阅读说明：本技术 一种煤制天然气联产甲醇和乙二醇的加工工艺 (Processing technology for co-production of methanol and ethylene glycol from coal-based natural gas ) 是由 刘阳 吴秀章 刘永健 王鹤鸣 夏俊兵 刘万洲 张艮行 刘学武 李国栋 于 2019-08-07 设计创作，主要内容包括：本发明涉及一种煤制天然气联产甲醇和乙二醇的加工工艺,包括：原料煤气化制取粗合成气的步骤,粗合成气除氧并脱有机硫的步骤,脱硫合成气低温净化的步骤,净化合成气低温深冷分离的步骤,PSA氢气提纯的步骤和乙二醇合成的步骤以及甲醇合成的步骤。此外,本发明加工工艺还可以根据市场需求情况进行灵活调整,以满足企业在不同的市场环境下生产出不同产量的天然气产品和/或甲醇产品和/或乙二醇产品。本发明通过多联产的方式,在产品结构、污染物处理等方面实现集成优化,从而提高全过程能量利用效率和项目的提质增效,不仅提高了煤炭的转化增值,而且提升了企业的盈利能力；同时本发明的加工工艺还具有操作灵活,生产方式便于调整的特点。(The invention relates to a processing technology for co-producing methanol and ethylene glycol from coal-based natural gas, which comprises the following steps: the method comprises the steps of preparing raw synthesis gas by gasifying raw material coal, removing oxygen and organic sulfur from the raw synthesis gas, purifying the desulfurized synthesis gas at low temperature, purifying the synthesis gas at low temperature, deeply cooling and separating, purifying PSA hydrogen, synthesizing ethylene glycol and synthesizing methanol. In addition, the processing technology can be flexibly adjusted according to market demand conditions so as to meet the requirement that enterprises produce natural gas products and/or methanol products and/or ethylene glycol products with different yields in different market environments. According to the invention, by means of poly-generation, integration and optimization are realized in aspects of product structure, pollutant treatment and the like, so that the energy utilization efficiency of the whole process and the quality and efficiency improvement of projects are improved, the conversion and value increment of coal are improved, and the profitability of enterprises is improved; meanwhile, the processing technology of the invention also has the characteristics of flexible operation and convenient adjustment of the production mode.)

1. A processing technology for co-production of methanol and ethylene glycol from coal-based natural gas is characterized by comprising the following steps:

s1: raw material coal gasification to prepare crude synthesis gas

The method comprises the steps of performing countercurrent contact on raw material coal and a gasifying agent (3.8-4.2 MPa high-pressure steam and oxygen) in a crushed coal pressure gasification device, and performing gasification reaction under a pressurized state (3.8-4.2 MPa) to generate crude synthesis gas, wherein the volume content of methane in the crude synthesis gas is 8-14%, and the volume content ratio of H2 to CO in the crude synthesis gas is 2.5-2.8;

s2: oxygen and organic sulfur removal from raw synthesis gas

Subjecting the raw synthesis gas prepared in step S1 to high temperature hydrogenation reaction to remove residual oxygen and olefin in the raw synthesis gas, and converting organic sulfur (without COS) into H₂S, hydrolyzing COS on the synthesis gas after the hydrogenation reaction through an isothermal hydrolysis reaction to obtain desulfurized synthesis gas;

s3: low temperature purification of desulfurized syngas

Cooling the desulfurized synthesis gas obtained in the step S2, and purifying the desulfurized synthesis gas by a low-temperature methanol washing process to remove high-concentration acid gas in the desulfurized synthesis gas to obtain purified synthesis gas, wherein the total sulfur content in the purified synthesis gas is reduced to 0.1 ppm;

