阅读说明：本技术 一种二氧化碳-碳-水合成甲醇的工艺 (Process for synthesizing methanol from carbon dioxide-carbon-water ) 是由 于杨 李海涛 李忠于 陈海波 殷玉圣 于 2019-10-12 设计创作，主要内容包括：本发明属于二氧化碳综合利用技术领域,具体涉及一种二氧化碳-碳-水合成甲醇的工艺。工艺包括三个主要单元：气化单元、制氢单元和甲醇合成单元,采用新颖的气化催化剂、制氢催化剂和甲醇合成催化剂及填装方式和反应热利用方式,能够实现二氧化碳的高效转化和甲醇的高效合成,突破了现有技术中氢气来源对二氧化碳制甲醇技术工业化进程的限制。(The invention belongs to the technical field of comprehensive utilization of carbon dioxide, and particularly relates to a process for synthesizing methanol from carbon dioxide-carbon-water. The process comprises three main units: the gasification unit, the hydrogen production unit and the methanol synthesis unit adopt novel gasification catalyst, hydrogen production catalyst, methanol synthesis catalyst, filling mode and reaction heat utilization mode, can realize high-efficiency conversion of carbon dioxide and high-efficiency synthesis of methanol, and break through the limitation of hydrogen source on the industrialization process of the technology for preparing methanol from carbon dioxide in the prior art.)

1. A process for synthesizing methanol from carbon dioxide-carbon-water features that under the action of gasifying catalyst, hydrogen preparing catalyst and methanol synthesizing catalyst, carbon monoxide and hydrogen are prepared from carbon dioxide-carbon-water, and the generated carbon monoxide and hydrogen are synthesized to obtain methanol.

2. The process of claim 1, wherein the process comprises three units: gasification unit, hydrogen production unit and methyl alcohol synthesis unit, three kinds of catalysts: gasification catalyst, hydrogen production catalyst and methanol synthesis catalyst.

3. The process of claim 1, wherein the process comprises: in the gasification unit, carbon dioxide and preheated carbon dioxide from the hydrogen production reactor enter a mixing tank to be mixed and then enter a gasification reactor, and the carbon dioxide and the carbonaceous material undergo catalytic gasification reaction in the gasification reactor to generate carbon monoxide; after water-cooling heat exchange and three air-cooling heat exchange, carbon monoxide generated by the gasification unit is divided into two paths by a carbon monoxide splitter, wherein one path enters a methanol synthesis reactor, and the other path enters a hydrogen production reactor; in the hydrogen production unit, carbon monoxide, water preheated by air cooling heat exchange and nitrogen are mixed in a mixing tank, then enter a hydrogen production reactor through a supercharger, react in the hydrogen production reactor to generate hydrogen and carbon dioxide, the hydrogen and the carbon dioxide are separated by a gas separator, the generated carbon dioxide is preheated by an air cooling heat exchanger and then enters a carbon dioxide mixing tank to be mixed with fresh carbon dioxide, the generated hydrogen enters a methanol synthesis reactor, and the nitrogen preheated by the air cooler are mixed and then enter the methanol synthesis reactor; in the methanol synthesis unit, carbon monoxide from the gasification unit, hydrogen from the hydrogen production unit, nitrogen preheated by the air-cooled heat exchanger and recycle gas after the methanol synthesis reactor are mixed in a mixing tank, and then enter the methanol synthesis reactor to carry out methanol synthesis reaction to produce methanol, tail gas is divided into two paths, one path enters the mixing tank in front of the methanol synthesis reactor after being pressurized, and the other path is discharged.

4. The process of claim 3, wherein the gasification reactor is operated at a temperature of 500 to 1000 ℃, a pressure of atmospheric pressure to 2MPa, and CO₂Has a mass space velocity of 0.5~3.5h^-1。

5. The process of claim 3 or 4, wherein the carbonaceous material in the gasification reactor is impregnated with a catalyst solution, the catalyst comprising at least one of potassium carbonate, sodium carbonate, magnesium carbonate, calcium carbonate, ammonium carbonate and ammonium bicarbonate, the amount of impregnation being 0.05% to 0.5% by mass of the carbonaceous material.

