Chemical preparation system and method of coal oxygen-enriched combustion coupling water electrolysis technology

Abstract

The invention provides a chemical preparation system of a coal oxygen-enriched combustion coupling water electrolysis technology. The system comprises an alkaline electrolytic cell unit, a hydrogen separating and cooling unit, an oxygen separating and cooling unit, a heat exchange unit, a coal oxygen-enriched combustion unit, a power generation unit, a flue gas treatment unit, a CO2 trapping unit and a unit for preparing chemicals such as methanol and ethanol through CO2 hydrogenation. And the unit for preparing chemicals such as methanol and ethanol through CO2 hydrogenation is used for receiving the treated hydrogen and the captured CO2 for preparing chemicals, so that the method is green and pollution-free, the carbon emission of the coal combustion unit is reduced, and the CO2 is subjected to resource utilization.

Description

Technical Field

[0001] The present invention relates to the field of energy utilization technology, and in particular to a chemical preparation system and method using coal oxygen-enriched combustion coupled with water electrolysis technology. Background Art

[0002] Chemicals such as methanol and ethanol are not only important chemical raw materials, but also a clean energy source. At present, the industrial chain of chemical application technology represented by methanol has basically matured and has been widely promoted and applied to replace traditional energy raw materials. However, how to prepare "green methanol, ethanol and other chemicals" on a large scale to meet the huge market demand for methanol, ethanol and other chemicals has become an urgent problem to be solved.

[0004] If CO2 is captured from the flue gas of coal oxygen-enriched combustion devices and used as a resource, and green hydrogen produced by electrolysis of water by photovoltaic or wind power is used to hydrogenate CO2 to produce green methanol, ethanol and other chemicals, not only can carbon emissions be greatly reduced, but methanol and ethanol are easier to store and transport than hydrogen, and can more effectively fill the energy gap.

[0005] Based on this application scenario, how to effectively couple coal oxygen-enriched combustion with green electricity electrolysis water technology to form a methanol preparation method using coal oxygen-enriched combustion coupled with electrolysis water technology, and design a new system for the preparation of methanol, ethanol and other chemicals using coal oxygen-enriched combustion coupled with electrolysis water technology, will be conducive to promoting the optimization and adjustment of my country's new energy structure. Summary of the invention

[0006] Based on the above technical problem that the carbon dioxide generated by coal combustion will pollute the environment if it is not utilized, a chemical preparation system and method of coal oxygen-enriched combustion coupled with water electrolysis technology is provided. The present invention mainly utilizes CO2 in the flue gas of coal oxygen-enriched combustion and hydrogen prepared by green electricity through water electrolysis to prepare methanol, ethanol and other chemicals, thereby greatly reducing the carbon emissions of the coal combustion unit, and can realize oxygen-enriched combustion of the coal combustion unit, and can prepare green methanol and ethanol chemicals that are easier to store and transport than hydrogen.

[0007] The technical means adopted by the present invention are as follows:

[0008] In one aspect, the present invention provides a chemical preparation system using coal oxygen-enriched combustion coupled with water electrolysis technology, comprising:

[0009] The alkaline electrolyzer unit is connected to the hydrogen separation cooling unit and the oxygen separation cooling unit, respectively, and is used to decompose the fresh water therein into hydrogen and oxygen, and transmit the hydrogen to the hydrogen separation cooling unit and transmit the oxygen to the oxygen separation cooling unit;

[0010] The hydrogen separation and cooling unit is respectively connected to the alkaline electrolyzer unit and the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals, and is used to receive the hydrogen, remove impurities contained in the hydrogen to obtain the treated hydrogen, and transmit the treated hydrogen to the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals;

[0011] The oxygen separation and cooling unit is connected to the alkaline electrolyzer unit and the heat exchange unit respectively, and is used to receive the oxygen, remove impurities contained in the oxygen to obtain the purified oxygen, and transmit the purified oxygen to the heat exchange unit;

[0012] The heat exchange unit is connected to the oxygen separation and cooling unit, the coal oxygen-enriched combustion unit, and the flue gas treatment unit, respectively, and is used to receive the purified oxygen and transmit it to the coal oxygen-enriched combustion unit, receive the flue gas generated by the coal oxygen-enriched combustion unit and transmit it to the flue gas treatment unit, receive the flue gas partially treated by the flue gas treatment unit and transmit it to the coal oxygen-enriched combustion unit, and use the flue gas generated by the coal oxygen-enriched combustion unit to preheat the purified oxygen and the treated flue gas;

[0013] The coal oxygen-enriched combustion unit is connected to the heat exchange unit and the power generation unit respectively, and is used to receive and utilize the purified oxygen and the partially treated flue gas to perform coal oxygen-enriched combustion, and transmit the generated heat to the power generation unit;

[0014] The power generation unit is connected to the coal oxygen-enriched combustion unit and is used to receive the heat and generate electricity based on the heat;

[0015] The flue gas treatment unit is connected to the heat exchange unit and the CO2 capture unit respectively, and is used to treat the flue gas after the flue gas is treated;

[0016] The CO2 capture unit is connected to the flue gas treatment unit, the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals, and the chimney, respectively, and is used to capture CO2 from another part of the treated flue gas and transmit it to the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals, and transmit the excess tail gas to the chimney;

[0017] The CO2 hydrogenation unit for producing chemicals such as methanol and ethanol is respectively connected to the hydrogen separation and cooling unit and the CO2 capture unit, and is used to receive the processed hydrogen and the captured CO2 to prepare chemicals.

[0018] Furthermore, it also includes:

[0019] an alkali solution filtering circulation unit, connected to the hydrogen separation cooling unit, the oxygen separation cooling unit, and the alkali solution cooling unit, respectively, for obtaining the alkali solution removed by the hydrogen separation cooling unit and the oxygen separation cooling unit, filtering the alkali solution, and transmitting the filtered alkali solution to the alkali solution cooling module;

[0020] The alkali solution cooling unit is connected to the alkali solution filtering and circulating unit and the alkaline electrolytic cell unit respectively, and is used to cool the filtered alkali solution to the required temperature of the alkaline electrolytic cell unit, and transmit the cooled alkali solution to the alkaline electrolytic cell unit.

