KR20200014627A - Recycling method of Cashew Nuts Shell Liquid sludge - Google Patents

Abstract

The present invention relates to a reprocessing method for cashew nut shell oil sludge. More specifically, provided is a method to reduce cost of disposal by reprocessing waste cashew nut shell oil sludge, and to further secure biofuel as an active ingredient. According to the method, the cost of disposal can be reduced by reprocessing waste CNSL sludge, and it is possible to efficiently extract an oil component, which is an active ingredient, by a reprocessing process.

Description

Recycling method of Cashew Nuts Shell Liquid sludge}

The present invention relates to a method for reprocessing cashew nut shell oil sludge, and to a method for reducing the cost of disposal and further securing an active ingredient biofuel by reprocessing the cashew nut shell oil sludge which is waste.

Currently, the world is making efforts to develop renewable energy such as alternative energy and clean energy due to global environmental problems and depletion of fossil fuel, and also by implementing the Renewable Portfolio Standard (RPS). In biomass power plants, the demand for biofuels is skyrocketing.

Biofuel is a fuel manufactured using animal and vegetable oils, and may be mixed with petroleum and petrochemicals and used as a biofueled fuel. One of the biofuels, Cashew Nuts Shell Liquid (CNSL), is a vegetable oil extracted from the nut shell of a plant called Cashew (Cashew) inhabiting the tropics. Blended fuels are similar to heavy oils in quality, with kinematic viscosity that affects fuel injection lower than heavy oil, ash content higher than heavy oil, and sulfur lower than heavy oil.

In particular, in case of CNSL, tens of thousands of tens of thousands of PPM Na, K ions are contained and can be used only when purified through washing or acid washing process when using bio heavy oil. As the acid cleaning process, weak acid and inexpensive citric acid are mainly used to prevent corrosion of equipment, and sulfuric acid and magnesium sulfate are also used.

However, the acid cleaning process for removing the metal from the CNSL generates a large amount of waste CNSL sludge due to the raw material characteristics, and a considerable cost is required for their treatment.

The problem to be solved by the present invention is to provide a method for treating and recycling the CNSL sludge generated and disposed in the demetallization process of CNSL.

The present invention to solve the above problems,

Adding CNSL sludge to the reactor in the presence of a solvent;

Stirring the homogenizer while maintaining the reactor at a temperature of 60 to 100 ° C. for 1 to 5 hours;

Leaving the obtained homogenate at a temperature of 60 to 100 ° C. for 1 to 5 hours to perform oil and water separation; And

It provides a method for reprocessing CNSL sludge comprising a; extracting the oil component by degassing at a temperature of 60 to 100 ℃ after recovering the supernatant from the reactor where the oil separation is completed.

According to the CNSL sludge reprocessing method of the present invention, the cost of waste can be reduced by reprocessing the CNSL sludge which is a waste, and the oil component which is an active ingredient can be extracted efficiently by reprocessing.

1 is a graph showing the oil-water separation efficiency according to Example 1. FIG.
2 is a graph showing the oil / water separation efficiency according to the second embodiment.
3 is a graph showing the oil / water separation efficiency according to the third embodiment.
4 is a graph showing the oil / water separation efficiency according to the fourth embodiment.
5 is a graph showing the oil / water separation efficiency according to the fifth embodiment.
6 is a graph showing the oil / water separation efficiency according to the sixth embodiment.
7 is a graph showing the oil / water separation efficiency according to the seventh embodiment.

The present invention provides a method for reprocessing CNSL sludge, the method comprising: adding CNSL sludge to a reactor in the presence of a solvent; Stirring the homogenizer while maintaining the reactor at a temperature of 60 to 100 ° C. for 1 to 5 hours; Leaving the obtained homogenate at a temperature of 60 to 100 ° C. for 1 to 5 hours to perform oil and water separation; And extracting an oil component by removing the solvent by degassing at a temperature of 60 to 100 ° C. after recovering the supernatant from the reactor in which oil separation is completed.

The CNSL sludge used in the present invention is a component that is generated in large amounts when extracting an oil component from CNSL (cashew nut shell oil), and its content may vary depending on the composition of the raw material. In the present invention, since only the CNSL component of the sludge component can be extracted and used, the sludge can be treated with wastewater instead of waste oil, thereby greatly reducing the disposal cost, and in particular, extracting the bio-oil in a reusable form.

The CNSL sludge used for reprocessing in the present invention is a waste generated during the purification of CNSL, and may be obtained in various forms according to the purification process. For example, if CNSL is used alone as a raw material, or if CNSL and animal fats are used in a 70:30 ratio, and CNSL and vegetable fats are used in a 70:30 ratio, the CNSL and biodiesel pitch are 70 The CNSL sludge component may vary depending on the ratio of: 30, and may also vary depending on the type of acid used in the acid cleaning process. The CNSL components of these various components may be used alone or in combination of two or more thereof. For example, the CNSL sludge used as the raw material in the present invention is 20 to 40% by weight of CNSL and fats and oils, 30 to 60% by weight of water, 10 to 15% by weight of acid, 3 to 5% by weight of ash, and other residual amounts. It may include minerals.

According to the present invention, solvent extraction is used to extract oil components from CNSL sludge. At this time, both solvents can be used as the solvent, but a polar or nonpolar solvent can be used. However, when the nonpolar solvent is used, the oil-water separation efficiency is high, and continuous recycling is possible. Such non-polar solvents may be used alone or in combination. For example, high-volatile diethyl ether is preferred because of its high separation rate, and n-hexane, n-octane, etc. are preferable because of excellent separation. . However, the solvent is not limited to these solvents, and any solvent used in the solvent extraction method can be used without limitation.

Such a non-polar solvent is about 1 to about 40% by weight, preferably about 3 to about 30% by weight, more preferably about 5 to about 20% by weight based on the total weight of the composition including the raw material CNSL sludge It can be used as a content. If it is out of such content, the extraction efficiency is lowered, which is not preferable.

After adding the above-mentioned CNSL sludge and the non-polar solvent to the reactor, the homogenization process by stirring it for about 1 to 5 hours, preferably about 2 to 4 hours at a temperature of about 60 to 100 ℃, preferably 70 to 90 ℃ Can be performed. In such a homogenization process, the micellar structure is effectively destroyed in the CNSL sludge in an emulsion state, thereby increasing the resolution of oil components. Since the sludge may contain a strong acid component, for example, a container such as fiber reinforced plastic (FRP) may be used as a reactor so that corrosion may be prevented.

The homogenization process is carried out under agitation, in which case a mechanical or magnetic stirrer may be used without limitation.

The homogenate obtained by treatment is left for 1 to 5 hours, preferably 2 to 4 hours at a temperature of 60 to 100 ℃, preferably 70 to 90 ℃ without separate stirring to perform oil and water separation. In this oil-water separation process, the oil component in CNSL sludge whose micelle structure is destroyed is dissolved in the solvent layer, and separation with the aqueous layer is performed.

Subsequently, the supernatant is separated from the reactor where the oil / water separation is completed, followed by degassing at a temperature of 60 to 100 ° C., preferably 70 to 90 ° C. to remove the solvent to extract the desired oil component. Such oil components can be recycled as biofuels.

As described above, the remaining water layer after separating the supernatant can be treated with wastewater rather than waste oil, thereby greatly reducing the treatment cost.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto, and a person skilled in the art will recognize that various modifications are possible from the embodiments of the present invention.

Preparation Example 1 Preparation of CNSL Sludge

CNSL 9000kg, process water 800kg, and 1000kg sulfuric acid with a concentration of 20% by weight were added to the reaction tank and reacted, and then separated in a sedimentation tank continuously and dehydrated to obtain a product from which metal components were removed. 1440 kg of highly concentrated CNSL sludge was discharged to the bottom.

Preparation Example 2 Preparation of CNSL Sludge

6300kg CNSL, 2700kg animal fat, 800kg process water, and 1000kg sulfuric acid with a concentration of 20% by weight were added to the reactor and reacted. In the separation process, 1440 kg of highly concentrated CNSL sludge was discharged to the bottom.

Preparation Example 3 Preparation of CNSL Sludge

6300 kg of CNSL, 2700 kg of vegetable oil, 700 kg of process water, and 1000 kg of citric acid having a concentration of 30% by weight were added to the reactor and reacted. In the separation process, 1440 kg of highly concentrated CNSL sludge was discharged to the bottom.

Preparation Example 4 Preparation of CNSL Sludge

CNSL 6300kg, biodiesel pitch 300kg, process water 700kg, and 30kg% citric acid 1000kg concentration were added to the reactor and reacted, and then they were continuously separated from the sedimentation tank at the same time and dehydrated to obtain a product free of metal components. In the separation process, 1440 kg of highly concentrated CNSL sludge was discharged downward.

Table 1 shows the component analysis table according to the CNSL raw material formulation in Preparation Examples 1 to 4, and CNSL sludge may be obtained by purification according to the preparation example.

division Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 Flash point (℃) 241 246 255 224 Kinematic viscosity (50 ℃, ㎠ / s) 53 35 48 32 Residual carbon 7.37 4.64 5.12 4.52 Sulfur (%) 0.02 0.015 0.027 0.018 Ash content (%) 0.67 0.45 0.58 0.44 moisture(%) 0.13 0.16 0.25 0.09 Na (ppm) 644 451 2548 483 Ca (ppm) 18 77 22 102 K (ppm) 3834 2785 2683 2562 Si + Al + Fe (ppm) 354 267 488 277 Phosphorus (ppm) 65 36 137 54 Calorific value (Cal / g) 9,714 9,697 9,684 9,706 Subsidiary Material Sulfuric acid Sulfuric acid Citric acid Citric acid CNSL Raw Material
Sludge Generation (%) 16 16 16 16

Preparation Example 5 Preparation of CNSL Sludge

CNSL sludges were obtained from seven refined CNSL companies in Korea, and the CNSL sludges of these seven companies were analyzed and listed in Table 2 below.

division Fertility
Bio Dongshin
chemistry Emerging
Enertech Liwon
Bio Emerging Dairy plus
chemical Daekyung
Orient Kinematic viscosity (50 ℃, ㎠ / s) 132 94 365 335 421 455 415 Density (15 ℃) 1.2304 1.1612 1.2441 1.1988 1.2561 1.2554 1.2317 Residual carbon 8.64 7.12 8.31 8.88 9.04 11.12 6.88 Sulfur (%) 8.31 0.35 0.42 7.64 0.25 0.16 0.25 Ash content (%) 5.4 4.3 8.1 7.3 6.3 8.2 5.9 moisture(%) 63.7 43.1 44.5 56.8 36.9 49.1 48.5 Na (ppm) 1,388 491 2,587 2,564 523 2,831 1,357 Ca (ppm) 331 1,871 318 196 258 324 318 K (ppm) 12,312 9,367 14,756 8,844 10,501 13,345 14.121 Si + Al + Fe (ppm) 2,000 1,419 1,474 4,234 1,340 1,270 998 Phosphorus (ppm) 364 298 371 188 289 264 354 Calorific value (Cal / g) 2,883 2,986 3,455 3,137 3,321 2,681 2,744 pH One 3 One One One One One Subsidiary Material Sulfuric acid Citric acid Citric acid Sulfuric acid Citric acid Citric acid Citric acid

The sample was analyzed by the following method.

-ICP-OES (Thermo Scientific ICAP-7400 Duo, IP501): Analyzer for measuring the metal content in bio heavy oil, the metal content is the quality standard of bio heavy oil, and the metal is Na, Ca, K, V, Al Fe, Si, P,

Ash (Lab house / Furnace, ISO 6245): Measures the ash remaining after biofuel is burned. If there is much ash, combustion efficiency will fall.

Kinematic Viscosity (Korean Science Waterbath, Canon Fenske Kinematic Viscometer, ASTM D7042): The kinematic viscosity of bio-heavy oil is measured. Kinematic viscosity is one of the important quality criteria in boilers using bio-heavy oil, and the higher the kinematic viscosity, the less fluidity is related to the injection pressure of fuel in the boiler.

-Sulfur analyzer (XRF, SLFA-1800 ASTM D5453): Petroleum products contain sulfur as an elemental composition. There are various forms of sulfur compounds contained, and according to the difference, it causes the quality deterioration to products such as odor, combustibility, and corrosiveness. Petroleum products specify the maximum allowable amount of sulfur.

-Moisture analyzer (Mettler Toledo, V10s Titrator. ISO 3733): The Karl Fischer method is appropriate for the analysis of moisture contained in general fats and oils.

-Calorimeter (Pan-6200 ASTM D240): The calorific value generated when a material is completely burned. It is an important basic value for commodity valuation of various fuels in combustion.

After preparing the representative sample by mixing the CNSL sludge samples obtained from the seven companies in the same weight ratio, it was used in Examples 1 to 7 below.

Example 1

CNSL sludge obtained from Preparation Example 5 and isopropyl alcohol were added to a reactor made of FRP material, and homogenized by stirring with a mechanical stirrer for 3 hours while maintaining the temperature at 80 ° C. At this time, the weight ratio of the sludge and the solvent was used in four ratios of 95: 5, 90:10, 85:15, and 80:20. Each homogenate was placed in a 100 ml measuring cylinder, which was then observed in an oven at 80 ° C. at 30 minute intervals, and the results are shown in FIG. 1. The time when the oil and water separation was completely made was 3 hours after the injection of the measuring cylinder. The supernatant was recovered after the separation process, and the yield was measured after completely degassing the solvent under reduced pressure at 80 ° C.

The results are shown in Table 3 below.

Example 2

CNSL sludge obtained from Preparation Example 5 and methanol were added to a reactor made of FRP material, and homogenized by stirring with a mechanical stirrer for 3 hours while maintaining the temperature at 80 ° C. At this time, the weight ratio of the sludge and the solvent was used in four ratios of 95: 5, 90:10, 85:15, and 80:20. Each homogenate was placed in a 100 ml measuring cylinder, which was then observed at 30 ° intervals in an oven at 80 ° C., and the results are shown in FIG. 2. After the separation of the oil and water was completely made into the cylinder after 3 hours, the supernatant was recovered after the separation process, and the yield was measured after completely degassing the solvent under reduced pressure at 80 ° C.

The results are shown in Table 3 below.

Example 3

CNSL sludge and ethanol obtained from Preparation Example 5 were added to a reactor made of FRP material, and homogenized by stirring with a mechanical stirrer for 5 hours while maintaining at 80 ° C. At this time, the weight ratio of the sludge and the solvent was used in four ratios of 95: 5, 90:10, 85:15, and 80:20. Each homogenate was placed in a 100 ml measuring cylinder, and the result of observing the flow of oil and water at 30 minutes intervals in an oven at 80 ° C. was shown in FIG. 3. After the separation of the oil and water was completely made into the cylinder after 3 hours, the supernatant was recovered after the separation process, and the yield was measured after completely degassing the solvent under reduced pressure at 80 ° C.

The results are shown in Table 3 below.

Example 4

CNSL sludge obtained from Preparation Example 5 and acetone were added to a reactor made of FRP material, and homogenized by stirring with a mechanical stirrer for 3 hours while maintaining the temperature at 80 ° C. At this time, the weight ratio of the sludge and the solvent was used in four ratios of 95: 5, 90:10, 85:15, and 80:20. After putting each homogenate in a 100 ml measuring cylinder, the result of observing the flow of oil and water at 30 minutes intervals in an oven at 80 ° C. was shown in FIG. 4. After the separation of the oil and water was completely made into the cylinder after 3 hours, the supernatant was recovered after the separation process, and the yield was measured after completely degassing the solvent under reduced pressure at 80 ° C.

The results are shown in Table 3 below.

Example 5

CNSL sludge obtained from Preparation Example 5 and n-hexane were added to a reactor made of FRP material, and homogenized by stirring with a mechanical stirrer for 3 hours while maintaining the temperature at 80 ° C. At this time, the weight ratio of the sludge and the solvent was used in four ratios of 95: 5, 90:10, 85:15, and 80:20. Each homogenate was placed in a 100 ml measuring cylinder, which was then observed in an oven at 80 ° C. every 30 minutes, and the results are shown in FIG. 5. After the separation of the oil and water was completely made into the cylinder after 3 hours, the supernatant was recovered after the separation process, and the yield was measured after completely degassing the solvent under reduced pressure at 80 ° C.

The results are shown in Table 3 below.

Example 6

CNSL sludge obtained from Preparation Example 5 and diethyl ether were added to a reactor made of FRP, and homogenized by stirring with a mechanical stirrer for 3 hours while maintaining the temperature at 80 ° C. At this time, the weight ratio of the sludge and the solvent was used in four ratios of 95: 5, 90:10, 85:15, and 80:20. Each homogenate was placed in a 100 ml measuring cylinder, which was then observed in an oven at 80 ° C. for 30 minutes at intervals, and the results are shown in FIG. 6. After the separation of the oil and water was completely made into the cylinder after 3 hours, the supernatant was recovered after the separation process, and the yield was measured after completely degassing the solvent under reduced pressure at 80 ° C.

The results are shown in Table 3 below.

Example 7

CNSL sludge obtained from Preparation Example 5 and n-octane were added to a reactor made of FRP material, and homogenized by stirring with a mechanical stirrer for 3 hours while maintaining the temperature at 80 ° C. At this time, the weight ratio of the sludge and the solvent was used in four ratios of 95: 5, 90:10, 85:15, and 80:20. Each homogenate was placed in a 100 ml measuring cylinder, which was then observed at 30 ° intervals in an oven at 80 ° C., and the results are shown in FIG. 7. The time when the oil and water separation was completely made was 3 hours after the injection of the measuring cylinder. The supernatant was recovered after the separation process, and the yield was measured after completely degassing the solvent under reduced pressure at 80 ° C.

The oil and water separation results are shown in Table 3 below.

division Input amount (% by weight) Oil phase
(Vol%) Awards
(Vol%) Separation completed
(minute) CNSL sludge menstruum Example 1 95% 5% 20 3.27 210 90% 10% 27 210 85% 15% 35 210 80% 20% 38 210 Example 2 95% 5% 20 5.22 210 90% 10% 22 210 85% 15% 26 210 80% 20% 28 210 Example 3 95% 5% 20 4.24 240 90% 10% 22 240 85% 15% 26 240 80% 20% 28 240 Example 4 95% 5% 21 3.26 300 90% 10% 27 300 85% 15% 34 300 80% 20% 38 300 Example 5 95% 5% 35 0.29 150 90% 10% 36 150 85% 15% 35 150 80% 20% 37 150 Example 6 95% 5% 37 0.33 240 90% 10% 40 240 85% 15% 39 240 80% 20% 35 240 Example 7 95% 5% 36 0.36 240 90% 10% 39 240 85% 15% 40 240 80% 20% 42 240

As can be seen in Table 3 above, as a result of the use of polar ketone series (acetone) and alcohol series (isopropyl alcohol, methanol, ethanol), the micelle structure of CNSL sludge is more than 10% of CNSL sludge. Dilute to propyl alcohol (330-> 46), methanol (330-> 72), ethanol (330-> 63), acetone (330-> 55) and solved very efficiently. However, the oil and water separation efficiency of the oil phase and the water phase shows a rather low result. As can be seen from the drawings of FIGS. 1 to 4, the polar solvent effectively destroys the emulsion, but it is considered that the resolution is lowered as the density of the water phase and the oil phase is the same. According to the result of the oil / water separation test, isopropyl alcohol shows the highest resolution when a polar solvent is used. Diethyl ether showed the highest separation rate, but ultimately, n-hexane and n-octane showed the highest resolution. n-hexane is more oily and is considered the most efficient solvent.

The oil recovery obtained in Examples 1 to 7 is shown in Table 4 below.

division CNSL sludge menstruum yield
(weight%) At maximum yield
Separation time (min) Example 1 95 wt% 5 wt% 14 60 90 wt% 10 wt% 17 60 85 wt% 15 wt% 20 80 80 wt% 20 wt% 18 80 Example 2 95 wt% 5 wt% 15 100 90 wt% 10 wt% 12 100 85 wt% 15 wt% 11 120 80 wt% 20 wt% 8 120 Example 3 95 wt% 5 wt% 14 60 90 wt% 10 wt% 16 80 85 wt% 15 wt% 18 80 80 wt% 20 wt% 17 100 Example 4 95 wt% 5 wt% 16 20 90 wt% 10 wt% 17 20 85 wt% 15 wt% 19 30 80 wt% 20 wt% 18 40 Example 5 95 wt% 5 wt% 33 40 90 wt% 10 wt% 35 40 85 wt% 15 wt% 31 60 80 wt% 20 wt% 28 60 Example 6 95 wt% 5 wt% 27 40 90 wt% 10 wt% 34 60 85 wt% 15 wt% 31 60 80 wt% 20 wt% 29 60 Example 7 95 wt% 5 wt% 30 60 90 wt% 10 wt% 32 60 85 wt% 15 wt% 31 60 80 wt% 20 wt% 27 80

As can be seen from Table 4, Examples 5 and 6 using diethyl ether and n-hexane showed the highest yield, the recovery was 34 to 35%, and the amount of solvent used was compared to the total weight. 10 weight%.

As mentioned above, although this invention was demonstrated in detail through the specific Example, this invention is not limited to the said Example, A various deformation | transformation is possible for a person with ordinary knowledge within the scope of the technical idea of this invention.

Claims (5)

Adding CNSL sludge to the reactor in the presence of a solvent;
Stirring the homogenizer while maintaining the reactor at a temperature of 60 to 100 ° C. for 1 to 5 hours;
Leaving the obtained homogenate at a temperature of 60 to 100 ° C. for 1 to 5 hours to perform oil and water separation; And
Recovering the supernatant from the reactor where the oil separation is completed, and degassing at a temperature of 60 to 100 ℃ to extract the oil component; Reprocessing of CNSL sludge comprising a. The method of claim 1,
The CNSL sludge is CNSL sludge comprising 20 to 45% by weight, 35 to 60% by weight of water, 5 to 10% by weight of acid component, 4 to 8% by weight of ash, and residual amounts of other inorganic materials. Reprocessing method. The method of claim 1,
The reprocessing method of CNSL sludge which said solvent is a nonpolar solvent. The method of claim 1,
A process for reprocessing CNSL sludge, wherein the solvent is diethyl ether, n-hexane or n-octane. The method of claim 1,
And wherein said solvent is present in an amount of from 5 to about 20 weight percent, based on the total weight of said CNSL sludge.

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