s4: cryogenic separation of purified syngas

And (3) deeply cooling the purified synthesis gas obtained in the step (S3) by adopting a cryogenic separation method, and separating a natural gas product and a feed gas for synthesizing methanol and glycol, wherein the feed gas comprises: the method comprises the following steps of (1) feeding CO gas, hydrogen-rich gas and flash gas into a methanol synthesis device and an ethylene glycol synthesis device according to the volume ratio (20-80%), feeding part of the separated hydrogen-rich gas into a PSA (pressure swing adsorption) device for hydrogen purification, and then feeding the other part of the hydrogen-rich gas and the flash gas into the methanol synthesis device;

s5: PSA hydrogen purification

Adsorbing the hydrogen-rich gas separated in step S4 by pressure swing adsorption to remove impurity components contained in the hydrogen-rich gas, and adsorbing the component H which is not easy to be adsorbed₂Separating and purifying to 99.9% for hydrogenation of ethylene glycol synthesis, and sending the residual desorption gas after hydrogen purification to a methanol synthesis device;

s6: ethylene glycol synthesis

S6-1: synthesizing dimethyl oxalate from the CO gas separated in the step S4 by adopting an oxidative coupling method;

s6-2: rectifying and purifying dimethyl oxalate and H purified in step S5₂Producing crude ethylene glycol by hydrogenation;

s6-3: rectifying the crude glycol to obtain finished product of refined glycol;

s7: methanol synthesis

S7-1: combining the CO gas separated in the step S4, the hydrogen-rich gas, the flash evaporation gas and the desorption gas remaining after hydrogen purification to form a methanol synthesis raw material gas;

s7-2: part of CO is extracted from the reaction process of the low-temperature methanol washing in the step S3₂The gas is used as a make-up gas to be supplemented into the methanol synthesis raw material gas, so that the weight fraction ratio of hydrogen to carbon of the methanol synthesis raw material gas reaches 2.0-2.2. (ii) a

S7-3: feeding the methanol synthesis raw material gas into a methanol synthesis device, and utilizing CO gas and CO under the condition that the pressure is 7.5-8.5MPaG₂Reacting the gas with hydrogen under the action of a methanol synthesis catalyst to generate crude methanol;

s7-4: and (4) rectifying the crude methanol prepared in the step S7-3 to remove dissolved gases and low boiling point substances in the crude methanol to obtain the finished product of refined methanol.

2. The process of claim 1, wherein when the process is mainly used for producing natural gas, the shift cooling reaction is added after the gasification in step S1 to produce raw syngas, so as to convert part of CO in the raw syngas into H₂Adjusting the ratio of carbon monoxide to hydrogen in the crude synthesis gas to 3.0, purifying the reaction gas after the change cooling reaction is finished by a low-temperature methanol washing process to remove high-concentration acid gas in the reaction gas to obtain purified synthesis gas, introducing the purified synthesis gas into a methane synthesis device for a large amount of methanation and methanation supplement reactions to finally generate a natural gas product, wherein CH in the product gas is₄The content is more than 95 percent.

3. The processing technology of co-production of methanol and ethylene glycol from coal-based natural gas according to claim 1, wherein when the processing technology is mainly used for producing natural gas and ethylene glycol, the processing technology comprises a step S1 of gasifying raw coal to prepare raw synthesis gas, a step S2 of removing oxygen and organic sulfur from raw synthesis gas, a step S3 of low-temperature purification of desulfurized synthesis gas, a step S4 of low-temperature cryogenic separation of purified synthesis gas, a step S5 of purification of PSA hydrogen, a step S6 of ethylene glycol synthesis and a step S8 of methanation synthesis, wherein the step S8 of methanation synthesis is located after the step S3 of low-temperature purification of desulfurized synthesis gas and before the step S4 of low-temperature cryogenic separation of purified synthesis gas, and the specific processing technology is as follows: part of the purified synthesis gas obtained in the step S3 is sent into a methane synthesis device, natural gas products are generated through methanation reaction, and CH in the product gas₄The content is more than 95 percent; purification of the other partAfter deep cooling of the formed gas by a cryogenic separation method, a natural gas product and a feed gas for synthesizing natural gas and ethylene glycol are separated, wherein the feed gas comprises: the method comprises the steps of feeding CO gas, hydrogen-rich gas and flash gas, wherein the separated CO gas is fed into a methane synthesis device and an ethylene glycol synthesis device according to the volume ratio (20-80%), feeding one part of the separated hydrogen-rich gas into a PSA device for hydrogen purification and then using the hydrogen-rich gas for ethylene glycol production, and feeding the other part of the hydrogen-rich gas, the flash gas and the desorption gas left after PSA hydrogen purification into the methane synthesis device.

