1. CO for chemical hydrogen production₂Zero release coal system methyl alcohol system, its characterized in that includes: air separation device for preparing oxygen, coal gasifier device for preparing high-temperature coarse gasification coal gas, synthesis gas purification device for preparing elemental sulfur, methanol synthesis and rectification device for synthesizing methanol and rectifying methanol, and device for preparing H₂H of S₂S preparation device and method for preparing SO₂SO of (A)₂A preparation device, a Bunsen reaction device for preparing sulfuric acid and hydrogen iodide and a HI decomposition device for preparing hydrogen and iodine,

the coal gasifier unit is in communication with the air separation unit to receive oxygen from the air separation unit;

the synthesis gas purification device is communicated with the HI decomposition device to receive low-temperature crude gasification gas from the HI decomposition device;

the methanol synthesis and rectification unit is in communication with the syngas purification unit to receive syngas from the syngas purification unit, and the methanol synthesis and rectification unit is in communication with the HI decomposition unit to receive hydrogen from the HI decomposition unit;

said H₂The S preparation device is communicated with the synthesis gas purification device to receive the elemental sulfur from the synthesis gas purification device; said H₂S preparation means is in communication with the HI decomposition means to receive hydrogen gas therefrom,

the SO₂Preparation apparatus and the same₂S preparation device connected to receive the said H₂S preparation of H of the apparatus₂S, the SO₂A preparation device is communicated with the Bunsen reaction device to receive sulfuric acid from the Bunsen reaction device;

the Bunsen reaction device and the SO₂A preparation device is communicated to receive the SO₂SO of preparation plant₂And water; the Bunsen reaction device is communicated with the HI decomposition device to receive iodine from the HI decomposition device;

the HI decomposition device is communicated with the Bunsen reaction device to receive HI from the Bunsen reaction device, and the HI decomposition device is communicated with the coal gasification furnace to receive high-temperature crude gasification coal gas from the coal gasification furnace.

2. CO for chemical hydrogen production₂The zero-emission coal-to-methanol method is characterized by comprising the following steps of:

s101: introducing air into an air separation device to prepare oxygen, introducing the oxygen and coal into a coal gasifier device to obtain high-temperature crude gasified coal gas, mixing the high-temperature crude gasified coal gas with a strand of low-temperature crude gasified coal gas which is divided after heat exchange is carried out on the high-temperature crude gasified coal gas and an HI decomposition device to obtain gasified coal gas, and introducing the gasified coal gas into the HI decomposition device to carry out heat exchange; introducing the other low-temperature crude gasified coal gas which is divided after the heat exchange of the HI decomposition device into a synthesis gas purification device to prepare elemental sulfur and purified synthesis gas, and introducing the elemental sulfur into H₂S preparation device prepares H₂S；

S102: mixing the clean synthesis gas prepared in the step S101 with the hydrogen prepared by the HI decomposition device to obtain synthesis gas, and introducing the synthesis gas into a methanol synthesis and rectification device to prepare methanol;

s103: introducing the hydrogen and the sulfur source prepared by the HI decomposition device into the H₂S preparation device for preparing H₂S；

S104: sulfuric acid is prepared and obtained through a Bunsen reaction device, and H₂S mixed and introduced into SO₂Preparation apparatus to obtain SO₂And water, the iodine prepared by the HI decomposition device is introduced into the Bunsen reaction device to prepare sulfuric acid and hydrogen iodide, the sulfuric acid is divided into two parts, the first part of sulfuric acid is taken as a product to be output, and the second part of sulfuric acid is introduced into the SO₂Preparing a device;

s105: introducing the HI prepared in the step S104 into the HI decomposition device to obtain hydrogen and iodine, dividing the hydrogen into two parts, wherein the first part of the hydrogen is used as a raw material in the step S102, and the second part of the hydrogen is used as a raw material and is introduced into the H₂And S, a preparation device, wherein iodine is introduced into the Bunsen reaction device for cyclic utilization.

3. CO for chemical hydrogen production according to claim 2₂The method for preparing methanol from zero-emission coal is characterized in that in the step S103, the sulfur source is at least one selected from iron disulfide, ferrous sulfide, iron trisulfide and sulfur.

