen generator of gas supercharging which includes a gas compressor, and/or a gas supercharger.

10. The apparatus according to claim 7, wherein the carbon capturer is composed of a scrubber for seawater and flue gas, and the device for restoring water quality, to which the carbon capturer is connected, is composed of a water mixing device.

11. The apparatus according to claim 7, wherein the device for increasing oxygen is connected to a device for recycling nitrogen through the passageway for discharging nitrogen, and the device for recycling nitrogen is composed of an ammonia synthesis device and/or a device for producing nitrogen fertilizer, and/or is composed of a device for storing and transporting chemical seal gas.

12. The apparatus according to claim 7, wherein the seawater outlet of the carbon capturer is connected to the pipe for discharging seawater through a thermoelectric generator and the device for restoring water quality, and the thermoelectric generator is electrically connected with the device for increasing oxygen and the device for pumping seawater through an internal power supply system.

13. A fossil fuel power plant with low carbon emissions, comprising the apparatus of claim 7.

14. A fossil fuel powered marine ship with low carbon emissions, comprising the apparatus of claim 7.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG. 1 is a schematic diagram showing the steps of an example of the process of the present invention.

[0045] FIG. 2 is a schematic diagram showing the structure of the apparatus for carrying out a process of the present invention.

[0046] FIG. 3 is a schematic diagram showing an example of remodeling coastal power plant according the scheme of process and apparatus of the present invention.

[0047] FIG. 4 is a schematic diagram showing an example of marine ship according the scheme of process of the present invention.

[0048] Names of components or structures corresponding to the reference numbers in the drawings are provided as below.

[0049] 1—device for increasing oxygen, 1.1—intake passageway, 1.2—passageway for supplying oxygen enriched air, 1.3—passageway for discharging nitrogen, 1.4—device for recycling nitrogen, 2—burner, 2.1—device for supplying fuel, 2.2—passageway for discharging flue gas, 2.3—device for converting and outputting energy, 3—carbon capturer, 3.1—passageway for entering of scrubbing water, 3.2—device for pumping seawater, 3.3—passageway for discharging decarbonized flue gas, 3.4—exhaust funnel, 3.5—seawater outlet, 3.6—device for restoring water quality, 3.7—pipe for discharging seawater, 3.8—thermoelectric generator, 3.9—ocean, 3.10—ocean current

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] Combined with the figures and examples, further description of the present invention is provided as below.

Example 1

[0051] This is a basic example of the process of the present invention. As shown in FIG. 1, the steps comprise:

[0052] 1) oxygen enriched combustion including: increasing the oxygen concentration in air for fossil fuel combustion to increase the concentration of carbon dioxide in flue gas in the course of combustion for producing heat energy;

[0053] 2) carbon capture of seawater scrubbing including: scrubbing the flue gas generated in the course of oxygen enriched combustion in step 1) with seawater so that the carbon dioxide in the flue gas is dissolved into the seawater to realize carbon capture, and generating clean decarburized flue gas and acid scrubbing water containing carbon dioxide of the flue gas;

[0054] 3) water quality restoration including: diluting the acid scrubbing water generated in step 2) with new seawater, so that a pH value of the acid scrubbing water is recovered to a legal value allowed to be discharged into the ocean, and scrubbing seawater discharges are generated;

[0055] 4) ocean carbon storage including: injecting the scrubbing seawater discharges generated in step 3) into the ocean to realize ocean carbon storage which is long-term, safe and environment-friendly on marine ecology;

[0056] 5) low carbon emission to atmosphere including: discharging the decarburized flue gas generated in step 2) into atmosphere; and

[0057] 6) energy outputting including: converting the heat energy generated in oxygen enriched combustion in step 1) into applied energy and outputting the applied energy.

Example 2

[0058] This is a group of examples based on Example 1. The fossil fuels include oil, natural gas, combustible ice, biomass fuel and coal. In these examples, biomass fuel can be also used as carbon-containing fuel for producing energy with low carbon emissions, as same as the common fossil fuel, and the combustion of biomass fuel with low carbon emissions has effect of climate mitigation of negative emission.

[0059] In another group of examples based on Example 1, the fossil fuels include a combination of oil and natural gas, a combination of natural gas and combustible ice, a combination of biomass fuel and coal, and a combination of oil and coal.

[0060] In another group of examples based on Example 1, in the process of increasing the oxygen concentration in air for fossil fuel combustion, the volume percentage of oxygen in air for fossil fuel combustion is increased to 21%-25%, or 25%-35%, or 35%-55%, or 55%-75%, or 75%-99%.

Example 3

[0061] This is a group of examples based on Example 1. After the process of increasing the concentration of carbon dioxide in flue gas in the course of combustion, the carbon dioxide concentration in the flue gas is increased by 1%-10%, or 10%-50%, or 50%-100% compared with that in the flue gas generated in combustion by ambient natural air.

