Method and device for preparing cosmetic-grade alkyl glycol by removing peculiar smell of alkyl glycol

Abstract

The invention provides a method and device for preparing cosmetic-grade alkyl glycol by removing peculiar smell of alkyl glycol, and belongs to the technical field of raw material treatment.The method comprises the following steps that crude alkyl glycol and steam stripping gas are preheated respectively, and preheated alkyl glycol and preheated steam stripping gas are obtained; the temperatures of the preheated alkyl glycol and the preheated stripping gas are independently 90-150 DEG C; and carrying out countercurrent mixing on the preheated alkyl glycol and the preheated stripping gas, and carrying out stripping to obtain the alkyl glycol with peculiar smell removed and a mixed gas. According to the method, the crude alkyl glycol and the steam stripping gas are preheated respectively, and then the preheated alkyl glycol and the preheated steam stripping gas are subjected to countercurrent mixing steam stripping, so that volatile odor substances in the alkyl glycol can be diffused into the steam stripping gas, the odor removal effect is enhanced, and the odor of the alkyl glycol can be fully removed.

Description

Technical Field

[0001] The invention relates to the technical field of raw material processing, and in particular to a method and a device for removing the odor of alkyl glycol to prepare cosmetic-grade alkyl glycol. Background Art

[0002] Alkyl diols are common moisturizers, including 1,3-butanediol, 1,3-propylene glycol, 1,2-pentanediol and 1,2-hexanediol. For example, 1,2-pentanediol is an excellent moisturizer. It is used as a solvent and preservative in cosmetics and beauty products. It has the functions of locking water, antibacterial, antiseptic and improving the water resistance of sunscreen products. It can be used in the high-end cosmetics industry, such as skin creams, eye creams, skin lotions, baby care products, sunscreen products and other skin care products. At present, the preparation method of 1,2-pentanediol is commonly used to prepare 1,2-pentanediol mixture by hydrogenation of furfuryl alcohol. The composition is relatively complex. Although the mass purity of 1,2-pentanediol can reach more than 99.5% or even more than 99.9% by distillation, the odor of the product cannot be eradicated.

[0003] However, the high-end cosmetics industry has strict control over the quality of raw materials, not only the quality and purity of raw materials, but also the odor. In order to solve this problem, the 1,2-pentanediol product prepared with furfuryl alcohol as raw material can be directly used in the cosmetics industry to improve the economic value of 1,2-pentanediol. Therefore, it is urgent to provide a method that can fully remove the odor of alkyl glycol. Summary of the invention

[0004] The object of the present invention is to provide a method and a device for removing the odor of alkyl glycol to prepare cosmetic-grade alkyl glycol. The method provided by the present invention can fully remove the odor of alkyl glycol to obtain cosmetic-grade alkyl glycol.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for removing the odor of alkyl glycol and preparing cosmetic-grade alkyl glycol, comprising the following steps:

[0007] (1) preheating an alkyl glycol and a stripping gas respectively to obtain a preheated alkyl glycol and a preheated stripping gas; the temperatures of the preheated alkyl glycol and the preheated stripping gas are independently 90 to 150° C.;

[0008] (2) The preheated alkyl glycol obtained in step (1) and the preheated stripping gas are countercurrently mixed and stripped to obtain cosmetic-grade alkyl glycol and mixed gas from which odor is removed.

[0009] Preferably, the alkyl glycol in step (1) comprises one or more of 1,2-pentanediol, 1,3-butanediol, 1,3-propylene glycol, 1,2-propylene glycol and 1,2-hexanediol.

[0010] Preferably, the purity of the alkyl glycol in step (1) is ≥99.5%.

[0011] Preferably, the stripping gas in step (1) comprises a mixture of one or more of nitrogen, air and carbon dioxide and water vapor.

[0012] Preferably, the stripping gas in step (1) is a mixture of nitrogen and water vapor, and the volume ratio of nitrogen to water vapor is 1 to 5:1.

[0013] Preferably, the gas-liquid feed ratio of the stripping gas to the alkyl glycol in step (1) is (50-500) Nm 3 / h: 1m 3 / h.