4. CO for chemical production of hydrogen according to claim 2 or 3₂The zero-emission coal-to-methanol method is characterized in that, in the step S104, the molar ratio of the hydrogen sulfide to the sulfuric acid is 1: (2.8-3.2).

5. CO for chemical hydrogen production according to claim 4₂The zero-emission coal-to-methanol method is characterized in that, in the step S104, the molar ratio of the hydrogen sulfide to the sulfuric acid is 1: 3.

6. CO for chemical hydrogen production according to any of claims 2 to 5₂The zero-emission coal-to-methanol method is characterized in that in the step S104, the first part of sulfuric acid accounts for 1/5-1/3 of the total volume of the sulfuric acid.

7. CO for chemical production of hydrogen according to any of claims 2 to 6₂The zero-emission coal-to-methanol method is characterized in that in the step S104, the first part of sulfuric acid accounts for 1/4 of the total volume of the sulfuric acid.

8. CO for chemical production of hydrogen according to any of claims 2 to 7₂The zero-emission coal-to-methanol method is characterized in that in the step S105, the first part of hydrogen accounts for 5/8-7/8 of the total volume of hydrogen.

9. CO for chemical production of hydrogen according to any of claims 2 to 8₂The zero-emission coal-to-methanol method is characterized in that the CO produced by chemical hydrogen production₂The hydrogen production energy utilization rate of the zero-emission coal-to-methanol method is not lower than 50%.

10. The method of claim 1CO of chemical hydrogen production₂Zero emission coal to methanol system and/or chemically produced CO according to any of claims 2 to 9₂The zero-emission coal-to-methanol method is applied to the field of hydrogen production.

Background

The realization of carbon peak reaching and carbon neutralization is a hard layer, and under the aim of 'double carbon', the rise and decay of coal-based energy are related to various related plates at the upstream and downstream of coal, coal electricity and coal chemical industry, so that the influence is very heavy. Based on the natural energy resource of rich coal, poor oil and little gas in China, the modern coal chemical industry is developed under the dual constraints of ensuring the national energy safety and coping with climate change, the energy transformation development path with unique Chinese characteristics is taken, the clean and efficient comprehensive utilization of coal is favorably realized, the independent controllability of an industrial chain and a supply chain is realized, and the external dependence of petroleum is reduced.

Due to the structure and the reaction process of coal, more than 2-3 tons of carbon dioxide are discharged from 1 ton of coal, and high carbon is one of the main problems of long-term fouling of the coal chemical industry. Meanwhile, a series of measures aiming at the project policy of high energy consumption and high emission are intensively taken out recently, the source prevention of the ecological environment of the project of high energy consumption and high emission is enhanced, the green transformation of the industry is promoted, and the chemical industry belongs to the key attention industry; due to large scale and high total energy consumption of modern coal chemical engineering projects, although the energy efficiency reaches the world advanced level, the modern coal chemical engineering projects are difficult to pass energy-saving examination.

In this context, hydrogen energy is considered as an important pathway for achieving carbon neutralization, and is classified as a national strategy by a plurality of countries. Firstly, hydrogen energy is used as a raw material, and is used for reducing steel making by hydrogen to replace a reducing agent CO in the steel making process so as to reduce CO discharged in the coking process₂(ii) a Secondly, the method is used for synthesizing ammonia to replace coal gasification hydrogen production; thirdly, the hydrogen is used for petroleum refining and coal chemical production chemicals to replace coal gasification followed by water gas shift hydrogen production or natural gas reforming hydrogen production so as to reduce CO discharged in the shift or reforming process₂. Secondly, hydrogen energy is used as fuel to replace fossil energy to realize CO₂Emission reduction, namely cement calcination, heat supply and power generation; secondly, the fuel cell is used for traffic and power generation; and thirdly, the energy storage device is used for storing energy, so that the flexibility of a power system is enhanced, and the development of a higher proportion of renewable energy in an energy structure can be promoted.

