Production device for producing dibutyl carbonate by transesterification method
By optimizing the design and process flow of the transesterification production unit, the problems of unstable product quality and low yield in the production of dibutyl carbonate were solved, and high-yield and high-purity dibutyl carbonate production was achieved, which is suitable for large-scale industrial application.
Patent Information
- Application Number
- CN202520019376.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-06
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2035-01-06
AI Technical Summary
Existing dibutyl carbonate production facilities suffer from complex processes, unstable product quality, and low yields, making it difficult to achieve large-scale industrial production. In particular, the transesterification process has a generally low product yield and the technology is not yet perfect.
A production apparatus was designed, comprising a dibutyl carbonate reactor, a mixing and discharging pump, a dibutyl carbonate distillation column, a distillation column condenser, a distillation column reflux tank, a fore-distillate tank, a transition distillate tank, a crude product tank, a product tank, a return pump, and a vacuum system. The apparatus achieves raw material recycling by heating a mixture of catalyst and n-butanol, combined with batch distillation and vacuum distillation, optimizing reaction conditions and separation processes.
It improves the yield and purity of dibutyl carbonate, ensures stable production, is suitable for large-scale industrial production, has fewer side reactions, and saves costs and heat.
Smart Images
Figure CN223669184U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the production technology field of carbonic acid dibutyl ester especially relates to a production device for producing carbonic acid dibutyl ester by ester exchange method. BACKGROUND
[0002] Carbonic acid dibutyl ester is a multipurpose chemical product, and is widely used in the fields of organic solvent, battery electrolyte, pharmaceutical intermediate, cosmetic solvent and the like. Meanwhile, as a carbonic acid ester product, carbonic acid dibutyl ester belongs to green chemical product, and has low toxicity, safety and environmental protection. Compared with other carbonic acid ester products, carbonic acid dibutyl ester has a longer chain structure, and is more stable in performance, and when used as lithium ion battery electrolyte, can make the battery more stable and safe. The odor of carbonic acid dibutyl ester is more moderate than other carbonic acid ester products, and has aromatic flavor, and has wide application in the field of cosmetics. In recent years, market supply shows that the demand for carbonic acid dibutyl ester gradually increases, and has good economic effect, but the yield of carbonic acid dibutyl ester is not high at present, and is mostly small-scale production. At present, the mainstream production method is urea alcoholysis method for producing carbonic acid dibutyl ester, and the reaction time is long, the reaction condition is harsh, the reaction environment of high temperature and high pressure is relatively dangerous, and ammonia gas is generated in the reaction process, which is relatively difficult to handle. The existing production device has complex process, unstable product quality, low product yield, and it is difficult to realize large-scale industrial production. The production process of carbonic acid dibutyl ester by ester exchange method has mild reaction condition, less pollution, easy treatment, and less impurities generated in the reaction process, and the product is more likely to be qualified. But at present, the production process of carbonic acid dibutyl ester by ester exchange method has not been popularized, and the related technology needs to be improved, and the product yield is generally low. The utility model provides a carbonic acid dibutyl ester production device which is simple in operation, high in product yield, stable in product quality, and suitable for large-scale industrial production. SUMMARY
[0003] The utility model solves the technical problem in providing a kind of production device for ester exchange method production carbonic acid dibutyl ester, the production device provided in the application can stably produce qualified carbonic acid dibutyl ester product, and product yield is high, product purity is high. In view of this, the production device for ester exchange method production carbonic acid dibutyl ester provided in the application includes: carbonic acid dibutyl ester reaction kettle, mixing and discharging pump, carbonic acid dibutyl ester rectifying column, rectifying column condenser, rectifying column reflux tank, front fraction tank, transition fraction tank, crude product tank, product tank, return pump, vacuum system;Wherein carbonic acid dibutyl ester reaction kettle bottom discharge port is connected with the import of mixing and discharging pump, and the outlet of mixing and discharging pump is connected with the feed inlet of carbonic acid dibutyl ester rectifying column column still, and the top gas phase outlet of carbonic acid dibutyl ester rectifying column is connected with the top of rectifying column condenser, and the bottom liquid phase outlet of rectifying column condenser is connected with the top of rectifying column reflux tank, and the bottom of reflux tank is connected with front fraction tank, transition fraction tank, crude product tank and product tank respectively, and the bottom of transition fraction tank is connected with the top of carbonic acid dibutyl ester reaction kettle, and the bottom discharge port of crude product tank is connected with the import of return pump, and the outlet of return pump is connected with the return port of carbonic acid dibutyl ester rectifying column column still, and the upper part of vacuum system is connected with rectifying column condenser.
