CN115368210A - Method for treating tail gas hydrogen of hydrogenation reaction - Google Patents
Method for treating tail gas hydrogen of hydrogenation reaction Download PDFInfo
- Publication number
- CN115368210A CN115368210A CN202211081772.3A CN202211081772A CN115368210A CN 115368210 A CN115368210 A CN 115368210A CN 202211081772 A CN202211081772 A CN 202211081772A CN 115368210 A CN115368210 A CN 115368210A
- Authority
- CN
- China
- Prior art keywords
- hydrogen
- hydrogenation
- hydrogenation reaction
- tail gas
- gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 196
- 239000001257 hydrogen Substances 0.000 title claims abstract description 196
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 179
- 238000005984 hydrogenation reaction Methods 0.000 title claims abstract description 113
- 239000007789 gas Substances 0.000 title claims abstract description 70
- 238000000034 method Methods 0.000 title claims abstract description 38
- 238000004519 manufacturing process Methods 0.000 claims abstract description 47
- 150000002431 hydrogen Chemical class 0.000 claims abstract description 18
- 239000007788 liquid Substances 0.000 claims abstract description 13
- 238000000746 purification Methods 0.000 claims abstract description 10
- 238000000926 separation method Methods 0.000 claims abstract description 8
- 239000002994 raw material Substances 0.000 claims abstract description 7
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 28
- 238000006243 chemical reaction Methods 0.000 claims description 18
- YIMQCDZDWXUDCA-UHFFFAOYSA-N [4-(hydroxymethyl)cyclohexyl]methanol Chemical compound OCC1CCC(CO)CC1 YIMQCDZDWXUDCA-UHFFFAOYSA-N 0.000 claims description 17
- KKEYFWRCBNTPAC-UHFFFAOYSA-N Terephthalic acid Chemical compound OC(=O)C1=CC=C(C(O)=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-N 0.000 claims description 16
- -1 terephthalic acid-bis (4-methylcyclohexane) Chemical compound 0.000 claims description 10
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 9
- OJURWUUOVGOHJZ-UHFFFAOYSA-N methyl 2-[(2-acetyloxyphenyl)methyl-[2-[(2-acetyloxyphenyl)methyl-(2-methoxy-2-oxoethyl)amino]ethyl]amino]acetate Chemical compound C=1C=CC=C(OC(C)=O)C=1CN(CC(=O)OC)CCN(CC(=O)OC)CC1=CC=CC=C1OC(C)=O OJURWUUOVGOHJZ-UHFFFAOYSA-N 0.000 claims description 8
- 230000008569 process Effects 0.000 claims description 8
- PXGZQGDTEZPERC-UHFFFAOYSA-N 1,4-cyclohexanedicarboxylic acid Chemical compound OC(=O)C1CCC(C(O)=O)CC1 PXGZQGDTEZPERC-UHFFFAOYSA-N 0.000 claims description 4
- LNGAGQAGYITKCW-UHFFFAOYSA-N dimethyl cyclohexane-1,4-dicarboxylate Chemical compound COC(=O)C1CCC(C(=O)OC)CC1 LNGAGQAGYITKCW-UHFFFAOYSA-N 0.000 claims description 4
- WOZVHXUHUFLZGK-UHFFFAOYSA-N dimethyl terephthalate Chemical compound COC(=O)C1=CC=C(C(=O)OC)C=C1 WOZVHXUHUFLZGK-UHFFFAOYSA-N 0.000 claims description 4
- 239000003345 natural gas Substances 0.000 claims description 4
- 239000003054 catalyst Substances 0.000 abstract description 14
- 230000008901 benefit Effects 0.000 abstract description 7
- 230000007613 environmental effect Effects 0.000 abstract description 2
- 239000012535 impurity Substances 0.000 description 17
- 239000000047 product Substances 0.000 description 10
- 238000010586 diagram Methods 0.000 description 8
- 239000000463 material Substances 0.000 description 8
- 239000007791 liquid phase Substances 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- 229910002091 carbon monoxide Inorganic materials 0.000 description 4
- 239000005416 organic matter Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 3
- 231100000331 toxic Toxicity 0.000 description 3
- 230000002588 toxic effect Effects 0.000 description 3
- 239000002341 toxic gas Substances 0.000 description 3
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 231100000252 nontoxic Toxicity 0.000 description 2
- 230000003000 nontoxic effect Effects 0.000 description 2
- 229910052703 rhodium Inorganic materials 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000009849 deactivation Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 238000000053 physical method Methods 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/17—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by hydrogenation of carbon-to-carbon double or triple bonds
- C07C29/19—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by hydrogenation of carbon-to-carbon double or triple bonds in six-membered aromatic rings
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
- C01B3/06—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of inorganic compounds containing electro-positively bound hydrogen, e.g. water, acids, bases, ammonia, with inorganic reducing agents