According to the analysis, the hydrogen energy can promote the transformation and upgrading of the traditional fossil energy, and the fuel is completely transformed into the raw material. Carbon in fossil energy can be combined with hydrogen to form carbon-chemical basic raw materials of CO and H₂The method can be used for producing textile clothing, beverage bottles, packaging materials, degradable plastics, tires, safety airbags and other daily chemical products meeting daily requirements of human beings, so that carbon resources in fossil energy are fully utilized, and CO is realized₂And (4) zero emission. So that it is high-effective, large-scale, low-energy consumption and low-CO₂The discharged hydrogen production system and process are particularly important in realizing a carbon neutralization path.

Thermochemical iodine sulfur closed cycle hydrogen production is considered to be the most efficient process which can realize large-scale production. The iodine-sulfur closed cycle hydrogen production process mainly comprises the following three chemical reactions: bunsen reaction (Bunsen reaction) SO₂+I₂+2H₂O＝2HI+H₂SO₄，H₂SO₄Thermal decomposition reaction H₂SO₄＝H₂O+SO₂HI decomposition reaction 2HI ═ I₂+H₂. Wherein, the decomposition temperature of the sulfuric acid is about 850 ℃, the decomposition temperature of the hydrogen iodide is about 400 ℃, and a large amount of high-temperature heat sources are consumed. Because the fourth generation advanced nuclear energy technology, a high-temperature gas cooled reactor (outlet temperature is 700-950 ℃) and an ultra-high temperature gas cooled reactor (outlet temperature is more than 950 ℃) are the most ideal heat sources for hydrogen production by high-temperature electrolysis at present, hydrogen production by thermochemical iodine-sulfur closed cycle is generally related to nuclear hydrogen production. But is limited by the installed scale of nuclear power, and the total amount of hydrogen produced by thermochemical iodine-sulfur closed cycle hydrogen production related to nuclear power is difficult to meet the hydrogen demand under the carbon neutralization target.

Disclosure of Invention

The technical problem to be solved by the invention is to solve the existing problemsThe technical deficiency is to provide CO for chemically producing hydrogen₂Zero release coal system methyl alcohol system, the sensible heat that produces the high temperature gasification coal gas of coal gasifier and the required heat of hydrogen iodide thermal decomposition hydrogen manufacturing match, the demand of adjusting synthetic gas hydrogen carbon ratio is satisfied to the hydrogen of production, the water gas shift link of traditional coal chemical industry process has been saved, process flow has been simplified, greatly reduced the coal consumption and the energy consumption of system, coal gasifier and synthetic gas purifier scale also descend by a wide margin, system investment has been reduced, the energy utilization efficiency of system has been promoted by a wide margin, system economic benefits also will be improved, the coal chemical industry process CO has been realized₂Zero emission, low energy consumption and low emission of coal, and high-efficiency clean utilization.

In a first aspect, the present invention provides a method for producing CO from hydrogen by chemical reaction₂Zero release coal system methyl alcohol system includes: air separation device for preparing oxygen, coal gasifier device for preparing high-temperature coarse gasification coal gas, synthesis gas purification device for preparing elemental sulfur, methanol synthesis and rectification device for synthesizing methanol and rectifying methanol, and device for preparing H₂H of S₂S preparation device and method for preparing SO₂SO of (A)₂A preparation device, a Bunsen reaction device for preparing sulfuric acid and hydrogen iodide and a HI decomposition device for preparing hydrogen and iodine,

the coal gasifier unit is in communication with the air separation unit to receive oxygen from the air separation unit;

the synthesis gas purification device is communicated with the HI decomposition device to receive low-temperature crude gasification gas from the HI decomposition device;

the methanol synthesis and rectification unit is in communication with the syngas purification unit to receive syngas from the syngas purification unit, and the methanol synthesis and rectification unit is in communication with the HI decomposition unit to receive hydrogen from the HI decomposition unit;

said H₂The S preparation device is communicated with the synthesis gas purification device to receive the elemental sulfur from the synthesis gas purification device; said H₂The S preparation device is communicated with the HI decomposition device to receive the HI from the HI decomposition deviceThe hydrogen gas of (a) is,