[0021] Furthermore, it also includes:

[0022] A fresh water supply unit is connected to the hydrogen separation cooling unit and the oxygen separation cooling unit, respectively, and is used to provide fresh water to the alkaline electrolyzer unit through the hydrogen separation cooling unit and the oxygen separation cooling unit.

[0023] Furthermore, the hydrogen separation and cooling unit is connected to the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals through a hydrogen purification unit;

[0024] The hydrogen purification unit is respectively connected to the hydrogen separation cooling unit and the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals, and is used to purify the hydrogen after being processed by the hydrogen separation cooling unit and transmit it to the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals.

[0025] Further, the alkaline electrolytic cell unit comprises an alkaline electrolytic cell;

[0026] The hydrogen separation cooling unit comprises a hydrogen separation cooler, a hydrogen scrubber and a hydrogen gas-liquid separator connected in sequence, wherein the hydrogen separation cooler is connected to the alkaline electrolyzer;

[0027] The oxygen separation cooling unit comprises an oxygen separation cooler, an oxygen scrubber, an oxygen liquid separator, a first regulating valve and a pressure transmitter connected end to end, and the oxygen separation cooler is connected to the alkaline electrolyzer;

[0028] The hydrogen purification unit comprises a hydrogen purification tower, a second regulating valve and a hydrogen buffer tank connected in sequence, wherein the hydrogen purification tower is connected to the hydrogen gas-liquid separator; and further comprises a liquid level difference transmitter, which is respectively connected to the hydrogen separation cooler, the oxygen separation cooler and the second regulating valve;

[0029] The heat exchange unit comprises a first heat exchanger, a flow regulating valve and a first induced draft fan connected in sequence, wherein the first heat exchanger is connected to the first regulating valve; and further comprises a second induced draft fan connected to the first heat exchanger;

[0030] The coal-oxygen combustion unit comprises a coal-oxygen combustion boiler module and a dust collector connected to each other, wherein the coal-oxygen combustion boiler module is connected to the first heat exchanger, and the dust collector is connected to the second induced draft fan;

[0031] The power generation unit includes a steam turbine generator connected to the coal-oxygen combustion boiler module;

[0032] The flue gas treatment unit comprises a booster fan, a desulfurization tower and a condenser connected in sequence, the booster fan is connected to the first heat exchanger, and the condenser is connected to the first induced draft fan;

[0033] The CO2 capture unit comprises an absorption tower, a rich liquid pump, a second heat exchanger, a desorption tower, a cooler and a separator connected in sequence, wherein the absorption tower is connected to the condenser and the chimney respectively; and further comprises a lean liquid pump, which is connected to the second heat exchanger and the chimney respectively;

[0034] The CO2 hydrogenation unit for producing methanol, ethanol and other chemicals includes a hydrogen booster pump, a methanol, ethanol and other chemical synthesis tower and a buffer tank connected in sequence, wherein the hydrogen booster pump is connected to the hydrogen buffer tank; and also includes a CO2 booster pump, which is respectively connected to the methanol, ethanol and other chemical synthesis tower and the separator.

[0035] Furthermore, it also includes:

[0036] an alkali solution filtering circulation unit, connected to the hydrogen separation cooling unit, the oxygen separation cooling unit, and the alkali solution cooling unit respectively;

[0037] The alkali solution cooling unit is connected to the alkali solution filtering and circulating unit and the alkaline electrolytic cell unit respectively;

[0038] The alkali solution filtering circulation unit comprises an alkali solution filter and an alkali solution circulation pump connected to each other, and the alkali solution filter is connected to the hydrogen separation cooler and the oxygen separation cooler respectively;

[0039] The alkali solution cooling unit comprises an alkali solution cooler, and the alkali solution cooler is connected to the alkali solution circulation pump and the alkaline electrolytic cell respectively.

[0040] Furthermore, it also includes:

[0041] a fresh water supply unit, connected to the hydrogen separation cooling unit and the oxygen separation cooling unit respectively;

[0042] The fresh water supply unit comprises a fresh water tank and a water replenishment metering pump connected to each other, and the water replenishment metering pump is connected to the hydrogen scrubbing tower and the oxygen scrubbing tower respectively.

[0043] On the other hand, the present invention also provides a method for preparing chemicals by using coal oxygen-enriched combustion coupled with water electrolysis technology, and a system for preparing chemicals by using any of the above-mentioned coal oxygen-enriched combustion coupled with water electrolysis technology, comprising:

[0044] The alkaline electrolyzer unit decomposes the fresh water therein into hydrogen and oxygen, transmits the hydrogen to the hydrogen separation cooling unit, and transmits the oxygen to the oxygen separation cooling unit;

[0045] The hydrogen separation and cooling unit receives the hydrogen, removes impurities contained in the hydrogen to obtain the treated hydrogen, and transmits the treated hydrogen to the CO2 hydrogenation unit to produce methanol, ethanol and other chemicals;

[0046] The oxygen separation and cooling unit receives the oxygen, removes impurities contained in the oxygen to obtain the purified oxygen, and transmits the purified oxygen to the heat exchange unit;

[0047] The heat exchange unit receives the purified oxygen and transmits it to the coal oxygen-enriched combustion unit, receives the flue gas generated by the coal oxygen-enriched combustion unit and transmits it to the flue gas treatment unit, and the flue gas treatment unit processes the flue gas to obtain the treated flue gas;

[0048] The heat exchange unit receives the flue gas partially treated by the flue gas treatment unit and transmits it to the coal oxygen-enriched combustion unit, and uses the flue gas generated by the coal oxygen-enriched combustion unit to preheat the purified oxygen and the treated flue gas;

[0049] The coal oxygen-enriched combustion unit receives and utilizes the purified oxygen and the partially treated flue gas to perform coal oxygen-enriched combustion, and transmits the generated heat to the power generation unit;

[0050] The power generation unit receives the heat and generates electricity according to the heat;

[0051] The CO2 capture unit captures CO2 from the flue gas after another part of the treatment and transmits it to the CO2 hydrogenation unit to produce methanol, ethanol and other chemicals, and transmits the excess tail gas to the chimney;

[0052] The CO2 hydrogenation unit for producing chemicals such as methanol and ethanol receives the processed hydrogen and the captured CO2 to prepare chemicals.