- C01B3/12—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of inorganic compounds containing electro-positively bound hydrogen, e.g. water, acids, bases, ammonia, with inorganic reducing agents by reaction of water vapour with carbon monoxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
- C01B3/22—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of gaseous or liquid organic compounds
- C01B3/24—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of gaseous or liquid organic compounds of hydrocarbons
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/50—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
- C07C1/02—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon
- C07C1/04—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon from carbon monoxide with hydrogen
- C07C1/0405—Apparatus
- C07C1/041—Reactors
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2601/00—Systems containing only non-condensed rings
- C07C2601/12—Systems containing only non-condensed rings with a six-membered ring
- C07C2601/14—The ring being saturated
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention provides a method for treating tail gas hydrogen of hydrogenation reaction, wherein one part of tail gas hydrogen obtained by gas-liquid separation after hydrogenation reaction is directly introduced into a hydrogenation reactor as internal circulation hydrogen, or the internal circulation hydrogen is treated by a methanation device and then directly introduced into the hydrogenation reactor, the other part of the tail gas hydrogen obtained by gas-liquid separation after hydrogenation reaction is introduced into a purification device in a hydrogen production system as external circulation hydrogen, hydrogen obtained by purifying and purifying the external circulation hydrogen and hydrogen prepared by a hydrogen production raw material through the hydrogen production system are jointly used as fresh high-purity hydrogen to be added into the hydrogenation reactor, and the fresh high-purity hydrogen and the internal circulation hydrogen which is or is not treated by the methanation device jointly form total hydrogen for the hydrogenation reaction. The method can effectively reduce the unit consumption of hydrogen and save the production cost. And simultaneously, the concentration of CO in a hydrogenation system is controlled, and the influence of CO on the catalyst is reduced. The method can obtain obvious economic benefit and environmental protection benefit.
Description
Technical Field
The invention relates to the field of organic matter hydrogenation reaction, in particular to a method for treating tail gas hydrogen of hydrogenation reaction.
Background
In the organic hydrogenation reaction (hydrogenation reaction), in order to increase the concentration of hydrogen in the reaction, the reaction conditions are usually high temperature and high pressure and a large excess of hydrogen and the excess of hydrogen is usually several times the theoretical requirement of the reaction. Therefore, in order to reduce the unit consumption of reaction hydrogen, it is necessary to recycle hydrogen in the hydrogenation reaction.
It appears that the hydrogen circulation is very simple, and the unreacted hydrogen can be returned to the hydrogenation reactor by installing a gas-liquid separator at the outlet of the reactor, separating the organic matters in a liquid phase and adding a compressor in a gas phase for pressure reduction. However, the problem is not so simple as it is, and carbon monoxide, carbon dioxide or other gases are produced by decomposition of a very small portion of the organic matter (raw material) during the hydrogenation reaction, and if these by-product gases cannot be effectively separated and discharged, they are continuously accumulated in the hydrogen recycle gas. This not only affects the concentration of hydrogen in the hydrogen recycle gas, but also slowly affects the hydrogenation efficiency of the hydrogenation reactor, and there is a more important problem that these impurity gases in the hydrogen recycle gas have a significant effect on the life of the hydrogenation catalyst. For example, pd and Rh are heavy metals commonly used in hydrogenation catalysts, while carbon monoxide and carbon dioxide are toxic gases of Pd and Rh, and only ppm amounts of toxic gases are required to accelerate the deactivation of the catalysts. These gases that affect catalyst life are generally referred to in the art as CO.