the SO₂Preparation apparatus and the same₂S preparation device connected to receive the said H₂S preparation of H of the apparatus₂S, the SO₂A preparation device is communicated with the Bunsen reaction device to receive sulfuric acid from the Bunsen reaction device;

the Bunsen reaction device and the SO₂A preparation device is communicated to receive the SO₂SO of preparation plant₂And water; the Bunsen reaction device is communicated with the HI decomposition device to receive iodine from the HI decomposition device;

the HI decomposition device is communicated with the Bunsen reaction device to receive HI from the Bunsen reaction device, and the HI decomposition device is communicated with the coal gasification furnace to receive high-temperature crude gasification coal gas from the coal gasification furnace.

The high-temperature coarse gasification gas in the invention is coarse gasification gas with the temperature of about 600-700 ℃, and the low-temperature coarse gasification gas is coarse gasification gas with the temperature of about 300-500 ℃.

CO of chemical hydrogen production of the invention₂The zero-emission coal-to-methanol system matches sensible heat of high-temperature gasified coal gas generated by the coal gasifier with heat required by hydrogen iodide thermal decomposition hydrogen production, and the generated hydrogen meets the requirement of adjusting the hydrogen-carbon ratio of synthesis gas, so that the water gas shift link in the traditional coal chemical industry process is omitted, and the process flow is simplified; meanwhile, as the hydrogen comes from the HI decomposition device, the CO does not need to be converted into CO₂Hydrogen is produced, so that carbon in the coal can be completely converted into products, and CO is not produced in the whole production process₂Under the condition of producing the same quantity of chemical products, the coal consumption and the energy consumption of the system are greatly reduced, the scale of the coal gasification furnace and the scale of the synthesis gas purification device are also greatly reduced, the system investment is reduced, the energy utilization efficiency of the system is greatly improved, the economic benefit of the system is also improved, and the CO production process of the coal chemical industry is realized₂Zero emission, low energy consumption and low emission of coal, and high-efficiency clean utilization.

In a second aspect, the invention provides CO for chemical hydrogen production₂Zero-emission coal-based methanol preparation methodThe method comprises the following steps:

s101: introducing air into an air separation device to prepare oxygen, introducing the oxygen and coal into a coal gasifier device to obtain high-temperature crude gasified coal gas, mixing the high-temperature crude gasified coal gas with a strand of low-temperature crude gasified coal gas which is divided after heat exchange is carried out on the high-temperature crude gasified coal gas and an HI decomposition device to obtain gasified coal gas, and introducing the gasified coal gas into the HI decomposition device to carry out heat exchange; introducing the other low-temperature crude gasified coal gas which is divided after the heat exchange of the HI decomposition device into a synthesis gas purification device to prepare elemental sulfur and purified synthesis gas, and introducing the elemental sulfur into H₂S preparation device prepares H₂S；

S102: mixing the clean synthesis gas prepared in the step S101 with the hydrogen prepared by the HI decomposition device to obtain synthesis gas, and introducing the synthesis gas into a methanol synthesis and rectification device to prepare methanol;

s103: introducing the hydrogen and the sulfur source prepared by the HI decomposition device into the H₂S preparation device for preparing H₂S；

S104: sulfuric acid is prepared and obtained through a Bunsen reaction device, and H₂S mixed and introduced into SO₂Preparation apparatus to obtain SO₂And water, the iodine prepared by the HI decomposition device is introduced into the Bunsen reaction device to prepare sulfuric acid and hydrogen iodide, the sulfuric acid is divided into two parts, the first part of sulfuric acid is taken as a product to be output, and the second part of sulfuric acid is introduced into the SO₂Preparing a device;

s105: introducing the HI prepared in the step S104 into the HI decomposition device to obtain hydrogen and iodine, dividing the hydrogen into two parts, wherein the first part of the hydrogen is used as a raw material in the step S102, and the second part of the hydrogen is used as a raw material and is introduced into the H₂And S, a preparation device, wherein iodine is introduced into the Bunsen reaction device for cyclic utilization.