4. The process of claim 1, wherein when the process is mainly used for producing natural gas and methanol, the process comprises the steps of gasifying raw coal to prepare raw syngas at step S1, removing oxygen and organic sulfur from the raw syngas at step S2, desulfurizing syngas at step S3 at low temperature, purifying syngas at step S4 at low temperature and cryogenically separating the purified syngas, synthesizing methanol at step S7, and synthesizing methane at step S8, wherein the step S8 at low temperature after purifying the desulfurized syngas at step S3 and before separating the purified syngas at step S4 at low temperature and the specific process is as follows: sending part of the purified synthesis gas obtained in the step S3 into a methane synthesis device, and generating a natural gas product through methanation reaction, wherein the content of CH4 in the product gas is more than 95%; and the other part of the purified synthesis gas is subjected to deep cooling by a cryogenic separation method to separate a natural gas product and a feed gas for synthesizing natural gas and methanol, wherein the feed gas comprises: the method comprises the following steps of feeding CO gas, hydrogen-rich gas and flash gas, wherein the separated CO gas is fed into a methane synthesis device and a methanol synthesis device according to the volume ratio (20-80%), and the separated hydrogen-rich gas and flash gas are fed into the methanol synthesis device.

5. The processing technology for coproducing methanol and ethylene glycol from coal-based natural gas as claimed in claim 1, wherein the desulfurized synthesis gas in the step S2 is subjected to separation heat exchange, the temperature is raised to 320-350 ℃, trace dust impurities and heavy oil in the desulfurized synthesis gas are removed, and then the synthesis process for removing the impurities and the heavy oil is carried outThe gas is subjected to a hydrogenation reaction to remove residual oxygen and olefins from the raw syngas and convert organic sulfur (without COS) to H₂And S, after the synthesis gas after the hydrogenation reaction is subjected to heat exchange, cooling and water replenishing, and when the temperature of the synthesis gas is 160-190 ℃, performing hydrolysis reaction to hydrolyze COS to obtain the desulfurization synthesis gas.

6. The processing technology for coproducing methanol and ethylene glycol from coal-based natural gas as claimed in claim 1, wherein the low-temperature methanol washing process in step S3 is as follows: methanol is used as an absorbent, the desulfurized synthetic gas is cooled to-32 ℃, then the desulfurized synthetic gas is washed, and in the washing process, the desulfurized synthetic gas is cooled step by step and simultaneously oil, HCN, CO in the desulfurized synthetic gas₂And H₂And S, washing to obtain qualified purified synthesis gas.

7. The process of claim 1, wherein the purified syngas of step S4 is subjected to cryogenic separation to remove trace amounts of methanol and carbon dioxide contained in the purified syngas, so as not to cause blockage of cryogenic equipment and pipes during cryogenic separation.

8. The processing technology for coproducing methanol and ethylene glycol from coal-based natural gas as claimed in claim 1, wherein the synthesis process for synthesizing dimethyl oxalate by using an oxidative coupling method in step S6 is as follows: from carbon monoxide, methanol and oxygen in the presence of a catalyst Pd/Al₂O₃Under the action of (3), dimethyl oxalate is synthesized.

9. The processing technology for coproducing methanol and ethylene glycol from coal-based natural gas as claimed in claim 1, wherein the raw material coal in step S1 is 6-50 mm lump coal, and the crushed coal pressurized gasification device is a crushed coal pressurized solid-state slagging gasification furnace.