[0014] Preferably, the stripping device in step (2) is a stripping tower, and the stripping tower is equipped with fillers, and the fillers include one or more of Raschig rings, step rings, ball rings, θ mesh rings, lattice rings, flat rings, conjugated rings, cross rings, inner spiral rings, corrugated fillers, grid fillers and pulse fillers.

[0015] Preferably, the mixed gas in step (2) is condensed to obtain liquid and waste gas; and the liquid is mixed with the alkyl glycol in step (1).

[0016] The present invention also provides a device used in the method described in the above technical solution, comprising a raw material heater, a stripping tower, a gas heater and a tower top condenser;

[0017] The stripping tower is filled with fillers;

[0018] A feed inlet is arranged on the side wall of the stripping tower near the top, and a gas outlet is arranged on the top of the stripping tower;

[0019] An air inlet is arranged on the side wall of the stripping tower near the bottom, and a discharge port is arranged at the bottom of the stripping tower;

[0020] The raw material heater is connected to the feed port;

[0021] The gas heater is connected to the air inlet;

[0022] The tower top condenser is connected with the gas outlet.

[0023] Preferably, the bottom of the top condenser comprises a liquid discharge port, and the liquid discharge port is connected to the feed port.

[0024] The present invention provides a method for removing the odor of alkyl glycol and preparing cosmetic-grade glycol, comprising the following steps: preheating alkyl glycol and stripping gas respectively to obtain preheated alkyl glycol and preheated stripping gas; the temperatures of the preheated alkyl glycol and preheated stripping gas are independently 90-150°C; countercurrently mixing the preheated alkyl glycol and preheated stripping gas to perform stripping to obtain cosmetic-grade alkyl glycol and mixed gas from which the odor is removed. The present invention can promote the diffusion of volatile odorous substances in alkyl glycol into the stripping gas by preheating the alkyl glycol and stripping gas respectively, and then countercurrently mixing the preheated alkyl glycol and preheated stripping gas to perform stripping, thereby enhancing the deodorization effect and fully removing the odor of alkyl glycol. The results of the examples show that the method provided by the present invention can significantly reduce the odor of alkyl glycol and solve the problem of strong odor of alkyl glycol. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of an apparatus for removing the odor of alkyl glycol and preparing cosmetic-grade alkyl glycol according to Examples 1 to 3 of the present invention;

[0026] Among them, 1 is a raw material heater, 2 is a gas heater, 3 is a stripping tower, and 4 is a tower top condenser. DETAILED DESCRIPTION

[0027] The present invention provides a method for removing the odor of alkyl glycol and preparing cosmetic-grade alkyl glycol, comprising the following steps:

[0028] (1) preheating an alkyl glycol and a stripping gas respectively to obtain a preheated alkyl glycol and a preheated stripping gas; the temperatures of the preheated alkyl glycol and the preheated stripping gas are independently 90 to 150° C.;

[0029] (2) The preheated alkyl glycol obtained in step (1) and the preheated stripping gas are countercurrently mixed and stripped to obtain cosmetic-grade alkyl glycol and mixed gas from which odor is removed.

[0030] The present invention preheats the alkyl glycol and the stripping gas respectively to obtain the preheated alkyl glycol and the preheated stripping gas.

[0031] In the present invention, the alkyl diol preferably includes one or more of 1,3-butanediol, 1,3-propylene glycol, 1,2-pentanediol and 1,2-hexanediol, and more preferably 1,2-pentanediol. In the present invention, the purity of the alkyl diol is preferably ≥99.5%.

[0032] In the present invention, the stripping gas preferably includes a mixture of one or more of nitrogen, air and carbon dioxide and water vapor, more preferably a mixture of nitrogen and water vapor or a mixture of air and water vapor. In the present invention, in the mixture of nitrogen and water vapor, the volume ratio of nitrogen to water vapor is preferably 1 to 5:1, more preferably 2 to 4:1; in the mixture of air and water vapor, the volume ratio of air to water vapor is preferably 1 to 5:1, more preferably 2 to 4:1. The present invention uses the above-mentioned stripping gas, which is more conducive to the dispersion of odorous small molecules into the gas, and then separation from alkyl glycol, thereby removing the odor in alkyl glycol.