CO of chemical hydrogen production of the invention₂The method for preparing the methanol by the zero-emission coal converts the process of preparing the sulfur dioxide by the thermal decomposition of the sulfuric acid into the process of preparing the sulfur dioxide by the chemical reaction of the sulfuric acid and the hydrogen sulfide, and saves a high-temperature heat source required by the thermal decomposition of the sulfuric acid. The hydrogen is produced by iodine-sulfur semi-open cycle, four main chemical reactions are carried out, and a chemical method is realizedThe method for preparing hydrogen by decomposing water is mild in reaction conditions, widens the scenes of industrial practice, reduces energy consumption, improves system energy efficiency, and is low in energy consumption and CO₂A hydrogen production system and a process method which have zero emission and can be applied in large-scale industry.

As a specific embodiment of the present invention, in the step S103, the sulfur source is at least one selected from the group consisting of iron disulfide, ferrous sulfide, ferric trisulfide, and sulfur.

By introducing iron disulfide, ferrous sulfide or ferric trisulfide or sulfur and by-producing a part of sulfuric acid, the traditional process for preparing sulfuric acid by oxidizing iron disulfide, ferrous sulfide, ferric trisulfide or sulfur is changed; when the iron disulfide, the ferrous sulfide or the ferric trisulfide are used as a sulfur source, hydrogen sulfide is generated through hydrogen reduction, and iron can be generated as a byproduct, so that the problems of low iron content and harmful element sulfur content when the iron disulfide, the ferrous sulfide or the ferric trisulfide is used for iron making are solved. Therefore, the process method of the system can produce hydrogen with low energy consumption, simultaneously can produce sulfuric acid and iron as by-products, realizes the semi-open type cycle hydrogen production process of iodine and sulfur, improves the energy utilization efficiency of the system, and reasonably and fully utilizes resources.

As a specific embodiment of the present invention, in the step S104, the molar ratio of the hydrogen sulfide to the sulfuric acid is 1: (2.8-3.2), for example, 1: 2.8,1: 3,1: 3.2 and any combination thereof, preferably 1: 3.

In step S104, the first portion of sulfuric acid accounts for 1/5 to 1/3 of the total volume of sulfuric acid, such as 1/5, 1/4, 1/3 and any combination thereof, preferably 1/4.

In step S105, the first portion of hydrogen gas accounts for 5/8 to 7/8 of the total volume of hydrogen gas, such as 5/8, 2/3, 7/8 and any combination thereof, preferably 2/3.

As a specific embodiment of the present invention, the chemically produced CO₂The hydrogen production energy utilization rate of the zero-emission coal-to-methanol method is not less than 50%, preferably not less than 55%.

In a third aspect, the invention provides the CO for chemically producing hydrogen₂Zero-emission coal-to-methanol system and/or CO produced by chemical hydrogen production₂The zero-emission coal-to-methanol method is applied to the field of hydrogen production.

The process of the invention comprises the following steps:

oxygen prepared by air entering the air separation device and coal enter the coal gasifier, generated high-temperature coarse gasification coal gas is mixed with low-temperature coarse gasification coal gas subjected to heat exchange by the HI decomposition device to form coarse gasification coal gas, the temperature of the coarse gasification coal gas is controlled to be below the ash melting point of the coal, molten fly ash carried by the high-temperature coal gas at the outlet of the coal gasifier is prevented from being bonded in a subsequent device, and the fly ash is cooled to be solid; the high-temperature crude gasification coal gas enters an HI decomposition device for heat exchange, and hydrogen iodide is heated and decomposed into hydrogen and iodine; the cooled crude gasified gas enters a synthesis gas purification device to obtain purified synthesis gas, organic sulfur and inorganic sulfur in the synthesis gas are removed, elemental sulfur is separated out, and the sulfur can enter H₂The S preparation device is used for producing hydrogen sulfide and can also be independently used as a product; mixing the clean synthesis gas with hydrogen prepared from the HI decomposition device to obtain synthesis gas, and adjusting the ratio of hydrogen to carbon monoxide in the mixed synthesis gas to be 2:1 so as to meet the requirement of subsequent methanol synthesis; the obtained methanol can be used as a product and also can be used as a raw material for preparing other chemicals such as olefin and the like.