[0053] Compared with the prior art, the present invention has the following advantages:

[0054] 1. The chemical preparation system and method of coal oxygen-enriched combustion coupled with water electrolysis technology provided by the present invention uses a CO2 hydrogenation unit to produce methanol, ethanol and other chemicals, and receives the treated hydrogen and captured CO2 to prepare chemicals in a green and pollution-free manner, thereby reducing carbon emissions from coal combustion units and utilizing CO2 as a resource.

[0055] 2. The chemical preparation system and method of the coal oxygen-enriched combustion coupled with electrolytic water technology provided by the present invention transmits the flue gas generated by the coal oxygen-enriched combustion unit to the flue gas treatment unit through the heat exchange unit, receives the flue gas partially treated by the flue gas treatment unit and transmits it to the coal oxygen-enriched combustion unit, which helps to achieve oxygen-enriched combustion in the coal oxygen-enriched combustion unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0057] Figure 1 A structural schematic diagram of a chemical preparation system of the coal oxygen-enriched combustion coupled with water electrolysis technology provided by the present invention.

[0058] Figure 2 Another structural schematic diagram of the chemical preparation system of the coal oxygen-enriched combustion coupled with water electrolysis technology provided by the present invention.

[0059] In the figure: 1. Chemical preparation system of oxygen-enriched coal combustion coupled with electrolytic water technology; 2. Alkaline electrolyzer unit; 3. Hydrogen separation cooling unit; 4. Hydrogen purification unit; 5. Oxygen separation cooling unit; 6. Alkaline solution filtration circulation unit; 7. Alkaline solution cooling unit; 8. Fresh water supply unit; 9. Heat exchange unit; 10. Oxygen-enriched coal combustion unit; 11. Power generation unit; 12. Flue gas treatment unit; 13. CO2 capture unit; 14. CO2 hydrogenation to produce methanol, ethanol and other chemicals unit; 21. Alkaline electrolyzer; 31. Hydrogen separation cooler; 32. Hydrogen scrubber; 33. Hydrogen gas-liquid separator; 41. Hydrogen purification tower; 42. Second regulating valve; 43. Liquid level difference transmitter; 44. Hydrogen buffer tank; 51. Oxygen separation cooler; 52. Oxygen scrubber; 53. Oxygen liquid separation device; 54, pressure transmitter; 55, first regulating valve; 61, alkali filter; 62, alkali circulation pump; 71, alkali cooler; 81, fresh water tank; 82, water metering pump; 91, first heat exchanger; 92, second induced draft fan; 93, flow regulating valve; 94, first induced draft fan; 101, coal-oxygen combustion boiler module; 102, dust collector; 111, steam turbine generator; 121, booster fan; 122, desulfurization tower; 123, condenser; 131, absorption tower; 132, rich liquid pump; 133, second heat exchanger; 134, lean liquid pump; 135, analytical tower; 136, cooler; 137, separator; 141, hydrogen booster pump; 142, methanol, ethanol and other chemical synthesis tower; 143, CO2 booster pump; 144, buffer tank. DETAILED DESCRIPTION

[0060] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0061] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0063] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0064] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0065] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0066] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0067] Combination Figure 1 , Figure 1 A structural schematic diagram of a chemical preparation system of the coal oxygen-enriched combustion coupled with electrolysis of water technology provided by the present invention is provided to illustrate a specific embodiment of the chemical preparation system 1 of the coal oxygen-enriched combustion coupled with electrolysis of water technology provided by the present invention, including:

[0068] The alkaline electrolyzer unit 2 is connected to the hydrogen separation cooling unit 3 and the oxygen separation cooling unit 5, respectively, and is used to decompose the fresh water inside the alkaline electrolyzer unit 2 into hydrogen and oxygen, and transmit the hydrogen to the hydrogen separation cooling unit 3 and transmit the oxygen to the oxygen separation cooling unit 5;

[0069] Specifically, the power interface of the alkaline electrolyzer unit 2 is connected to green electricity such as photovoltaic / wind power, the hydrogen outlet of the alkaline electrolyzer unit 2 is connected to the hydrogen separation cooling unit 3, the oxygen outlet of the alkaline electrolyzer unit 2 is connected to the oxygen separation cooling module, the alkali liquid inlet of the alkaline electrolyzer unit 2 is connected to the outlet of the alkali liquid cooling unit 7, and the fresh water in the alkaline electrolyzer unit 2 is decomposed into hydrogen and oxygen under the action of green electricity.

[0070] The hydrogen separation cooling unit 3 is respectively connected to the alkaline electrolyzer unit 2 and the CO2 hydrogenation unit 14 for producing methanol, ethanol and other chemicals, and is used to receive hydrogen, remove impurities contained in the hydrogen to obtain treated hydrogen, and transmit the treated hydrogen to the CO2 hydrogenation unit 14 for producing methanol, ethanol and other chemicals;

[0071] Specifically, the hydrogen inlet of the hydrogen separation cooling unit 3 is connected to the hydrogen outlet of the alkaline electrolyzer unit 2. The hydrogen separation cooling unit 3 performs gas-liquid separation, washing, and cooling on the hydrogen entering the hydrogen separation cooling unit 3 from the alkaline electrolyzer unit 2 to remove the alkaline solution contained in the hydrogen.