[0004] First, the catalyst and n-butanol are added to the reaction kettle, mixed thoroughly and heated to 100 to 150 DEG C, then dimethyl carbonate is added for reaction, and the reaction time is controlled at 30 to 80 minutes, after the reaction is completed, the reaction liquid is transported to the carbonic acid dibutyl ester rectifying column column still by mixing and discharging pump for intermittent rectification. First, heat the raw material, then react to shorten the reaction time, reduce the occurrence of side reactions and improve the product pass rate. When the preheating temperature of the mixed liquid is lower than 100 DEG C, it is not conducive to the reaction, and the product yield will be reduced. When the preheating temperature is higher than 150 DEG C, side reactions are more likely to occur, affecting product quality. When the reaction time is less than 30 minutes, the reaction is insufficient, and the product yield is low. When the reaction time exceeds 80 minutes, side reactions are likely to occur, affecting product quality. When the preheating temperature of the catalyst and n-butanol mixed liquid is high, a shorter reaction time can be selected.
[0005] The reaction liquid is heated by column still, and is rectified in the carbonic acid dibutyl ester rectifying column. The diameter of the carbonic acid dibutyl ester rectifying column column still is 1.5 to 5 times larger than the column section diameter, and the volume of the carbonic acid dibutyl ester rectifying column column still is 1.5 to 3 times larger than the volume of the carbonic acid dibutyl ester reaction kettle. The carbonic acid dibutyl ester rectifying column adopts intermittent rectification, and the rectification time is 5h to 8h. The larger column still volume can accommodate multiple batches of reaction materials, and rectification can be carried out simultaneously, reducing personnel operation and improving yield.
[0006] First, normal pressure rectification is carried out, methanol and excess dimethyl carbonate in the reaction liquid are separated, the fraction is collected to the front fraction tank, and the reaction is promoted in the forward direction by the methanol generated by the separation reaction; after the front fraction collection is completed, the overhead discharge is switched to the transition fraction tank, and the unreacted n-butanol separated out is collected; after the transition fraction separation is completed, the overhead discharge is switched to the crude product tank, and the vacuum system is started, vacuum rectification is carried out, the vacuum degree is maintained at 20 kapA to 0 kpaA, and the crude dibutyl carbonate containing a small amount of n-butanol is collected; after the overhead discharge reaches the product qualified standard, the overhead discharge is switched to the product tank. The high-boiling-point product is subjected to vacuum rectification, which can effectively save heat. The higher the vacuum degree, the more heat is saved, and the higher the product yield. The product yield of the reaction in the reaction kettle is 60%, but the utility model continuously removes the methanol generated by the reaction to promote the reaction in the forward direction, and the unreacted raw material is recycled and utilized, so that the raw material conversion rate is improved, the yield is improved, and the product yield can reach more than 95%.
[0007] The transition fraction containing n-butanol is transported from the transition fraction tank to the dibutyl carbonate reaction kettle by gravity flow and participates in the next reaction as raw material, and the crude dibutyl carbonate containing a small amount of n-butanol is transported from the crude product tank to the dibutyl carbonate rectification tower by the return pump to participate in the next refining. The raw material is recycled, the n-butanol can be almost completely reacted, and the cost is saved.
