Organic acid ester deacidification agent and deacidification method

Abstract

The embodiment of the invention discloses an organic acid ester deacidification agent and a deacidification method. The deacidification agent disclosed by the invention is any one or two of Ca (OH) 2 and CaO. The deacidification agent provided by the invention is wide in source and low in price, has the advantages of good deacidification effect, simplicity and convenience in operation, green process, high product yield and the like when being used for deacidifying organic acid ester, and has a good application prospect as discharged residues can be recycled as a desulfurizing agent of a power plant.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of fine chemical industry, and in particular to an organic acid ester deacidification agent and a deacidification method. Background Art

[0002] Organic acid esters produced in fine chemical processes mainly include monobasic acid esters, dibasic acid esters, polybasic acid esters, carbonates, sulfonates, sulfites, etc., which are widely used as solvents and synthetic raw materials. Organic acid esters are often synthesized by esterification reaction of organic acids and alcohols under the catalysis of acidic catalysts. Due to thermodynamic equilibrium limitations, incompletely reacted organic acids are inevitably present in the reaction process. In addition, the raw materials from the previous step often contain acidic substances such as humic acid, tar acid, HNO3, H2O2, etc. The acid value range of the crude product usually falls between 1 and 30 mg KOH / g, and the presence of trace acidic substances will seriously affect the quality of the product.

[0003] Patent CN101049550A discloses a solid base adsorbent for deacidification of liquid organic acid esters. The preparation steps of the adsorbent include molding, drying, roasting and other processes. The whole process is complicated, which limits its industrial application. Patent CN111389344A discloses a deacidification and dehydration adsorbent in ester compounds. The adsorbent is prepared by grinding, extrusion molding, roasting and other steps with γ-Al2O3, binder, pore-forming agent, MgO and the like as raw materials. The whole process is complicated and the cost is high. Patent CN105566117A discloses a method for deacidification of isooctyl nitrate using a saturated sodium chloride solution of sodium hydroxide. The method has the disadvantages of large amount of deacidification agent, low product yield, and a large amount of high-salt wastewater discharge. Patent CN109135920A discloses a method for removing acid value in oils and fats using neutral or alkaline alumina as an adsorbent. The method has the disadvantages of large amount of adsorbent, long time consumption, and vacuuming is required during the removal process, generating solid waste and the like. Summary of the invention

[0004] To this end, an embodiment of the present invention provides an organic acid ester deacidification agent and a deacidification method. The deacidification agent is Ca(OH)2 or CaO or a mixture of the two, which is widely available and inexpensive. The deacidification agent is used for the deacidification of organic acid esters and has the advantages of good deacidification effect, simple operation, green process, high product yield, etc. The discharged residue can be recycled as a desulfurization agent in power plants, and has good application prospects.

[0005] In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:

[0006] According to a first aspect of an embodiment of the present invention, the present invention provides an organic acid ester deacidification agent, wherein the deacidification agent is any one or both of Ca(OH)2 and CaO.

[0007] Furthermore, when the deacidifying agent is composed of Ca(OH)2 and CaO, the mass ratio of Ca(OH)2 and CaO is (1-5):1.

[0008] Furthermore, the particle size of the deacidifying agent is 120-600 mesh, preferably 200-400 mesh.

[0009] According to a second aspect of an embodiment of the present invention, the present invention provides use of the deacidification agent as described in any one of the above items in the deacidification of organic acid esters.

[0010] According to a third aspect of the embodiments of the present invention, the present invention provides a method for deacidification of an organic acid ester, using the deacidification agent as described in any one of the above items to perform single-stage or multi-stage deacidification of the organic acid ester.

[0011] Furthermore, the single-stage deacidification comprises: mixing the organic acid ester with the deacidification agent, and separating the solid and the liquid to obtain a deacidification product;

[0012] The mass ratio of the organic acid ester to the deacidifying agent is 100:(0.2-2); the mixing conditions are: room temperature-80°C, 2-60 minutes, preferably 40-60°C, 2-20 minutes; the solid-liquid separation conditions are: 1500-2000rpm, 5-20 minutes.