[0062] This is a group of examples based on Example 1. After the process of increasing the concentration of carbon dioxide in flue gas in the course of combustion, the carbon dioxide concentration in the flue gas is increased by 1-2 times, or 2-5 times, or 5-10 times, or 10-20 times, or 20-30 times compared with that in the flue gas generated in combustion by ambient natural air.

Example 4

[0063] This is a group of examples based on Example 1. In the process that the carbon dioxide in the flue gas is dissolved into the seawater to realize carbon capture, the amount of carbon dioxide in flue gas dissolved in the seawater reaches 3%-5%, or 5%-15%, or 15%-35%, or 35%-55%, or 55%-75%, or 75%-99%.

Example 5

[0064] This is another basic example based on Example 1. In the process of increasing the oxygen concentration in air for fossil fuel combustion, the increased oxygen is obtained from a separation method of cryogenic liquefied air. In another basic example, the increased oxygen is obtained from a pressure swing adsorption method. In another example, the increased oxygen is obtained from a membrane separation method.

[0065] In another basic example based on Example 1, in the process of converting the heat energy generated in oxygen enriched combustion into applied energy and outputting the applied energy in step 6), the heat energy is converted into electrical energy through a method of heating the boiler to produce steam to push the turbine generator, and the electrical energy is outputted to the power grid. In another example, the heat energy generated in oxygen enriched combustion is converted into kinetic energy for ship propulsion by internal-combustion engine. In another example, the heat energy generated in oxygen enriched combustion is converted into hot steam and/or hot water medium by heating boiler and the hot steam and/or hot water medium are outputted. In another example, the heat energy generated in oxygen enriched combustion is converted into kinetic energy by gas turbine. In another example, the heat energy generated in oxygen enriched combustion is converted into an applied energy combination of electric energy, kinetic energy and thermal energy medium.

Example 6

[0066] This is a basic example of the apparatus of the present invention. As shown in FIG. 2, the apparatus comprises:

[0067] a device for increasing oxygen 1, a burner 2 and a carbon capturer 3, wherein:

[0068] the device for increasing oxygen 1, which is configured for increasing the oxygen concentration, includes an intake passageway 1.1, a passageway for supplying oxygen enriched air 1.2 and a passageway for discharging nitrogen 1.3, wherein the intake passageway 1.1 is communicated with the atmosphere, and the passageway for supplying oxygen enriched air 1.2 is communicated with the burner 2:

[0069] the burner 2 includes a device for supplying fuel 2.1, a passageway for discharging flue gas 2.2 and a device for converting and outputting energy 2.3, wherein the passageway for discharging flue gas 2.2 is connected to the carbon capturer 3; and

[0070] the carbon capturer 3 includes a passageway for entering of scrubbing water 3.1, a device for pumping seawater 3.2 and a passageway for discharging decarbonized flue gas 3.3, wherein: [0071] the passageway for entering of scrubbing water 3.1 is connected to the device for pumping seawater 3.2; [0072] the passageway for discharging decarbonized flue gas 3.3 is communicated with atmosphere through an exhaust funnel 3.4; [0073] a seawater outlet 3.5 is connected to a pipe for discharging seawater 3.7 through a device for restoring water quality 3.6; and [0074] an outlet of the pipe for discharging seawater 3.7 is communicated with the ocean.

Example 7

[0075] This is an example based on Example 6. As shown in FIG. 2, the carbon capturer 3 is composed of a scrubber for seawater and flue gas. The device for restoring water quality 3.6, to which the carbon capturer 3 is connected, is composed of a water mixing device, so that the new seawater and acid seawater are well mixed in a space isolated from the atmosphere.

[0076] In another group of examples based on Example 6, the device for increasing oxygen comprises an apparatus for increasing oxygen including a separation device of cryogenic liquefied air, and/or a device of pressure swing adsorption, and/or a device of membrane separation.

[0077] In another group of examples based on Example 6, the burner is composed of a boiler burning carbon-containing fossil and/or biomass fuels, and/or an internal combustion engine, and/or a gas turbine.

[0078] In another group of examples based on Example 6, the device for converting and outputting energy, to which the burner is connected, is composed of a turbine generator, and/or a heating boiler, and/or an internal combustion engine, and/or a propeller, and/or a gas turbine.

Example 8

[0079] This is an example based on Example 6. As shown in FIG. 3, the device for increasing oxygen 1 is connected to a device for recycling nitrogen 1.4 through the passageway for discharging nitrogen 1.3. The device for recycling nitrogen is composed of a whole plant for producing synthetic ammonia. In another example, the device for recycling nitrogen is composed of a whole plant for producing nitrogenous fertilizer. In another example, the device for recycling nitrogen is composed of a device for storing and transporting chemical seal gas.

[0080] In above examples, in the process for producing oxygen, nitrogen is recycled as by-product. Therefore, this a CCUS example including carbon capture, utilization and storage.

Example 9

[0081] This is an example for remodeling a power plant based on Example 6 and Example 7. As shown in FIG. 2, the burner is a supercritical coal-fired boiler matched with 600 MW steam turbine generator unit, and pulverized coal and biomass fuels are used as the fuel. The remodeling is carried out in two phases.

