CN102964248B - Method for producing nitric oxide and synthesizing dimethyl oxalate through carbonylation - Google Patents
Method for producing nitric oxide and synthesizing dimethyl oxalate through carbonylation Download PDFInfo
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- CN102964248B CN102964248B CN201210542727.3A CN201210542727A CN102964248B CN 102964248 B CN102964248 B CN 102964248B CN 201210542727 A CN201210542727 A CN 201210542727A CN 102964248 B CN102964248 B CN 102964248B
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Abstract
The invention discloses a method for producing nitric oxide and synthesizing dimethyl oxalate through carbonylation and relates to the technical field of dimethyl oxalate. According to the method disclosed by the invention, nitric oxide production and synthetic process of dimethyl oxalate through carbonylation are combined, so that the safety in a nitric oxide producing process is improved and utilization rate of raw material is increased. In the method disclosed by the invention, the nitric oxide is produced by reacting sodium nitrite with dilute nitric acid, and a raw material of carbonylation reaction, namely carbonic oxide, is taken as gas for stirring, so that the sodium nitrite and the dilute nitric acid fully react in a reactor to obtain the nitric oxide; then the nitric oxide is supplemented to a dimethyl oxalate circulating system along with the carbonic oxide to be esterified and carbonylated; and finally the dimethyl oxalate product is synthesized. The method disclosed by the invention can be used for avoiding the phenomenon that a potential safety hazard exists in the existing production and storage process of dimethyl oxalate and also overcoming the defects of the existing synthetic process of dimethyl oxalate through carbonylation.
Description
Technical field
The present invention relates to nitrogen protoxide industry preparation and the method for carbonylation dimethyl oxalate, relate to a kind of extensive nitrogen protoxide in particular and produce and the method for carbonylation dimethyl oxalate.
Background technology
Dimethyl oxalate is mainly used in organic synthesis, also can be used for the industries such as softening agent, pharmacy, agricultural chemicals.Carbon monoxide gas-phase catalytic coupling synthesizing dimethyl oxalate, as a part for synthetic gas preparing ethylene glycol technology, has become research topic important in domestic C-1 chemistry and organic chemical industry field.The research units such as Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Fujian Inst. of Matter Structure, Chinese Academy of Sciences, southwestern chemical research institute, Zhejiang University, University Of Tianjin, East China University of Science are successively had to be devoted to the catalyst preparation in this field, processing condition competition and engineering development.
CO catalytic coupling is prepared dimethyl oxalate process and is related generally to two steps:
The first step be carbon monoxide under catalyst action, generate DMO and nitrogen protoxide with methyl nitrite linked reaction, reaction formula is: 2CH
3oNO+2CO=(COOCH
3)
2+ 2NO
Second step is esterification, and enter esterifier and methyl alcohol and oxygen reaction and generate methyl nitrite after the NO that the first step generates and product separation, reaction formula is: 2CH
3oH+2NO+0.5O
2=2CH
3oNO+H
2o
The methyl nitrite generated returns the first step CO coupling process and participates in reaction.The net reaction that CO linked reaction prepares dimethyl oxalate is: 2CH
3oH+2CO+0.5O
2=(COOCH
3)
2+ H
2o
CO catalytic coupling prepares dimethyl oxalate method, the gentle nitrogen protoxide of reaction conditions and methyl nitrite constantly circulate and regeneration in whole process, say that NO need not supplement in theory, but in dimethyl oxalate synthetic reaction process, due to side reaction and periodic off-gases, can cause NO component loss in circulation gas, this just needs in the recycle system, to supplement NO, to maintain each component optimum proportion of building-up reactions in good time.In actually operating, two kinds of ways are usually had to supplement the loss of NO: directly to supplement NO or supplementary methyl nitrite.
At present, research institution or enterprise adopt the method for supplementary methyl nitrite usually, and the preparation principle of methyl nitrite is: NaNO
2+ HNO
3+ CH
3oH=NaNO
3+ CH
3oNO+H
2o, this principle is utilized to need to produce pure state methyl nitrite as intermediates, but in methyl nitrite preparation with storage process, there is more labile factor: methyl nitrite steam can form explosive mixture with air, all easily decompose by solar radiation or be heated, have the danger of blasting.Therefore, suitability for industrialized production hidden danger is applied to very large.
