Refining apparatus and process using DMC
阅读说明：本技术 用dmc精制装置及工艺 (Refining apparatus and process using DMC ) 是由 魏力 曹宗元 沈光海 蒋京利 陶玉红 段聪仁 陈安跃 于 2019-10-09 设计创作，主要内容包括：本发明提供一种DMC精制装置及工艺,涉及碳酸二甲酯生产装置技术领域,所述工艺包括DMC合成、DMC洗净、亚硝酸甲酯合成以及硝酸还原,所述DMC合成以CO和亚硝酸甲酯原料,在气相状态下以氯化钯催化剂为媒介进行反应生成碳酸二甲酯,将所述DMC合成阶段生成DMC、DMO以及副产物进行冷却,洗净分离；所述DMC合成阶段生成的副产物中的一氧化氮与甲醇进行反应,生成亚硝酸甲酯、H<Sub>2</Sub>O和HNO<Sub>3</Sub>；所述亚硝酸甲酯合成阶段生成的HNO<Sub>3</Sub>和NO、甲醇进行反应,生成亚硝酸甲酯；其中,所述硝酸还原阶段生产的MN进入DMC合成阶段,参与DMC合成。本发明制备的碳酸二甲酯(DMC)纯度达到为99.93～99.97％、含甲醇(ME)为100～200ppm、含H2O为0～100ppm。(The invention provides a DMC refining plant and process, relate to dimethyl carbonate production facility technical field, said process includes DMC synthesis, DMC cleaning, methyl nitrite synthesis and nitric acid reduction, said DMC synthesis uses CO and methyl nitrite raw materials, take palladium chloride catalyst as the medium to react and produce dimethyl carbonate under the gaseous phase state, produce DMC, DMO and by-product to cool said DMC synthesis stage, clean and separate; the nitric oxide in the by-product generated in the DMC synthesis stage reacts with methanol to generate methyl nitrite and H 2 O and HNO 3 (ii) a Said methyl nitrite synthesis stage generatingHNO of (2) 3 Reacting with NO and methanol to generate methyl nitrite; and MN produced in the nitric acid reduction stage enters a DMC synthesis stage to participate in DMC synthesis. The purity of the dimethyl carbonate (DMC) prepared by the invention is 99.93-99.97%, the Methanol (ME) content is 100-200 ppm, and the H2O content is 0-100 ppm.)
1. A DMC refinement process, said process comprising:
DMC synthesis, wherein CO and methyl nitrite raw materials are subjected to reaction in a gas phase state by taking a palladium chloride catalyst as a medium to generate dimethyl carbonate;
washing DMC, cooling DMC, DMO and by-product generated in the DMC synthesis stage, washing and separating;
methyl nitrite synthesis, wherein nitric oxide in the by-product generated in the DMC synthesis stage reacts with methanol to generate methyl nitrite and H 2O and HNO 3；
Reduction of nitric acid, HNO generated in the stage of synthesis of methyl nitrite 3Reacting with NO and methanol to generate methyl nitrite;
and MN produced in the nitric acid reduction stage enters a DMC synthesis stage to participate in DMC synthesis.
2. The DMC refining process of claim 1, wherein the recycle gas from the nitric acid reduction stage is subjected to gas-liquid separation, wherein CO, methyl nitrite and feed gas CO are mixed and preheated for DMC synthesis.
3. The DMC refinement process of claim 1, wherein the DMC cleaning comprises DMC rectification.
4. The DMC refining process of claim 3, wherein the DMC rectification comprises a DMC lightness removal process and a DMC separation process;
the DMC lightness removing treatment is used for separating methanol and light components in the DMC; and the DMC after the light removal treatment enters DMC separation treatment, and the DMC separation treatment is used for separating out methanol and dimethyl oxalate.