[0082] In an example of the first phase remodeling, a device for increasing oxygen is installed in the boiler passageway for entering of air, and a carbon capturer of seawater scrubbing is installed in the passageway for exhausting flue gas. The installed device for increasing oxygen is a separation device of cryogenic liquefied air, by which the oxygen volume concentration in the entering air of boiler is increased to about 40%, and the volume concentration of carbon dioxide in the combustion flue gas is about 36%. In the installed carbon capturer of seawater scrubbing, a packed tower is used to reduce the height, and the height of water distributor is about 9 m. The existing cooling seawater of the power plant is directly used as scrubbing seawater, and no additional drainage facilities are built. In this example, the annual amount of capture and storage of carbon dioxide is about 300,000 tons, the CO.sub.2 emissions of the power plant are reduced by about 10%, the SO.sub.2 emissions are reduced by about 99%, and the combustion efficiency of the boiler is increased by about 3% through the oxygen enriched combustion.

[0083] In an example of the second phase remodeling, based on the first phase remodeling, the scale and power of the device for increasing oxygen installed in the boiler passageway for entering of air are increased, another carbon capturer of seawater scrubbing is added in the passageway for exhausting flue gas, and a pumping station for pumping seawater is added. The added devices for increasing oxygen include a device of pressure swing adsorption and two devices of membrane separation. After the increasing of the scale and power of the device for increasing oxygen, the oxygen volume concentration in the entering air of boiler reached to about 80%, and the volume concentration of carbon dioxide in the combustion flue gas is about 76%. The amount of scrubbing seawater is increased to about 210,000 t/h, which comes from the added pump for pumping seawater. The pH value of the scrubbing seawater is adjusted by a device for restoring water quality to reach to a value of no less than 6.5 according to legal provisions of the environmental management department. Then the scrubbing seawater is injected under atmospheric pressure through a pipe into the ocean at a location which is near the water quality restoration location. In this example, the annual amount of capture and storage of carbon dioxide is about 2,300,000 tons, and the CO.sub.2 emissions of the power plant are reduced by about 80%.

[0084] The example of the second phase remodeling meets the requirements of large-scale CCS for the development of hydrogen energy industry.

Example 10

[0085] This is an example of fossil fuel power plant with low carbon emissions, comprising one or more technical features of the apparatus for utilizing fossil energy with low carbon emissions mentioned in Example 6, or Example 7, or Example 8, or Example 9.

[0086] In another example of gas-steam combined cycle power plant based on Example 6, the device for increasing oxygen is an oxygen generator of gas supercharging, which is composed of a gas compressor of gas turbine and oxygen-nitrogen separation membrane.

Example 11

[0087] This is an example of marine ship based on Example 6 and Example 7. As shown in FIG. 4, the burner 2 includes one 23 MW marine diesel engine as the main propulsion engine connected to the propeller, and one heating boiler as auxiliary. An oxygen generator of gas supercharging is installed at the are inlet of the engine and the boiler. The oxygen generator of gas supercharging is composed of gas turbocharger of diesel engine and an oxygen nitrogen separation membrane. The seawater outlet 3.5 of the carbon capturer 3 is connected to the pipe for discharging seawater 3.7 through a device for restoring water quality 3.6. A ship carbon capturer of seawater scrubbing is installed in tail gas passageway. The drainage is in accordance with MEPC rules under Annex VI of MARPOL convention, which is allowed to be discharged into the ocean. CO.sub.2 in ship flue gas is reduced by 3%-5% (the specific value is related to the seawater quality and temperature where the ship sails), and SO.sub.2 is reduced by 99%. the efficiency of the ship diesel engine is increased by about 3.8% through the oxygen enriched combustion.

[0088] In another example of ship, the fuel is LNG and it produces less carbon emissions than coal and oil, but it still belongs to the fossil energy needed to reduce and control the carbon emissions.

Example 12

[0089] This is an example of marine ship based on Example 11. As shown in FIG. 4, the seawater outlet 3.5 of the carbon capturer 3 is connected to the pipe for discharging seawater 3.7 through a thermoelectric generator 3.8 and a device for restoring water quality 3.6. The thermoelectric generator 3.8 is electrically connected with the device for increasing oxygen 1 and the device for pumping seawater 3.2 through an internal power supply system. Due to the high temperature of flue gas from ship internal combustion engine, it is easier for seawater to absorb the waste heat of the flue gas during scrubbing process (no less than 60% of fuel heat). This part of waste heat can be used for thermoelectric power generation to reduce the energy consumption of device for increasing oxygen and the seawater scrubbing. In this example, the emission of CO.sub.2 in tail gas is reduced by 5%-10%.

Example 13

[0090] This is a group of examples of fossil fuel powered marine ship with low carbon emissions, comprising one or more technical features of the apparatus for utilizing fossil energy with low carbon emissions mentioned in Example 6, or Example 7, or Example 11, or Example 12.

[0091] The protection scope of the claim of the present invention is not limited to the above examples.