[0033] In the present invention, the temperature of the preheated alkyl glycol and the preheated stripping gas is independently 90 to 150° C., preferably 100 to 125° C., and more preferably 100 to 120° C. The present invention can promote the diffusion of volatile odorous substances in the alkyl glycol into the stripping gas by preheating the alkyl glycol and the stripping gas, thereby enhancing the deodorization effect and fully removing the odor of the alkyl glycol.

[0034] The present invention has no special limitation on the device for preheating the alkyl glycol and the stripping gas. A conventional heating device can be used to make the temperature of the alkyl glycol and the stripping gas reach 90-150°C.

[0035] In the present invention, the feed ratio of the stripping gas to the alkyl glycol is preferably (50-500) Nm 3 / h: 1m 3 / h, preferably (60~100)Nm 3 / h: 1m 3 / h. The present invention controls the feed ratio of stripping gas to alkyl glycol within the above range, which is more conducive to improving the mass transfer effect, and further improving the removal effect of odorous substances.

[0036] After obtaining the preheated alkyl glycol and the preheated stripping gas, the present invention countercurrently mixes the preheated alkyl glycol and the preheated stripping gas to perform stripping, thereby obtaining the cosmetic-grade alkyl glycol and the mixed gas from which odor is removed.

[0037] The present invention can control the countercurrent mixing of preheated alkyl glycol and preheated stripping gas by adopting stripping, thereby improving the mass transfer effect and being more conducive to the diffusion of odorous substances into the stripping gas.

[0038] In the present invention, the stripping device is preferably a stripping tower, the stripping tower is preferably a distillation tower, and the structure of the distillation tower is preferably a vertical structure. The present invention does not specifically limit the model of the stripping tower, and it can be selected according to needs. In the present invention, the interior of the stripping tower is preferably equipped with packing, and the packing preferably includes one or more of Raschig rings, step rings, ball rings, θ mesh rings, lattice rings, flat rings, conjugated rings, cross rings, inner spiral rings, corrugated packing, grid packing and pulse packing.

[0039] In the present invention, the number of theoretical plates of the stripping tower is preferably 5 to 20, more preferably 6 to 10. In the present invention, the parameters of the stripping tower also preferably include maintaining the tower temperature at 100°C to 125°C and the tower pressure at -20 to 40KPaG (gauge pressure). The present invention controls the number of theoretical plates of the stripping tower within the above range, which is more conducive to improving the stripping efficiency, thereby improving the odor removal effect.

[0040] In the present invention, the mixed gas preferably includes gas condensation to obtain liquid and waste gas; the liquid is mixed with the alkyl glycol. The present invention can recover the alkyl glycol in the mixed gas by mixing the liquid obtained by condensing the mixed gas with the alkyl glycol, and stripping the alkyl glycol to reduce the loss of the alkyl glycol.

[0041] In the present invention, the exhaust gas is preferably discharged into the atmosphere.

[0042] The method provided by the present invention can promote the diffusion of volatile odorous substances in the alkyl glycol into the stripping gas, enhance the deodorizing effect, and further fully remove the odor of the alkyl glycol by preheating the alkyl glycol and the stripping gas respectively first, and then countercurrently mixing the preheated alkyl glycol and the preheated stripping gas for stripping.

[0043] The present invention also provides a device used in the method described in the above technical solution, comprising a raw material heater, a stripping tower, a gas heater and a tower top condenser;

[0044] The stripping tower is filled with fillers;

[0045] A feed inlet is arranged on the side wall of the stripping tower near the top, and a gas outlet is arranged on the top of the stripping tower;

[0046] An air inlet is arranged on the side wall of the stripping tower near the bottom, and a discharge port is arranged at the bottom of the stripping tower;

[0047] The raw material heater is connected to the feed port;

[0048] The gas heater is connected to the air inlet;

[0049] The tower top condenser is connected with the gas outlet.

[0050] like Figure 1 As shown, in the present invention, the device includes a raw material heater. The present invention preheats the alkyl glycol by the raw material heater. The present invention has no special limitation on the model of the raw material heater, and any conventional heating device can be used.