5. A DMC refining apparatus, characterized in that the apparatus comprises:
the DMC reactor is used for generating dimethyl carbonate by using CO and methyl nitrite raw materials and using a palladium chloride catalyst as a medium in a gas phase state;
a methyl nitrite regeneration tower for reacting nitric oxide with methanol to produce methyl nitrite, H2O and HNO 3;
the nitric acid reduction tank is used for reacting the byproducts HNO3 and NO sent from the methyl nitrate regeneration tower with methanol to generate methyl nitrite;
and the methyl nitrite generated by the nitric acid reduction tank enters a DMC reactor to participate in DMC synthesis.
6. The DMC refining apparatus of claim 1, further comprising:
a DMC lightness removing tower used for separating methanol and light components in DMC;
and the DMC separation tower is connected with the DMC lightness-removing tower and is used for separating out the methanol and the dimethyl oxalate after the DMC lightness-removing treatment.
7. The DMC refining apparatus of claim 6, wherein the DMC lightness removal column comprises a lightness removal column feed tank comprising:
the feeding device is communicated with the light component removal tower pipeline;
the condenser is communicated with the feeding device; and, the condenser includes:
the water-saving device comprises a shell, a water inlet and a water outlet, wherein a cavity is formed in the shell, the lower end of the shell is provided with the water inlet, and the upper end of the shell is provided with the water outlet;
a graphite heat exchange tube disposed inside the housing along the longitudinal direction inside the housing;
the graphite baffle plates are arranged inside the shell along the transverse direction inside the shell, and the graphite baffle plates are distributed inside the shell in a mutually staggered mode.
8. The DMC refining apparatus of claim 7, wherein the condenser further comprises:
the air inlet is positioned at the upper end part of the shell;
the discharge hole is positioned at the lower end part of the shell;
the air inlet is communicated with a pipeline of the feeding device, and the discharge hole is communicated with the pipeline of the feeding device.
9. The DMC refining apparatus of claim 8, wherein the condenser further comprises:
and the gas-liquid separation device is positioned at the lower end part, and a gas outlet is formed in the side wall of the gas-liquid separation device.
10. The DMC refining apparatus according to any one of claims 7 to 9, wherein impregnated graphite tube sheets are provided at both the upper and lower ends of the casing.
Technical Field
The invention relates to the technical field of dimethyl carbonate production devices, in particular to a DMC refining device and a DMC refining process.
Background
Dimethyl carbonate (DMC) is an important organic synthesis intermediate, contains functional groups such as carbonyl, methyl, methoxy and the like in a molecular structure, has various reaction performances, is an environment-friendly green chemical product due to very wide application, is one of important organic chemical raw materials, and enjoys the name of an organic synthesis new-base stone product.
At present, the industrial production process of dimethyl carbonate (DMC) at home and abroad mainly comprises the following steps: phosgene method and ester exchange method. But the prior dimethyl carbonate (DMC) has low production purity and low raw material conversion rate.
Disclosure of Invention
Based on the technical problems in the background art, the invention provides a DMC refining device and a process, which solve the technical problems of low purity and low raw material conversion rate of the existing dimethyl carbonate (DMC).
In order to achieve the purpose, the invention provides the following technical scheme:
in one aspect, a DMC refinement process is provided, the process comprising:
DMC synthesis, wherein CO and methyl nitrite raw materials are subjected to reaction in a gas phase state by taking a palladium chloride catalyst as a medium to generate dimethyl carbonate;
washing DMC, cooling DMC, DMO and by-product generated in the DMC synthesis stage, washing and separating;
methyl nitrite synthesis, wherein nitric oxide in a by-product generated in the DMC synthesis stage reacts with methanol to generate methyl nitrite, H2O and HNO 3;
reducing by nitric acid, wherein HNO3 generated in the methyl nitrite synthesis stage reacts with NO and methanol to generate methyl nitrite;
and MN produced in the nitric acid reduction stage enters a DMC synthesis stage to participate in DMC synthesis.
