Supercritical CO2 and organic Rankine cycle coupled green coal-to-methanol preparation system and preparation method

Abstract

The invention relates to a green coal-to-methanol preparation system coupled with supercritical CO2 and organic Rankine cycle and a preparation method thereof.The system comprises an electrolytic bath, a gasification furnace, a combustion furnace, a reaction furnace, a heat exchanger, a turbine, a generator, a condenser, a compressor and the like, and effective utilization of heat energy and generation of electric energy are achieved through supercritical CO2 cycle and organic Rankine cycle; and the generated electric energy is used in the methanol preparation process, so that the purpose of efficiently utilizing green energy is achieved. By means of the scheme, efficient storage and utilization of green energy are achieved, energy waste is reduced, meanwhile, recycling of carbon dioxide is achieved, and environmental protection is facilitated. In addition, the energy utilization efficiency of the system is further improved through turbine acting and organic Rankine cycle.

Description

Technical Field

[0001] The present invention relates to the technical field of green energy storage, and specifically to a green coal-to-methanol preparation system and preparation method coupling supercritical CO2 and organic Rankine cycle. Background Art

[0002] With the proposal of "carbon peak and carbon neutrality" in my country, vigorously developing renewable energy has become the main means to solve my country's energy security and environmental pollution problems. However, renewable energy, especially wind power and photovoltaic power generation, is greatly affected by natural conditions and has obvious unfavorable factors such as volatility, periodicity and uncertainty. Its large-scale grid connection not only brings unprecedented challenges to the power grid system, but also causes huge energy waste. Energy storage technology can store abandoned wind and light, and release energy to generate electricity when wind and light are insufficient. It is a key technology to solve the large-scale consumption and stable output of renewable energy and improve the efficiency and safety of the power system.

[0003] Therefore, there is an urgent need to develop a process that can convert wind and solar power abandonment into other forms of energy storage to solve the above problems. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a green coal-to-methanol preparation system and preparation method that couples supercritical CO2 and organic Rankine cycle, relying on green energy such as wind and solar energy to produce clean energy, so as to achieve the purpose of cross-regional and cross-seasonal energy storage.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a green coal-to-methanol preparation system coupling supercritical CO2 and organic Rankine cycle, comprising an electrolytic cell, the electrolytic cell is connected to a reactor through a hydrogen delivery pipeline, and the reactor is connected to a methanol storage tank; The electrolytic cell is also connected to the combustion furnace through an oxygen delivery pipeline. The combustion furnace is provided with a pipeline connected to the heat exchanger. The heat exchanger is connected to the second condenser through a pipeline. The second condenser is connected to the fourth condenser through a pipeline. The fourth condenser is provided with a pipeline connected to the reaction furnace and a pipeline connected to the combustion furnace.

[0006] In a preferred solution, the oxygen delivery pipeline on the electrolyzer is divided into two output ends, and the two output ends are respectively connected to the gasification furnace and the combustion furnace; Adding raw coal into the gasifier; The gasifier is also connected to the combustion furnace.

[0007] In a preferred embodiment, the heat exchanger is connected to the first turbine through a pipeline, the first turbine is connected to the regenerator through a pipeline, the regenerator is connected to the first compressor through a pipeline, the first compressor pipeline is connected to the regenerator, and the regenerator is connected to the heat exchanger through a pipeline; The heat exchanger, the first turbine, the regenerator and the first compressor form a supercritical CO2 circulation loop.

[0008] In a preferred embodiment, the first turbine is connected to a first generator.

[0009] In a preferred solution, a first condenser is provided on the connecting pipe between the regenerator and the first compressor, the first condenser is connected to the second condenser through a pipe, the second condenser is connected to the second turbine through a pipe, the second turbine is connected to the third condenser through a pipe, the third condenser is connected to the liquid storage tank through a pipe, the liquid storage tank is connected to the second compressor through a pipe, and the second compressor is connected to the first condenser through a pipe; The first condenser, the second condenser, the second turbine, the third condenser, the liquid storage tank and the second compressor form an organic Rankine cycle loop.

[0010] In a preferred embodiment, the second turbine is connected to a second generator.

[0011] In a preferred embodiment, the energy source of the electrolytic cell is electricity generated by wind and solar power generation.

[0012] In a preferred solution, the electric energy generated by the first generator and the second generator is used as energy for the reaction in the reactor to carry out methanol reaction.