In addition, in current process unit production process, because side reaction and periodic off-gases amount are comparatively large, the NO of consumption or methyl nitrite amount are also just comparatively large, and finally cause starting material Sodium Nitrite, nitric acid, methanol usage large, production cost is high.
Therefore, developing the dimethyl oxalate production method of the higher methyl nitrite of a kind of safety coefficient or NO preparation method and low raw material consumption, is improve the security of current dimethyl oxalate production process and one of approach reducing production cost.
Summary of the invention
The object of the invention is to overcome current nitrous ester methyl ester to produce and react the shortcoming with technique with storage security hidden danger, carbonylation dimethyl oxalate, a kind of method being suitable for scale operation dimethyl oxalate is provided, supports to take synthetic gas as the operational path of waste ethylene glycol.
NO produces and adopts dust technology and Sodium Nitrite to react the method preparing NO, by-product sodium nitrate simultaneously.Sodium Nitrite needs first to be made into certain density solution, then Reactive Synthesis NO is carried out in a kettle. with dust technology, pass into CO gas in reaction process to stir, the NO of generation adds to dimethyl oxalate synthesis system with CO, through esterification, the final synthesizing dimethyl oxalate of carbonylation.
Nitrogen protoxide of the present invention is produced and the method for carbonylation dimethyl oxalate, utilize the raw material carbon monoxide of oxonation as gas stirring, Sodium Nitrite and dust technology fully react obtained nitrogen protoxide in NO preparation feedback device, add to the dimethyl oxalate recycle system and carry out esterification, carbonylation, final synthesizing dimethyl oxalate together with the carbon monoxide stirred; Specifically comprise following processing step:
1. NO producing process dust technology concentration controls at 50-65%, and sodium nitrite solution concentration controls NO ratio CO: NO=1-8 being not less than 98.5%, CO and generation in 30-45%, CO purity;
2. arrange independently gas mixer before esterification, the oxygen making purity be greater than 99% fully mixes with circulation gas and the oxidizing reaction of NO tentatively occurs, and then gas mixture enters esterifier and generates methyl nitrite; Wherein, esterifier adopts packing tower, number of theoretical plate 10-40 block, and top arranges water cooler, phlegma total reflux, and in phegma, the content of methyl alcohol is greater than 99%, and bottom arranges reboiler, and bottom temperature is 70-120 DEG C; Fresh methanol fills into and is arranged on return tank, and purity is not less than 99.8%;
3. by esterifier top gas out through gas purifier process, be mixed into oxonation device with raw material CO after removing impurity component, pressure is 0.1-0.5MPa, and temperature of reaction is 120-150 DEG C, final oxalic dimethyl ester;
4. enter Methanol Wash Column from oxonation device material out, utilize liquid methanol gas mixture dimethyl oxalate in preparation to be cleaned; This tower arranges tower top water cooler and tower reactor reboiler, and tower top temperature is 10-20 DEG C, and bottom temperature is 70-110 DEG C, and fresh methanol is added into return tank, and alcohol wash methanol usage and air-fuel mixture amount mol ratio are 1: 4-8;
5. methanol wash top of tower gas mixture is out separated through vapour liquid separator, and separation accuracy is 5-30 μm, then delivers to esterifier through recycle gas compressor supercharging;
6. enter dimethyl oxalate treating tower from methanol wash tower bottom material out, tower top temperature is 60-75 DEG C, and bottom temperature is 150-170 DEG C, obtains dimethyl oxalate product at the bottom of tower, and tower top is methyl alcohol, methylcarbonate and water.
Described step 1. described in prepare in NO process, stir with CO (carbon monoxide converter) gas, and the NO of CO flow and generation measures ratio CO: NO=7.23.
Described step 2. described in esterifier adopt packing tower, number of theoretical plate 15-30 block.