[0008] The utility model has the following advantages:
[0009] (1) The reaction is rapid, and the side reaction is less;
[0010] (2) The raw material is recycled, the n-butanol can be completely reacted, and the cost is saved;
[0011] (3) The raw material conversion rate is high, and the product yield is high;
[0012] (4) The production is stable, and the operation is simple;
[0013] (5) The high-boiling-point product is subjected to vacuum rectification, and heat is saved. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 It is the device schematic drawing of the utility model. The dibutyl carbonate reaction kettle (R1), the mixing and discharging pump (P1), the dibutyl carbonate rectification tower (T1), the rectification tower condenser (E1), the rectification tower reflux tank (V1), the front fraction tank (V2), the transition fraction tank (V3), the crude product tank (V4), the product tank (V5), the return pump (P2) and the vacuum system (P3) are shown in the figure. DETAILED DESCRIPTION
[0015] The utility model further describes in combination with examples, the following embodiments are intended to illustrate the utility model, and are not limited to the utility model. For the industrial production of carbonic acid dibutyl ester, the utility provides a production device for producing carbonic acid dibututyl ester by ester exchange method, which comprises: carbonic acid dibutyl ester reaction kettle (R1), mixing and discharging pump (P1), carbonic acid dibutyl ester rectifying tower (T1), rectifying tower condenser (E1), rectifying tower reflux tank (V1), front fraction tank (V2), transition fraction tank (V3), crude product tank (V4), product tank (V5), return pump (P2), vacuum system (P3); wherein the bottom discharge port of carbonic acid dibutyl ester reaction kettle (R1) is connected with the inlet of mixing and discharging pump (P1), the outlet of mixing and discharging pump (P1) is connected with the column still inlet of carbonic acid dibutyl ester rectifying tower (T1), the top gas phase outlet of carbonic acid dibutyl ester rectifying tower (T1) is connected with the upper portion of rectifying tower condenser (E1), the bottom liquid phase outlet of rectifying tower condenser (E1) is connected with the top portion of rectifying tower reflux tank (V1), the bottom portion of reflux tank is connected with front fraction tank (V2), transition fraction tank (V3), crude product tank (V4) and product tank (V5) respectively, the bottom portion of transition fraction tank (V3) is connected with the top portion of carbonic acid dibutyl ester reaction kettle (R1), the bottom discharge port of crude product tank (V4) is connected with the inlet of return pump (P2), the outlet of return pump (P2) is connected with the column still return port of carbonic acid dibutyl ester rectifying tower (T1), and the upper portion of vacuum system (P3) is connected with rectifying tower condenser (E1).
[0016] For the industrial production of carbonic acid dibutyl ester, the utility provides a production device for producing carbonic acid dibututyl ester by ester exchange method, which comprises: carbonic acid dibutyl ester reaction kettle (R1), mixing and discharging pump (P1), carbonic acid dibutyl ester rectifying tower (T1), rectifying tower condenser (E1), rectifying tower reflux tank (V1), front fraction tank (V2), transition fraction tank (V3), crude product tank (V4), product tank (V5), return pump (P2), vacuum system (P3); wherein the bottom discharge port of carbonic acid dibutyl ester reaction kettle (R1) is connected with the inlet of mixing and discharging pump (P1), the outlet of mixing and discharging pump (P1) is connected with the column still inlet of carbonic acid dibutyl ester rectifying tower (T1), the top gas phase outlet of carbonic acid dibutyl ester rectifying tower (T1) is connected with the upper portion of rectifying tower condenser (E1), the bottom liquid phase outlet of rectifying tower condenser (E1) is connected with the top portion of rectifying tower reflux tank (V1), the bottom portion of reflux tank is connected with front fraction tank (V2), transition fraction tank (V3), crude product tank (V4) and product tank (V5) respectively, the bottom portion of transition fraction tank (V3) is connected with the top portion of carbonic acid dibutyl ester reaction kettle (R1), the bottom discharge port of crude product tank (V4) is connected with the inlet of return pump (P2), the outlet of return pump (P2) is connected with the column still return port of carbonic acid dibutyl ester rectifying tower (T1), and the upper portion of vacuum system (P3) is connected with rectifying tower condenser (E1).