[0013] The preparation method of the green coal-to-methanol preparation system based on the above-mentioned coupling supercritical CO2 and organic Rankine cycle comprises the following steps: 1) The electricity generated by wind and solar power is used to supply energy to the electrolyzer for water electrolysis to produce H2 and O2; 2) The H2 produced in the electrolyzer is transported to the reactor, reacts with the CO2 condensed by the fourth condenser in the reactor to produce methanol, and then is transported to the methanol storage tank for storage; 3) Part of the O2 produced in the electrolyzer is transported to the gasifier as a gasifying agent, and produces synthesis gas with the raw coal and enters the combustion furnace; 4) Part of the O2 produced in the electrolyzer directly enters the combustion furnace, reacts with the synthesis gas and burns to form a mixed gas of CO2 and water vapor; 5) The formed mixed gas part enters the heat exchanger and joins the turbine work stage; 6) Another part of the formed mixed gas is added to the organic Rankine cycle; 7) The remaining part of the mixed gas is sent to the fourth condenser to be condensed into water and CO2, and the CO2 separated from the water is sent to the reactor for methanol preparation reaction.

[0014] In a preferred embodiment, in the turbine working stage in step 5), the supercritical CO2 drives the first generator to generate electricity through the first turbine and then enters the regenerator. After the regenerator heats the supercritical CO2 to a preset temperature, the pressure of the gas is increased by the first compressor, and the low-temperature and low-pressure gas is compressed into a high-temperature and high-pressure gas to realize circulation; In the organic Rankine cycle in step 6), the gas after passing through the second condenser is used as a working medium to pass through the second turbine to drive the second generator to generate electricity, and then passes through the third condenser, the liquid storage tank, and the second compressor for recycling to realize the organic Rankine cycle.

[0015] The present invention provides a system and method for adjusting the force of a thrust bearing of a hydro-turbine generator applicable to a support bolt support structure. By adopting the method and system, the following beneficial effects are achieved: (1) It has realized the production of clean energy such as methanol from green energy such as wind energy and solar energy, achieving the purpose of cross-regional and cross-season energy storage; (2) The supercritical carbon dioxide cycle and organic Rankine cycle are used to achieve heat recovery and high-efficiency utilization of low-temperature heat sources, and only condensed water is discharged, realizing the recycling of carbon dioxide and achieving the goal of zero carbon dioxide emissions; (3) Supercritical carbon dioxide is used to drive a generator through a turbine to generate electricity, and the generated electricity is used for the reaction in the reactor. The waste heat discharged by the turbine is recovered, which effectively reduces the energy loss of the system, greatly reduces the construction cost, and improves the operating economy of the system and the energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 It is a schematic diagram of the overall structure of the present invention. DETAILED DESCRIPTION

[0017] Embodiment 1: A green coal-to-methanol production system coupled with supercritical CO2 and organic Rankine cycle, comprising an electrolytic cell 1, the electrolytic cell 1 is connected to a reactor 2 via a hydrogen delivery pipeline, and the reactor 2 is connected to a methanol storage tank 18; The electrolytic cell 1 is also connected to the combustion furnace 4 through an oxygen delivery pipeline. The combustion furnace 4 is provided with a pipeline connected to the heat exchanger 5. The heat exchanger 5 is connected to the second condenser 11 through a pipeline. The second condenser 11 is connected to the fourth condenser 17 through a pipeline. The fourth condenser 17 is provided with a pipeline connected to the reaction furnace 2 and a pipeline connected to the combustion furnace 4.

[0018] In a preferred solution, the oxygen delivery pipeline on the electrolytic cell 1 is divided into two output ends, and the two output ends are respectively connected to the gasification furnace 3 and the combustion furnace 4; Adding raw coal into the gasifier 3; The gasification furnace 3 is also connected to the combustion furnace 4 .

[0019] In a preferred solution, the heat exchanger 5 is connected to the first turbine 6 through a pipeline, the first turbine 6 is connected to the regenerator 8 through a pipeline, the regenerator 8 is connected to the first compressor 9 through a pipeline, the first compressor 9 is connected to the regenerator 8 through a pipeline, and the regenerator 8 is connected to the heat exchanger 5 through a pipeline; The heat exchanger 5, the first turbine 6, the regenerator 8 and the first compressor 9 form a supercritical CO2 circulation loop.

[0020] In a preferred solution, the first turbine 6 is connected to a first generator 7 .

[0021] In a preferred solution, a first condenser 10 is provided on the connecting pipe between the regenerator 8 and the first compressor 9, the first condenser 10 is connected to the second condenser 11 through a pipe, the second condenser 11 is connected to the second turbine 12 through a pipe, the second turbine 12 is connected to the third condenser 14 through a pipe, the third condenser 14 is connected to the liquid storage tank 15 through a pipe, the liquid storage tank 15 is connected to the second compressor 16 through a pipe, and the second compressor 16 is connected to the first condenser 10 through a pipe; The first condenser 10, the second condenser 11, the second turbine 12, the third condenser 14, the liquid storage tank 15 and the second compressor 16 form an organic Rankine cycle loop.

