阅读说明：本技术 一种环己烷-1,2-二羧酸二异辛酯粗品的脱色方法 (Method for decoloring cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product ) 是由 高燕 李正利 鲁红勇 白璐 董传涛 于 2021-08-23 设计创作，主要内容包括：本发明公开了一种环己烷-1,2-二羧酸二异辛酯粗品的脱色方法,所述脱色方法包括如下步骤：将活性炭进行热处理；将热处理后的活性炭和环己烷-1,2-二羧酸二异辛酯粗品进行超声混合,得到混合物；将混合物进行静置吸附,再进行固液分离,得到脱色的环己烷-1,2-二羧酸二异辛酯；该脱色方法通过对活性炭的热处理、添加量、吸附参数的控制,能够充分吸附去除环己烷-1,2-二羧酸二异辛酯粗品中的杂质,达到对环己烷-1,2-二羧酸二异辛酯粗品更好的脱色效果。(The invention discloses a method for decoloring a cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product, which comprises the following steps: carrying out heat treatment on the activated carbon; ultrasonically mixing the activated carbon subjected to heat treatment and a cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product to obtain a mixture; standing and adsorbing the mixture, and then carrying out solid-liquid separation to obtain decolored cyclohexane-1, 2-dicarboxylic acid diisooctyl ester; the decoloring method can fully adsorb and remove impurities in the cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product by controlling the heat treatment, the addition amount and the adsorption parameters of the activated carbon, and achieves a better decoloring effect on the cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product.)

1. A method for decoloring a crude product of cyclohexane-1, 2-dicarboxylic acid diisooctyl ester is characterized by comprising the following steps:

(a) carrying out heat treatment on the activated carbon;

(b) ultrasonically mixing the activated carbon subjected to heat treatment and a cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product to obtain a mixture;

(c) and (3) standing and adsorbing the mixture, and then carrying out solid-liquid separation to obtain the decolored cyclohexane-1, 2-dicarboxylic acid diisooctyl ester.

2. The decolorization method according to claim 1, wherein the mesh particle size of said activated carbon is 150 to 300 mesh.

3. The decolorization method according to claim 1, wherein said heat treatment is carried out by subjecting the activated carbon to a temperature of 100 to 110 ℃ for 0.5 to 2 hours.

4. The decoloring method according to claim 1, wherein the mass of the activated carbon is 6% or more of the mass of the crude diisooctyl cyclohexane-1, 2-dicarboxylate.

5. The decolorization method according to claim 1, wherein said ultrasonic mixing time is 0.5-2 min.

6. The decoloring method according to claim 1, wherein the standing adsorption temperature is 50 to 70 ℃ and the time is not less than 40 min.

7. The decolorization method according to claim 1, characterized in that said still standing adsorption temperature is 60 ℃.

8. The decolorization method according to claim 1, wherein said solid-liquid separation means is suction filtration under reduced pressure or centrifugation.

9. The decolorization method according to claim 7, wherein the centrifugation is a secondary centrifugation, the first centrifugation is performed at 8000-12000 r/min for 3-5 min; the second centrifugation rotating speed is 11000 to 14000r/min, and the time is 2 to 3 min.

Technical Field

The invention relates to the technical field of decolorization, in particular to a method for decolorizing a cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product.

Background

The plasticizer is used as an additive widely added in the plastic processing industry, can change the property of the plasticizer to improve the processing performance of the plasticizer, is an important fine chemical product, and is applied to the fields of food packaging, medical appliances, cosmetics, building materials, cables and the like. The traditional Phthalate (PAEs) plasticizer has ideal plasticizing effect, maximum using amount and widest using range, and mainly comprises dioctyl phthalate (DOP), dibutyl phthalate (DBP), diisononyl phthalate (DINP) and the like. The traditional plasticizer is easy to volatilize and added into the product, has certain exudation and can generate certain harm to organisms and environment, and particularly, the plasticizer added into food packages such as snack boxes, preservative films and the like can cause carcinogenic risk after being ingested by human bodies. Lange Rosa et al found that almost every urine sample could detect a metabolite of the plasticizer in the study; paragraph morning glory et al indicate the ubiquitous presence of PAEs plasticizers in lakes and rivers across the country; ranunculus et al found that PAEs in the mulch remained in the soil and migrated to the crop where they were ingested by the body through the food chain. In recent years, the safety problem of plasticizers has been increasingly emphasized in various countries.