6. The process of claim 3, wherein the working temperature of the hydrogen production reactor is 220-270 ℃, the pressure is 3-10 MPa, and the volume space velocity of the raw material gas is 2000-20000 h^-1。

7. The process of claim 3 or 6, wherein the catalyst filled in the hydrogen production reactor is a copper-zinc-aluminum composite oxide hydrogen production catalyst, the catalyst is divided into two layers, wherein the copper-zinc-aluminum composite oxide catalyst filled in the upper layer needs to be subjected to high-temperature treatment, and the treatment temperature is 400-800 ℃; the filling mass ratio of the upper layer catalyst to the lower layer catalyst is 1: 5-1: 1.

8. The process of claim 3, wherein the working temperature of the methanol synthesis reactor is 220-270 ℃, the pressure is 2-8 MPa, and the volume space velocity of the raw material gas is 5000-20000 h^-1。

9. The process of claim 8, wherein the feed gas carbon dioxide is present in a molar ratio to water of 1:1 to 1: 4.

Technical Field

The invention belongs to the technical field of comprehensive utilization of carbon dioxide, and particularly relates to a process for synthesizing methanol by taking carbon dioxide, carbon and water as raw materials.

Background

Carbon dioxide is a main greenhouse gas on the earth, the concentration of the carbon dioxide increases year by year and has a plurality of adverse effects on the earth biosphere, and the emission reduction of the carbon dioxide becomes a hot spot of global attention. The use of carbon dioxide as a raw material for the synthesis of chemicals is the most effective route for carbon dioxide remediation.

Methanol is an important energy carrier and a chemical raw material, and plays an irreplaceable role in national economic development.

The rapid development of methanol in the downstream of MTO, MTP, MTA, MTG and the like in the modern coal chemical industry and the maturity and popularization of a large methanol technology greatly promote the progress of the methanol industry and related technologies. The technology for preparing methanol from carbon dioxide is provided earlier, and the technology is favorable for simultaneously solving the problems of environment and energy safety.

At present, a carbon dioxide hydrogenation method is generally adopted for preparing methanol from carbon dioxide, and the main restriction factor limiting the industrialization of the method is that no cheap and large amount of non-fossil hydrogen exists at present.

Therefore, the search for a more feasible process technology for preparing methanol from carbon dioxide has important practical significance and strategic significance.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a process technology for preparing methanol from carbon dioxide without additionally providing hydrogen.

The technical scheme is as follows: the purpose of the invention is realized by the following technical scheme.

The invention is mainly characterized in that under the action of a novel gasification catalyst, a hydrogen production catalyst and a methanol synthesis catalyst, the invention adopts integration innovation to prepare carbon monoxide and hydrogen by using carbon dioxide-carbon-water, and the generated carbon monoxide and hydrogen are synthesized into methanol.

The invention provides a process for synthesizing methanol from carbon dioxide-carbon-water, which comprises three units: gasification unit, hydrogen production unit and methyl alcohol synthesis unit, three kinds of catalysts: gasification catalyst, hydrogen production catalyst and methanol synthesis catalyst.

The main process of the invention is that in the gasification unit, carbon dioxide and preheated carbon dioxide from the hydrogen production reactor enter a mixing tank to be mixed and then enter a gasification reactor, and the carbon dioxide and carbon-containing materials are subjected to catalytic gasification reaction in the gasification reactor to generate carbon monoxide; after water-cooling heat exchange and three air-cooling heat exchange, carbon monoxide generated by the gasification unit is divided into two paths by a carbon monoxide splitter, wherein one path enters a methanol synthesis reactor, and the other path enters a hydrogen production reactor; in the hydrogen production unit, carbon monoxide, water preheated by air cooling heat exchange and nitrogen are mixed in a mixing tank, and then enter a hydrogen production reactor through pressurization, the reaction is carried out in the hydrogen production reactor to generate hydrogen and carbon dioxide, the hydrogen and the carbon dioxide are separated by a gas separator, the generated carbon dioxide enters a carbon dioxide mixing tank after being preheated by an air cooling heat exchanger to be mixed with fresh carbon dioxide, the generated hydrogen enters a methanol synthesis reactor, and the nitrogen preheated by the air cooler are mixed and then enter the methanol synthesis reactor; in the methanol synthesis unit, carbon monoxide from the gasification unit, hydrogen from the hydrogen production unit, nitrogen preheated by the air-cooled heat exchanger and recycle gas after the methanol synthesis reactor are mixed in a mixing tank, and then enter the methanol synthesis reactor to carry out methanol synthesis reaction to produce methanol, tail gas is divided into two paths, one path enters the mixing tank in front of the methanol synthesis reactor after being pressurized, and the other path is discharged.

Preferably, the working temperature of the gasification reactor is 500-1000 ℃, the pressure is normal pressure-2 MPa, and CO is₂The mass airspeed of the catalyst is between 0.5 and 3.5h^-1。

Preferably, the carbonaceous material in the gasification reactor is subjected to impregnation treatment by a catalyst solution, the catalyst comprises at least one of potassium carbonate, sodium carbonate, magnesium carbonate, calcium carbonate, ammonium carbonate and ammonium bicarbonate, and the impregnation amount is 0.05-0.5% of the mass of the carbonaceous material.

Preferably, the working temperature of the hydrogen production reactor is 220-270 ℃, the pressure is 3-10 MPa, and the volume space velocity of the raw material gas is 2000-20000 h^-1。

Preferably, the catalyst filled in the hydrogen production reactor is a copper-zinc-aluminum composite oxide hydrogen production catalyst, the catalyst is divided into two layers, wherein the copper-zinc-aluminum composite oxide catalyst filled in the upper layer needs to be subjected to high-temperature treatment, and the treatment temperature is 400-800 ℃; the filling mass ratio of the upper layer catalyst to the lower layer catalyst is 1: 5-1: 1.

Preferably, the working temperature of the methanol synthesis reactor is 220-270 ℃, the pressure is 2-8 MPa, and the volume space velocity of the raw material gas is 5000-20000 h^-1The molar ratio of the raw material gas carbon dioxide to water is 1: 1-1: 4.

Advantageous effects

The process of the invention does not need to provide hydrogen, overcomes the limitation of immature non-fossil energy hydrogen production technology on the application prospect of carbon dioxide hydrogenation technology, develops a new way, creatively adopts a carbon dioxide-carbon-water route to synthesize methanol with easily available raw materials, feasible technology and low carbon, even negative carbon, and has obvious progress compared with the prior art.

Drawings

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

In fig. 1, 1: mixing tank, 2: gasification reactor, 3: water-cooled heat exchanger (generating high-pressure steam), 4: air cooled heat exchanger (preheated feed gas or recycle gas), 5: supercharger, 6: hydrogen production reactor, 7: gas separator, 8: methanol synthesis reactor, 9: gas-liquid separator, 10: methanol synthesis tail gas, 11: evacuation of methanol synthesis tail gas, 12: cycle compressor, 13: a carbon monoxide splitter.

Detailed Description

The following examples and figures are intended to further illustrate the present invention and are not intended to limit the invention.

The following example process refers to figure 1.

Example 1

In the gasification unit, carbon dioxide and preheated carbon dioxide from the hydrogen production reactor enter a mixing tank to be mixed and then enter a gasification reactor, and the carbon dioxide and the carbonaceous material undergo catalytic gasification reaction in the gasification reactor to generate carbon monoxide; after water-cooling heat exchange and three air-cooling heat exchange, carbon monoxide generated by the gasification unit is divided into two paths by a carbon monoxide splitter, wherein one path enters a methanol synthesis reactor, and the other path enters a hydrogen production reactor; in the hydrogen production unit, carbon monoxide, water preheated by air cooling heat exchange and nitrogen are mixed in a mixing tank, then enter a hydrogen production reactor through a supercharger, react in the hydrogen production reactor to generate hydrogen and carbon dioxide, the hydrogen and the carbon dioxide are separated by a gas separator, the generated carbon dioxide is preheated by an air cooling heat exchanger and then enters a carbon dioxide mixing tank to be mixed with fresh carbon dioxide, the generated hydrogen enters a methanol synthesis reactor, and the nitrogen preheated by the air cooler are mixed and then enter the methanol synthesis reactor; in the methanol synthesis unit, carbon monoxide from the gasification unit, hydrogen from the hydrogen production unit, nitrogen preheated by the air-cooled heat exchanger and recycle gas after the methanol synthesis reactor are mixed in a mixing tank, and then enter the methanol synthesis reactor to carry out methanol synthesis reaction to produce methanol, tail gas is divided into two paths, one path enters the mixing tank in front of the methanol synthesis reactor after being pressurized, and the other path is discharged.

Wherein the working temperature of the gasification reactor is 500 ℃, the pressure is 2MPa, and CO is₂Mass space velocity of 0.5h^-1. And (3) soaking coke in the gasification reactor by using a catalyst solution, wherein the catalyst is potassium carbonate, and the soaking amount is 0.05 percent of the mass of the coke. The working temperature of the hydrogen production reactor is 220 ℃, the pressure is 10MPa, and the volume space velocity of the raw material gas is 2000h^-1. The catalyst filled in the hydrogen production reactor is a copper-zinc-aluminum composite oxide hydrogen production catalyst, the catalyst is divided into two layers, wherein the copper-zinc-aluminum composite oxide catalyst filled in the upper layer is treated for 10 hours at 400 ℃; the filling mass ratio of the upper layer catalyst to the lower layer catalyst is 1: 5. The working temperature of the methanol synthesis reactor is 220 ℃, the pressure is 8MPa, and the volume space velocity of the raw material gas is 5000h^-1Wherein the mol ratio of the carbon dioxide to the water is 1: 1.

The results show that CO₂The total conversion rate reaches 99.95%, the total yield of methanol reaches 99.95%, and the water-cooled heat exchange unit generates high-grade steam of 10 MPa.

Example 2

The process flow is the same as in example 1.

Wherein the working temperature of the gasification reactor is 600 ℃, the pressure is 1.5MPa, and CO is₂Mass space velocity of 1.0h^-1. The coke in the gasification reactor is impregnated by catalyst solution, the catalyst is magnesium carbonate, and the impregnation amount is 0.08 percent of the mass of the coke. System for makingThe working temperature of the hydrogen reactor is 230 ℃, the pressure is 8MPa, and the volume space velocity of the raw material gas is 5000h^-1. The catalyst filled in the hydrogen production reactor is a copper-zinc-aluminum composite oxide hydrogen production catalyst, the catalyst is divided into two layers, wherein the copper-zinc-aluminum composite oxide catalyst filled in the upper layer is treated for 8 hours at 600 ℃; the filling mass ratio of the upper layer catalyst to the lower layer catalyst is 1: 4. The working temperature of the methanol synthesis reactor is 220 ℃, the pressure is 7MPa, and the volume space velocity of the raw material gas is 8000h^-1Wherein the mol ratio of the carbon dioxide to the water is 1: 2.

The results show that CO₂The total conversion rate reaches 99.91%, the total yield of methanol reaches 99.92%, and the water-cooled heat exchange unit generates 11MPa high-grade steam.

Example 3

The process flow is the same as in example 1.

Wherein the working temperature of the gasification reactor is 700 ℃, the pressure is 1.0MPa, and CO is₂Mass space velocity of 2.0h^-1. The coke in the gasification reactor is impregnated by catalyst solution, the catalyst is calcium carbonate, and the impregnation amount is 0.1 percent of the mass of the coke. The working temperature of the hydrogen production reactor is 250 ℃, the pressure is 7MPa, and the volume space velocity of the raw material gas is 10000h^-1. The catalyst filled in the hydrogen production reactor is a copper-zinc-aluminum composite oxide hydrogen production catalyst, the catalyst is divided into two layers, wherein the copper-zinc-aluminum composite oxide catalyst filled in the upper layer is treated for 8 hours at 700 ℃; the filling mass ratio of the upper layer catalyst to the lower layer catalyst is 1: 3. The working temperature of the methanol synthesis reactor is 240 ℃, the pressure is 6MPa, and the volume space velocity of the raw material gas is 12000h^-1Wherein the mol ratio of the carbon dioxide to the water is 1: 3.

The results show that CO₂The total conversion rate reaches 99.99 percent, the total yield of the methanol reaches 99.95 percent, and the water-cooling heat exchange unit generates high-grade steam of 12 MPa.

Example 4

The process flow is the same as in example 1.

Wherein the working temperature of the gasification reactor is 800 ℃, the pressure is 0.8 MPa, and CO is₂Mass space velocity of 2.5h^-1. The coke in the gasification reactor is soaked by catalyst solution, and the catalyst is magnesium carbonate and ammonium carbonate (mass ratio is1: 2), the impregnation amount was 0.2% of the coke mass. The working temperature of the hydrogen production reactor is 270 ℃, the pressure is 6MPa, and the volume space velocity of the raw material gas is 12000h^-1. The catalyst filled in the hydrogen production reactor is a copper-zinc-aluminum composite oxide hydrogen production catalyst, the catalyst is divided into two layers, wherein the copper-zinc-aluminum composite oxide catalyst filled in the upper layer is treated for 5 hours at 800 ℃; the filling mass ratio of the upper layer catalyst to the lower layer catalyst is 1: 4. The working temperature of the methanol synthesis reactor is 260 ℃, the pressure is 5MPa, and the volume space velocity of the raw material gas is 15000h^-1Wherein the molar ratio of the carbon dioxide to the water is 1: 4.