Technical Field

The invention belongs to the technical field of energy and chemical industry, and particularly relates to a processing technology for co-producing methanol and ethylene glycol from coal-based natural gas.

Background

Coal-based natural gas is one of the important ways to solve the shortage of natural gas supply in China. Since 'twelve five's, a plurality of coal-based natural gas demonstration projects are approved and demonstrated to operate, and by 1 month in 2019, the number of coal-based natural gas projects put into production in China is four, and the total number of the projects can reach 51.5 billion cubic meters per year. The production operation of the coal-based natural gas demonstration project promotes the independent innovation and the technical upgrade of the coal chemical industry in China. But at the same time, most coal-based natural gas projects have the problems of large investment, low energy efficiency and the like, and the production mode of a single product has larger market risk. In recent years, the price of international main energy products fluctuates greatly and is limited by national administrative gas price-fixing policies, so that the profitability of coal-based natural gas projects is greatly weakened. On the other hand, the natural gas market has the obvious characteristic that the consumption has seasonal imbalance, for example, the ratio of wave crest to wave trough of the Beijing natural gas demand can reach about 10 times. The peak-valley characteristic of natural gas demand along with seasons has already severely limited the release of capacity, and becomes an important factor for restricting the survival and the industry development of coal-based natural gas enterprises.

In recent years, the nation has paid high attention to and developed the coal chemical industry, points out that a clean, efficient, low-carbon, safe and sustainable coal utilization system is constructed, and is the target and direction of the development of the modern coal chemical industry. The coal-based poly-generation process can realize the diversification of the structure of the terminal product and the high-valued product through the integrated optimization of various coal conversion process technologies, such as the coal-based production of methanol or the production of ethylene glycol.

Methanol is an important and greatly-demanded basic organic chemical raw material and is also a clean energy source. Particularly, under the drive of the technological development of the process for preparing olefin from methanol in recent years, the demand of China on methanol is greatly increased. In 2017, the total yield of the Chinese methanol is 4528.8 ten thousand tons, and the amplification is 7.1 percent. However, the demand of the coal-based methanol to olefin project on methanol is huge, and about 1500 million tons of methanol are still imported in China in 2017. On the other hand, the gas head ammonia-alcohol co-production device is eliminated, and meanwhile, the cost of the natural gas methanol is not competitive, so that the yield and the utilization rate of the methanol built in the future are in a descending trend. Therefore, the methanol market in the future still has a large gap.

Ethylene glycol is an important organic chemical raw material, wherein the consumption percentage of the polyester industry is about 85 percent. As a world large country for polyester production, the development of the polyester industry brings about rapid increase of the demand of ethylene glycol. In the last decade, the productivity and the yield of ethylene glycol in China are steadily increased, but the productivity increase speed is far lower than the acceleration of apparent consumption, and the external dependence is always kept above 60%. By 2017, the yield of ethylene glycol in China already exceeds 600 ten thousand tons, but the net import amount still reaches 860 ten thousand tons. The domestic ethylene glycol capacity can not meet the market demand in a short time, and still mainly depends on import. In the next 5 years, the status of China as a world large polyester production country is expected to be unchanged, and the demand for ethylene glycol is still vigorous.

Disclosure of Invention

In view of this, a first objective of the present invention is to provide a processing technology for co-producing methanol and ethylene glycol from coal-based natural gas, which aims to realize diversification of end product structures and high value of products by a coal-based poly-generation method, and finally solve the problem of gaps in supply of natural gas, methanol and ethylene glycol in the current market.

The second purpose of the invention is to flexibly adjust the process according to market demand conditions on the basis of the processing process provided by the invention so as to meet the requirement that enterprises produce natural gas products and/or methanol products and/or ethylene glycol products with different yields in different market environments, thereby improving the energy utilization efficiency and the quality and efficiency improvement of projects in the whole process of coal conversion, finally improving the conversion and value increment of coal and simultaneously improving the profitability of enterprises.