[0072] The oxygen separation cooling unit 5 is connected to the alkaline electrolyzer unit 2 and the heat exchange unit 9 respectively, and is used to receive oxygen, remove impurities contained in the oxygen to obtain purified oxygen, and transmit the purified oxygen to the heat exchange unit 9;

[0073] Specifically, the oxygen inlet of the oxygen separation cooling unit 5 is connected to the oxygen outlet of the alkaline electrolyzer unit 2, and the oxygen outlet of the oxygen separation cooling unit 5 is connected to the heat exchange unit 9. The oxygen separation cooling unit 5 performs gas-liquid separation, washing, and cooling on the oxygen and alkaline liquid entering the oxygen separation cooling unit 5 from the alkaline electrolyzer unit 2, thereby improving the oxygen purity, thereby increasing the CO2 content in the flue gas generated by coal combustion, which is beneficial to increase the CO2 capture amount.

[0074] The heat exchange unit 9 is respectively connected to the oxygen separation cooling unit 5, the coal oxygen-enriched combustion unit 10, and the flue gas treatment unit 12, and is used to receive the purified oxygen and transmit it to the coal oxygen-enriched combustion unit 10, receive the flue gas generated by the coal oxygen-enriched combustion unit 10 and transmit it to the flue gas treatment unit 12, receive the flue gas partially treated by the flue gas treatment unit 12 and transmit it to the coal oxygen-enriched combustion unit 10, and use the flue gas generated by the coal oxygen-enriched combustion unit 10 to preheat the purified oxygen and the treated flue gas;

[0075] Specifically, the oxygen inlet of the heat exchange unit 9 is connected to the oxygen outlet of the oxygen separation cooling unit 5; the oxygen outlet of the heat exchange unit 9 is connected to the oxygen inlet of the coal oxygen-enriched combustion unit 10; the flue gas inlet of the heat exchange unit 9 is connected to the flue gas outlet of the coal oxygen-enriched combustion unit 10; the flue gas outlet of the heat exchange unit 9 is connected to the flue gas inlet of the flue gas treatment unit 12; the treated flue gas inlet of the heat exchange unit 9 is connected to the outlet of the flue gas treatment unit 12; the treated flue gas outlet of the heat exchange unit 9 is connected to the treated flue gas inlet of the coal oxygen-enriched combustion unit 10. The heat exchange unit 9 uses the flue gas heat discharged by the coal oxygen-enriched combustion unit 10 to preheat the oxygen and the flue gas after the flue gas treatment to meet the intake temperature requirement of the coal oxygen-enriched combustion unit 10.

[0076] The coal oxygen-enriched combustion unit 10 is connected to the heat exchange unit 9 and the power generation unit 11 respectively, and is used to receive and utilize the purified oxygen and part of the treated flue gas to perform coal oxygen-enriched combustion, and transmit the generated heat to the power generation unit 11;

[0077] Specifically, the oxygen inlet of the coal oxygen-enriched combustion unit 10 is connected to the oxygen outlet of the heat exchange unit 9, the treated flue gas inlet of the coal oxygen-enriched combustion unit 10 is connected to the treated flue gas outlet of the heat exchange unit 9, and the flue gas outlet of the coal oxygen-enriched combustion unit 10 is connected to the flue gas inlet of the heat exchange unit 9. The coal oxygen-enriched combustion unit 10 uses green electricity to electrolyze water to generate oxygen and treated flue gas for coal oxygen-enriched combustion, thereby increasing the CO2 content in flue gas carbon emissions, thereby facilitating CO2 capture from the flue gas, and the generated heat is supplied to the power generation unit 11.

[0078] The power generation unit 11 is connected to the coal oxygen-enriched combustion unit 10 and is used to receive heat and generate electricity according to the heat;

[0079] The flue gas treatment unit 12 is connected to the heat exchange unit 9 and the CO2 capture unit 13 respectively, and is used to treat the flue gas to obtain the treated flue gas;

[0080] Specifically, the flue gas inlet of the flue gas treatment unit 12 is connected to the flue gas outlet of the heat exchange unit 9, and the flue gas outlet of the flue gas treatment unit 12 is connected to the flue gas inlet of the CO2 capture unit 13 and the treated flue gas inlet of the heat exchange unit 9. The flue gas treatment unit 12 desulfurizes and condenses the flue gas to facilitate further CO2 capture.

[0081] The CO2 capture unit 13 is connected to the flue gas treatment unit 12, the CO2 hydrogenation unit 14 for producing methanol, ethanol and other chemicals, and the chimney, respectively, and is used to capture CO2 from another part of the treated flue gas and transmit it to the CO2 hydrogenation unit 14 for producing methanol, ethanol and other chemicals, and transmit the excess tail gas to the chimney;

[0082] Specifically, the flue gas inlet of the CO2 capture unit 13 is connected to the flue gas outlet of the flue gas treatment unit 12, the tail gas outlet of the CO2 capture unit 13 is discharged to the chimney, and the CO2 outlet of the CO2 capture unit 13 is connected to the CO2 inlet of the CO2 hydrogenation unit 14 for producing methanol, ethanol and other chemicals. The CO2 capture unit 13 captures CO2 in the flue gas and supplies it to the CO2 hydrogenation unit 14 for producing methanol, ethanol and other chemicals as a raw material.

[0083] The CO2 hydrogenation unit 14 for producing chemicals such as methanol and ethanol is respectively connected to the hydrogen separation and cooling unit 3 and the CO2 capture unit 13, and is used for receiving the treated hydrogen and the captured CO2 to prepare chemicals.

[0084] Specifically, the CO2 inlet of the CO2 hydrogenation unit 14 to produce methanol, ethanol and other chemicals is connected to the CO2 outlet of the CO2 capture unit 13. The CO2 hydrogenation unit 14 to produce methanol, ethanol and other chemicals uses the hydrogen prepared by electrolyzing water with green electricity and the CO2 captured from the flue gas generated by oxygen-enriched combustion of coal by the CO2 capture unit 13 as raw materials to prepare methanol.

