阅读说明：本技术 一种超高纯一氧化碳制备装置与工艺 (Device and process for preparing ultra-pure carbon monoxide ) 是由 田叶盛 李虎林 谢宜桉 黄志杰 龙磊 方华仁 许博文 王学莹 于 2020-07-30 设计创作，主要内容包括：本发明涉及一种超高纯一氧化碳制备装置与工艺,包括依次串联的甲酸脱水反应装置、碱洗塔、低温冷阱、脱氧塔、吸附干燥塔、低温精馏塔,其中甲酸脱水反应装置中发生甲酸脱水反应,碱洗塔用于脱除所述混合气中的酸性杂质组分；低温冷阱对经过碱洗塔后的气体进行冷凝脱水；脱氧塔对经过低温冷阱的气体进行除氧；低温精馏塔对经过吸附干燥塔的气体进行精馏再提纯,在塔釜可得到纯度不低于99.9999％的超高纯一氧化碳产品。与现有技术相比,本发明整体技术工艺以较低的能耗和设备投入取得了优质的电子级一氧化碳产品,可实现工业化的推广；同时得到Na<Sub>2</Sub>SO<Sub>4</Sub>、NaHSO<Sub>4</Sub>副产品,有效提升了资源利用率,节约了制备成本,提升了产品的经济效益。(The invention relates to a device and a process for preparing ultra-pure carbon monoxide, which comprises a formic acid dehydration reaction device, an alkaline washing tower, a low-temperature cold trap, an oxygen removal tower, an adsorption drying tower and a low-temperature rectifying tower which are sequentially connected in series, wherein the formic acid dehydration reaction device generates a formic acid dehydration reaction, and the alkaline washing tower is used for removing acidic impurity components in the mixed gas; the low-temperature cold trap condenses and dehydrates the gas after passing through the alkaline washing tower; the oxygen removal tower removes oxygen from the gas passing through the low-temperature cold trap; the gas passing through the adsorption drying tower is rectified and purified by the low-temperature rectifying tower, and an ultra-pure carbon monoxide product with the purity of not less than 99.9999 percent can be obtained at the tower bottom. Compared with the prior art, the whole technical process obtains high-quality electronic-grade carbon monoxide products with lower energy consumption and equipment investment, and can realize industrialized popularization; simultaneously obtain Na 2 SO 4 、NaHSO 4 The by-product effectively improves the resource utilization rate, saves the preparation cost and improves the economic benefit of the product.)

1. An ultra-high purity carbon monoxide preparation device is characterized by comprising the following components in series in sequence:

a formic acid dehydration reaction unit (6) in which a formic acid dehydration reaction occurs to produce a mixed gas rich in carbon monoxide;

an alkaline washing tower for removing acidic impurity components in the mixed gas;

the low-temperature cold trap (12) is used for condensing and dehydrating the gas after passing through the alkaline tower;

a deoxygenation tower (14) for deoxygenating the gas passing through the cryotrap (12);

an adsorption drying tower (16) for deeply removing carbon dioxide and water by adsorption from the gas passing through the deoxidation tower (14);

and the low-temperature rectifying tower (18) is used for rectifying and purifying the gas passing through the adsorption drying tower (16), low-boiling-point components are enriched at the top of the tower, carbon monoxide is used as a heavy component to be concentrated at the bottom of the tower, an ultra-pure carbon monoxide product with the purity of not less than 99.9999 percent can be obtained at the bottom of the tower, and fuel gas rich in CO is obtained at the top of the tower.

2. The apparatus for producing ultra-high purity carbon monoxide according to claim 1, wherein a condensing evaporator (26) is provided on the top of the cryogenic rectification column (18), and the condensing evaporator (26) is a total condenser.

3. The apparatus for preparing ultra-high purity carbon monoxide according to claim 2, wherein the condensing evaporator (26) uses liquid nitrogen as a cold source, the liquid nitrogen is fed by a pipeline, and is vaporized by heat exchange to generate nitrogen gas which is discharged by the pipeline.

4. The device for preparing the ultra-high purity carbon monoxide according to claim 1, wherein the number of theoretical plates of the low-temperature rectifying tower (18) is 60-200, the pressure in the tower is 80-300 kPa, the temperature in the tower is 80-90K, the tower is filled with metal corrugated structured packing, and the peak height of the packing is 5-10 mm.

5. The apparatus for preparing ultra-high purity carbon monoxide according to claim 1, wherein the adsorption drying tower (16) is filled with a molecular sieve adsorbent.