In order to achieve the purpose, the technical scheme is as follows:

a processing technology for co-production of methanol and ethylene glycol from coal-based natural gas is characterized by comprising the following steps:

s1: raw material coal gasification to prepare crude synthesis gas

The method comprises the steps of performing countercurrent contact on raw material coal and a gasifying agent (3.8-4.2 MPa high-pressure steam and oxygen) in a crushed coal pressure gasification device, and performing gasification reaction under a pressurized state (3.8-4.2 MPa) to generate crude synthesis gas, wherein the volume content of methane in the crude synthesis gas is 8-14%, and the volume content ratio of H2 to CO in the crude synthesis gas is 2.5-2.8;

s2: oxygen and organic sulfur removal from raw synthesis gas

Subjecting the raw synthesis gas prepared in step S1 to high temperature hydrogenation reaction to remove residual oxygen and olefin in the raw synthesis gas, and converting organic sulfur (without COS) into H₂S, hydrolyzing COS on the synthesis gas after the hydrogenation reaction through an isothermal hydrolysis reaction to obtain desulfurized synthesis gas;

s3: low temperature purification of desulfurized syngas

Cooling the desulfurized synthesis gas obtained in the step S2, and purifying the desulfurized synthesis gas by a low-temperature methanol washing process to remove high-concentration acid gas in the desulfurized synthesis gas to obtain purified synthesis gas, wherein the total sulfur content in the purified synthesis gas is reduced to 0.1 ppm;

s4: cryogenic separation of purified syngas

And (3) deeply cooling the purified synthesis gas obtained in the step (S3) by adopting a cryogenic separation method, and separating a natural gas product and a feed gas for synthesizing methanol and glycol, wherein the feed gas comprises: the method comprises the following steps of (1) feeding CO gas, hydrogen-rich gas and flash gas into a methanol synthesis device and an ethylene glycol synthesis device according to the volume ratio (20-80%), feeding part of the separated hydrogen-rich gas into a PSA (pressure swing adsorption) device for hydrogen purification, and then feeding the other part of the hydrogen-rich gas and the flash gas into the methanol synthesis device;

s5: PSA hydrogen purification

Adsorbing the hydrogen-rich gas separated in step S4 by pressure swing adsorption to remove impurity components contained in the hydrogen-rich gas, and adsorbing the component H which is not easy to be adsorbed₂Separating and purifying to 99.9% for hydrogenation of ethylene glycol synthesis, and sending the residual desorption gas after hydrogen purification to a methanol synthesis device;

s6: ethylene glycol synthesis

S6-1: synthesizing dimethyl oxalate from the CO gas separated in the step S4 by adopting an oxidative coupling method;

s6-2: rectifying and purifying dimethyl oxalate and H purified in step S5₂Producing crude ethylene glycol by hydrogenation;

s6-3: rectifying the crude glycol to obtain finished product of refined glycol;

s7: methanol synthesis

S7-1: combining the CO gas separated in the step S4, the hydrogen-rich gas, the flash evaporation gas and the desorption gas remaining after hydrogen purification to form a methanol synthesis raw material gas;

s7-2: part of CO is extracted from the reaction process of the low-temperature methanol washing in the step S3₂Supplementing gas serving as make-up gas into the methanol synthesis raw material gas so as to enable the weight fraction ratio of hydrogen to carbon of the methanol synthesis raw material gas to reach 2.0-2.2;

s7-3: feeding the methanol synthesis raw material gas into a methanol synthesis device, and utilizing CO gas and CO under the condition that the pressure is 7.5-8.5MPaG₂Reacting the gas with hydrogen under the action of a catalyst (copper catalyst) to generate crude methanol;

s7-4: and (4) rectifying the crude methanol prepared in the step S7-3 to remove dissolved gases and low boiling point substances in the crude methanol to obtain the finished product of refined methanol.