In the prior art, a lot of researches have disclosed separating impurity gases in hydrogen recycle gas (tail gas hydrogen of hydrogenation reaction), for example, US6179996 uses a specially designed membrane to concentrate hydrogen for reducing the loss of hydrogen in the tail gas of hydrogenation reaction and also can effectively remove the impurity gases. Accordingly, the flow rate of the circulating hydrogen can be increased, and the CO concentration in the hydrogenation reactor can be controlled within a reasonable range.
Instead of physically removing the impurity gases, chemical methods may be used to remove these impurity gases. Such as the methanation reaction described in patents US3967936 and CN102600771, which is effective in converting CO, which is toxic to the catalyst, to methane. The method can effectively reduce the CO concentration in the circulating hydrogen, but the methane concentration in the circulating hydrogen is improved a lot, and the hydrogen concentration in the circulating hydrogen is reduced, thereby influencing the reaction efficiency of the hydrogenation reaction.
The two methods for treating tail gas hydrogen of hydrogenation reaction have certain advantages, but are not perfect. The first physical method, in which as the concentration of impurity gases increases, the method often requires an additional large investment. The second chemical method is to convert the impurity gas toxic to the hydrogenation catalyst into a gas non-toxic to the hydrogenation catalyst, which solves the problem of catalyst poisoning, but the newly produced impurity gas (such as methane) also needs to be effectively removed.
Therefore, there is a need in the art for a new method for treating tail gas hydrogen from hydrogenation reactions.
Disclosure of Invention
The invention provides a method for treating tail gas hydrogen of hydrogenation reaction, wherein one part of tail gas hydrogen obtained by gas-liquid separation after hydrogenation reaction is directly introduced into a hydrogenation reactor as internal recycle hydrogen, or the internal recycle hydrogen is firstly converted into methane by a methanation device and then the treated internal recycle hydrogen is directly introduced into the hydrogenation reactor, the other part of tail gas hydrogen obtained by gas-liquid separation after hydrogenation reaction is introduced into a purification device in a hydrogen production system as external recycle hydrogen, hydrogen obtained by purifying and purifying the external recycle hydrogen and hydrogen prepared by a hydrogen production raw material through the hydrogen production system are jointly used as fresh high-purity hydrogen to be added into the hydrogenation reactor, and the fresh high-purity hydrogen and the internal recycle hydrogen treated by or not by the methanation device jointly form total hydrogen for the hydrogenation reaction.
In a specific embodiment, the ratio of internal recycle hydrogen to external recycle hydrogen is from 0.5 to 5:1, preferably 0.8 to 4:1, more preferably 1 to 3:1.
in a specific embodiment, the hydrogenation reaction is one of the following reactions: terephthalic acid hydrogenation to 1,4-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid hydrogenation to 1,4-cyclohexanedimethanol, terephthalic acid continuous two stage hydrogenation to 1,4-cyclohexanedimethanol, dimethyl terephthalate hydrogenation to 1,4-dimethyl cyclohexanedicarboxylate, 1,4-dimethyl cyclohexanedicarboxylate hydrogenation to 1,4-cyclohexanedimethanol, terephthalic acid-bis (4-methylcyclohexane) dimethyl ester hydrogenation to 1,4-cyclohexanedicarboxylate-bis (4-methylcyclohexane) dimethyl ester, 1,4-cyclohexanedicarboxylic acid-bis (4-methylcyclohexane) dimethyl ester hydrogenation to 1,4-cyclohexanedimethanol, terephthalic acid-bis (4-methylcyclohexane) dimethyl ester continuous two stage hydrogenation to 1,4-cyclohexanedimethanol.
In a specific embodiment, the hydrogen production system is a natural gas hydrogen production system or a methanol hydrogen production system.
In a particular embodiment, the internal recycle hydrogen has a CO concentration after treatment in the methanation unit of less than 20ppm, preferably less than 10ppm.
In a particular embodiment, the hydrogen consumption per unit of hydrogenation is not higher than 1.1 times the theoretical value, preferably not higher than 1.05 times, more preferably not higher than 1.03 times.
In a particular embodiment, the CO concentration of the total hydrogen used in the hydrogenation reaction is less than 30ppm, preferably less than 25ppm, more preferably less than 20ppm.
In a specific embodiment, the exhaust amount of the tail gas hydrogen obtained by gas-liquid separation after the hydrogenation reaction before a part of the tail gas hydrogen enters the hydrogen production system is zero.