Described step 2. described in oxonation device import gas mixture component be NO1-5%, CO15-25%, methyl nitrite 5-15%, methyl alcohol 8-2O%, all the other are N
2.
Described step 3. in by esterifier top gas out through cleaner process, be mixed into oxonation device with raw material CO, pressure 0.2-0.4MPa, temperature of reaction 130-145 DEG C after removing impurity component.
Described step 4. middle methanol wash methanol usage and air-fuel mixture amount mol ratio is 1: 5.
Described step 5. middle methanol wash top of tower gas mixture is out separated through vapour liquid separator, and separation accuracy is 8-24 μm.
Present invention process process is simple, operation of equipment safety, cost are low, and byproduct SODIUMNITRATE has good marketable value.
Embodiment
Below in conjunction with embodiment, the invention will be further described, and to make those skilled in the art can better understand the present invention, but illustrated embodiment is not as a limitation of the invention.
Dust technology and sodium nitrite solution are joined in NO preparation feedback device, pass into CO gas at reactor bottom simultaneously and stir, nitric acid and Sodium Nitrite are fully reacted, and the NO of generation adds to dimethyl oxalate synthesis cycle system with CO.The pure oxygen that circulation gas is sent here with outside in gas mixer fully mixes pre-reaction, then esterifier is entered, with adverse current and under methanol solution fully contact the generation methyl nitrite that reacts, gas mixture enters oxonation device reaction oxalic dimethyl ester after gas purifier purification, after heat exchange, enter Methanol Wash Column gas dimethyl oxalate in preparation is fully reclaimed, the gas going out Methanol Wash Column delivers to gas mixer after recycle gas compressor pressurization, completes and once circulates.Dimethyl oxalate treating tower delivered to by Methanol Wash Column bottom liquid material, and bottom obtains high-purity oxalic acid dimethyl ester, and top obtains the mixtures such as methyl alcohol, water, methylcarbonate.Fresh methanol is added into esterifier return tank and Methanol Wash Column return tank continuously.
Embodiment 1: the scale of Production Equipment of 2000 t Capacity Per dimethyl oxalate
Reaction raw materials specification is as follows:
Dust technology concentration 50%, sodium nitrite solution concentration 45%, CO purity 98.5%, methanol purity 99.8%, oxygen purity 99.5%.
Reaction feed amount is as follows:
CO：109Nm
3/h，
O
2：27Nm
3/h，
Methyl alcohol: 770Kg/h,
Nitric acid: 38Kg/h,
Sodium Nitrite: 46Kg/h.
Oxonation major control index is as follows:
Enter gas reactor component: NO 2.5%, CO 15%, methyl nitrite 10%, methyl alcohol 15%, all the other are N
2.
Reaction pressure: 0.3MPa.
Temperature of reaction: 140 DEG C.
Product and methanol consumption situation as follows:
Product dimethyl oxalate amount is: 280K g/h,
Dimethyl oxalate purity: >=99.5%,
Methanol consumption: 2.3K g/h,
Dimethyl oxalate treating tower top products amount (methyl alcohol, methylcarbonate etc.): 640K g/h.
Embodiment 2: the scale producing 5000 tons of dimethyl oxalates per year
Reaction raw materials specification is as follows:
Dust technology concentration 50%, sodium nitrite solution concentration 45%, CO purity 98.5%, methanol purity 99.8%, oxygen purity 99.5%.
Reaction feed amount is as follows:
CO：270Nm
3/h，
O
2：67.5Nm
3/h，
Methyl alcohol: 1850Kg/h,
Nitric acid: 93Kg/h,
Sodium Nitrite: 109Kg/h.
Oxonation major control index is as follows:
Enter gas reactor component: NO 3.0%, CO 18%, methyl nitrite 10%, methyl alcohol 16%, all the other are N
2.
Reaction pressure: 0.4MPa.
Temperature of reaction: 140 DEG C.