Cyclohexane carboxylate plasticizers such as diisooctyl cyclohexane-1, 2-Dicarboxylate (DEHCH) have a structure similar to that of hydrogenated products of conventional phthalate plasticizers and excellent plasticizing properties. The plasticizer is green, environment-friendly, non-toxic, biodegradable, high in comprehensive application and use value and becomes the first choice for replacing phthalate plasticizers. The effective decolorization of the DEHCH crude product is directly related to the quality of the product. Common methods for decolorization of plasticizers include both chemical and physical adsorption methods. The chemical method is a method for reducing or oxidizing colored substances in the plasticizer product into colorless substances through redox reaction in the chemical reaction, and then separating and purifying to realize decoloration; the physical adsorption method is a method for realizing decolorization by utilizing porous physical adsorption of an adsorbent to colored substances in a plasticizer product and then filtering and separating. Considering that new impurities are introduced due to saponification in the chemical adsorption method, the physical adsorption method which is simple to operate and low in price is generally selected as the industrial decoloring route of the crude DEHCH product.

The activated carbon has large specific surface area, is a common adsorbent and is widely applied to decolorization of organic compounds and treatment of sewage. At present, in the process of decoloring the activated carbon by the plasticizer, the plasticizer needs to be diluted by an organic solvent and then adsorbed, so that the decoloring rate is low, and the loss of the plasticizer caused by the adsorption of the plasticizer by the activated carbon is easily caused in the decoloring process.

Disclosure of Invention

The invention aims to provide a method for decoloring a cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product, which can efficiently adsorb and remove impurities in the cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product to achieve the aim of decoloring.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

the invention provides a method for decoloring a crude product of cyclohexane-1, 2-dicarboxylic acid diisooctyl ester, which comprises the following steps:

(a) carrying out heat treatment on the activated carbon;

(b) ultrasonically mixing the activated carbon subjected to heat treatment and a cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product to obtain a mixture;

(c) and (3) standing and adsorbing the mixture, and then carrying out solid-liquid separation to obtain the decolored cyclohexane-1, 2-dicarboxylic acid diisooctyl ester.

Preferably, the mesh particle size of the activated carbon is 150-300 meshes.

Preferably, the heat treatment is to treat the activated carbon at 100-110 ℃ for 0.5-2 h.

Preferably, the mass of the activated carbon is more than 6% of the mass of the crude product of cyclohexane-1, 2-dicarboxylic acid diisooctyl ester.

Preferably, the ultrasonic mixing time is 0.5-2 min.

Preferably, the standing adsorption temperature is 50-70 ℃, and the time is not less than 40 min.

Preferably, the still standing adsorption temperature is 60 ℃.

Preferably, the solid-liquid separation mode is vacuum filtration or centrifugation.

Preferably, the centrifugation is secondary centrifugation, the first centrifugation rotating speed is 8000-12000 r/min, and the time is 3-5 min; the second centrifugation rotating speed is 11000 to 14000r/min, and the time is 2 to 3 min.

Compared with the prior art, the invention has the beneficial effects that at least:

the decoloring method can fully adsorb and remove impurities in the cyclohexane-1, 2-diisooctyl dicarboxylate crude product by controlling the heat treatment, the addition amount and the adsorption parameters of the activated carbon, so as to achieve better decoloring effect on the cyclohexane-1, 2-diisooctyl dicarboxylate crude product; in addition, the method for decoloring the cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product directly adopts the activated carbon to decolor the cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product without dilution, and can effectively avoid the loss of the cyclohexane-1, 2-dicarboxylic acid diisooctyl ester caused by the adsorption of the activated carbon to impurities and the adsorption of the cyclohexane-1, 2-dicarboxylic acid diisooctyl ester.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a gas chromatogram of a crude DEHCH solution at different dosages of activated carbon in the experimental examples of the present application;

FIG. 2 is an enlarged view of the segment 34.450-35.000min in the gas chromatogram of FIG. 1;

FIG. 3 is an enlarged view of the segment 35.300-35.485 min in the gas chromatogram of FIG. 1;

FIG. 4 is a diagram showing the UV absorption spectrum of the DEHCH product in the experimental example of the present application;

FIG. 5 is a diagram showing the UV absorption spectra of crude DEHCH after decolorization at different adsorption times in the experimental examples of the present application;

FIG. 6 shows the measurement results of DEHCH decolorization ratio at different adsorption times in the experimental examples of the present application;

FIG. 7 is a diagram showing the UV absorption spectra of the crude DEHCH product after adsorption decolorization with different amounts of activated carbon in the experimental examples of the present application;

FIG. 8 shows the measurement results of DEHCH decolorization ratio for different amounts of activated carbon in the experimental examples of the present application;

FIG. 9 is a diagram showing the UV absorption spectra of the DEHCH crude product after adsorption and decolorization at different adsorption temperatures in the experimental examples of the present application;

FIG. 10 shows the measurement results of DEHCH decolorization ratio at different adsorption temperatures in the experimental examples of the present application.