[0022] In a preferred solution, the second turbine 12 is connected to a second generator 13 .

[0023] In a preferred solution, the energy source of the electrolytic cell 1 is the electric energy generated by wind and solar power generation.

[0024] In a preferred solution, the electric energy generated by the first generator 7 and the second generator 13 is used as energy for the reaction in the reactor 2 to carry out methanol reaction.

[0025] Embodiment 2: The preparation method of the green coal-to-methanol preparation system coupled with supercritical CO2 and organic Rankine cycle described in Example 1 specifically comprises the following steps: 1) The electricity generated by wind and solar power generation supplies energy to the electrolyzer 1 to electrolyze water to produce H2 and O2; 2) The H2 produced in the electrolytic cell 1 is transported to the reactor 2, reacts with the CO2 condensed by the fourth condenser 17 in the reactor 2 to produce methanol, and then is transported to the methanol storage tank 18 for storage; 3) Part of the O2 produced in the electrolytic cell 1 is transported to the gasifier 3 as a gasifying agent, and produces synthesis gas with the raw coal and enters the combustion furnace 4; 4) Part of the O2 produced in the electrolytic cell 1 directly enters the combustion furnace 4, reacts with the synthesis gas and burns to form a mixed gas of CO2 and water vapor; 5) The formed mixed gas part enters the heat exchanger 5 and joins the turbine work stage; 6) Another part of the formed mixed gas is added to the organic Rankine cycle; 7) The remaining part of the mixed gas is sent to the fourth condenser 17 to be condensed into water and CO2, and the CO2 separated from the water is sent to the reaction furnace 2 to perform methanol preparation reaction.

[0026] In the above system and method, in the green methanol production stage, green energy is used as the power source in the electrolyzer 1 to decompose water into hydrogen and oxygen. The hydrogen is transported to the reactor 2 and reacts with the carbon dioxide condensed by the fourth condenser 17 in the reactor 2 to produce methanol, and the methanol is collected in the storage tank 18 to end.

[0027] In the oxygen-rich combustion stage, the pure oxygen produced in the electrolytic cell 1 is used as a gasifying agent and the synthesis gas produced by the gasification of coal in the gasifier 3 enters the combustion furnace 4. The electrolytic cell 1 produces sufficient oxygen and is introduced into the high-temperature and high-pressure combustion furnace 4. The synthesis gas reacts with sufficient oxygen and burns to generate carbon dioxide and water vapor.

[0028] In the turbine working stage, supercritical CO2 is used as the energy storage medium, and the energy in the medium is converted into mechanical energy through the first turbine 6 to drive the first generator 7 to generate electricity. The electric energy generated by the first generator 7 is used as the energy source for the reaction of the reactor 2, thus realizing the efficient utilization of energy. The excellent thermodynamic properties and environmentally friendly characteristics of supercritical CO2 not only improve the overall efficiency of the system and enhance the sustainability of the system, but also help to achieve more efficient energy storage, which is of great significance for promoting the development of sustainable energy solutions.

[0029] In the organic Rankine cycle stage, the gas after passing through the second condenser 11 is used as a working fluid to pass through the second turbine 12 to drive the second generator 13 to generate electricity (the electric energy generated by the second generator 13 is used as the energy for the reaction of the reactor 2), and then passes through the third condenser 14, the liquid storage tank 15, the compressor 216, etc. for recycling to realize the organic Rankine cycle.

Claims

1. A green coal-to-methanol production system coupling supercritical CO2 and organic Rankine cycle, characterized by: The electrolytic cell (1) is connected to a reaction furnace (2) via a hydrogen delivery pipeline, and the reaction furnace (2) is connected to a methanol storage tank (18); The electrolytic cell (1) is also connected to the combustion furnace (4) via an oxygen delivery pipeline. The combustion furnace (4) is provided with a pipeline connected to the heat exchanger (5). The heat exchanger (5) is connected to the second condenser (11) via a pipeline. The second condenser (11) is connected to the fourth condenser (17) via a pipeline. The fourth condenser (17) is provided with a pipeline connected to the reaction furnace (2) and a pipeline connected to the combustion furnace (4).