[0051] like Figure 1 As shown, the device provided by the present invention also includes a vertical stripping tower.

[0052] In the present invention, the stripping tower is filled with fillers. In the present invention, the fillers preferably include one or more of Raschig rings, step rings, ball rings, θ mesh rings, lattice rings, flat rings, conjugated rings, cross rings, inner spiral rings, corrugated fillers, grid fillers and pulse fillers, and more preferably Raschig rings. The present invention uses the above fillers to increase the gas-liquid contact area and enhance the mass transfer effect.

[0053] In the present invention, a feed port is provided at 1 to 1 / 3 of the total theoretical plate of the stripping tower. In the present invention, the raw material heater is connected to the feed port. By connecting the raw material heater to the feed port, the present invention enables the preheated alkyl glycol to enter the stripping tower from the top of the stripping tower.

[0054] In the present invention, the feed port is preferably arranged above the first theoretical plate. By arranging the feed port at the above position, it is more conducive to improving the stripping effect.

[0055] In the present invention, a gas outlet is arranged at the top of the stripping tower. By arranging the gas outlet at the top of the stripping tower, the present invention can discharge the mixed gas after stripping out of the stripping tower.

[0056] In the present invention, the side wall of the stripping tower near the bottom is provided with an air inlet. In the present invention, the gas heater is connected to the air inlet. By connecting the gas heater to the air inlet, the present invention enables the preheated stripping gas to enter the stripping tower from the bottom of the stripping tower, and then countercurrently mix with the preheated alkyl glycol entering the stripping tower from the top.

[0057] In the present invention, the air inlet is preferably arranged at the bottom of the tower. By arranging the air inlet at the above position, it is more conducive to improving the stripping effect.

[0058] In the present invention, a discharge port is arranged at the bottom of the stripping tower. By arranging a discharge port at the bottom of the stripping tower, the present invention can discharge the liquid phase after stripping out of the stripping tower, and the liquid phase is the alkyl glycol with deodorized odor.

[0059] like Figure 1 As shown, in the present invention, the device further comprises a tower top condenser. In the present invention, the tower top condenser is connected to the gas outlet. The present invention can condense the mixed gas discharged from the top of the stripping tower through the tower top condenser to obtain liquid and waste gas. In the present invention, the liquid is the alkyl glycol carried in the mixed gas, and the present invention can recover the alkyl glycol carried in the mixed gas through the condenser.

[0060] In the present invention, the bottom of the tower top condenser preferably comprises a liquid discharge port, and the liquid discharge port is connected to the feed port to recover the alkyl glycol.

[0061] In the present invention, the top of the tower top condenser preferably includes a waste gas outlet. The present invention can discharge the waste gas in the tower top condenser by arranging the waste gas outlet at the top of the tower top condenser.

[0062] The device provided by the present invention can be operated continuously, and thus can fully remove the odor of alkyl glycol.

[0063] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. 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.

[0064] Example 1

[0065] A method for removing the odor of 1,2-pentanediol, comprising the following steps:

[0066] (1) The product of preparing 1,2-pentanediol by hydrogenation of furfuryl alcohol is crude 1,2-pentanediol (purity ≥ 99.5%), which is derived from the distillation and purification product after hydrogenation of furfuryl alcohol (supplier: Henan Haosen Biological Co., Ltd.). After odor evaluation, the odor level of the raw material is level 3; among them, the odor detection of the compound adopts the method commonly used in the industry to detect whether the odor meets the standard. Five odor judges are selected to conduct odor evaluation, and the evaluation standard is 6 levels. 1 is no odor; 2 is a slight odor; 3 is a smell, but not irritating; 4 is a pungent odor; 5 is a strong irritating odor; 6 is an unbearable smell;

[0067] The crude 1,2-pentanediol with a raw material odor grade of 3 after odor evaluation and nitrogen are preheated to 100°C respectively to obtain preheated 1,2-pentanediol and preheated nitrogen. At the same time, water vapor is introduced into the tower. The water vapor temperature is 115°C superheated steam with a slightly positive pressure. The feed ratio of nitrogen, water vapor and crude 1,2-pentanediol is 5Nm 3 / h: 2Nm 3 / h: 0.1m 3 / h; the pressure of the stripping tower is maintained at -20Kpa, and the temperature of the whole tower is maintained at 108℃;

[0068] (2) The preheated 1,2-pentanediol obtained in step (1) and the preheated nitrogen are mixed countercurrently in a stripping tower for stripping to obtain odor-free 1,2-pentanediol and mixed gas; wherein the filler in the stripping tower is Raschig ring, and the number of theoretical plates is 6.