The iron disulfide, ferrous sulfide, iron trisulfide or sulfur and hydrogen produced by HI decomposition device enter H₂S, a preparation device, which performs the following reduction reaction according to different raw materials: FeS₂+2H₂＝Fe+2H₂S，FeS+H₂＝Fe+H₂S，Fe₂S₃+3H₂＝2Fe+3H₂S，S+H₂＝H₂S; if the raw materials are iron disulfide, ferrous sulfide or ferric trisulfide, the raw materials are reduced into iron 2, and meanwhile, the sulfur element in the iron disulfide, ferrous sulfide or ferric trisulfide or sulfur is converted into hydrogen sulfide; hydrogen sulfide and sulfuric acid generated from the Bunsen reaction device enter SO₂A manufacturing apparatus, in which the following redox reaction occurs: 3H₂SO₄+H₂S＝4SO₂+4H₂And O, sulfuric acid and hydrogen sulfide react according to a molar ratio of 3:1, the sulfuric acid is reduced into sulfur dioxide, the hydrogen sulfide is oxidized into sulfur dioxide, sulfur dioxide and water are generated, and the sulfur dioxide and the water, the iodine from the HI decomposition device and water supplemented from the outside enter the Bunsen reaction device together to perform the following redox reaction: SO (SO)₂+2H₂O+I₂＝H₂SO₄+2HI to produce sulfuric acid and hydrogen iodide, with part of the sulfuric acid produced as product and the other part entering SO₂Preparing a device as a reactant; hydrogen iodide enters an HI decomposition device, and the following thermal decomposition reaction is carried out at about 400 ℃: 2HI ═ I₂+H₂Hydrogen and iodine are generated, a part of hydrogen generated by the reaction is used as raw material to be mixed with synthesis gas to adjust the hydrogen-carbon ratio, and the other part of hydrogen enters H₂And the S preparation device is used as a reactant, and the iodine is returned to the Bunsen reaction device for cyclic utilization.

The invention has the following beneficial effects:

1) the sensible heat of the high-temperature gasified coal gas generated by the coal gasifier is matched with the heat required by hydrogen iodide thermal decomposition hydrogen production, the generated hydrogen meets the requirement of adjusting the hydrogen-carbon ratio of the synthesis gas, the water gas shift link of the traditional coal chemical process is omitted, and the process flow is simplified; meanwhile, as the hydrogen comes from the HI decomposition device, the CO does not need to be converted into CO₂Hydrogen is produced, so that carbon in the coal can be completely converted into products, and CO is not produced in the whole production process₂Under the condition of producing the same quantity of chemical products, the coal consumption and the energy consumption of the system are greatly reduced, the scale of the coal gasification furnace and the scale of the synthesis gas purification device are also greatly reduced, the system investment is reduced, the energy utilization efficiency of the system is greatly improved, the economic benefit of the system is also improved, and the CO production process of the coal chemical industry is realized₂Zero emission, low energy consumption and low emission of coal, and high-efficiency clean utilization.

2) The invention converts the process of preparing sulfur dioxide by thermal decomposition of sulfuric acid into the process of preparing sulfur dioxide by chemical reaction of sulfuric acid and hydrogen sulfide, thereby saving a high-temperature heat source required by thermal decomposition of sulfuric acid. By iodine sulfur semi-open cycleHydrogen production is carried out, reaction conditions are mild, scenes applied to industrial practice are widened, energy consumption is reduced, system energy efficiency is improved, and the method is low-energy-consumption CO₂A hydrogen production system and a process method which have zero emission and can be applied in large-scale industry.

3) By introducing iron disulfide, ferrous sulfide or ferric trisulfide or sulfur and by-producing a part of sulfuric acid, the traditional process for preparing sulfuric acid by oxidizing iron disulfide, ferrous sulfide, ferric trisulfide or sulfur is changed; when the iron disulfide, the ferrous sulfide or the ferric trisulfide are used as a sulfur source, hydrogen sulfide is generated through hydrogen reduction, and iron can be generated as a byproduct, so that the problems of low iron content and harmful element sulfur content when the iron disulfide, the ferrous sulfide or the ferric trisulfide are used for iron making are solved; because trace elements such as cobalt, nickel, copper, gold, selenium and the like also exist in the components of pyrite such as pyrite and the like, when the content is higher, the trace elements can be comprehensively recovered and utilized in the process of realizing sulfur conversion, so that resources are reasonably and efficiently utilized.