[0013] Furthermore, the multi-stage deacidification includes: mixing the organic acid ester with the deacidification agent, solid-liquid separation, completing the single-stage deacidification, repeating the deacidification process of mixing with the deacidification agent and solid-liquid separation to obtain a deacidified product;

[0014] In each stage of deacidification, the mass ratio of organic acid ester to deacidification agent is 100:(0.1-1); the mixing conditions are: room temperature-80°C, 2-30 minutes, preferably 40-60°C, 2-10 minutes; the solid-liquid separation conditions are: 1500-2000rpm, 5-10 minutes;

[0015] The multi-stage deacidification includes secondary deacidification or tertiary deacidification.

[0016] Furthermore, the method comprises the following steps:

[0017] (1) feeding the organic acid ester and the deacidifying agent into a first powder suction mixing system and a first horizontal screw centrifuge in sequence to obtain a liquid phase and a residue;

[0018] (2) The liquid phase and the deacidifying agent are sequentially fed into a second powder suction mixing system and a second horizontal screw centrifuge to obtain an ester product and a residue.

[0019] Furthermore, the method further comprises: using the residues of step (1) and step (2) as a desulfurizing agent for desulfurization in a power plant.

[0020] Furthermore, the organic acid ester includes monobasic acid ester, dibasic acid ester, tribasic acid ester, preferably dimethyl dibasic acid ester, diethyl dibasic acid ester, mixed dimethyl dibasic acid ester, triacetin, geranyl acetate, isopropyl myristate, soybean oil, fish oil, olive oil, peanut oil, and sunflower oil.

[0021] The embodiments of the present invention have the following advantages:

[0022] The deacidification method provided by the present invention can remove the acidic substance concentration in the organic acid ester to meet the product requirements (usually the acid value requirement of the product is 0.2-0.4 mg NaOH / g product), and can also absorb trace moisture in the product to reduce the moisture content. In addition, during the deacidification process, by controlling the residence time of the deacidification agent in the liquid phase, the temperature of the deacidification process and other parameters, the solubility of the deacidification agent in the liquid phase is reduced, so that the total metal ion content (including calcium ions from the deacidification agent) in the deacidified product also meets the standard, and the ignition residue content is less than 10ppm (i.e. 0.001%). The present invention adopts a method of high-speed centrifugation after the solid-liquid mixing of the deacidification agent and the organic acid ester for a certain period of time, which can ensure that the product after deacidification is clear and transparent, and there is no solid deacidification agent powder residue. The deacidification method of the present invention is not only suitable for the deacidification of synthetic organic acid esters, but also suitable for the deacidification of oils and fats, such as soybean oil, fish oil, olive oil, peanut oil, sunflower seed oil, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0024] Figure 1 A schematic diagram of a deacidification process of an organic acid ester provided in Example 1 of the present invention;

[0025] Among them, S-1: the first powder suction mixing system; S-2: the second powder suction mixing system; C-1: the first horizontal screw centrifuge; C-2: the second horizontal screw centrifuge. DETAILED DESCRIPTION

[0026] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0028] Example 1

[0029] This embodiment provides a method for deacidification of organic acid esters:

[0030] (1) 0.2 g of Ca(OH)2 powder (300 mesh) was mixed with 20 g of crude mixed dimethyl ester (i.e., a mixture of dimethyl succinate, dimethyl glutarate and dimethyl adipate, industrially known as DBE oil, with a water content of 0.5 wt % and an acid value of 20.0 mg NaOH / g oil), stirred at 40°C for 10 min, and centrifuged at 1800 rpm for 10 min to obtain a liquid phase and a solid phase;

[0031] (2) Add 0.05 g of Ca(OH)2 to the liquid phase obtained in step (1), stir at 40°C for 10 min, and centrifuge at 1800 rpm for 5 min to obtain a liquid deacidification product and a solid phase, and analyze the deacidification product.