Preferably, after the gas-liquid separation of the recycle gas from the nitric acid reduction stage, the CO and the methyl nitrite in the recycle gas are mixed with the feed gas CO and participate in DMC synthesis after preheating.
Preferably, the DMC washing comprises DMC rectification.
Preferably, the DMC rectification comprises DMC lightness removing treatment and DMC separation treatment;
the DMC lightness removing treatment is used for separating methanol and light components in the DMC; and the DMC after the light removal treatment enters DMC separation treatment, and the DMC separation treatment is used for separating out methanol and dimethyl oxalate.
In another aspect, a DMC refining apparatus is provided, the apparatus comprising:
the DMC reactor is used for generating dimethyl carbonate by using CO and methyl nitrite raw materials and using a palladium chloride catalyst as a medium in a gas phase state;
a methyl nitrite regeneration tower for reacting nitric oxide with methanol to produce methyl nitrite, H2O and HNO 3;
the nitric acid reduction tank is used for reacting the byproducts HNO3 and NO sent from the methyl nitrate regeneration tower with methanol to generate methyl nitrite;
and the methyl nitrite generated by the nitric acid reduction tank enters a DMC reactor to participate in DMC synthesis.
Preferably, the DMC refining apparatus further comprises:
a DMC lightness removing tower used for separating methanol and light components in DMC;
and the DMC separation tower is connected with the DMC lightness-removing tower and is used for separating out the methanol and the dimethyl oxalate after the DMC lightness-removing treatment.
Preferably, the DMC lightness-removing column comprises a lightness-removing column feed tank comprising:
the feeding device is communicated with the light component removal tower pipeline;
the condenser is communicated with the feeding device; and, the condenser includes:
the water-saving device comprises a shell, a water inlet and a water outlet, wherein a cavity is formed in the shell, the lower end of the shell is provided with the water inlet, and the upper end of the shell is provided with the water outlet;
a graphite heat exchange tube disposed inside the housing along the longitudinal direction inside the housing;
the graphite baffle plates are arranged inside the shell along the transverse direction inside the shell, and the graphite baffle plates are distributed inside the shell in a mutually staggered mode.
Preferably, the condenser further comprises:
the air inlet is positioned at the upper end part of the shell;
the discharge hole is positioned at the lower end part of the shell;
the air inlet is communicated with a pipeline of the feeding device, and the discharge hole is communicated with the pipeline of the feeding device.
Preferably, the condenser further comprises:
and the gas-liquid separation device is positioned at the lower end part, and a gas outlet is formed in the side wall of the gas-liquid separation device.
Preferably, the upper end and the lower end of the shell are both provided with impregnated graphite tube plates.
The embodiment of the invention provides a DMC refining device and a process, which have the following beneficial effects:
the purity of the dimethyl carbonate (DMC) prepared by the invention reaches 99.93-99.97%, the Methanol (ME) content is 100-200 ppm, and the H2O content is 0-100 ppm;
the graphite heat exchange tubes are arranged in the condenser shell of the light component removal tower feeding tank along the longitudinal direction, the graphite baffle plates are arranged in the transverse direction, the graphite heat exchange tubes are distributed in the shell, and the graphite baffle plates are distributed in the shell in a mutually staggered manner, so that the heat exchange area is increased and the heat transfer efficiency is improved compared with the existing condenser; and the material has strong impact resistance and high pressure resistance (1.0MPa), can meet the requirements of acid, alkali, organic solvent and other use conditions, and has wide application range.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic diagram of the DMC synthesis process flow of an embodiment of the present invention;
FIG. 2 is a schematic diagram of the DMC lightness removal process flow of the embodiment of the present invention;
FIG. 3 is a schematic view of the DMC separation process according to an embodiment of the present invention;
FIG. 4 is a schematic view of the flow structure of an alkali treatment process according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of a flow chart of a methanol dehydration process according to an embodiment of the present invention;
FIG. 6 is a schematic view of the overall structure of the feed tank of the lightness-removing column.