Further, when the process is mainly used for producing natural gas, a shift cooling reaction is added after the gasification in step S1 to produce raw synthesis gas, in order to shift part of CO in the raw synthesis gas to H₂Adjusting the ratio of carbon monoxide to hydrogen in the crude synthesis gas to 3.0, purifying the reaction gas after the change cooling reaction is finished by a low-temperature methanol washing process to remove high-concentration acid gas in the reaction gas to obtain purified synthesis gas, introducing the purified synthesis gas into a methane synthesis device for a large amount of methanation and methanation supplement reactions to finally generate a natural gas product, wherein CH in the product gas is₄The content is more than 95 percent.

Further, when the processing technology is mainly used for producing natural gas and ethylene glycol, the processing technology comprises the steps of preparing raw synthesis gas by gasifying raw coal in the step S1, removing oxygen from the raw synthesis gas in the step S2 and removing oxygen from the raw synthesis gasThe method comprises the following steps of mechanical sulfur, low-temperature purification of desulfurized synthetic gas in step S3, low-temperature cryogenic separation of purified synthetic gas in step S4, hydrogen purification in step S5PSA, ethylene glycol synthesis in step S6 and methanation synthesis in step S8, wherein the methanation synthesis in step S8 is positioned after the low-temperature purification of desulfurized synthetic gas in step S3 and before the low-temperature cryogenic separation of purified synthetic gas in step S4, and the specific processing technology is as follows: part of the purified synthesis gas obtained in the step S3 is sent into a methane synthesis device, natural gas products are generated through methanation reaction, and CH in the product gas₄The content is more than 95 percent; and deeply cooling the other part of the purified synthesis gas by using a cryogenic separation method to separate a natural gas product and a feed gas for synthesizing natural gas and ethylene glycol, wherein the feed gas comprises: the method comprises the steps of feeding CO gas, hydrogen-rich gas and flash gas, wherein the separated CO gas is fed into a methane synthesis device and an ethylene glycol synthesis device according to the volume ratio (20-80%), feeding one part of the separated hydrogen-rich gas into a PSA device for hydrogen purification and then using the hydrogen-rich gas for ethylene glycol production, and feeding the other part of the hydrogen-rich gas, the flash gas and the desorption gas left after PSA hydrogen purification into the methane synthesis device.

Further, when the processing technology is mainly used for producing natural gas and methanol, the processing technology comprises a step S1 of gasifying raw material coal to prepare raw synthesis gas, a step S2 of deoxidizing the raw synthesis gas and removing organic sulfur, a step S3 of low-temperature purification of desulfurized synthesis gas, a step S4 of low-temperature cryogenic separation of purified synthesis gas, a step S7 of methanol synthesis and a step S8 of methanation synthesis, wherein the step S8 of methanation synthesis is positioned after the step S3 of low-temperature purification of desulfurized synthesis gas and before the step S4 of low-temperature cryogenic separation of purified synthesis gas, and the specific processing technology is as follows: sending part of the purified synthesis gas obtained in the step S3 into a methane synthesis device, and generating a natural gas product through methanation reaction, wherein the content of CH4 in the product gas is more than 95%; and the other part of the purified synthesis gas is subjected to deep cooling by a cryogenic separation method to separate a natural gas product and a feed gas for synthesizing natural gas and methanol, wherein the feed gas comprises: the method comprises the following steps of feeding CO gas, hydrogen-rich gas and flash gas, wherein the separated CO gas is fed into a methane synthesis device and a methanol synthesis device according to the volume ratio (20-80%), and the separated hydrogen-rich gas and flash gas are fed into the methanol synthesis device.

Further, after the desulfurized syngas in the step S2 is subjected to separation and heat exchange and heated to 320-350 ℃, a trace amount of dust impurities and heavy oil in the desulfurized syngas are removed, and then the syngas from which the impurities and the heavy oil are removed is subjected to a hydrogenation reaction to remove residual oxygen and olefin in the raw syngas, and organic sulfur (without COS) is converted into H₂And S, after the synthesis gas after the hydrogenation reaction is subjected to heat exchange, cooling and water replenishing, and when the temperature of the synthesis gas is 160-190 ℃, performing hydrolysis reaction to hydrolyze COS to obtain the desulfurization synthesis gas.