[0085] In some optional embodiments, continue to refer to Figure 1 The chemical preparation system 1 of coal oxygen-enriched combustion coupled with water electrolysis technology provided in this embodiment also includes:

[0086] The alkali solution filtering circulation unit 6 is respectively connected to the hydrogen separation cooling unit 3, the oxygen separation cooling unit 5, and the alkali solution cooling unit 7, and is used to obtain the alkali solution removed by the hydrogen separation cooling unit 3 and the oxygen separation cooling unit 5, filter the alkali solution, and transmit the filtered alkali solution to the alkali solution cooling module;

[0087] Specifically, the alkali liquid inlet of the alkali liquid filtering circulation unit 6 is connected to the alkali liquid main pipe formed by the alkali liquid outlet of the hydrogen separation cooling unit 3 and the alkali liquid outlet of the oxygen separation cooling unit 5, and the alkali liquid outlet of the alkali liquid filtering circulation unit 6 is connected to the alkali liquid cooling unit 7. The alkali liquid filtering circulation unit 6 completes the forced circulation of the alkali liquid in the alkaline electrolyzer unit 2 and the hydrogen separation cooling unit 3 and the oxygen separation cooling unit 5, and can filter impurities in the alkali liquid.

[0088] The alkali solution cooling unit 7 is connected to the alkali solution filtering and circulating unit 6 and the alkaline electrolytic cell unit 2 , respectively, and is used to cool the filtered alkali solution to a temperature required by the alkaline electrolytic cell unit 2 , and transmit the cooled alkali solution to the alkaline electrolytic cell unit 2 .

[0089] Specifically, the alkali liquid inlet of the alkali liquid cooling unit 7 is connected to the alkali liquid outlet of the alkali liquid filtering circulation unit 6; the alkali liquid outlet of the alkali liquid cooling unit 7 is connected to the alkali liquid inlet of the alkali liquid electrolyzer unit. In the forced circulation of the alkali liquid, the alkali liquid cooling unit 7 cools the hot alkali liquid to meet the electrolysis temperature requirement of the electrolyzer.

[0090] In some optional embodiments, continue to refer to Figure 1 The chemical preparation system 1 of coal oxygen-enriched combustion coupled with water electrolysis technology provided in this embodiment also includes:

[0091] The fresh water supply unit 8 is connected to the hydrogen separation cooling unit 3 and the oxygen separation cooling unit 5 , respectively, and is used to provide fresh water to the alkaline electrolyzer unit 2 through the hydrogen separation cooling unit 3 and the oxygen separation cooling unit 5 .

[0092] Specifically, the fresh water outlet of the fresh water supply unit 8 is connected to the fresh water inlets of the hydrogen separation cooling unit 3 and the oxygen separation cooling unit 5 , and the fresh water supply unit 8 supplies the alkaline electrolytic cell 21 with raw fresh water for electrolysis.

[0093] In some optional embodiments, continue to refer to Figure 1 , the hydrogen separation and cooling unit 3 is connected to the CO2 hydrogenation unit 14 for producing methanol, ethanol and other chemicals through the hydrogen purification unit 4;

[0094] The hydrogen purification unit 4 is respectively connected to the hydrogen separation cooling unit 3 and the CO2 hydrogenation unit 14 for producing methanol, ethanol and other chemicals, and is used to purify the hydrogen treated by the hydrogen separation cooling unit 3 and transmit it to the CO2 hydrogenation unit 14 for producing methanol, ethanol and other chemicals.

[0095] Specifically, the hydrogen inlet of the hydrogen purification unit 4 is connected to the hydrogen outlet of the hydrogen separation and cooling unit 3; the hydrogen outlet of the hydrogen purification unit 4 is connected to the inlet of the CO2 hydrogenation unit 14 for producing methanol, ethanol and other chemicals. The hydrogen purification unit 4 removes oxygen, water and other impurities through catalytic reaction, molecular sieve adsorption and other principles, and finally purifies the hydrogen to 99.999%.

[0096] In some optional embodiments, referring to Figure 1 and Figure 2 , Figure 2 Another structural schematic diagram of the chemical preparation system of the coal oxygen-enriched combustion coupled with water electrolysis technology provided by the present invention, the alkaline electrolysis cell unit 2 includes an alkaline electrolysis cell 21, and the alkaline electrolysis cell 21 realizes the production of hydrogen and oxygen by electrolyzing water using green electricity;

[0097] The hydrogen separation cooling unit 3 comprises a hydrogen separation cooler 31, a hydrogen scrubber 32 and a hydrogen gas-liquid separator 33 connected in sequence, and the hydrogen separation cooler 31 is connected to the alkaline electrolyzer 21;

[0098] The oxygen separation cooling unit 5 includes an oxygen separation cooler 51, an oxygen scrubber 52, an oxygen liquid separator 53, a first regulating valve 55 and a pressure transmitter 54 connected end to end, and the oxygen separation cooler 51 is connected to the alkaline electrolytic cell 21;

[0099] Specifically, the oxygen-liquid separator 53 realizes the gas-liquid separation and cooling functions of oxygen and alkali liquid, and the pressure transmitter 54 is the pressure transmitter 54 of the oxygen separation cooler 51, which is used to adjust the opening of the first regulating valve 55 through pressure setting to achieve the system pressure being stable at the set value.

[0100] The hydrogen purification unit 4 includes a hydrogen purification tower 41, a second regulating valve 42 and a hydrogen buffer tank 44 connected in sequence, the hydrogen purification tower 41 is connected to the hydrogen gas-liquid separator 33; and also includes a liquid level difference transmitter 43, which is respectively connected to the hydrogen separation cooler 31, the oxygen separation cooler 51 and the second regulating valve 42;

[0101] Specifically, the liquid level difference transmitter 43 is a liquid level difference transmitter of the hydrogen separation cooler 31 and the oxygen separation cooler 51 , and is used to control the opening of the second regulating valve 42 , thereby maintaining liquid level balance between the hydrogen separation cooler 31 and the oxygen separation cooler 51 .