[0017] The pilot test is carried out on the device for producing 2000 tons of carbon dioxide butyl ester by using the ester exchange method per year, n-butyl alcohol and catalyst are added into the carbon dioxide butyl ester reaction kettle to be mixed uniformly and heated to 150 DEG C, then carbon dioxide dimethyl ester is added to react, after the reaction for 40 minutes, the carbon dioxide butyl ester mixture is transported to the carbon dioxide butyl ester rectifying tower for intermittent rectification through the mixture discharge pump. First, normal pressure rectification is carried out, the front fraction composed of methanol and carbon dioxide dimethyl ester and the transition fraction containing n-butyl alcohol are collected, the vacuum system is started to make the carbon dioxide butyl ester rectifying tower maintain at 10 kapA, the carbon dioxide butyl ester crude product containing a small amount of n-butyl alcohol and the carbon dioxide butyl ester product are collected. The collected transition fraction is returned to the carbon dioxide butyl ester reaction kettle for recycling; the collected carbon dioxide butyl ester crude product is returned to the carbon dioxide butyl ester rectifying tower for rectification and purification again. The test result shows that the content of the carbon dioxide butyl ester product produced by using the device for producing carbon dioxide butyl ester by using the ester exchange method reaches more than 99.8% in two months, the production is stable, and the product yield is stable at 95.4%.
[0018] The above embodiment is only one implementation form of the device for producing carbon dioxide butyl ester by using the ester exchange method, according to other deformations of the scheme provided by the device, the components or steps are increased or reduced, or the device is applied to the technical field similar to the device, which all belong to the protection scope of the device.
Claims
1. A production apparatus for producing dibutyl carbonate via transesterification, characterized in that it comprises: The dibutyl carbonate reactor (R1), the mixing and discharging pump (P1), the dibutyl carbonate rectifying tower (T1), the rectifying tower condenser (E1), the rectifying tower reflux tank (V1), the front fraction tank (V2), the transition fraction tank (V3), the crude product tank (V4), the product tank (V5), the return pump (P2), and the vacuum system (P3); wherein the bottom outlet of the dibutyl carbonate reactor (R1) is connected with the inlet of the mixing and discharging pump (P1), the outlet of the mixing and discharging pump (P1) is connected with the tower kettle inlet of the dibutyl carbonate rectifying tower (T1), the top gas phase outlet of the dibutyl carbonate rectifying tower (T1) is connected with the upper part of the rectifying tower condenser (E1), the bottom liquid phase outlet of the rectifying tower condenser (E1) is connected with the top part of the rectifying tower reflux tank (V1), the bottom part of the reflux tank is connected with the front fraction tank (V2), the transition fraction tank (V3), the crude product tank (V4), and the product tank (V5), the bottom part of the transition fraction tank (V3) is connected with the top part of the dibutyl carbonate reactor (R1), the bottom outlet of the crude product tank (V4) is connected with the inlet of the return pump (P2), the outlet of the return pump (P2) is connected with the tower kettle return inlet of the dibutyl carbonate rectifying tower (T1), and the vacuum system (P3) is connected with the upper part of the rectifying tower condenser (E1).
2. The production apparatus for producing dibutyl carbonate by transesterification according to claim 1, characterized by The tower kettle diameter of the dibutyl carbonate rectifying tower (T1) is 1.5 to 5 times larger than the tower section diameter, and the tower kettle volume of the dibutyl carbonate rectifying tower (T1) is 1.5 to 3 times larger than the volume of the dibutyl carbonate reactor (R1).
3. The production apparatus for producing dibutyl carbonate by transesterification according to claim 1, wherein The dibutyl carbonate rectifying tower (T1) adopts the intermittent rectification mode to separate and collect different fractions, and normal pressure rectification is used to collect the front fraction, the transition fraction, and the crude product, and the vacuum system (P3) is opened to collect the product, so that the pressure in the dibutyl carbonate rectifying tower is maintained at 20 kpaA to 0 kpaA.