Further, the low-temperature methanol washing process in the step S3 is as follows: methanol is used as an absorbent, the desulfurized synthetic gas is cooled to-32 ℃, then the desulfurized synthetic gas is washed, and in the washing process, the desulfurized synthetic gas is cooled step by step and simultaneously oil, HCN, CO in the desulfurized synthetic gas₂And H₂And S, washing to obtain qualified purified synthesis gas.

Further, before the cryogenic separation is performed on the purified synthesis gas in the step S4, a trace amount of methanol and carbon dioxide contained in the purified synthesis gas needs to be removed first, so as to avoid blockage of cryogenic equipment and pipelines during the cryogenic separation.

Further, the synthesis process of synthesizing dimethyl oxalate by using an oxidative coupling method in step S6 is as follows: from carbon monoxide, methanol and oxygen in the presence of a catalyst Pd/Al₂O₃Under the action of (3), dimethyl oxalate is synthesized.

Further, the raw material coal in the step S1 is lump coal of 6-50 mm, and the crushed coal pressure gasification device is a crushed coal pressure solid-state slagging gasification furnace.

The invention has the beneficial effects that: the invention provides a processing technology for coproducing methanol and glycol from coal-to-natural gas, which is characterized in that a raw material coal crushed coal is gasified by a pressure gasification device to prepare crude synthesis gas, acid gas and the like in the crude synthesis gas are removed by deoxidization and organic sulfur removal and a low-temperature methanol washing process, then a methane product and a raw material gas for a methanol synthesis device and a glycol synthesis device are obtained from the purified synthesis gas obtained by the low-temperature methanol washing process through a cryogenic separation step, and the raw material gas is produced in a methanol device and a glycol device which are operated in parallel to obtain refined methanol and polyester-grade glycol. Therefore, the processing technology provided by the invention realizes integrated optimization in product structure, pollutant treatment and other aspects by a coal-based poly-generation production mode, not only improves the conversion and value-added of coal, but also can flexibly adjust the technology according to market demand conditions, specifically provides four operation working conditions, and provides powerful support for enterprises to realize economic benefit maximization according to product price and demand.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic process flow diagram according to a first embodiment of the present invention;

FIG. 2 is a schematic process flow diagram of a second embodiment of the present invention;

FIG. 3 is a schematic process flow diagram of a third embodiment of the present invention;

fig. 4 is a schematic process flow diagram of a fourth embodiment of the invention.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Before the following embodiments of the present invention are described in detail, a brief summary of the present invention will be provided to describe the processing of coal-to-natural gas with methanol and ethylene glycol, i.e., the present invention produces three main products: natural gas, methanol and ethylene glycol. The brief procedure is as follows:

firstly, raw synthetic gas generated by a crushed coal pressure gasification device is directly sent into a coal gas purification device after being deoxidized and cooled by organic sulfur removal without being adjusted in hydrogen-carbon ratio by a shift reactor. The purified synthesis gas from the outlet of the coal gas purification device enters the deep cooling separation device. Methane is separated in the cryogenic separation unit and sent out as a product. The separated carbon monoxide is sent to a methanol synthesis device and an ethylene glycol synthesis device according to a proportion. One part of the separated hydrogen-rich gas is sent to a PSA device for hydrogen purification for ethylene glycol production, and the other part is sent to a methanol synthesis device for methanol production. The purge gas of cryogenic separation and the tail gas of the PSA device are mixed and then sent to a methanol synthesis device through a compressor under pressure.

On the basis of the processing technology, the flexible adjustment can be made to produce different products. For example: the natural gas can be produced independently, or the natural gas and the methanol can be produced, or the natural gas and the glycol can be produced.

Various embodiments are described in detail below with reference to the drawings.