[0032] Analysis of results: Under the conditions that the dosage of the primary deacidifying agent is 0.2 / 20=1% and the dosage of the secondary deacidifying agent is 0.05 / 20=0.25%, the acid value of the deacidified product is 0.3mg NaOH / g product, the dehydration rate is 70%, the product yield is 96.0%, and the ignition residue content is 6ppm.

[0033] Embodiments 2 to 18

[0034] The organic acid esters treated in Examples 2 to 18 are DBE oils (same as in Example 1). The difference from Example 1 is that the deacidification conditions are different, such as the composition and dosage of the deacidification agent, the mixing temperature and time, the deacidification degree, etc. Other conditions remain unchanged. The results are shown in Table 1 below.

[0035] Table 1 Deacidification examples and results of DBE oil

[0036]

[0037]

[0038] Note: The dosage of deacidifying agent refers to the mass ratio of deacidifying agent to raw material ester (DBE oil).

[0039] Examples 19 to 28

[0040] The deacidification methods of Examples 19 to 28 differ from those of Example 1 in that the deacidification conditions are different, such as the type of raw ester, the composition and dosage of the deacidification agent, the deacidification temperature of each stage is fixed at 60°C, the deacidification time of each stage is fixed at 5 minutes, and other conditions remain unchanged. The results are shown in Table 2 below.

[0041] Table 2 Deacidification examples and results of different organic acid esters

[0042]

[0043]

[0044] Note: The dosage of deacidifying agent refers to the mass ratio of deacidifying agent to raw material ester.

[0045] Embodiment 29

[0046] 500 kg / h of crude mixed dimethyl ester (DBE oil, acid value 25 mg NaOH / g, water content 0.6%, temperature 60°C) and 5 kg / h of Ca(OH)2 / CaO (mass ratio 4:1) powder (300 mesh) were fed into the Figure 1 The first powder suction mixing system S-1 shown in the figure stayed for 4 minutes, entered the first horizontal screw centrifuge C-1 (2000rpm, 10 minutes), completed the first deacidification, and the resulting liquid phase was sent to the second powder suction mixing system S-2 at 500kg / h and 3.0kg / h of Ca(OH)2 / CaO (mass ratio 4:1) powder (300 mesh), stayed for 4 minutes, and entered the second horizontal screw centrifuge C-2 (2000rpm, 6 minutes) to complete the second deacidification and obtain the liquid phase deacidification product. The deacidification product was analyzed.

[0047] Result analysis:

[0048] The acid value of the product is 0.2 mg NaOH / g product, the dehydration rate is 81%, the yield is 96.2%, and the ignition residue content is 5 ppm.

[0049] Embodiment 30

[0050] 1000 kg / h of crude diisopropyl adipate (acid value 5.0 mg NaOH / g, water content 0.4%, temperature 60°C) and 5.0 kg / h of Ca(OH)2 powder (300 mesh) were continuously fed into the reactor. Figure 1The first powder suction mixing system S-1 shown in the figure stayed for 5 minutes, entered the first horizontal screw centrifuge C-1 (2000rpm, 15 minutes), completed the first deacidification, and the resulting liquid phase continuously entered the second powder suction mixing system S-2 with 1000kg / h and 3.0kg / h of Ca(OH)2 powder (300 mesh), stayed for 4 minutes, and was sent to the second horizontal screw centrifuge C-2 (1800rpm, 10 minutes) to complete the second deacidification and obtain a liquid phase deacidification product. The deacidification product was analyzed.

[0051] Result analysis:

[0052] The acid value of the product is 0.2 mg NaOH / g product, the dehydration rate is 75%, the yield is 97.5%, and the ignition residue content is 5 ppm.