Has the advantages that: the method can effectively reduce the unit consumption of hydrogen and save the production cost. And simultaneously, the concentration of CO in a hydrogenation system is controlled, and the influence of CO on the catalyst is reduced. The method of the invention can obtain obvious economic benefit and environmental protection benefit.
Drawings
FIG. 1 is a flow diagram of hydrogen treatment of the tail gas of a hydrogenation reaction in the prior art.
FIG. 2 is a flow diagram of hydrogen treatment of the tail gas from another hydrogenation reaction of the prior art.
FIG. 3 is a schematic diagram of the introduction of hydrogen as a tail gas of a hydrogenation reaction into a hydrogen production system in accordance with the present invention.
FIG. 4 is a flow chart showing a process for treating hydrogen as a tail gas in a hydrogenation reaction according to the present invention, in which a methanation unit is not provided.
FIG. 5 is a flow chart of the method for treating hydrogen as a tail gas in a hydrogenation reaction according to the present invention, in which a methanation apparatus is provided.
FIG. 6 is a flow diagram of the process for the hydrogenation of terephthalic acid to 1,4-cyclohexanedimethanol in accordance with the present invention.
Detailed Description
FIG. 1 is a flow diagram of hydrogen treatment of the tail gas of a hydrogenation reaction in the prior art. In FIG. 1, if stream (1) is 100 moles of organics, stream (2) is 300.074 moles of fresh hydrogen (containing 5ppm of CO), stream (3) is 200 moles of internal recycle hydrogen, and stream (4) has a total hydrogen flow of 500 moles, to achieve the reaction 5:1 (hydrogen: organic) 100mol of organic will react with 99.99mol of hydrogen to produce 99.99mol of product under the designed reaction conditions, the remaining 0.01mol of organic will decompose to produce 0.01mol of CO to form stream (5). In the gas-liquid separator, the product (6) is separated in the liquid phase, the remaining gas is the stream (7), and the total amount of gas discharged in the stream (8) is 200mol in order to discharge 0.01mol of CO in the stream (8). The corresponding stream balances of FIG. 1 are shown in Table 1.
TABLE 1
| |
① | ② | ③ | ④ | ⑤ | ⑥ | ⑦ | ⑧ |
| Hydrogen gas | / | 300.07 | 200.04 | 500.11 | 400.12 | / | 400.08 | 200.04 |
| CO | / | 0.002 | 0.01 | 0.01 | 0.02 | / | 0.02 | 0.01 |
| Organic matter | 100.00 | / | / | / | / | / | / | / |
| Product(s) | 99.99 | 99.99 | ||||||
| Total flow rate | 100.00 | 300.07 | 200.05 | 500.12 | 500.13 | 99.99 | 400.10 | 200.05 |
In the above case, the evacuation ratio (the percentage of the evacuated amount (8) to the total amount of gas (7)) was 50%, and the flow rate of fresh hydrogen (2) in this state was 300.07mol, while the CO concentration of the hydrogenation reactor feed was 25ppm. If the amount of fresh hydrogen (2) is reduced, the CO concentration at the inlet of the hydrogenation reactor increases and the evacuation ratio correspondingly decreases. As the purge ratio decreases, the CO concentration in the hydrogenation reactor increases, which is extremely harmful to the catalyst. Generally, the acceptable CO concentration in the hydrogenation reactor is below 30ppm, so the input amount of fresh hydrogen (2) is required to be more than 250mol, which is 2.5 times of the theoretical value of the hydrogen used in the hydrogenation reactor, and the emptying amount (8) is required to be more than 150mol, which causes the unit consumption of hydrogen to be increased greatly, and the mode is not feasible for industrial production.
Therefore, in the prior art, in the industrial process of the hydrogenation reaction, a methanation device is generally added to treat the tail gas hydrogen of the hydrogenation reaction, so that CO in the tail gas hydrogen is hydrogenated into methane, and the gas toxic to the hydrogenation catalyst is converted into the non-toxic gas. FIG. 2 depicts a flow diagram of hydrogen treatment of the tail gas of another hydrogenation reaction of the prior art.