Product and methanol consumption situation as follows:
Product dimethyl oxalate amount is: 700K g/h,
Dimethyl oxalate purity: >=99.5%,
Methanol consumption: 5.7K g/h,
Dimethyl oxalate treating tower top products amount (methyl alcohol, methylcarbonate etc.): 1580K g/h.
Embodiment 3: the scale producing 10000 tons of dimethyl oxalates per year
Reaction raw materials specification is as follows:
Dust technology concentration 50%, sodium nitrite solution concentration 45%, CO purity 98.5%, methanol purity 99.8%, oxygen purity 99.5%.
Reaction feed amount is as follows:
CO：561Nm
3/h，
O
2：138Nm
3/h，
Methyl alcohol: 3980Kg/h,
Nitric acid: 92Kg/h,
Sodium Nitrite: 370Kg/h.
Oxonation major control index is as follows:
Enter gas reactor component: NO 2.0%, CO 15%, methyl nitrite 12%, methyl alcohol 15%, all the other are N
2.
Reaction pressure: 0.35MPa.
Temperature of reaction: 135 DEG C.
Product and methanol consumption situation as follows:
Product dimethyl oxalate amount is: 1460K g/h,
Dimethyl oxalate purity: >=99.5%,
Methanol consumption: 11.8K g/h,
Dimethyl oxalate treating tower top products amount (methyl alcohol, methylcarbonate etc.): 3200K g/h.
Comparative example: the scale of Production Equipment of 2000 t Capacity Per dimethyl oxalate
Raw material specification is as follows:
Dust technology concentration 50%, sodium nitrite solution concentration 45%, CO purity 98.5%, methanol purity 99.8%, oxygen purity 99.5%.
Reaction feed amount is as follows:
CO：110Nm
3/h
O
2：27Nm
3/h
Methyl alcohol: 770Kg/h
Nitric acid: 45Kg/h
Sodium Nitrite: 54Kg/h
Oxonation major control index is as follows:
Enter gas reactor component: NO 2.0%, CO 15%, methyl nitrite 12%, methyl alcohol 15%, all the other are N
2.
Reaction pressure: 0.3MPa
Temperature of reaction: 135 DEG C
Product and methanol consumption situation as follows:
Product dimethyl oxalate amount is: 280K g/h
Dimethyl oxalate purity: >=99.5%
Methanol consumption: 2.8K g/h
Dimethyl oxalate treating tower top products amount (methyl alcohol, methylcarbonate etc.): 640K g/h.
The main technique index of different scales and production Expenditure Levels per hour is listed in above embodiment and comparative example, for the ease of comparing with comparative example, need first production consumption to be scaled unit consumption (namely producing the material quantity that 1 ton of dimethyl oxalate consumes), concrete comparing result sees the following form:
Claims (7)
1. a nitrogen protoxide is produced and the method for carbonylation dimethyl oxalate, it is characterized in that: utilize the raw material carbon monoxide of oxonation as gas stirring, Sodium Nitrite and dust technology fully react obtained nitrogen protoxide in NO preparation feedback device, add to the dimethyl oxalate recycle system and carry out esterification, carbonylation, final synthesizing dimethyl oxalate together with the carbon monoxide stirred; Specifically comprise following processing step:
1. NO producing process dust technology concentration controls at 50-65%, and sodium nitrite solution concentration controls the NO ratio CO:NO=1-8 being not less than 98.5%, CO and generation in 30-45%, CO purity;
2. arrange independently gas mixer before esterification, the oxygen making purity be greater than 99% fully mixes with circulation gas and the oxidizing reaction of NO tentatively occurs, and then gas mixture enters esterifier and generates methyl nitrite; Wherein, esterifier adopts packing tower, number of theoretical plate 10-40 block, and top arranges water cooler, phlegma total reflux, and in phegma, the content of methyl alcohol is greater than 99%, and bottom arranges reboiler, and bottom temperature is 70-120 DEG C; Fresh methanol fills into and is arranged on return tank, and purity is not less than 99.8%;
3. by esterifier top gas out through gas purifier process, be mixed into oxonation device with raw material CO after removing impurity component, pressure is 0.1-0.5MPa, and temperature of reaction is 120-150 DEG C, final oxalic dimethyl ester;
4. enter Methanol Wash Column from oxonation device material out, utilize liquid methanol gas mixture dimethyl oxalate in preparation to be cleaned; This tower arranges tower top water cooler and tower reactor reboiler, and tower top temperature is 10-20 DEG C, and bottom temperature is 70-110 DEG C, and fresh methanol is added into return tank, and alcohol wash methanol usage and air-fuel mixture amount mol ratio are 1:4-8;
5. methanol wash top of tower gas mixture is out separated through vapour liquid separator, and separation accuracy is 5-30 μm, then delivers to esterifier through recycle gas compressor supercharging;
6. enter dimethyl oxalate treating tower from methanol wash tower bottom material out, tower top temperature is 60-75 DEG C, and bottom temperature is 150-170 DEG C, obtains dimethyl oxalate product at the bottom of tower, and tower top is methyl alcohol, methylcarbonate and water.