6. The apparatus for producing ultra-high purity carbon monoxide according to claim 1, wherein the interior of the deoxygenation column (14) is filled with a deoxygenation catalyst.

7. The ultra-high purity carbon monoxide production unit as recited in claim 1, wherein the caustic tower comprises a first stage caustic tower (8) and a second stage caustic tower (10) forming a two-stage caustic washing structure;

in the two-stage alkaline washing structure, 5% -10% NaOH solution is adopted as the spray liquid of the second-stage alkaline washing tower (10), and the spray liquid collected from the bottom of the second-stage alkaline washing tower (10) is sent to the top of the first-stage alkaline washing tower (8) and is used as the spray liquid of the first-stage alkaline washing tower.

8. The ultra-high purity carbon monoxide preparation device according to claim 1, wherein a formic acid storage tank (2) is connected in front of the formic acid dehydration reaction device (6) and used for storing and providing formic acid raw materials for the formic acid dehydration reaction device (6).

9. Use of an apparatus for the preparation of ultra-high purity carbon monoxide according to any one of claims 1 to 8, comprising the steps of:

(a) sending a formic acid raw material into a formic acid dehydration reaction device (6) through a metering pump (4) to perform formic acid dehydration cracking reaction to produce a mixed gas rich in carbon monoxide;

(b) the mixed gas rich in carbon monoxide enters the bottom of a first-stage alkaline washing tower (8) under the pushing of pressure difference, most of acid gas impurity components are removed, and then the mixed gas enters the bottom of a second-stage alkaline washing tower (10), so that the acid impurity components are deeply removed;

(c) inputting the residual gas from which the acidic impurity components are removed into a low-temperature cold trap (12), and condensing at low temperature in the low-temperature cold trap (12) to remove most of water in the gas;

(d) feeding the dehydrated gas into the bottom of a deoxygenation tower (14), removing trace oxygen in the gas through a catalytic conversion reaction, then feeding the deoxygenated gas into the bottom of an adsorption drying tower (16), deeply removing trace carbon dioxide and water, and obtaining high-purity carbon monoxide gas with the purity of not less than 99% at the top of the adsorption drying tower (16);

(e) and (3) feeding the obtained high-purity carbon monoxide gas into a low-temperature rectifying tower (18) for rectification and purification, removing trace hydrogen and nitrogen, and obtaining an ultrapure electronic grade carbon monoxide product with the purity of not less than 99.9999% at the tower kettle of the low-temperature rectifying tower (18).

10. The use of the ultra-high purity carbon monoxide production plant according to claim 9, wherein the formic acid dehydration reaction unit (6) performs formic acid dehydration cracking reaction to produce a dilute sulfuric acid solution of 60-70 wt%;

washing alkali liquor in the first-stage alkaline tower (8) and the second-stage alkaline tower (9) to remove acid gas, generating alkali solution, mixing the dilute sulfuric acid solution with the alkali solution for reaction, and generating Na₂SO₄And NaHSO₄By-products.

Technical Field

The invention relates to the field of preparation of high-purity carbon monoxide, in particular to a device and a process for preparing ultrahigh-purity carbon monoxide.

Background

Carbon monoxide is an important organic chemical raw material, and can be used for preparing ammonia, phosgene, alcohol, acid, anhydride, ester, aldehyde, ether amine, alkane and olefin, various homogeneous reaction catalysts, high-purity nickel extraction and the like. With the rapid development of semiconductor and electronic industries, high-purity carbon monoxide electronic gas has the characteristic of forming low-boiling-point carbonyl complexes with transition metals such as copper, molybdenum, tantalum, tungsten and the like, and is widely used in semiconductor process technologies such as plasma-assisted vapor deposition cavity purging, etching and the like; in addition, high-purity carbon monoxide is widely applied to the fields of medical intermediates, standard gas preparation, carbon monoxide lasers, environmental monitoring, scientific research and the like.

In recent years, various carbon monoxide preparation technologies are developed in China, and the technologies can be mainly divided into the following technologies:

(1) the method takes coal gas, coke oven gas, flue gas and the like as raw materials, and removes complex impurity components through various pressure swing adsorption processes and devices to obtain more than 99.9 percent of carbon monoxide. The process is complex, has many impurity components, and is not easy to control the product quality.

(2) The methanol cracking method is adopted, methanol is cracked at high temperature under the action of a catalyst to obtain mixed gas rich in carbon monoxide, then impurities such as hydrogen, alkane and olefin are removed through pressure swing adsorption, and carbon monoxide with the purity of 99.9% is obtained after adsorption and purification. The method has the defects of complex process, expensive methanol cracking catalyst, low methanol utilization rate, active methanol, flammability and explosiveness and difficult storage.