In FIG. 2, stream (1) is 100 moles of organics, stream (2) is 160.75 moles of fresh hydrogen (containing 5ppm CO) plus 339.25 moles of internal recycle hydrogen for stream (3), and the total hydrogen flow for stream (4) is 500 moles, to achieve the reaction 5:1 (hydrogen: organic) operation, 100mol of organic will react with 99.99mol of hydrogen to produce 99.99mol of product under the designed reaction conditions, and the remaining 0.01mol of organic will decompose to produce 0.01mol of CO, forming stream (5). In the gas-liquid separator, the product (6) is separated in the liquid phase, the remaining gas is stream (7), and the total gas discharge of stream (8) is 60.77mol in order to discharge 0.01mol of impurity gas in stream (8). The remaining internal recycle gas (9) is passed to the methanation unit, assuming that 90% of the CO is converted to CH in the methanation unit 4 The concentration of CO entering the hydrogenation reactor can be effectively reduced.
Compared with the graph 1, the methanation device is added in the graph 2, so that the concentration of CO in the hydrogenation reactor can be effectively controlled, the normal operation of the hydrogenation reaction is ensured, and the input amount of fresh hydrogen is obviously reduced. However, a new problem occurs, namely new impurity methane is introduced into the hydrogenation reactor, and the concentration of the methane is inversely proportional to the input amount of fresh hydrogen, if the unit consumption of the hydrogen is reduced, the concentration of the methane in the hydrogenation reactor is inevitably increased, and the high concentration of the methane reduces the concentration and partial pressure of the hydrogen in the hydrogenation reaction system, so that the hydrogenation reaction has uncertain influence. Therefore, the method is also worth further improvement.
According to the method, a part of tail gas hydrogen is introduced into the hydrogen production system, and the high-purity hydrogen obtained after purification by the hydrogen production system is recycled to the hydrogenation reaction, so that the unit consumption of the hydrogen is effectively reduced, and the production cost is saved; and the concentration of CO in the hydrogenation reaction system can be controlled, and the influence of CO on the hydrogenation catalyst is reduced.
The existing hydrogen production system generally comprises two types of hydrogen production by natural gas and hydrogen production by methanol, the hydrogen production cost of the former is gradually reduced, and the advantage of the former is more and more obvious.
The chemical formula is as follows:
2CH 4 +O 2 →2CO+4H 2
CO+H 2 O→CO 2 +H 2
after the reaction is finished, CO is required to be added 2 CO and CH 4 Gas from H 2 And (5) purifying and separating. Therefore, the hydrogen production system needs to be provided with a purification device for purifying H 2 To remove impurities such as CO 2 CO and CH 4 Etc., and providing H in an amount greater than 99.999% 2 . Therefore, if the hydrogenation reaction process of the enterprise is matched with a special hydrogen production device (namely, a hydrogen production system), the tail gas hydrogen in the hydrogenation reaction is purified by using a purification and purification device which is already equipped in the hydrogen production system without additionally adding a methanation device as shown in FIG. 2 to treat the tail gas hydrogen. Therefore, the overall use efficiency of the hydrogen is improved, and simultaneously, a tail gas circulating device corresponding to the hydrogenation reaction is correspondingly simplified, and the investment amount is reduced.
FIG. 3 provides a schematic diagram of a purification apparatus for introducing hydrogen from the tail gas of a hydrogenation reaction into a hydrogen production system in accordance with the present invention. As shown in fig. 3, a part of the hydrogen in the tail gas of the hydrogenation reaction is introduced into the hydrogen production system, and enters the purification device in the hydrogen production system together with the crude hydrogen after the reaction in the converter, and S, CO is removed in the purification device 2 、CO、CH 4 After impurities are removed, H with the content of more than 99.999 percent is provided 2 Used for hydrogenation reaction.
Specifically, in the method for treating hydrogen as a tail gas in a hydrogenation reaction according to the present invention, a methanation device as shown in fig. 2 may be provided, or a methanation device as shown in fig. 2 may not be provided. When no methanation device is provided, a flow chart of the treatment method is shown in FIG. 4.