[0102] The heat exchange unit 9 includes a first heat exchanger 91, a flow regulating valve 93 and a first induced draft fan 94 connected in sequence, wherein the first heat exchanger 91 is connected to the first regulating valve 55; and further includes a second induced draft fan 92 connected to the first heat exchanger 91;

[0103] Specifically, the second induced draft fan 92 is used to transport the flue gas, the flow regulating valve 93 can control the flow of the treated flue gas entering the heat exchanger, and the first induced draft fan 94 is used to transport the treated flue gas.

[0104] The coal oxygen-enriched combustion unit 10 comprises a coal oxygen-enriched combustion boiler module 101 and a dust collector 102 connected to each other, wherein the coal oxygen-enriched combustion boiler module 101 is connected to the first heat exchanger 91, and the dust collector 102 is connected to the second induced draft fan 92;

[0105] Specifically, the dust collector 102 performs dust removal on the flue gas.

[0106] The power generation unit 11 includes a steam turbine generator 111, which is connected to the coal-oxygen combustion boiler module 101 to realize the steam power generation function;

[0107] The flue gas treatment unit 12 includes a booster fan 121, a desulfurization tower 122 and a condenser 123 connected in sequence, the booster fan 121 is connected to the first heat exchanger 91, and the condenser 123 is connected to the first induced draft fan 94;

[0108] Specifically, the booster fan 121 provides power for transporting the treated flue gas, and the desulfurization tower 122 and the condenser 123 desulfurize and cool the treated flue gas.

[0109] The CO2 capture unit 13 includes an absorption tower 131, a rich liquid pump 132, a second heat exchanger 133, a desorption tower, a cooler 136 and a separator 137 connected in sequence, the absorption tower 131 is connected to the condenser 123 and the chimney respectively; and also includes a lean liquid pump 134, which is connected to the second heat exchanger 133 and the chimney respectively;

[0110] Specifically, the absorption tower 131 absorbs CO2 in the treated flue gas, and the rich liquid pump 132 preheats the liquid containing a large amount of CO2 through a heat exchanger and then transports it to the analysis tower 135 for analysis. The analyzed CO2 is cooled by the cooler 136 and then enters the separator 137 for further separation to obtain high-purity CO2. The lean liquid pump 134 is used to extract the liquid containing trace amounts of CO2 from the analysis tower 135 and transport it to the absorption tower 131 after being cooled by the heat exchanger.

[0111] The CO2 hydrogenation unit 14 for producing methanol, ethanol and other chemicals includes a hydrogen booster pump 141, a methanol, ethanol and other chemical synthesis tower 142 and a buffer tank 144 connected in sequence, and the hydrogen booster pump 141 is connected to the hydrogen buffer tank 44; it also includes a CO2 booster pump 143, which is respectively connected to the methanol, ethanol and other chemical synthesis tower 142 and the separator 137.

[0112] Specifically, the hydrogen booster pump 143 is used to pressurize high-purity hydrogen as required and transport it to the methanol, ethanol and other chemical synthesis tower 142. The CO2 booster pump 143 is used to pressurize high-purity CO2 gas as required and transport it to the methanol, ethanol and other chemical synthesis tower 142. The methanol, ethanol and other chemical synthesis tower 142 uses high-purity hydrogen and CO2 to synthesize methanol, ethanol and other chemicals. The synthesized methanol, ethanol and other chemicals enter the buffer tank 144 and can then be exported.

[0113] In some optional embodiments, continue to refer to Figure 1 and Figure 2 The chemical preparation system 1 of coal oxygen-enriched combustion coupled with water electrolysis technology provided in this embodiment also includes:

[0114] The alkali solution filtering circulation unit 6 is connected to the hydrogen separation cooling unit 3, the oxygen separation cooling unit 5 and the alkali solution cooling unit 7 respectively. The alkali solution filtering circulation unit 6 provides power for alkali solution circulation and filters impurities.

[0115] The alkali solution cooling unit 7 is connected to the alkali solution filtering and circulating unit 6 and the alkaline electrolytic cell unit 2 respectively;

[0116] The alkali solution filtering circulation unit 6 comprises an alkali solution filter 61 and an alkali solution circulation pump 62 connected to each other, and the alkali solution filter 61 is connected to the hydrogen separation cooler 31 and the oxygen separation cooler 51 respectively;

[0117] The alkali solution cooling unit 7 comprises an alkali solution cooler 71 , and the alkali solution cooler 71 is connected to the alkali solution circulation pump 62 and the alkaline electrolytic cell 21 respectively.

[0118] In some optional embodiments, continue to refer to Figure 1 and Figure 2 The chemical preparation system 1 of coal oxygen-enriched combustion coupled with water electrolysis technology provided in this embodiment also includes:

[0119] The fresh water supply unit 8 is connected to the hydrogen separation cooling unit 3 and the oxygen separation cooling unit 5 respectively, and the fresh water supply unit 8 replenishes the electrolytic water raw material for the alkaline electrolytic cell 21;

[0120] The fresh water supply unit 8 includes a fresh water tank 81 and a water replenishment metering pump 82 which are connected to each other. The water replenishment metering pump 82 is connected to the hydrogen scrubbing tower 32 and the oxygen scrubbing tower 52 respectively.

[0121] Based on the same inventive concept, the present invention also provides a specific embodiment of a method for preparing chemicals using coal oxygen-enriched combustion coupled with electrolytic water technology. A chemical preparation system 1 using coal oxygen-enriched combustion coupled with electrolytic water technology using any of the above embodiments comprises:

[0122] The alkaline electrolyzer unit 2 decomposes the fresh water inside it into hydrogen and oxygen, transmits the hydrogen to the hydrogen separation cooling unit 3, and transmits the oxygen to the oxygen separation cooling unit 5;

[0123] The hydrogen separation and cooling unit 3 receives hydrogen, removes impurities contained in the hydrogen to obtain treated hydrogen, and transmits the treated hydrogen to the CO2 hydrogenation unit 14 for producing chemicals such as methanol and ethanol;

[0124] The oxygen separation cooling unit 5 receives oxygen, removes impurities contained in the oxygen to obtain purified oxygen, and transmits the purified oxygen to the heat exchange unit 9;