Detailed Description

The following describes embodiments of the present invention in detail with reference to the following embodiments. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.

Example 1

This example is a method for decolorizing crude diisooctyl cyclohexane-1, 2-dicarboxylate, which comprises the following steps:

(a) treating the activated carbon with the mesh size of 200 meshes at 100 ℃ for 2 h;

(b) ultrasonically mixing the activated carbon subjected to heat treatment and a cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product for 0.5min to obtain a mixture, wherein the mass of the activated carbon is 8% of that of the cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product;

(c) standing and adsorbing the mixture at 50 ℃ for 70min, and then centrifuging for the second time, wherein the first centrifugation rotating speed is 12000r/min, and the time is 3 min; and the second centrifugation rotation speed is 14000r/min, the time is 2min, and the decolored cyclohexane-1, 2-dicarboxylic acid diisooctyl ester is obtained.

Example 2

This example is a method for decolorizing crude diisooctyl cyclohexane-1, 2-dicarboxylate, which comprises the following steps:

(a) treating the activated carbon with the mesh size of 200 meshes at 110 ℃ for 0.5 h;

(b) ultrasonically mixing the activated carbon subjected to heat treatment and a cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product for 2min to obtain a mixture, wherein the mass of the activated carbon is 7% of that of the cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product;

(c) standing and adsorbing the mixture at 70 deg.C for 50min, and centrifuging again at 8000r/min for 5 min; and the second centrifugation rotation speed is 11000r/min, and the time is 3min, so that the decolored cyclohexane-1, 2-dicarboxylic acid diisooctyl ester is obtained.

Example 3

This example is a method for decolorizing crude diisooctyl cyclohexane-1, 2-dicarboxylate, which comprises the following steps:

(a) treating activated carbon with a mesh size of 200 meshes at 105 ℃ for 1 h;

(b) ultrasonically mixing the activated carbon subjected to heat treatment and a cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product for 1min to obtain a mixture, wherein the mass of the activated carbon is 6% of that of the cyclohexane-1, 2-dicarboxylic acid diisooctyl ester crude product;

(c) standing and adsorbing the mixture at 60 deg.C for 40min, and centrifuging again at 10000r/min for 4 min; and the second centrifugation rotation speed is 12000r/min, the time is 3min, and the decolored cyclohexane-1, 2-dicarboxylic acid diisooctyl ester is obtained.

Examples of the experiments

1. Reagent, consumable and instrument

Reagent: crude and finished product of DEHCH (Puyang flourishing energy science and technology Co., Ltd.), absolute ethyl alcohol (Hengcheng flourishing fine chemical Co., Ltd.), 95% ethyl alcohol (Jiangsu Qiangsheng functional chemical Co., Ltd.), and 200-mesh active carbon for medical use (Shanghai Meclin biochemistry Co., Ltd.).

Consumable material: a pipette, quantitative filter paper, a beaker, a centrifuge tube, a quartz cuvette and the like.

The instrument comprises the following steps: an electric heating constant temperature air blast drying oven (Shanghai essence macro experimental facilities, Co., Ltd. DHG-9070A); a heat-collecting heating stirrer (DF-101S, manufactured by Changzhou ordinary instruments Co., Ltd.); electronic balance (shanghai yuepin scientific instruments (suzhou) manufacturing ltd FA 1004B); a centrifugal machine (Hunan instrument TG 16-W); an ultraviolet-visible spectrophotometer (shimadzu U3900, japan); gas chromatography-mass spectrometer (shimadzu, japan QP 2020); circulating water type multipurpose vacuum pump (Hightech instrument factory of Ongyu, Guyi);

2. research on influence of DEHCH crude product diluted by absolute ethyl alcohol on activated carbon adsorption

On the basis of accurately preparing the solution, the absorbance of a crude solution diluted by 100 times is measured to be about 3.6, and the absorbance of a finished solution diluted by 100 times of DEHCH (finished product) decolorized by a factory is measured to be about 3.1, and the absorbance is shown in Table 1:

TABLE 1 Absorbance of diluted crude and finished DEHCH products

Diluting a DEHCH crude product by 100 times with absolute ethyl alcohol, weighing 0.1g, 0.2g, 0.3g, 0.4g, 0.5g, 0.6g, 0.8g, 1.0g, 1.5g and 2.0g of activated carbon for an adsorption experiment of 0.2mL of a crude product solution diluted by 100 times, mixing the activated carbon and the crude product solution, performing ultrasonic oscillation for 60s, standing and adsorbing the mixed solution at 60 ℃ for 40min, and performing secondary centrifugation, wherein the first centrifugation speed is 10000r/min, and the time is 4 min; the second centrifugation rotating speed is 12000r/min, the time is 3min, and the decolored DEHCH is obtained; the absorbance of the solution after adsorption was measured, and the measurement results are shown in table 2:

TABLE 2 relationship between activated carbon dosage and absorbance

As can be seen from table 1, the more the amount of activated carbon is used, the lower the absorbance of the obtained sample is, when the amount of activated carbon is greater than 0.5g, the absorbance of the sample is 2.967, which is initially less than the absorbance of the finished product diluted by 100 times, and the absorbance of the sample after adsorption continuously decreases with the amount of activated carbon and is less than the absorbance of the finished product after a certain amount, the research shows that because the diluted DEHCH is diluted with absolute ethanol, a double-solute solution system is formed in which DEHCH is used as a main solute and impurities in the crude product are trace solutes, the activated carbon can adsorb the main solute DEHCH while adsorbing the trace solutes, and the formation of the double-solute system may be unfavorable for decoloring the crude product solution.

Adopting gas chromatography-mass spectrometry to quantitatively analyze the double adsorption of the activated carbon on trace solute (namely impurities) and main solute (namely DEHCH), wherein gas chromatograms of DEHCH crude product solutions under different activated carbon dosage are shown in figures 1,2 and 3;

as can be seen from fig. 1: through similarity comparison, the peak of DEHCH is determined within 34.450-35.000min retention time. According to a quantitative analysis method of a gas chromatogram, selecting retention time 34.450-35.000min as an integral interval, calculating peak areas at the position under different active carbon dosage, analyzing the change of DEHCH content, and according to the formula, determining that the solution concentration diluted by 100 times of a crude product is 100% in an enlarged gas chromatogram (namely figure 2):calculating the relative content of DEHCH in the obtained solution under different using amounts of the active carbon; the calculation results are shown in table 3;

TABLE 3 relative content of DEHCH in 34.450-35.000 retention periods under different conditions

As shown in Table 3, the relative content of solute DEHCH is continuously reduced with the increase of the dosage of the activated carbon, and the content of DEHCH in the solution is only 41.87% when the dosage of the activated carbon reaches 2.0g, and the adsorption loss of the activated carbon is 58.13%.

Analyzing the byproducts in the region of 35.300-35.485 min by the same method, and carrying out an amplified gas chromatogram of the byproducts, as shown in FIG. 3; the peak areas in the region under different conditions were determined, and the content change of the by-product was analyzed, and the specific calculation results are shown in table 4:

TABLE 4 relative content of impurities at different conditions in 35.300-35.485 min retention period

As shown in Table 5, the relative content of the by-product was continuously decreased with the increase of the amount of activated carbon, and the content of the by-product in the solution was 40.67% when the amount of activated carbon reached 2.0g, which was 59.33% adsorbed by activated carbon.

In conclusion, the active carbon absorbs the main solute DEHCH by almost the same times while absorbing the trace impurities in the crude product solution, and thus the aim of decolorization cannot be achieved and the loss of DEHCH is caused. Research shows that the DEHCH is equivalent to a main solute in a double-solute solution system formed after the DEHCH crude product is diluted, impurities are equivalent to trace solutes, the active carbon can adsorb the DEHCH and the impurities without difference and lose the main solute DEHCH, and the quantitative analysis result of gas chromatography shows that the decolorization effect of the DEHCH diluted solution cannot be accurately reflected by absorbance.