FIG. 7 is a partial structural schematic diagram of a feed tank condenser of the light component removal tower.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention provides a DMC refining process, which comprises DMC synthesis, DMC cleaning, methyl nitrite synthesis and nitric acid reduction, wherein the DMC synthesis uses CO and methyl nitrite as raw materials to react in a gas phase state by taking a palladium chloride catalyst as a medium to generate dimethyl carbonate, DMC, DMO and byproducts generated in the DMC synthesis stage are cooled, cleaned and separated; the nitric oxide in the by-product generated in the DMC synthesis stage reacts with methanol to generate methyl nitrite and H 2O and HNO 3(ii) a HNO generated in the stage of synthesizing methyl nitrite 3Reacting with NO and methanol to generate methyl nitrite; and MN produced in the nitric acid reduction stage enters a DMC synthesis stage to participate in DMC synthesis.
In one embodiment, after the gas-liquid separation of the recycle gas from the nitric acid reduction stage, the CO, methyl nitrite and feed gas CO are mixed and preheated to participate in DMC synthesis.
In one embodiment, the DMC cleaning includes DMC rectification.
In one embodiment, the DMC rectification comprises a DMC lightness removal process and a DMC separation process; the DMC lightness removing treatment is used for separating methanol and light components in the DMC; and the DMC after the light removal treatment enters DMC separation treatment, and the DMC separation treatment is used for separating out methanol and dimethyl oxalate.
The details are set forth below in connection with the DMC refining apparatus:
as shown in FIG. 1, in the DMC reactor (R-64101), CO and MN (methyl nitrite) mainly react in a gas phase to produce DMC. The circulating gas (containing CO and MN) from the MN regeneration tower (C-64102) firstly enters a gas-liquid separation tank (V-65101) for gas-liquid separation, and then enters a circulating gas compressor (K-65101) for compression and pressure increase. The pressurized recycle gas, after mixing with the feed gas CO, is fed to a DMC reactor preheater (E-64101) for preheating and then fed to the DMC reactor. The active agent HCL of the DMC catalyst is premixed with part of the raw gas CO and then is fed to the inlet of the DMC reactor to be mixed with the circulating gas. The DMC reactor is a vertical tubular reactor, and a catalyst and active carbon are filled in a reaction tube. In the DMC reactor, the reaction of CO and MN is the main reaction to generate DMC. The accumulated liquid in the gas-liquid separation tank (V-65101) is sent to the alkali treatment tank (V-66005) by pressure.
The DMC reactor outlet gas was fed to an activated carbon reactor (R-64102). HCL, as the DMC catalyst activator, is converted to less corrosive MeCl (methyl chloride) in an activated carbon reactor before being sent to a DMC gas removal column.
The shell side of the DMC reactor was passed hot water pumped from a DMC reactor drum pump (P-64101A/B) to remove heat generated during the reactor reaction. The temperature of the DMC reactor is controlled in cascade mainly by the hot water temperature at the inlet of the reactor. The hot water from the reactor is fed to the DMC reactor drum (V-64107) and, since the hot water absorbs the heat of reaction and partly vaporizes into steam (is lost), it is necessary to frequently replenish the DMC reactor drum with Hot Water (HW).
Nitrogen from nitrogen storage tank No. 2 (V-64105) was used when emergency isolation of the DMC reactor was required for nitrogen replacement, and the purged nitrogen was vented to the DMC purge gas storage tank (V-64106).
The gas from the activated carbon reactor was passed to a DMC gas removal column (C-64101A/B). In the DMC gas removal column, crude DMO was pumped to the middle section of the column using a circulating DMO (dimethyl oxalate) pump (P-68001A/B), and the DMC of the gas was recovered to the liquid side using the crude DMO. In addition, the reaction products DMC, DMO, and other by-products were cooled, washed and separated by using MeOH condensed at a condenser (E-64102) at the top of the DMC gas removal column and MeOH replenished at the top of the column via a methanol feed pump (P-68003A/B).