[0069] Samples are taken from the bottom of the stripping tower for odor evaluation. The odor level of the samples can reach level 1, which means there is no odor.

[0070] Example 2

[0071] A method for removing the odor of 1,2-pentanediol, comprising the following steps:

[0072] (1) Preheating crude 1,2-pentanediol and air to 110° C. respectively to obtain preheated 1,2-pentanediol and preheated air, and simultaneously introducing water vapor into the tower, wherein the water vapor temperature is 125° C. superheated steam with a slightly positive pressure; the feed ratio of the air, water vapor and crude 1,2-pentanediol is 20 Nm 3 / h: 5Nm 3 / h: 0.1m 3 / h.

[0073] The product of 1,2-pentanediol prepared by hydrogenation of furfuryl alcohol is crude 1,2-pentanediol (purity ≥ 99.5%). After odor evaluation, the odor level of the raw material is level 3; the pressure of the stripping tower is maintained at 20Kpa, and the tower temperature is maintained at 117℃;

[0074] (2) The preheated 1,2-pentanediol obtained in step (1) and the preheated air are mixed countercurrently in a stripping tower for stripping to obtain odor-free 1,2-pentanediol and mixed gas; wherein the filler in the stripping tower is Raschig ring, and the number of theoretical plates is 9.

[0075] Samples are taken from the bottom of the stripping tower for odor evaluation, and the sample odor level can reach level 1.

[0076] Comparative Example 1

[0077] A method for removing the odor of 1,2-pentanediol, comprising the following steps:

[0078] (1) Preheating crude 1,2-pentanediol and nitrogen to 120° C. respectively to obtain preheated 1,2-pentanediol and preheated nitrogen; the feed ratio of nitrogen to crude 1,2-pentanediol is 8 Nm 3 / h: 0.1m 3 / h.

[0079] The product of 1,2-pentanediol prepared by hydrogenation of furfuryl alcohol is crude 1,2-pentanediol (purity ≥ 99.5%), which is derived from the distillation and purification product after hydrogenation of furfuryl alcohol (supplier: Henan Haosen Biological Co., Ltd.). After odor evaluation, the odor level of the raw material is level 3; the pressure of the stripping tower is maintained at 20Kpa, and the tower temperature is basically maintained at 120℃ throughout the tower;

[0080] (2) The preheated 1,2-pentanediol obtained in step (1) and the preheated nitrogen are mixed countercurrently in a stripping tower for stripping to obtain odor-free 1,2-pentanediol and mixed gas; wherein the filler in the stripping tower is Raschig ring, and the number of theoretical plates is 6.

[0081] Samples were taken from the bottom of the stripping tower for odor evaluation, and the odor level of the samples could only reach level 2.

[0082] Example 3

[0083] A method for removing the odor of 1,3-propylene glycol, comprising the following steps:

[0084] (1) Preheating crude 1,3-propylene glycol and air to 120° C. respectively to obtain preheated 1,3-propylene glycol and preheated nitrogen, and simultaneously introducing water vapor into the tower, wherein the water vapor temperature is 120° C. superheated steam with a slightly positive pressure; the feed ratio of nitrogen, water vapor to crude 1,2-pentanediol is 5 Nm 3 / h: 2Nm 3 / h: 0.1m 3 / h.

[0085] The product of 1,3-propylene glycol prepared by biological fermentation is crude 1,3-propylene glycol (purity ≥ 99.8%), which is derived from the purified product after selective hydrogenation of glycerol. After odor evaluation, the odor level of the raw material is 4; the pressure of the stripping tower is maintained at 10Kpa, and the tower temperature is maintained at 120℃ throughout the tower;

[0086] (2) The preheated 1,3-propylene glycol obtained in step (1) and the preheated air are mixed countercurrently in a stripping tower for stripping to obtain odor-free 1,3-propylene glycol and mixed gas; wherein the filler in the stripping tower is Raschig rings with a theoretical plate number of 4.

[0087] Samples are taken from the bottom of the stripping tower for odor evaluation, and the sample odor level can reach level 1.

[0088] Example 4

[0089] The apparatus of the method described in Examples 1 to 3 is as follows Figure 1 As shown, it consists of a raw material heater, a stripping tower, a gas heater and a tower top condenser;

[0090] The stripping tower is filled with Raschig rings;

[0091] A feed inlet is arranged on the side wall of the stripping tower near the top, and a gas outlet is arranged on the top of the stripping tower;

[0092] An air inlet is arranged on the side wall of the stripping tower near the bottom, and a discharge port is arranged at the bottom of the stripping tower;

[0093] The raw material heater is connected to the feed port;

[0094] The gas heater is connected to the air inlet;

[0095] The tower top condenser is connected with the gas outlet.

[0096] The present invention preheats crude 1,2-pentanediol and stripping gas respectively, and then countercurrently mixes and strips the preheated 1,2-pentanediol and the preheated stripping gas, thereby promoting the diffusion of volatile odor substances in the 1,2-pentanediol into the stripping gas, enhancing the deodorization effect, and further being able to fully remove the odor of the 1,2-pentanediol.

[0097] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for removing the odor of alkyl glycol to prepare cosmetic grade alkyl glycol, comprising the following steps: (1) preheating an alkyl glycol and a stripping gas respectively to obtain a preheated alkyl glycol and a preheated stripping gas; the temperatures of the preheated alkyl glycol and the preheated stripping gas are independently 90 to 150° C.; (2) The preheated alkyl glycol obtained in step (1) and the preheated stripping gas are countercurrently mixed and stripped to obtain cosmetic-grade alkyl glycol and mixed gas from which odor is removed.

2. The method according to claim 1, characterized in that The alkyl glycol in step (1) includes one or more of 1,2-pentanediol, 1,3-butanediol, 1,3-propylene glycol, 1,2-propylene glycol and 1,2-hexanediol.

3. The method according to claim 1 or 2, characterized in that: The purity of the alkyl glycol in step (1) is ≥99.5%.

4. The method according to claim 1, characterized in that The stripping gas in step (1) comprises a mixture of one or more of nitrogen, air and carbon dioxide and water vapor.

5. The method according to claim 4, characterized in that The stripping gas in step (1) is a mixture of nitrogen and water vapor, and the volume ratio of the nitrogen to the water vapor is 1 to 5:

1.

6. The method according to claim 1, characterized in that The gas-liquid feed ratio of the stripping gas to the alkyl glycol in step (1) is (50-500) Nm 3 / h: 1m 3 / h.

7. The method according to claim 1, characterized in that The stripping device in step (2) is a stripping tower, and the stripping tower is equipped with fillers, which include one or more of Raschig rings, step rings, ball rings, θ mesh rings, lattice rings, flat rings, conjugated rings, cross rings, inner spiral rings, corrugated fillers, grid fillers and pulse fillers.

8. The method according to claim 1, characterized in that The mixed gas in step (2) is condensed to obtain liquid and waste gas; the liquid is mixed with the alkyl glycol in step (1).

9. The apparatus used in the method according to any one of claims 1 to 8, comprising a feed heater, a stripping tower, a gas heater and a tower top condenser; The stripping tower is filled with fillers; A feed inlet is arranged on the side wall of the stripping tower near the top, and a gas outlet is arranged on the top of the stripping tower; An air inlet is arranged on the side wall of the stripping tower near the bottom, and a discharge port is arranged at the bottom of the stripping tower; The raw material heater is connected to the feed port; The gas heater is connected to the air inlet; The tower top condenser is connected with the gas outlet.

10. The device according to claim 9, characterized in that The bottom of the tower top condenser comprises a liquid discharge port, and the liquid discharge port is connected to the feed port.

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