2. A green coal-to-methanol production system coupling supercritical CO2 and organic Rankine cycle according to claim 1, characterized in that: The oxygen delivery pipeline on the electrolytic cell (1) is divided into two output ends, and the two output ends are respectively connected to the gasification furnace (3) and the combustion furnace (4); Adding raw coal into the gasifier (3); The gasifier (3) is also connected to the combustion furnace (4).

3. A green coal-to-methanol production system coupling supercritical CO2 and organic Rankine cycle according to claim 1, characterized in that: The heat exchanger (5) is connected to the first turbine (6) through a pipeline, the first turbine (6) is connected to the regenerator (8) through a pipeline, the regenerator (8) is connected to the first compressor (9) through a pipeline, the first compressor (9) is connected to the regenerator (8) through a pipeline, and the regenerator (8) is connected to the heat exchanger (5) through a pipeline; The heat exchanger (5), the first turbine (6), the regenerator (8) and the first compressor (9) form a supercritical CO2 circulation loop.

4. A green coal-to-methanol production system coupling supercritical CO2 and organic Rankine cycle according to claim 3, characterized in that: The first turbine (6) is connected to a first generator (7).

5. A green coal-to-methanol production system coupling supercritical CO2 and organic Rankine cycle according to claim 4, characterized in that: A first condenser (10) is provided on the connecting pipe between the regenerator (8) and the first compressor (9); the first condenser (10) is connected to a second condenser (11) via a pipe; the second condenser (11) is connected to a second turbine (12) via a pipe; the second turbine (12) is connected to a third condenser (14) via a pipe; the third condenser (14) is connected to a liquid storage tank (15) via a pipe; the liquid storage tank (15) is connected to a second compressor (16) via a pipe; and the second compressor (16) is connected to the first condenser (10) via a pipe; The first condenser (10), the second condenser (11), the second turbine (12), the third condenser (14), the liquid storage tank (15) and the second compressor (16) form an organic Rankine cycle loop.

6. A green coal-to-methanol production system coupling supercritical CO2 and organic Rankine cycle according to claim 5, characterized in that: The second turbine (12) is connected to a second generator (13).

7. A green coal-to-methanol production system coupling supercritical CO2 and organic Rankine cycle according to claim 1, characterized in that: The energy source of the electrolytic cell (1) is the electric energy generated by wind and solar power generation.

8. A green coal-to-methanol production system coupling supercritical CO2 and organic Rankine cycle according to claim 6, characterized in that: The electric energy generated by the first generator (7) and the second generator (13) is used as energy for the reaction furnace (2) to carry out methanol reaction.

9. A method for preparing a green coal-to-methanol production system coupling supercritical CO2 and organic Rankine cycle according to any one of claims 1 to 8, characterized in that The following steps are involved: 1) The electricity generated by wind and solar power is used to supply energy to the electrolyzer (1) for water electrolysis to produce H2 and O2; 2) H2 generated in the electrolytic cell (1) is transported to the reaction furnace (2), reacts with CO2 condensed by the fourth condenser (17) in the reaction furnace (2) to produce methanol, and then is transported to the methanol storage tank (18) for storage; 3) Part of the O2 produced in the electrolytic cell (1) is transported to the gasifier (3) as a gasifying agent, and is combined with the raw coal to produce synthesis gas, which then enters the combustion furnace (4); 4) Part of the O2 generated in the electrolytic cell (1) directly enters the combustion furnace (4) to react with the synthesis gas and burn to form a mixed gas of CO2 and water vapor; 5) The resulting mixed gas part enters the heat exchanger (5) and joins the turbine power generation stage; 6) Another part of the formed mixed gas is added to the organic Rankine cycle; 7) The remaining part of the mixed gas is sent to the fourth condenser (17) to be condensed into water and CO2, and the CO2 separated from the water is sent to the reaction furnace (2) to carry out methanol preparation reaction.

10. The method for preparing a green coal-to-methanol preparation system based on coupling supercritical CO2 and organic Rankine cycle according to claim 9, characterized in that: In the turbine working stage in step 5), the supercritical CO2 drives the first generator (7) to generate electricity through the first turbine (6) and then enters the regenerator (8). The regenerator (8) heats the supercritical CO2 to a preset temperature and then increases the pressure of the gas by means of the first compressor (9). The low-temperature and low-pressure gas is compressed into a high-temperature and high-pressure gas to realize circulation; In the organic Rankine cycle in step 6), the gas after passing through the second condenser (11) is used as a working fluid to pass through the second turbine (12) to drive the second generator (13) to generate electricity, and then passes through the third condenser (14), the liquid storage tank (15), and the second compressor (16) for recycling, thereby realizing the organic Rankine cycle.

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