In FIG. 4, stream (1) is 100 moles of organics, stream (2) is 302.57 moles of fresh hydrogen (5 ppm CO) stream (3) is 197.43 moles of internal recycle hydrogen, and stream (4) has a total hydrogen flow of 500 moles to achieve the reaction 5:1 (hydrogen: organic) operation requirement that 100mol of organic will react with 99.99mol of hydrogen under the designed reaction conditions99.99mol of product are produced, and the remaining 0.01mol of organic matter will decompose to produce 0.01mol of CO, forming stream (5). In the gas-liquid separator, the product (6) is separated in a liquid phase, the rest gas is a material flow (7), one part of the material flow (7) directly flows back to the hydrogenation reactor in an internal circulation mode through the material flow (3), the rest part of the material flow (8) in the material flow (7) is externally circulated to the hydrogen production system, impurities in the material flow (8) are discharged together with other impurities generated in the hydrogen production system, and the hydrogen in the material flow (8) becomes one part of fresh hydrogen
The hydrogen produced by using hydrogen-producing raw material is (r).
When a methanation device is arranged in the method, the flow chart of the treatment method is shown in FIG. 5.
In FIG. 5, stream (1) is 100 moles of organics, stream (2) is 249.98 moles of fresh hydrogen (containing 4ppm of CO), stream (3) is 250.02 moles of internal recycle hydrogen, and stream (4) has a total hydrogen flow of 500 moles to achieve the reaction 5:1 (hydrogen: organic) operation, 100mol of organic will react with 99.99mol of hydrogen to produce 99.99mol of product under the designed reaction conditions, and the remaining 0.01mol of organic will decompose to produce 0.01mol of CO, forming stream (5). In the gas-liquid separator, the product (6) is separated in the liquid phase, the remaining gas is the stream (7), the internal recycle gas stream
Enters a methanation unit, and the assumption is that 90 percent of CO is converted into CH in the methanation unit 4 And directly refluxing the converted product into a hydrogenation reactor as a stream (3). The residual tail gas hydrogen stream (8) in the stream (7) is externally recycled to the hydrogen production system, impurities in the stream (8) are discharged together with other impurities generated in the hydrogen production system, and the hydrogen in the stream (8) becomes a part of fresh hydrogen
The hydrogen produced by using the hydrogen production raw material is r.
In FIG. 5, the composition of stream (8) is 149.99mol hydrogen, 0.004mol CO and 0.07mol CH 4 . After the scheme is adopted to directly and externally circulate the material flow (8) to the hydrogen production system, part of the tail gas hydrogen passes through the hydrogen production system to become fresh hydrogen; purifying the CO component in a purifying device of the hydrogen production system and then emptying the CO component; CH in stream (8) 4 The components become raw materials of a hydrogen production system (natural gas hydrogen production) and are used for preparing fresh hydrogen. Thereby realizing 100 percent of cyclic utilization of the hydrogen in the tail gas of the hydrogenation reaction, reducing the unit consumption of the hydrogen of the hydrogenation reaction and saving the production cost; simultaneously effectively treating impurities in tail gas hydrogen of hydrogenation reaction and controlling CO and CH in a hydrogenation system 4 The influence of the internal recycle hydrogen on the hydrogenation catalyst is reduced.
Example 1
Taking continuous hydrogenation of terephthalic acid (TPA) to produce 1,4-Cyclohexanedimethanol (CHDM) as an example, in the prior art, a methanation device shown in figure 2 is adopted to treat hydrogen in tail gas of hydrogenation reaction, the emptying amount of hydrogen is controlled to enable the CO concentration at the inlet of a hydrogenation reactor to be below 30ppm, and after the operation for many months, the average unit consumption of hydrogen is 1250Nm 3 Per ton CHDM. After the method and the process shown in FIG. 6 are adopted, FIG. 6 is a process flow diagram of the tail hydrogen treatment method of the hydrogenation reaction for producing 1,4-cyclohexanedimethanol from terephthalic acid according to the present invention, and a part of the tail hydrogen of the hydrogenation reaction is introduced into a hydrogen production system. After more months of operation, the average hydrogen consumption is reduced to 1099Nm 3 Per ton of CHDM, the unit consumption is only 101% of theory. Compared with the prior art, the method reduces the hydrogen consumption by 12.1 percent. The hydrogen is saved by 45.3 ten thousand Nm in 3000 tons of CHDM produced per year 3 。
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions and substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.