3. Exploration of optimal conditions for activated carbon decolorization DEHCH

Factors influencing the decolorizing effect of the activated carbon include the using amount of the activated carbon, adsorption time, adsorption temperature and the like, the optimal conditions of the thermally activated medical 200-mesh activated carbon decolorizing DEHCH are researched by using a controlled variable method, and the decolorizing effect is quantitatively described by using the integral area of an ultraviolet absorption spectrum in a certain wavelength range. Measuring the ultraviolet absorption spectrum of the undiluted DEHCH finished product in the wavelength range of 200-500nm by using the undiluted DEHCH crude product as a reference solution (figure 4), wherein the integral area of the obtained spectrum is Sigma A₀. Similarly, the crude product is taken as reference, the ultraviolet absorption spectrum of the sample obtained after a certain amount of activated carbon decolorization is measured in the wavelength range of 200-500nm, and the integral area of the obtained spectrogram is sigma-delta A_iUsing formula for calculating decolorization ratioThe decolorization ratio of the sample was calculated.

3.1 Effect of adsorption time on decolorizing Effect

Taking 0.4g of activated carbon to perform an adsorption experiment on 10g of undiluted DEHCH crude product, wherein the adsorption temperature is 60 ℃, the adsorption time is respectively 5min, 10min, 15min, 20min, 30min, 40min, 60min and 80min, the influence of the adsorption time on the decoloring effect is researched, the ultraviolet absorption spectrum of a decolored sample is shown in figure 5, and the measurement results of DEHCH decoloring rates under different adsorption times are shown in figure 6.

As can be seen from FIGS. 5 and 6, the decoloring effect increases and tends to be stable with the increase of the adsorption time, the adsorption time is 0-15 min, the decoloring rate is increased from 0 to 16.07%, and the change of the decoloring effect is obvious. The adsorption time is 15-40 min, the decolorization rate is increased from 16.07 percent to 18.07 percent, and the decolorization effect is not greatly increased. The adsorption time is more than 40min, the decolorization effect is basically stable, the activated carbon reaches adsorption saturation, the decolorization rate is not increased along with the increase of the adsorption time, and the optimal adsorption time for decolorizing the DEHCH crude product by using the medical 200-mesh activated carbon is 40 min.

3.2 Effect of activated carbon dosage on decolorization

An adsorption experiment is carried out on 10g of undiluted DEHCH crude product by respectively taking 0.1g, 0.2g, 0.3g, 0.4g, 0.6g, 0.8g and 1.0g of activated carbon, the adsorption temperature is 60 ℃, the adsorption time is 40min, the influence of the amount of the activated carbon on the decolorization effect is researched, an ultraviolet absorption spectrogram of a decolorized sample is shown in figure 7, and DEHCH decolorization rates under different amounts of the activated carbon are shown in figure 8.

From fig. 7 and 8, it can be seen that the decolorizing effect increases and tends to be stable with the increase of the using amount of the activated carbon, the using amount of the activated carbon is increased from 0.1g to 0.3g, the decolorizing rate is increased from 6.65% to 16.11%, and the decolorizing rate of the activated carbon is increased by 4.73% when the average adding amount of the activated carbon is 0.1 g; the using amount of the active carbon is increased from 0.3g to 0.6g, and the decolorization rate of the active carbon is increased by 1.81 percent when the average adding amount of the active carbon is increased by 0.1 g; the decolorization rate of the activated carbon is increased by 0.13 percent when the activated carbon is increased to 1.0g from 0.6g, and the decolorization effect is almost unchanged when the average decolorization rate of the activated carbon is increased by 0.1g, and the activated carbon reaches adsorption saturation. In consideration of the decolorization efficiency, the optimal active carbon dosage for decolorizing the DEHCH crude product by using 200-mesh active carbon is 0.6g, namely when the dosage of the active carbon is 6 percent of the mass of the DEHCH crude product, the decolorization effect is best.

3.3 Effect of adsorption temperature on decolorizing Effect

0.6g of activated carbon is taken to carry out adsorption experiments on 10g of undiluted DEHCH crude product at 30 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃ and 90 ℃ respectively, the adsorption time is 40min, and the influence of the adsorption temperature on the decolorization effect is researched. The ultraviolet absorption spectrum of the sample after decolorization is shown in FIG. 9, and the DEHCH decolorization rate at different adsorption temperatures is shown in FIG. 10.

As can be seen from fig. 9 and 10, the decoloring effect of the activated carbon increases and then decreases with the increase of the adsorption temperature, and when the temperature exceeds 60 ℃, the decoloring rate begins to decrease with the increase of the temperature, which is because the molecular thermal motion is severe due to the overhigh temperature, which is not beneficial to the adsorption of the activated carbon, that is, the optimal decoloring temperature for decoloring the DEHCH crude product by the medical 200-mesh activated carbon is 60 ℃.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.