While the bottom liquid of the gas removal column (containing DMC, DMO, MeOH) was sent to the crude DMC feed tank (V-66022A/B) in the 66 rectification unit by its own system pressure.
The gas at the gas phase outlet of the top of the DMC gas removal tower enters a condenser at the top of the tower for cooling, then enters a reflux tank (V-64102) at the top of the tower for separating non-condensable gas and condensate, and the condensate is sent back to the top of the gas removal tower through a reflux pump (P-64103A/B). The small part of the non-condensable gas is sent to a nitric acid reduction tank (V-64104A/B), and the large part is sent to an oxygen mixer (X-6101) to be mixed with oxygen and then sent to an MN regeneration tower (C-64102).
In the MN regeneration tower, NO in the circulating gas, O2 and MeOH react to generate MN and H2O. The side reaction produces HNO 3.
The tower lower part of the MN regeneration tower is a reaction zone, and tower bottom liquid is pumped to the middle section of the tower through a tower bottom pump (P-64102A/B) of the MN regeneration tower for circulation; while removing heat generated in the reaction of producing MN by using the bottom cooler (E-64103) of the MN regeneration tower. Part of the bottoms liquid was pumped to the nitric acid reduction tank (V-64104A/B) via the MN regeneration column bottoms. The upper part of the tower is a water absorption area which can absorb H2O generated during the synthesis of MN. MeOH is pumped overhead via a methanol feed pump (P-68003A/B) and can not only draw off H2O, but also become one of the starting materials for the synthesis of MN.
Most of the gas from the gas phase outlet pipeline at the top of the MN regeneration tower passes through a recycle gas-liquid separation tank and is sent to a recycle gas compressor; a small portion of the incoming MeOH, pumped through the methanol feed, recovered the MN, was sent to the tail gas treatment system as purge gas.
In a nitric acid reduction tank (V-64104A/B), the byproduct HNO3, NO sent from the MN regeneration tower react with MeOH to generate MN.
Part of the gas from the DMC gas removal tower is sent to a nitric acid reduction tank to be used as bubbling gas; the remainder of the gas phase is sent to the nitric acid reduction tank for diluting the MN concentration in the gas phase outlet of the nitric acid reduction tank.
The tower bottom liquid of the MN regeneration tower is sent to a nitric acid reduction tank through a tower bottom pump of the MN regeneration tower; HNO3 was sent from a nitric acid feed pump (P-0108) of a nitric acid storage tank (T-0105) to a nitric acid reduction tank.
The generated gas is sent to the middle section of the MN regeneration tower, and the whole reaction liquid is sent to alkali treatment.
As shown in FIG. 2, the DMC gas removal column bottoms contained dissolved gas (mainly MN, CO2) and was depressurized (let down) in a DMC lights removal column feed tank (V-66022A/B). In order to prevent the generation of detonating gas in the gas phase, it is necessary to fill nitrogen gas into the gas phase frequently. DMC in the purge gas is condensed by DMC lightness-removing tower feeding pot emptying cooler (E-66021), after recovery, the uncondensed gas is sent to lightness-removing tower feeding pot emptying gas washing tower (C-66006). Thus, the amount of DMC passing through the alkali treatment (V-66005) was small, and the amount of salt generated upon neutralization with an acid or an alkali was reduced.
The liquid in the DMC lightness-removing tower feeding tank is sent to a DMC lightness-removing tower feeding filter (F-66601A/B) through a lightness-removing tower feeding pump (P-66011A/B/C), and the active carbon powder entrained from the active carbon reactor is filtered out and then sent to the middle section of the DMC lightness-removing tower (C-66001A). The light component and methanol in DMC are separated by the light component and DMC and methanol can be azeotroped, so it can not be separated by normal distillation. DMO is supplied from a recovered DMO tank (T-68001) and sent to the DMC lightness-removing column via a recovered DMO pump (P-68001A/B).