[0053] Embodiment 31

[0054] The solid phase Ca(OH)2 residue obtained by separation in the first decanter centrifuge C-1 and the second decanter centrifuge C-2 in Example 30 was collected, water was added to prepare a suspension with a solid content of 50 g / L, and sent to a slurry bed desulfurization tower to simulate the flue gas (temperature 120°C, SO2 content 3000 mg / m 3 Keeping the same conditions, a suspension with the same solid content prepared with pure Ca(OH)2 was used as the desulfurizing agent, and parallel experiments were carried out.

[0055] The comparison results show that the desulfurization rate of Ca(OH)2 residue as a desulfurizer is 98%, and no VOCs emissions are detected in the tail gas after desulfurization; the desulfurization rate of pure Ca(OH)2 as a desulfurizer is 96%, which is slightly lower. It can be seen that the solid phase residue after deacidification of organic acid esters has a good enhancement effect on the reaction rate and reaction completion of SO2 because it is attached with organic acid calcium salt as an activator.

[0056] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. An organic acid ester deacidification agent, characterized in that The deacidifying agent is any one or both of Ca(OH)2 and CaO.

2. The organic acid ester deacidification agent according to claim 1, characterized in that When the deacidifying agent is composed of Ca(OH)2 and CaO, the mass ratio of Ca(OH)2 to CaO is (1-5):

1.

3. The organic acid ester deacidification agent according to claim 1, characterized in that The particle size of the deacidifying agent is 120-600 mesh, preferably 200-400 mesh.

4. Use of the deacidification agent according to any one of claims 1 to 3 in the deacidification of organic acid esters.

5. A method for deacidification of an organic acid ester, characterized in that: The organic acid ester is subjected to single-stage or multi-stage deacidification using the deacidification agent as described in any one of claims 1 to 3.

6. The method for deacidification of organic acid esters according to claim 5, characterized in that: The single-stage deacidification comprises: mixing the organic acid ester with the deacidification agent, and separating the solid and the liquid to obtain a deacidification product; The mass ratio of the organic acid ester to the deacidifying agent is 100:(0.2-2); the mixing conditions are: room temperature-80°C, 2-60 minutes, preferably 40-60°C, 2-20 minutes; the solid-liquid separation conditions are: 1500-2000rpm, 5-20 minutes.

7. The method for deacidification of organic acid esters according to claim 5, characterized in that: The multi-stage deacidification includes: mixing the organic acid ester with the deacidification agent, separating the solid and the liquid, completing the single-stage deacidification, repeating the deacidification process of mixing with the deacidification agent and separating the solid and the liquid, and obtaining the deacidification product; In each stage of deacidification, the mass ratio of organic acid ester to deacidification agent is 100:(0.1-1); the mixing conditions are: room temperature-80°C, 2-30 minutes, preferably 40-60°C, 2-10 minutes; the solid-liquid separation conditions are: 1500-2000rpm, 5-10 minutes; The multi-stage deacidification includes secondary deacidification or tertiary deacidification.

8. The method for deacidification of organic acid esters according to claim 5, characterized in that: The method comprises the following steps: (1) feeding the organic acid ester and the deacidifying agent into a first powder suction mixing system and a first horizontal screw centrifuge in sequence to obtain a liquid phase and a residue; (2) The liquid phase and the deacidifying agent are sequentially fed into a second powder suction mixing system and a second horizontal screw centrifuge to obtain an ester product and a residue.

9. The method for deacidification of organic acid esters according to claim 8, characterized in that: The method further comprises: using the residues from step (1) and step (2) as an activated desulfurizing agent for tail gas from a power plant.

10. The method for deacidification of organic acid esters according to claim 5, characterized in that: The organic acid esters include monobasic acid esters, dibasic acid esters, and tribasic acid esters, preferably dimethyl dibasic acid ester, diethyl dibasic acid ester, mixed dimethyl dibasic acid ester, triacetin, geranyl acetate, isopropyl myristate, soybean oil, fish oil, olive oil, peanut oil, and sunflower oil.

Images