CN-122006404-A - Process and device for removing impurities from carbon monoxide after deep cooling separation of synthesis gas

CN122006404ACN 122006404 ACN122006404 ACN 122006404ACN-122006404-A

Abstract

The invention belongs to the technical field of coal-to-ethylene glycol, and particularly relates to a process and a device for refining and removing impurities from carbon monoxide after deep cooling separation of synthetic gas, wherein the device comprises a impurity removing device, and the impurity removing device is a desulfurizing tank, a dechlorination tank and a decarbonylation tank which are sequentially connected in series, or is an adsorption tower filled with desulfurizing, dechlorination and decarbonylation adsorbents in sequence; the impurity removing device is arranged to remove trace hydrogen sulfide, hydrogen chloride, carbonyl iron and carbonyl nickel in the CO after cryogenic separation, so that the impurity ppb level in the CO is removed, the poisoning of a downstream dimethyl oxalate (DMO) synthesis catalyst is avoided, the service life of the catalyst is prolonged, the production cost of enterprises is reduced, and the operation stability of the device is improved.

Inventors

CAO BIN
JU WENZHANG
ZHOU ZHIQIANG
Qiang Junfei
TANG HONGJIAN
YANG JUN
CAO ZHIYE
WEI DONG
LIANG HAIHUI
WANG FAYOU
CAO GUANGYUAN
Liu Xiongzu

Assignees

新疆天业汇合新材料有限公司

Dates

Publication Date: 20260512
Application Date: 20260317

Claims (10)

1. A process for removing impurities from CO after deep cooling separation of synthetic gas is characterized by comprising the steps of purifying the synthetic gas by a deep cooling separation device to obtain CO product gas with the pressure of 2.0-5.0 MPa and the temperature of 20-40 ℃ and the purity of more than or equal to 99.9%, introducing the CO product gas into a impurity removal device, adsorbing impurities in the CO product gas by using an adsorbent filled in the impurity removal device, operating the whole process under the pressure of 20-40 ℃ and the pressure of 2.0-5.0 MPa, monitoring the impurity content in real time by an online monitor, and conveying the CO product gas with the impurity removed to a DMO synthesis section.
2. The process for refining and removing impurities from carbon monoxide after cryogenic separation of synthesis gas according to claim 1, wherein the impurity removing device comprises a desulfurizing tank, a dechlorinating tank and a decarbonylating tank which are sequentially connected in series, wherein the desulfurizing tank, the dechlorinating tank and the decarbonylating tank are respectively filled with a desulfurizing adsorbent, a dechlorinating adsorbent and a decarbonylating adsorbent.
3. The process for refining and removing impurities from carbon monoxide after cryogenic separation of synthesis gas according to claim 1, wherein the impurity removing device is an adsorption tower, a desulfurization section, a dechlorination section and a decarbonylation section are sequentially arranged in the adsorption tower, and a desulfurization adsorbent, a dechlorination adsorbent and a decarbonylation adsorbent are respectively filled in the desulfurization section, the dechlorination section and the decarbonylation section.
4. A process for removing impurities from CO after deep cooling separation of synthesis gas according to claim 2 or 3, wherein the desulfurization adsorbent is nano ZnO-CeO 2 composite adsorbent, the dechlorination adsorbent is CuO-gamma-Al 2 O 3 modified adsorbent, and the decarbonylation adsorbent is Fe 2 O 3 -modified coconut activated carbon adsorbent.
5. The process for refining and removing impurities from carbon monoxide after cryogenic separation of synthesis gas according to any one of claims 1 to 4, wherein the impurity removing device is further provided with a standby impurity removing device, and the process is automatically switched to the standby impurity removing device when the impurity content index in the standard CO product gas is close to a threshold value.
6. The process for refining and removing impurities from carbon monoxide after cryogenic separation of synthesis gas according to claim 1, wherein the impurities in the CO product gas comprise H 2 S、HCl、Fe(CO) 5 、Ni(CO) 4 , H 2 S is less than or equal to 0.01ppm, HCl is less than or equal to 0.001ppm, and carbonyl (Fe+Ni) is less than or equal to 0.001ppm after treatment.
7. A device for precisely removing impurities from carbon monoxide after deep cooling separation of synthetic gas is characterized by comprising a impurity removing device, wherein a CO inlet of the impurity removing device is communicated with a CO outlet of the deep cooling separation device through a pipeline, a CO outlet of the impurity removing device is communicated with a CO inlet of a DMO synthesis device through a pipeline, the impurity removing device comprises a desulfurizing tank, a dechlorinating tank and a decarbonylating tank which are sequentially connected in series, and an on-line monitoring and automatic control unit, the desulfurizing tank, the dechlorinating tank and the decarbonylating tank are pressure-resistant tanks, desulfurizing adsorbent, dechlorinating adsorbent and decarbonylating adsorbent are respectively filled in the desulfurizing tank, the dechlorinating tank and the decarbonylating tank, and the on-line monitoring and automatic control unit comprises a total sulfur on-line monitor, a total chlorine on-line monitor, a carbonyl on-line monitor, a switching valve and a controller, wherein the monitor and the switching valve are respectively and electrically connected with the controller.
8. A device for precisely removing impurities from carbon monoxide after deep cooling separation of synthesis gas is characterized by comprising a impurity removing device, wherein a CO inlet of the impurity removing device is communicated with a CO outlet of the deep cooling separation device through a pipeline, a CO outlet of the impurity removing device is communicated with a CO inlet of a DMO synthesis device through a pipeline, the impurity removing device is an adsorption tower, a desulfurization section, a dechlorination section and a decarbonylation section are sequentially arranged in the adsorption tower, desulfurization adsorbents, dechlorination adsorbents and decarbonylation adsorbents are respectively filled in the desulfurization section, the dechlorination section and the decarbonylation section, and the on-line monitoring and automatic control unit comprises a total sulfur on-line monitor, a total chlorine on-line monitor, a carbonyl on-line monitor, a switching valve and a controller, wherein the monitor and the switching valve are respectively and electrically connected with the controller.
9. The device for removing impurities from carbon monoxide after cryogenic separation of synthesis gas according to claim 7, wherein adsorbent beds in the desulfurizing tank, the dechlorinating tank and the decarbonylating tank are filled in gradient pore size sections.
10. The device for removing impurities from carbon monoxide after cryogenic separation of synthesis gas according to claim 9, wherein the gradient pore diameter sectional filling is that a fine pore adsorbent with a pore diameter of 1-3 nm is filled in an upper layer, and a coarse pore adsorbent with a pore diameter of 5-10 nm is filled in a lower layer.