2. nitrogen protoxide is produced and the method for carbonylation dimethyl oxalate according to claim 1, it is characterized in that: described step 1. in NO producing process, stir with CO (carbon monoxide converter) gas, and the NO of CO flow and generation measures ratio CO:NO=7.23.
3. nitrogen protoxide is produced and the method for carbonylation dimethyl oxalate according to claim 1, it is characterized in that: described step 2. described in esterifier adopt packing tower, number of theoretical plate 15-30 block.
4. nitrogen protoxide is produced and the method for carbonylation dimethyl oxalate according to claim 1, it is characterized in that: described step 3. described in oxonation device import gas mixture component be NO1-5%, CO15-25%, methyl nitrite 5-15%, methyl alcohol 8-20%, all the other are N
2.
5. nitrogen protoxide is produced and the method for carbonylation dimethyl oxalate according to claim 1, it is characterized in that: described step 3. in by esterifier top gas out through cleaner process, oxonation device is mixed into raw material CO after removing impurity component, pressure 0.2-0.4MPa, temperature of reaction 130-145 DEG C.
6. nitrogen protoxide is produced and the method for carbonylation dimethyl oxalate according to claim 1, it is characterized in that: described step 4. middle alcohol wash methanol usage and air-fuel mixture amount mol ratio is 1:5.
7. nitrogen protoxide is produced and the method for carbonylation dimethyl oxalate according to claim 1, it is characterized in that: described step 5. middle methanol wash top of tower gas mixture is out separated through vapour liquid separator, and separation accuracy is 8-24 μm.
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| CN106984294B (en) * | 2016-12-05 | 2018-04-10 | 武汉聚川科技有限公司 | A kind of oxidative carbonylation synthesis technique, its liquid waste processing catalyst and preparation method thereof |
| CN108329210A (en) * | 2018-04-08 | 2018-07-27 | 西安汉术化学工程股份有限公司 | The recovery system and method for nitric oxide, methyl nitrite in a kind of tail gas of carbonylation dimethyl oxalate |
| CN113828267A (en) * | 2021-09-28 | 2021-12-24 | 杨翠萍 | Dimethyl oxalate synthesis device and process |
| CN113956161A (en) * | 2021-11-22 | 2022-01-21 | 中国科学院宁波材料技术与工程研究所 | Method and system for continuously producing dimethyl carbonate |
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| CN1056135C (en) * | 1996-09-18 | 2000-09-06 | 天津大学 | Diethyl oxalate by gas phase CO link-coupled regeneration catalyzing circulation |
| JP4214858B2 (en) * | 2002-08-13 | 2009-01-28 | 宇部興産株式会社 | Production method of dialkyl oxalate |
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Effective date of registration: 20191016 Address after: 017100 Erdos new road, Zhungeer Qi, the Inner Mongolia Autonomous Region Patentee after: Jiu Tai energy (Ordos) Co., Ltd. Address before: The middle of the 276017 Shandong province Linyi Luo Ba Lu District of Luozhuang City Patentee before: Long Thai Energy Technology Co., Ltd. |