[0125] The heat exchange unit 9 receives the purified oxygen and transmits it to the coal oxygen-enriched combustion unit 10, receives the flue gas generated by the coal oxygen-enriched combustion unit 10 and transmits it to the flue gas treatment unit 12, and the flue gas treatment unit 12 treats the flue gas to obtain treated flue gas;

[0126] The heat exchange unit 9 receives part of the flue gas treated by the flue gas treatment unit 12 and transmits it to the coal oxygen-enriched combustion unit 10, and uses the flue gas generated by the coal oxygen-enriched combustion unit 10 to preheat the purified oxygen and the treated flue gas;

[0127] The coal oxygen-enriched combustion unit 10 receives and utilizes the purified oxygen and part of the treated flue gas to perform coal oxygen-enriched combustion, and transmits the generated heat to the power generation unit 11;

[0128] The power generation unit 11 receives the heat and generates electricity according to the heat;

[0129] The CO2 capture unit 13 captures CO2 from another part of the treated flue gas and transmits it to the CO2 hydrogenation unit 14 to produce methanol, ethanol and other chemicals, and transmits the excess tail gas to the chimney;

[0130] The CO2 hydrogenation unit 14 for producing chemicals such as methanol and ethanol receives the processed hydrogen and the captured CO2 to prepare chemicals.

[0131] The present invention can not only utilize the CO2 captured in the flue gas of oxygen-enriched combustion of coal as a resource through the coupling of green electricity, oxygen-enriched combustion of coal, and alkaline electrolysis of water technology, but also use the hydrogen prepared by electrolysis of water with green electricity to hydrogenate CO2 to produce methanol, ethanol and other chemicals. At the same time, the oxygen generated in the process of electrolysis of water by green electricity can be supplied to the coal combustion unit to meet the conditions of oxygen-enriched combustion. Therefore, the present invention can not only greatly reduce the carbon emissions of the coal combustion unit, but also realize the oxygen-enriched combustion of the coal combustion unit, and can prepare green methanol, ethanol and other chemicals that are easier to store and transport than hydrogen. The methanol, ethanol and other chemical preparation systems that use oxygen-enriched combustion of coal coupled with electrolysis of water technology can be arranged near coal-using enterprises such as thermal power plants or areas with abundant green electricity, which is conducive to the nearby consumption of green electricity and emitted CO2.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A chemical preparation system using coal oxygen-enriched combustion coupled with water electrolysis technology, characterized in that: include: The alkaline electrolyzer unit is connected to the hydrogen separation cooling unit and the oxygen separation cooling unit, respectively, and is used to decompose the fresh water therein into hydrogen and oxygen, and transmit the hydrogen to the hydrogen separation cooling unit and transmit the oxygen to the oxygen separation cooling unit; The hydrogen separation and cooling unit is respectively connected to the alkaline electrolyzer unit and the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals, and is used to receive the hydrogen, remove impurities contained in the hydrogen to obtain the treated hydrogen, and transmit the treated hydrogen to the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals; The oxygen separation and cooling unit is connected to the alkaline electrolyzer unit and the heat exchange unit respectively, and is used to receive the oxygen, remove impurities contained in the oxygen to obtain the purified oxygen, and transmit the purified oxygen to the heat exchange unit; The heat exchange unit is connected to the oxygen separation and cooling unit, the coal oxygen-enriched combustion unit, and the flue gas treatment unit, respectively, and is used to receive the purified oxygen and transmit it to the coal oxygen-enriched combustion unit, receive the flue gas generated by the coal oxygen-enriched combustion unit and transmit it to the flue gas treatment unit, receive the flue gas partially treated by the flue gas treatment unit and transmit it to the coal oxygen-enriched combustion unit, and use the flue gas generated by the coal oxygen-enriched combustion unit to preheat the purified oxygen and the treated flue gas; The coal oxygen-enriched combustion unit is connected to the heat exchange unit and the power generation unit respectively, and is used to receive and utilize the purified oxygen and the partially treated flue gas to perform coal oxygen-enriched combustion, and transmit the generated heat to the power generation unit; The power generation unit is connected to the coal oxygen-enriched combustion unit and is used to receive the heat and generate electricity based on the heat; The flue gas treatment unit is connected to the heat exchange unit and the CO2 capture unit respectively, and is used to treat the flue gas after the flue gas is treated; The CO2 capture unit is connected to the flue gas treatment unit, the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals, and the chimney, respectively, and is used to capture CO2 from another part of the treated flue gas and transmit it to the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals, and transmit the excess tail gas to the chimney; The CO2 hydrogenation unit for producing chemicals such as methanol and ethanol is respectively connected to the hydrogen separation and cooling unit and the CO2 capture unit, and is used to receive the processed hydrogen and the captured CO2 to prepare chemicals.

2. The chemical preparation system of coal oxygen-enriched combustion coupled with water electrolysis technology according to claim 1 is characterized in that: Also includes: an alkali solution filtering circulation unit, connected to the hydrogen separation cooling unit, the oxygen separation cooling unit, and the alkali solution cooling unit, respectively, for obtaining the alkali solution removed by the hydrogen separation cooling unit and the oxygen separation cooling unit, filtering the alkali solution, and transmitting the filtered alkali solution to the alkali solution cooling module; The alkali solution cooling unit is connected to the alkali solution filtering and circulating unit and the alkaline electrolytic cell unit respectively, and is used to cool the filtered alkali solution to the required temperature of the alkaline electrolytic cell unit, and transmit the cooled alkali solution to the alkaline electrolytic cell unit.

3. The chemical preparation system of coal oxygen-enriched combustion coupled with water electrolysis technology according to claim 1 or 2, characterized in that: Also includes: A fresh water supply unit is connected to the hydrogen separation cooling unit and the oxygen separation cooling unit, respectively, and is used to provide fresh water to the alkaline electrolyzer unit through the hydrogen separation cooling unit and the oxygen separation cooling unit.