4) The invention has low energy consumption and CO₂When methanol is produced in zero discharge, sulfuric acid and iron can be produced as by-products, the semi-open type cycle chemical hydrogen production process of iodine and sulfur is realized, the comprehensive energy utilization efficiency of the system is improved, and resources are reasonably and fully utilized.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings.

FIG. 1 shows a chemical hydrogen production-based CO of the present invention₂A process flow diagram of a zero-emission coal-to-methanol system;

wherein: 1-air; 2-oxygen; 3-coal; 4-high temperature coarse gasification of coal gas; 5-mixing the coarse gasification gas; 6-low-temperature coarse gasification of coal gas; 7-low-temperature coarse gasification of coal gas; 8-clean syngas; 9-synthesis gas; 10-methanol; 11-a source of sulfur; 12-iron; 13-sulphur; 14-hydrogen; 15-hydrogen sulfide; 16-water; 17-sulfur dioxide; 18-sulfuric acid; 19-water; 20-sulfuric acid; 21-hydrogen iodide; 22-iodine; 23-hydrogen; 101-an air separation unit; 102-a coal gasifier; 103-a syngas purification device; 104-methanol synthesis and rectification device; 105-H₂S, preparing a device; 106-SO₂Preparing a device; 107-Bunsen reaction device; 108-HI decomposition device.

Detailed Description

In order that the invention may be more readily understood, the following detailed description of the invention is given, with reference to the accompanying examples and drawings, which are given by way of illustration only and are not intended to limit the scope of the invention.

CO based on chemical hydrogen production, as shown in FIG. 1₂The invention discloses a zero-emission coal-to-methanol system, which comprises:

1) an air separation unit 101 for producing oxygen 2 connected to a coal gasifier 102 through a pipeline;

2) a coal gasifier device 102, wherein the generated high-temperature crude gasification coal gas 4 (600-700 ℃) is mixed with the low-temperature crude gasification coal gas 6 (300-500 ℃) subjected to heat exchange by the HI decomposition device 108 to form crude gasification coal gas 5(500 ℃), the crude gasification coal gas is connected with the HI decomposition device 108 through a pipeline for heat exchange, and the cooled crude gasification coal gas 7 is connected with the synthesis gas purification device 103 through a pipeline;

3) a synthesis gas purification device 103 for separating the elemental sulfur 13 which can be used as raw material to enter H₂The S preparation device 105 is used for producing hydrogen sulfide and obtaining clean synthesis gas 8, the clean synthesis gas 8 is mixed with hydrogen 23 from the HI decomposition device 108 to form synthesis gas 9, and the synthesis gas 9 is connected with the methanol synthesis and rectification device 104 through a pipeline to produce methanol 10;

4) h for producing hydrogen sulfide₂S preparation device 105, hydrogen sulfide 15 prepared by the device passes through a pipeline and SO₂The preparation device 106 is connected;

5) SO for producing sulfur dioxide₂The preparation device 106 is used for respectively connecting the sulfur dioxide 17 and the water 16 prepared by the device with the Bunsen reaction device 107 through pipelines;

6) a Bunsen reaction apparatus 107 for producing sulfuric acid and hydrogen iodide, the apparatus producing sulfuric acid divided into two parts, one part 18 as reactant passing through the pipeline and SO₂The preparation device is connected, and the other part 20 is output as a product;

7) a HI decomposition unit 108 for producing hydrogen and iodine, the hydrogen produced by the unit being divided into two parts, one part 14 being fed as reactantThrough pipe and H₂The S preparation device 105 is connected, and the other part 23 and the clean synthesis gas 8 adjust the hydrogen-carbon ratio to meet the requirement of methanol synthesis.