Claims (8)
1. A treatment method of tail gas hydrogen of hydrogenation reaction is characterized in that one part of tail gas hydrogen obtained by gas-liquid separation after hydrogenation reaction is directly introduced into a hydrogenation reactor as internal circulation hydrogen, or the internal circulation hydrogen is firstly converted into methane by a methanation device and then the treated internal circulation hydrogen is directly introduced into the hydrogenation reactor, the other part of the tail gas hydrogen obtained by gas-liquid separation after hydrogenation reaction is introduced into a purification device in a hydrogen production system as external circulation hydrogen, hydrogen obtained by purifying and purifying the external circulation hydrogen and hydrogen prepared by a hydrogen production raw material through the hydrogen production system are jointly used as fresh high-purity hydrogen to be added into the hydrogenation reactor, and the fresh high-purity hydrogen and the internal circulation hydrogen which is or is not treated by the methanation device jointly form total hydrogen for the hydrogenation reaction.
2. The method of claim 1, wherein the ratio of internal recycle hydrogen to external recycle hydrogen is in the range of 0.5 to 5:1, preferably 0.8 to 4:1, more preferably 1 to 3:1.
3. the method of claim 1, wherein the hydrogenation reaction is one of the following reactions: terephthalic acid hydrogenation to 1,4-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid hydrogenation to 1,4-cyclohexanedimethanol, terephthalic acid continuous two stage hydrogenation to 1,4-cyclohexanedimethanol, dimethyl terephthalate hydrogenation to 1,4-dimethyl cyclohexanedicarboxylate, 1,4-dimethyl cyclohexanedicarboxylate hydrogenation to 1,4-cyclohexanedimethanol, terephthalic acid-bis (4-methylcyclohexane) dimethyl ester hydrogenation to 1,4-cyclohexanedicarboxylate-bis (4-methylcyclohexane) dimethyl ester, 1,4-cyclohexanedicarboxylic acid-bis (4-methylcyclohexane) dimethyl ester hydrogenation to 1,4-cyclohexanedimethanol, terephthalic acid-bis (4-methylcyclohexane) dimethyl ester continuous two stage hydrogenation to 1,4-cyclohexanedimethanol.
4. The method of claim 1, wherein the hydrogen production system is a natural gas hydrogen production system or a methanol hydrogen production system.
5. The process according to claim 1, characterized in that the internal recycle hydrogen has a CO concentration after being treated by the methanation unit of less than 20ppm, preferably less than 10ppm.
6. The process according to claim 1, wherein the hydrogen consumption in the hydrogenation reaction is not higher than 1.1 times, preferably not higher than 1.05 times, more preferably not higher than 1.03 times the theoretical value.
7. The process according to claim 1, characterized in that the CO concentration of the total hydrogen used in the hydrogenation reaction is lower than 30ppm, preferably lower than 25ppm, more preferably lower than 20ppm.
8. The method according to any one of claims 1 to 7, wherein the exhaust amount of tail gas hydrogen obtained by gas-liquid separation after hydrogenation reaction is zero before a part of the tail gas hydrogen enters a hydrogen production system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211081772.3A CN115368210B (en) | 2022-09-06 | 2022-09-06 | Treatment method of tail gas hydrogen of hydrogenation reaction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211081772.3A CN115368210B (en) | 2022-09-06 | 2022-09-06 | Treatment method of tail gas hydrogen of hydrogenation reaction |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115368210A true CN115368210A (en) | 2022-11-22 |
| CN115368210B CN115368210B (en) | 2024-04-30 |
Family
ID=84068851
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211081772.3A Active CN115368210B (en) | 2022-09-06 | 2022-09-06 | Treatment method of tail gas hydrogen of hydrogenation reaction |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115368210B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1944239A (en) * | 2006-10-24 | 2007-04-11 | 四川亚连科技有限责任公司 | Method for preparing hydrogen by reforming methanol with high recovery rate |
| CN102849680A (en) * | 2012-08-30 | 2013-01-02 | 苏州金宏气体股份有限公司 | Method for synthesis and purification of hydrogen from natural gas |