The results show that CO₂The total conversion rate reaches 99.99 percent, the total yield of the methanol reaches 99.99 percent, and the water-cooling heat exchange unit generates high-grade steam of 15 MPa.

Example 5

The process flow is the same as in example 1.

Wherein the working temperature of the gasification reactor is 900 ℃, the pressure is 0.5 MPa, and CO is₂Mass space velocity of 3.0h^-1. The coke in the gasification reactor is impregnated by a catalyst solution, wherein the catalyst is magnesium carbonate and calcium carbonate (the mass ratio is 1: 1), and the impregnation amount is 0.3 percent of the mass of the coke. The working temperature of the hydrogen production reactor is 250 ℃, the pressure is 5MPa, and the volume space velocity of the raw material gas is 15000h^-1. The catalyst filled in the hydrogen production reactor is a copper-zinc-aluminum composite oxide hydrogen production catalyst, the catalyst is divided into two layers, wherein the copper-zinc-aluminum composite oxide catalyst filled in the upper layer is treated for 5 hours at 800 ℃; the filling mass ratio of the upper layer catalyst to the lower layer catalyst is 1: 2. The working temperature of the methanol synthesis reactor is 250 ℃, the pressure is 5MPa, and the volume space velocity of the raw material gas is 20000h^-1. The molar ratio of the carbon dioxide to the water in the raw material gas is 1: 4.

The results show that CO₂The total conversion rate reaches 99.99 percent, the total yield of the methanol reaches 99.99 percent, and the water-cooling heat exchange unit generates high-grade steam of 18 MPa.

Example 6

The process flow is the same as in example 1.

Wherein the working temperature of the gasification reactor is 1000 ℃, the pressure is 0.2 MPa, and CO is₂Mass space velocity of 3.5h^-1. Char in gasification reactorThe catalyst is potassium carbonate and magnesium carbonate (the mass ratio is 1: 1) after the impregnation treatment of the catalyst solution, and the impregnation amount is 0.5 percent of the mass of the coke. The working temperature of the hydrogen production reactor is 270 ℃, the pressure is 3MPa, and the volume space velocity of the raw material gas is 20000h^-1. The catalyst filled in the hydrogen production reactor is a copper-zinc-aluminum composite oxide hydrogen production catalyst, the catalyst is divided into two layers, wherein the copper-zinc-aluminum composite oxide catalyst filled in the upper layer is treated for 5 hours at 800 ℃; the filling mass ratio of the upper layer catalyst to the lower layer catalyst is 1: 1. The working temperature of the methanol synthesis reactor is 270 ℃, the pressure is 4MPa, and the volume space velocity of the raw material gas is 20000h^-1. The molar ratio of the carbon dioxide to the water in the raw material gas is 1: 4.

The results show that CO₂The total conversion rate reaches 99.99 percent, the total yield of the methanol reaches 99.99 percent, and the water-cooling heat exchange unit generates high-grade steam of 20 MPa.

Example 7

The process flow is the same as in example 1.

Wherein the working temperature of the gasification reactor is 1000 ℃, the normal pressure is high, and CO is generated₂Mass space velocity of 3.5h^-1. The coke in the gasification reactor is impregnated by a catalyst solution, wherein the catalyst is potassium carbonate and ammonium bicarbonate (the mass ratio is 1: 1), and the impregnation amount is 0.5 percent of the mass of the coke. The working temperature of the hydrogen production reactor is 270 ℃, the pressure is 6MPa, and the volume space velocity of the raw material gas is 20000h^-1. The catalyst filled in the hydrogen production reactor is a copper-zinc-aluminum composite oxide hydrogen production catalyst, the catalyst is divided into two layers, wherein the copper-zinc-aluminum composite oxide catalyst filled in the upper layer is treated for 5 hours at 800 ℃; the filling mass ratio of the upper layer catalyst to the lower layer catalyst is 1: 1. The working temperature of the methanol synthesis reactor is 270 ℃, the pressure is 2MPa, and the volume space velocity of the raw material gas is 20000h^-1. The molar ratio of the carbon dioxide to the water in the raw material gas is 1: 4.

The results show that CO₂The total conversion rate reaches 99.99 percent, the total yield of the methanol reaches 99.99 percent, and the water-cooling heat exchange unit generates high-grade steam of 22 MPa.