Description

Process and device for removing impurities from carbon monoxide after deep cooling separation of synthesis gas The invention belongs to the technical field of coal-to-ethylene glycol, and particularly relates to a process and a device for refining and removing impurities from carbon monoxide after cryogenic separation of synthesis gas. Background In the process of preparing ethylene glycol from coal, after CO is purified by cryogenic separation, the synthesis gas is required to be conveyed to a DMO synthesis section to react with methyl nitrite to generate DMO, the core catalyst of the section is a palladium noble metal catalyst which has extremely sensitivity to S, cl, fe, ni impurities, and irreversible poisoning can occur when the H 2 S content exceeds 0.1ppm, the HCl content exceeds 0.01ppm and the carbonyl (Fe+Ni) content exceeds 0.01ppm, so that the catalyst activity is quickly attenuated and the selectivity is reduced, the service life of the catalyst is further shortened, and the equipment shutdown maintenance frequency and the production cost are increased. The prior art generally adopts a concentrated purification before deep cooling strategy, and impurities are controlled at ppm level by a low-temperature methanol washing unit, a fine desulfurization unit, a dechlorination unit and a carbonyl decomposition/adsorption unit and then enter a deep cooling separation system. However, in actual production, the upstream purification unit has the problems of adsorbent penetration, working condition fluctuation, start-up/stop impact and the like, so that trace impurities in CO rebound after cryogenic separation directly threatens the safety of the DMO catalyst. Meanwhile, the technical prejudice that impurities are not required to be removed after deep cooling exists in the industry, the impurities are considered to be extremely low after deep cooling, the low-temperature and high-pressure environment after deep cooling can cause poor activity of the adsorbent, difficult regeneration and overhigh cost, so that a special fine impurity removal scheme is not designed for CO after deep cooling in the prior art, double insurance of impurity removal cannot be formed, and the risk of catalyst poisoning always exists. Disclosure of Invention The invention aims to solve the problems that trace impurities in CO are easy to cause poisoning of a DMO catalyst and the service life is short after cryogenic separation in the prior art, and provides a process and a device for removing trace hydrogen sulfide (H 2 S), hydrogen chloride (HCl), carbonyl iron (Fe (CO) 5) and carbonyl nickel (Ni (CO) 4) in CO after cryogenic separation. In order to achieve the above purpose, the invention adopts the following technical scheme: A process for removing impurities from CO after deep cooling separation of synthetic gas includes such steps as purifying synthetic gas by deep cooling separation unit to obtain CO product gas with pressure of 2.0-5.0 MPa, temp. of 20-40 deg.C and purity greater than or equal to 99.9%, introducing trace H 2S（≤0.1ppm）、HCl(≤0.01ppm)、Fe(CO)5(≤0.01ppm)、Ni(CO)4 (less than or equal to 0.005 ppm), adsorbing impurities in CO product gas by adsorbent, real-time monitoring the content of impurities, and delivering the CO product gas to DMO synthesis section. Further, the CO inlet of the impurity removing device is communicated with the CO outlet of the cryogenic separation device through a pipeline, the CO outlet of the impurity removing device is communicated with the CO inlet of the DMO synthesis device through a pipeline, and the impurity removing device comprises a desulfurizing tank, a dechlorinating tank and a decarbonylating tank which are sequentially connected in series. Further, a CO inlet of the impurity removing device is communicated with a CO outlet of the cryogenic separation device through a pipeline, a CO outlet of the impurity removing device is communicated with a CO inlet of the DMO synthesis device through a pipeline, the impurity removing device is an adsorption tower, and a desulfurization adsorbent, a dechlorination adsorbent and a decarbonylation adsorbent are sequentially filled in the adsorption tower. Further, the impurity removing device is further provided with a standby impurity removing device, and the standby impurity removing device is automatically switched to when the impurity content index in the standard CO product gas is close to the threshold value. Further, nano ZnO-CeO 2 composite adsorbent is filled in the desulfurization tank, cuO-gamma-Al 2O3 modified adsorbent is filled in the dechlorination tank, and Fe 2O3 -modified coconut activated carbon adsorbent is filled in the decarbonylation tank. Further, the impurities in the CO product gas comprise H 2S、HCl、Fe(CO)5、Ni(CO)4, wherein H 2 S is less than or equal to 0.01ppm, HCl is less than or equal to 0.001ppm and carbonyl (Fe+Ni) is less than or equal to 0.001ppm after impurity removal treatment. The device comprises a impur