(3) A formic acid dehydration cracking method is adopted, formic acid is subjected to dehydration reaction under the catalysis of concentrated sulfuric acid to produce mixed gas rich in carbon monoxide, and then carbon monoxide products with the purity of 99.9% are obtained through purification treatment. The method is simple and convenient to operate, is easy for medium-scale industrial preparation, and adopts typical patent technologies such as CN 107188176A, CN 106365164A, CN 105084359B and the like at present.

However, in the prior art, the purity of the prepared carbon monoxide gas cannot meet the requirements of modern super-large-scale integrated circuits, and the prior art has the defects of high production cost, insufficient resource utilization, inconvenient operation and the like.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a device and a process for preparing ultra-pure carbon monoxide, wherein an electronic grade carbon monoxide product with the purity of not less than 99.9999 percent is prepared by combining a plurality of technologies such as catalytic conversion, adsorption separation, chemical absorption, low-temperature rectification separation and the like, and meanwhile, the resource utilization rate is effectively improved, the preparation cost is saved and the economic benefit of the product is improved by effectively configuring resources.

The purpose of the invention can be realized by the following technical scheme:

the ultrahigh-purity carbon monoxide preparation device comprises a formic acid dehydration reaction device, an alkaline washing tower, a low-temperature cold trap, a deoxygenation tower, an adsorption drying tower and a low-temperature rectifying tower which are sequentially connected in series, wherein specifically:

formic acid dehydration reaction is carried out in the formic acid dehydration reaction device to generate a mixed gas rich in carbon monoxide;

the alkaline washing tower is used for removing acidic impurity components in the mixed gas;

the low-temperature cold trap condenses and dehydrates the gas after passing through the alkaline washing tower;

the oxygen removal tower removes oxygen from the gas passing through the low-temperature cold trap;

the adsorption drying tower deeply removes carbon dioxide and water from the gas passing through the deoxidation tower through adsorption;

the low-temperature rectifying tower rectifies and purifies the gas passing through the adsorption drying tower, low-boiling-point components are enriched at the tower top, carbon monoxide is concentrated at the tower bottom as a heavy component, an ultra-pure carbon monoxide product with the purity of not less than 99.9999% can be obtained at the tower bottom, and fuel gas rich in CO is obtained at the tower top.

Further, a condensation evaporator is arranged at the top of the low-temperature rectifying tower, and the condensation evaporator is a full condenser.

Further, the condensing evaporator takes liquid nitrogen as a cold source, the liquid nitrogen is fed by a pipeline, and is vaporized by heat exchange to generate nitrogen which is discharged by the pipeline.

Furthermore, the number of theoretical plates of the low-temperature rectifying tower is 60-200, the pressure in the tower is 80-300 kPa, the temperature in the tower is 80-90K, the tower is filled with metal corrugated regular packing, and the packing peak height is 5-10 mm.

Furthermore, the adsorption drying tower is filled with a molecular sieve adsorbent.

Further, the interior of the deoxygenation tower is filled with a deoxygenation catalyst.

Further, the alkaline washing tower comprises a first-stage alkaline washing tower and a second-stage alkaline washing tower, and a two-stage alkaline washing structure is formed;

in the two-stage alkaline washing structure, 5-10% of NaOH solution is adopted as the spray liquid of the second-stage alkaline washing tower, and the spray liquid collected at the bottom of the second-stage alkaline washing tower is sent to the top of the first-stage alkaline washing tower and is used as the spray liquid of the first-stage alkaline washing tower.

Further, a formic acid storage tank is connected in front of the formic acid dehydration reaction device and used for storing and providing formic acid raw materials for the formic acid dehydration reaction device.

When the ultrahigh-purity carbon monoxide preparation device is used in specific production, the ultrahigh-purity carbon monoxide preparation device comprises the following steps:

(a) sending a formic acid raw material into a formic acid dehydration reaction device through a metering pump to perform formic acid dehydration cracking reaction to produce a mixed gas rich in carbon monoxide;

(b) the mixed gas rich in carbon monoxide enters the bottom of a first-stage alkaline washing tower under the pushing of pressure difference, most of acid gas impurity components are removed, and then the mixed gas enters the bottom of a second-stage alkaline washing tower, so that acid impurity components are deeply removed;