Gas is produced at the top of the DMC lightness-removing tower, condensed by a DMC lightness-removing tower condenser (E-66002), and sent to a DMC lightness-removing tower reflux tank (V-66001) for gas-liquid separation; the non-condensable gas is fed to a tail gas absorption column (C-66003), while the methanol-based condensate is partly returned to the column via a DMC lightness-removing column reflux pump (P-66001A/B), and partly to a lightness-removing column feed tank vent gas washing column (C-66006) for washing DMC in the purge gas from the DMC lightness-removing column feed tank and finally to an alkali treatment.
Nitrogen is required to be injected into a vent pipeline of a reflux tank of the DMC light removing tower frequently to reduce the partial pressure of MN and ensure safety. The bottom liquid of the DMC lightness-removing column was circulated through a DMC lightness-removing column reboiler (E-66003A/B) and heated. The bottom liquid is sent to DMC separation via DMC lightness-removing column bottom pump (P-66002A/B).
As shown in fig. 3, the top outlet gas of the DMC separation column is cooled by the DMC separation column top condenser (E-2104) and then sent to the DMC separation column reflux drum (V-6602) for gas-liquid separation; a part of the condensate mainly containing DMC is returned to the tower through a reflux pump (P-66003A/B) at the top of the DMC separation tower, and a part of the condensate is returned to a feed tank of the DMC lightness-removing tower.
DMC obtained from the side of DMC separation tower is first transferred to side-sampling DMC storage tank (V-66003), then transferred to DMC intermediate storage tank (T-68002) by side-sampling DMC pump (P-66605A/B), and the quality of DMC in the storage tank is analyzed, and after the quality is confirmed, the DMC is transferred to pipeline DMC finished product tank for shipment.
The DMC column bottoms were circulated and heated by a DMC column reboiler (E-6607). The tower bottom liquid is sent to a DMC separation tower bottom filter (F-6603A/B) through a DMC separation tower bottom pump (P-66004A/B), a small amount of impurities (slurry) carried in the previous refining section are separated, then sent to a circulating DMO cooler (E-66008) for cooling, and finally sent to a recovered DMO storage tank. And recovering DMO in the DMO storage tank, and respectively sending the DMO to a DMC gas removal tower and a DMC light removal tower for evaporation and extraction. In addition, the byproduct DMO will self-accumulate in the system, and part of DMO needs to be discharged outside the battery limits.
As shown in FIG. 4, 32 wt% NaOH in the tank car was sent to the NaOH storage tank (T-0102) via the NaOH discharge pump (P-6602A/B). 32 wt% NaOH in the NaOH storage tank is sent to a tail gas absorption tower NaOH mixer (M-2101) through a NaOH feeding pump (P-6603A/B), mixed with desalted water, diluted to 20 wt% concentration, sent to a dilute NaOH cooler (E-2122), and sent to the tail gas absorption tower after the diluted heat is removed.
The liquid in the nitric acid reduction tank is sent to alkali treatment by using the system pressure. The distillate from the top of the DMC lightness-removing tower is sent to a lightness-removing tower feeding tank emptying gas washing tower and then sent to alkali treatment.
In addition to neutralizing HNO3 and trace CL ions, small amounts of DMO, MF, and a portion of DMC were hydrolyzed during the alkaline treatment. Therefore, in order to prevent MN detonating gas from forming in the gas phase, it is necessary to frequently perform nitrogen gas introduction.