4. The chemical preparation system of coal oxygen-enriched combustion coupled with water electrolysis technology according to claim 1 is characterized in that: The hydrogen separation and cooling unit is connected to the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals through a hydrogen purification unit; The hydrogen purification unit is respectively connected to the hydrogen separation cooling unit and the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals, and is used to purify the hydrogen after being processed by the hydrogen separation cooling unit and transmit it to the CO2 hydrogenation unit for producing methanol, ethanol and other chemicals.

5. The chemical preparation system of coal oxygen-enriched combustion coupled with water electrolysis technology according to claim 4 is characterized in that: The alkaline electrolytic cell unit comprises an alkaline electrolytic cell; The hydrogen separation cooling unit comprises a hydrogen separation cooler, a hydrogen scrubber and a hydrogen gas-liquid separator connected in sequence, wherein the hydrogen separation cooler is connected to the alkaline electrolyzer; The oxygen separation cooling unit comprises an oxygen separation cooler, an oxygen scrubber, an oxygen liquid separator, a first regulating valve and a pressure transmitter connected end to end, and the oxygen separation cooler is connected to the alkaline electrolyzer; The hydrogen purification unit comprises a hydrogen purification tower, a second regulating valve and a hydrogen buffer tank connected in sequence, wherein the hydrogen purification tower is connected to the hydrogen gas-liquid separator; and further comprises a liquid level difference transmitter, which is respectively connected to the hydrogen separation cooler, the oxygen separation cooler and the second regulating valve; The heat exchange unit comprises a first heat exchanger, a flow regulating valve and a first induced draft fan connected in sequence, wherein the first heat exchanger is connected to the first regulating valve; and further comprises a second induced draft fan connected to the first heat exchanger; The coal-oxygen combustion unit comprises a coal-oxygen combustion boiler module and a dust collector connected to each other, wherein the coal-oxygen combustion boiler module is connected to the first heat exchanger, and the dust collector is connected to the second induced draft fan; The power generation unit includes a steam turbine generator connected to the coal-oxygen combustion boiler module; The flue gas treatment unit comprises a booster fan, a desulfurization tower and a condenser connected in sequence, the booster fan is connected to the first heat exchanger, and the condenser is connected to the first induced draft fan; The CO2 capture unit comprises an absorption tower, a rich liquid pump, a second heat exchanger, a desorption tower, a cooler and a separator connected in sequence, wherein the absorption tower is connected to the condenser and the chimney respectively; and further comprises a lean liquid pump, which is connected to the second heat exchanger and the chimney respectively; The CO2 hydrogenation unit for producing methanol, ethanol and other chemicals includes a hydrogen booster pump, a methanol, ethanol and other chemical synthesis tower and a buffer tank connected in sequence, wherein the hydrogen booster pump is connected to the hydrogen buffer tank; and also includes a CO2 booster pump, which is respectively connected to the methanol, ethanol and other chemical synthesis tower and the separator.

6. The chemical preparation system of coal oxygen-enriched combustion coupled with water electrolysis technology according to claim 5 is characterized in that: Also includes: an alkali solution filtering circulation unit, connected to the hydrogen separation cooling unit, the oxygen separation cooling unit, and the alkali solution cooling unit respectively; The alkali solution cooling unit is connected to the alkali solution filtering and circulating unit and the alkaline electrolytic cell unit respectively; The alkali solution filtering circulation unit comprises an alkali solution filter and an alkali solution circulation pump connected to each other, and the alkali solution filter is connected to the hydrogen separation cooler and the oxygen separation cooler respectively; The alkali solution cooling unit comprises an alkali solution cooler, and the alkali solution cooler is connected to the alkali solution circulation pump and the alkaline electrolytic cell respectively.

7. The chemical preparation system of coal oxygen-enriched combustion coupled with water electrolysis technology according to claim 5 is characterized in that: Also includes: a fresh water supply unit, connected to the hydrogen separation cooling unit and the oxygen separation cooling unit respectively; The fresh water supply unit comprises a fresh water tank and a water replenishment metering pump connected to each other, and the water replenishment metering pump is connected to the hydrogen scrubbing tower and the oxygen scrubbing tower respectively.

8. A method for preparing chemicals by coupling coal oxygen-enriched combustion with water electrolysis technology, characterized in that: A chemical preparation system using the coal oxygen-enriched combustion coupled with water electrolysis technology according to any one of claims 1 to 7, comprising: The alkaline electrolyzer unit decomposes the fresh water therein into hydrogen and oxygen, transmits the hydrogen to the hydrogen separation cooling unit, and transmits the oxygen to the oxygen separation cooling unit; The hydrogen separation and cooling unit receives the hydrogen, removes impurities contained in the hydrogen to obtain the treated hydrogen, and transmits the treated hydrogen to the CO2 hydrogenation unit to produce methanol, ethanol and other chemicals; The oxygen separation and cooling unit receives the oxygen, removes impurities contained in the oxygen to obtain the purified oxygen, and transmits the purified oxygen to the heat exchange unit; The heat exchange unit receives the purified oxygen and transmits it to the coal oxygen-enriched combustion unit, receives the flue gas generated by the coal oxygen-enriched combustion unit and transmits it to the flue gas treatment unit, and the flue gas treatment unit processes the flue gas to obtain the treated flue gas; The heat exchange unit receives the flue gas partially treated by the flue gas treatment unit and transmits it to the coal oxygen-enriched combustion unit, and uses the flue gas generated by the coal oxygen-enriched combustion unit to preheat the purified oxygen and the treated flue gas; The coal oxygen-enriched combustion unit receives and utilizes the purified oxygen and the partially treated flue gas to perform coal oxygen-enriched combustion, and transmits the generated heat to the power generation unit; The power generation unit receives the heat and generates electricity according to the heat; The CO2 capture unit captures CO2 from the flue gas after another part of the treatment and transmits it to the CO2 hydrogenation unit to produce methanol, ethanol and other chemicals, and transmits the excess tail gas to the chimney; The CO2 hydrogenation unit for producing chemicals such as methanol and ethanol receives the processed hydrogen and the captured CO2 to prepare chemicals.

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