(c) inputting the residual gas after removing the acidic impurity components into a low-temperature cold trap, and carrying out low-temperature condensation in the low-temperature cold trap to remove most of water in the gas;

(d) feeding the dehydrated gas into the bottom of a deoxygenation tower, removing trace oxygen in the gas through a catalytic conversion reaction, feeding the deoxygenated gas into the bottom of an adsorption drying tower, deeply removing trace carbon dioxide and water, and obtaining high-purity carbon monoxide gas with the purity of not less than 99% at the top of the adsorption drying tower;

(e) and (3) feeding the obtained high-purity carbon monoxide gas into a low-temperature rectifying tower for rectification and purification, removing trace hydrogen and nitrogen, and obtaining an ultrapure electronic grade carbon monoxide product with the purity of not less than 99.9999% at a tower kettle of the low-temperature rectifying tower.

Furthermore, the temperature range of the low-temperature cold trap is-5 to-40 ℃.

Furthermore, the alkaline washing tower and the alkaline washing tower are both packed towers, and the tower body is made of modified special materials such as glass fiber reinforced plastics, polyvinyl chloride and polypropylene plastics or made of steel lined polyvinyl chloride plastics. The tower is filled with acid and alkali corrosion resistant plastic Raschig rings, pall rings and other random packing or regular packing made of polyvinyl chloride, polypropylene and other plastic materials.

Furthermore, a deoxidation catalyst is filled in the deoxidation tower, carbon monoxide and trace oxygen are subjected to oxidation reaction under the action of the catalyst to generate carbon dioxide and water, and the reaction equation is as follows:

CO+O₂→CO₂+H₂O

furthermore, the adsorption drying tower is filled with a molecular sieve adsorbent, so that the content of carbon dioxide and water can be reduced to below 1 ppm.

Furthermore, the formic acid dehydration reaction device is made of corrosion-resistant materials such as enamel and glass, and the dehydration catalyst is concentrated sulfuric acid.

Wherein, the technical scheme of the invention also generates a part of byproducts, and the main generation process is as follows: the formic acid dehydration reaction device generates formic acid dehydration cracking reaction to generate 60 wt% -70 wt% of dilute sulfuric acid solution;

washing alkali liquor in the first-stage alkaline tower and the second-stage alkaline tower to remove acid gas, generating alkali solution, mixing the dilute sulfuric acid solution and the alkali solution for reaction, and generating Na₂SO₄And NaHSO₄By-products.

Compared with the prior art, the invention has the following advantages:

1) according to the invention, through the combination of a plurality of technologies such as catalytic conversion, adsorption separation, chemical absorption, low-temperature rectification separation and the like, the key technical problem of deep removal of trace impurities in high-purity electronic grade gas is solved, the electronic grade carbon monoxide product with the purity of not less than 99.9999% is prepared, the high-quality electronic grade carbon monoxide product is obtained by the whole technical process with low energy consumption and equipment investment, the added value of the product is high, the industrial popularization can be realized, and the method has a good industrial application prospect.

2) The method has the advantages of mild reaction conditions, no high-temperature and high-pressure operation, simple and convenient operation, small influence of amplification effect and easy large-scale production.

3) Meanwhile, Na is obtained through effective allocation of resources₂SO₄、NaHSO₄The by-product effectively improves the resource utilization rate, saves the preparation cost and improves the economic benefit of the product.

4) The technical scheme adopts an intermittent production mode, and along with the reaction, when the concentration of the sulfuric acid is reduced to be below 70%, the feeding of the formic acid is stopped, so that the high-quality control is realized in the reaction stage.

Drawings

FIG. 1 is a schematic diagram of a rectification process of the present invention.

In the figure: 1-formic acid raw material, 2-formic acid storage tank, 3-formic acid delivery pipeline a, 4-metering pump, 5-formic acid delivery pipeline b, 6-formic acid dehydration reaction device, 7-carbon monoxide delivery pipeline a, 8-first stage alkaline tower, 9-carbon monoxide delivery pipeline b, 10-second stage alkaline tower, 11-carbon monoxide delivery pipeline c, 12-cryogenic cold trap, 13-carbon monoxide delivery pipeline d, 14-deoxygenation tower, 15-carbon monoxide delivery pipeline e, 16-adsorption drying tower, 17-carbon monoxide delivery pipeline f, 18-cryogenic rectification tower, 19-carbon monoxide gas, 20-carbon monoxide liquid, 21-liquid nitrogen, 22-nitrogen, 23-fuel gas, 24-ultrapure carbon monoxide product, 25-condensation discharge valve, 26-condensation evaporator.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.