And (4) conveying the gas subjected to alkali treatment to a tail gas absorption tower, and washing by using a NaOH aqueous solution. In addition, the gas from the gas washing tower is discharged from the feeding tank of the light component removal tower, and the gas from the reflux tank of the DMC light component removal tower also completely enters the tail gas absorption tower and is washed by NaOH aqueous solution. The liquid involved in the washing is sent to an alkali treatment after washing and is used for neutralization and hydrolysis. The liquid treated by the alkali is firstly sent to a methanol tank containing salt (V-66004), and then sent to a feed tank (T-68004) of a methanol dehydrating tower through a methanol tank containing salt by a methanol delivery pump (P-66006A/B). The pressure of the gas from the tail gas absorption tower is increased by a tail gas blower (K-60001), and then the gas is sent to a tail gas incineration device.
As shown in FIG. 5, the neutralized and hydrolyzed liquid was fed to the feed tank of the methanol dehydrating tower and sent to the middle stage N1a-C of the methanol dehydrating tower (C-66004) via the feed pump of the methanol dehydrating tower (P-68004A/B).
The gas discharged from the top of the dehydration tower is cooled by a methanol dehydration tower condenser (E-66012) and then enters a dehydration tower reflux tank (V-66007) for gas-liquid separation; one part of the condensate is sent back to the top of the dehydration tower by a reflux pump (P-66009A/B) of the dehydration tower, and the other part is sent to a recovered methanol storage tank (T-68004) after being cooled by a recovered methanol cooler (E-66014).
The bottom liquid of the dehydration column was heated cyclically by a methanol dehydration column reboiler (E-66015). The bottom liquid is cooled by a methanol dehydration tower bottom cooler (E-2116), and then sent to a waste water tank (T-68005) by a methanol dehydration tower bottom pump (P-66010A/B).
As shown in fig. 7, the embodiment of the present invention further provides a DMC lightness-removing tower feeding tank, which includes a feeding device 1 communicated with the lightness-removing tower pipeline and a
And a water inlet 6 and a water outlet 7 are respectively arranged on two sides of the shell.
In the embodiment, the
In one embodiment, an air inlet hole 8 is formed in the upper end of the
In one embodiment, the feeding device 1 is disposed at the lower end of the
In one embodiment, the shell 3 is provided with impregnated
Specifically, a through hole matched with the graphite heat exchange tube 4 is formed in the impregnated
In summary, the following steps: after the crude DMC enters the feeding device 1, volatile gas of the crude DMC enters the
Because the cooling medium adopted by the condenser is circulating water, and water and dimethyl oxalate (DMO) cannot leak into the coarse DMC medium, the dimethyl oxalate (DMO) in the medium reacts with water to generate oxalate, so that the oxalate corrodes equipment in a subsequent device, and simultaneously, the dimethyl oxalate (DMO) blocks a light component removal tower and a DMC separation tower filler to cause the tower to form a flooding phenomenon, thereby seriously influencing the normal separation work of the tower.
The performance comparison results of the condenser in the present invention with the existing condenser are as follows:
the equipment adopted by the invention replaces the existing feeding equipment in the application practice, and has obvious advantages: the heat exchange efficiency is high, the gas condensation recovery rate is 96%, the equipment cost is low in economy, the service life is long, and the investment and production cost are reduced; in conclusion, the improvement optimizes the process equipment, improves the stability of the device and reduces the investment and the operating cost.
According to the DMC refining device and the DMC refining process provided by the embodiment of the invention, the DMC device is initially debugged and operated in 2018 and 10 months until qualified products are produced, and the production process, equipment and instruments of the device are safe and stable in operation. A. The product yield is as follows: the product is stable at 175-180 tons/day and can reach 207 tons/day (the design capacity is 50000 tons/300 days is 166.6 tons/day), and exceeds the design capacity; b, product quality: the content of dimethyl carbonate (DMC) is 99.93-99.97%, the content of Methanol (ME) is 100-200 ppm, the content of H2O is 0-100 ppm, and the method completely meets the design requirements and belongs to an advanced level in China; the product has low cost, high price and considerable economic benefit.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：一种(R)-3-羟基丁酸及其低聚物的制备方法