CO based on chemical hydrogen production according to the invention₂The zero-emission coal-to-methanol process method comprises the following steps:

1) air 1 enters an air separation device 101 to prepare oxygen 2, the oxygen 2 and coal 3 enter a coal gasification furnace 102 together, generated high-temperature rough gasification coal gas 4 and low-temperature rough gasification coal gas 24 after heat exchange through an HI decomposition device 108 are divided into two strands, one strand 6 is mixed with the high-temperature rough gasification coal gas 4 to form rough gasification coal gas 5, the rough gasification coal gas enters the HI decomposition device 108 for heat exchange, the other strand 7 enters a synthesis gas purification device 103, simple substance sulfur 13 is separated out, and pure synthesis gas 8 is obtained and can enter H₂The S preparation device 105 is used to produce hydrogen sulfide;

2) the clean synthesis gas 8 is mixed with hydrogen 23 from the HI decomposition device 108 to form synthesis gas 9, and the synthesis gas enters a methanol synthesis and rectification device 104 to obtain methanol 10 which can be used as a product and also can be used as a raw material for preparing other chemicals such as olefin and the like;

3) hydrogen 14 and a sulfur source (iron disulfide, ferrous sulfide, iron trisulfide or sulfur) 11 from the HI decomposition device 108 enter H₂S, preparing a device 105, reducing iron disulfide, ferrous sulfide or ferric trisulfide into iron 12, and simultaneously converting sulfur in a sulfur source 11 into hydrogen sulfide 15;

4) hydrogen sulfide 15 and sulfuric acid 18 generated from the Bunsen reaction device 107 enter SO₂The sulfuric acid reacts with the hydrogen sulfide to generate sulfur dioxide 17 and water 16, and the sulfur dioxide 17 and the water 16 enter the Bunsen reaction device 107 together with iodine 22 from the HI decomposition device 108 and externally supplemented water 19 to generate sulfuric acid and hydrogen iodide 21, wherein one part of the sulfuric acid is used as a product 20, and the other part of the sulfuric acid enters SO₂Preparation apparatus 106 serves as reactant 18;

5) hydrogen iodide 21 is fed to HI decomposition unit 108 to produce hydrogen and iodine 22, one part of the hydrogen is used as raw material 23 to be mixed with the clean synthesis gas 8, and the other part is fed to H₂The S preparation apparatus 105 is used as the reactant 14, and the iodine 22 is returned to the Bunsen reaction apparatus 107 for recycling.

The present invention will be described in more detail below with reference to examples and the accompanying drawings, but the present invention is not limited to the examples.

Example 1

Calculation of the overall system performance at base load for example 1 was performed using the above method and system based on 60 million tons/year of methanol produced. The composition parameters of the raw coal are shown in table 1. Generally, the comprehensive energy utilization efficiency of the coal-to-methanol process is about 37% -44%, and the coal is used as CO in the raw material production process₂The discharge amount is 112 ten thousand tons per year, and the coal consumption is 111 ten thousand tons per year. As shown in Table 2, the system of example 1 produced hydrogen with an energy efficiency of about 55%, and CO produced during the production process₂The discharge amount is 0, and the coal consumption is reduced by 53 ten thousand tons per year.

TABLE 1 compositional parameters of the feed coal

Water content, mass%	Ash content, mass%	Volatile matter content, mass%	Fixed carbon, mass%	Calorific value, MJ/kg
					8	27.6	9.14	55.26	22.36

Table 2 example 1 bulk performance data

Wherein, the calculation formula of the methanol energy utilization rate eta is as follows:

wherein, HHV_Methanol-high calorific value of methanol MJ/kg;

m_methanol-mass of methanol, kg;

q_{coal and its production method}-calorific value of coal, MJ/kg;

m_{coal and its production method}-mass of coal, kg;

q_pyrite-the calorific value of pyrite, MJ/kg;

m_pyrite-mass of pyrite, kg;

W_{air separation}Power consumption of air separation, MJ;

η_{air separation}-efficiency of air separation heat energy conversion to useful work;

∑Q_iheat directly input by the system, MJ.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.