| CN104649864A (en) * | 2013-11-19 | 2015-05-27 | 中国石油天然气股份有限公司 | Method for producing 1,4-cyclohexanedimethanol through hydrogenation of dialkyl terephthalate |
| CN105385473A (en) * | 2015-11-11 | 2016-03-09 | 中国科学院山西煤炭化学研究所 | Coal hydrogen and methane process based on chemical-looping gasification |
| CN106518608A (en) * | 2016-10-28 | 2017-03-22 | 中国石油化工股份有限公司 | A continuous preparing method and apparatus for cyclohexanedimethanol |
| CN107986232A (en) * | 2017-11-28 | 2018-05-04 | 四川亚联高科技股份有限公司 | The method of methanol preparing high purity hydrogen |
| CN110437033A (en) * | 2018-05-02 | 2019-11-12 | 湖南长岭石化科技开发有限公司 | The method for producing 1,4 cyclohexane dimethanol |
| CN111111398A (en) * | 2020-01-20 | 2020-05-08 | 周莞尔 | Propane dehydrogenation tail gas comprehensive utilization system |
-
2022
- 2022-09-06 CN CN202211081772.3A patent/CN115368210B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1944239A (en) * | 2006-10-24 | 2007-04-11 | 四川亚连科技有限责任公司 | Method for preparing hydrogen by reforming methanol with high recovery rate |
| CN102849680A (en) * | 2012-08-30 | 2013-01-02 | 苏州金宏气体股份有限公司 | Method for synthesis and purification of hydrogen from natural gas |
| CN104649864A (en) * | 2013-11-19 | 2015-05-27 | 中国石油天然气股份有限公司 | Method for producing 1,4-cyclohexanedimethanol through hydrogenation of dialkyl terephthalate |
| CN105385473A (en) * | 2015-11-11 | 2016-03-09 | 中国科学院山西煤炭化学研究所 | Coal hydrogen and methane process based on chemical-looping gasification |
| CN106518608A (en) * | 2016-10-28 | 2017-03-22 | 中国石油化工股份有限公司 | A continuous preparing method and apparatus for cyclohexanedimethanol |
| CN107986232A (en) * | 2017-11-28 | 2018-05-04 | 四川亚联高科技股份有限公司 | The method of methanol preparing high purity hydrogen |
| CN110437033A (en) * | 2018-05-02 | 2019-11-12 | 湖南长岭石化科技开发有限公司 | The method for producing 1,4 cyclohexane dimethanol |
| CN111111398A (en) * | 2020-01-20 | 2020-05-08 | 周莞尔 | Propane dehydrogenation tail gas comprehensive utilization system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115368210B (en) | 2024-04-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108463450B (en) | Methanol process | |
| EP3658489B1 (en) | Method for the preparation of ammonia synthesis gas | |
| EA039241B1 (en) | Process for synthesising methanol | |
| RU2753269C2 (en) | Method for producing methanol | |
| CN115368210B (en) | Treatment method of tail gas hydrogen of hydrogenation reaction | |
| CN113248068A (en) | Resourceful treatment method and system for PTA oxidation tail gas washing tower discharge liquid | |
| CN111732083A (en) | Fluidized bed hydrogen peroxide process | |
| RU2203214C1 (en) | Methanol production process | |
| US2251000A (en) | Process for purifying gases | |
| CN210934466U (en) | Impurity removal system for oxygen-containing argon tail gas | |
| KR100300795B1 (en) | Method and apparatus for processing contact reforming product | |
| CN112871090A (en) | Process system and method for synthesizing chloroethylene by mercury-free catalyst | |
| CN1508064A (en) | Method for preparing high-purity nitrogen gas | |
| CN107106923B (en) | Process for revamping a plant for the production of cyclohexanone | |
| CN220478148U (en) | Comprehensive utilization system for hydrogen in cyclohexanone device by esterification method | |
| CN103992198A (en) | Benzene production technology taking coke oven gas as raw material | |
| US20240059637A1 (en) | Process and plant for producing methanol and synthesis gas | |
| CN218834066U (en) | Novel separation system for acrylic acid device | |
| CN113277924B (en) | Heat exchange system for propylene preparation | |
| CN219942763U (en) | System for preparing methanol by carbon dioxide hydrogenation | |
| CN113512013B (en) | System and method for preparing propylene oxide from large-scale industrial methanol | |
| EP0139423A2 (en) | A process for the preparation of high-purity hydrogen | |
| CN213172129U (en) | Device for preparing methanol and co-producing ethylene glycol from coal-based synthetic gas | |
| CN113213431A (en) | Process for producing hydrogen peroxide by high-efficiency anthraquinone method | |
| RU2052444C1 (en) | Method for production of methanol |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |