KR20120002022A - Biodiesel feedstock oil production method and biodiesel production method using the biodiesel feedstock oil - Google Patents

Abstract

PURPOSE: A producing method of raw biodiesel oil and a producing method of biodiesel using the raw biodiesel oil are provided to remove phospholipids from the raw biodiesel oil by performing a pre-treatment process without a degumming process. CONSTITUTION: A producing method of raw biodiesel oil comprises the following steps: removing solids from oil obtained by oil-pressing biomasses containing fat(S300); esterifying the oil without the solids in the presence of an acid catalyst and alcohol without performing a degumming process(S302); removing phospholipids and free fatty acids from the oil(S304); dissolving the alcohol contained in the oil with cleaning water; separating the oil into an upper alcohol layer and a lower oil layer; and removing the alcohol and the moisture from the oil layer using a decompress-evaporating process.

Description

Biodiesel feedstock oil production method and biodiesel production method using the biodiesel feedstock oil {Biodiesel feedstock oil production method and Biodiesel production method using the biodiesel feedstock oil}

The present invention relates to a method for producing biodiesel raw material oil and a method for producing biodiesel using the biodiesel raw material oil, wherein the method for producing biodiesel raw material oil can efficiently increase the production yield while removing phospholipids contained in biodiesel. It relates to a biodiesel production method using biodiesel raw oil.

In recent years, the world has tightened regulations on environmental pollutants due to rising oil prices, depletion of fossil raw materials and the entry into force of the Kyoto Convention, which tightens regulations on carbon dioxide emissions. Therefore, research on the development of energy to replace fossil fuels is actively underway, and interest in the distribution of biofuels for transportation is increasing.

Biodiesel produced by reacting animal fats or vegetable oils in the presence of alcohols and catalysts is a biofuel that is considered a replacement for fossil fuels as a renewable biological fuel. Biodiesel has long been known for making methanol from triglycerides. However, in the early 1990s, fatty acid methyl esters were certified as diesel fuels and full-scale electricity was provided as an environmentally friendly alternative energy.

Biodiesel has almost the same physical and chemical properties as diesel and is an eco-friendly alternative energy that generates little pollution than diesel, and can be used directly on existing diesel engines and existing gas stations. The biodiesel is mixed with 5% to 20% diesel and some countries in Europe use 100% biodiesel. Biodiesel accounts for about 70% of total production costs, and as biodiesel production rapidly increases, it is difficult to secure stable raw materials and increase raw material prices. As a solution to this problem, rather than using high-quality fats with low free fatty acids such as soybean oil and rapeseed oil, the development of production processes using low fats with high free fatty acids such as waste oil such as waste cooking oil or jatropha oil, which is a non-edible crop, is being studied. have.

Most vegetable oils are suitable as raw materials for producing biodiesel. In general, the more volatile carbohydrates, the higher the autoignition temperature. Therefore, in the distillation process of crude oil, the components of medium volatility with a boiling point of 250 ~ 370 ℃ are suitably used as diesel fuel. Diesel is made up of paraffin, naphthene, olefin, and aromatics, which have 12 to 18 carbon atoms. Therefore, in order to be used as a substitute for diesel fuel, biodiesel must meet these technical problems, be economically competitive, environmentally sound and easily obtainable.

Biodiesel is produced from raw materials such as vegetable oils and animal fats. Vegetable oils consist of one mole of glycerol and three moles of fatty acid, called triglycerides. Vegetable oils are composed mainly of fatty acids with 12 to 24 carbon atoms. Biodiesel has been mainly studied for vegetable oils and has been found to be suitable for various vegetable oils such as soybean oil, palm oil, coconut, rapeseed oil and sunflower oil. Of course, animal fats can also be used as a raw material, but research on biodiesel is mainly done on vegetable oils.

FIG. 1 illustrates a biodiesel raw oil manufacturing process according to the prior art. Referring to FIG. 1, oil is obtained through shelling or non-shelling milking (step 100).

Thereafter, a process for removing solids from the obtained oil is performed (step 102), and water soluble degumming, acid degumming and distilled water washing processes are sequentially performed to remove free fatty acids and phospholipids (steps 104 to 108).

Colloidal impurities such as phospholipids, proteins and carbohydrates in vegetable oils are called gums, and the process of removing them is called degumming.

In the degumming process, as in steps 104 to 108, water-soluble degumming by hydration, acid degumming using acid and washing degumming (distilled water washing), and the like, mainly remove phospholipids contained in oil. .

Thereafter, a water removal process is performed (step 110), and a pretreatment process using an acid catalyst and an alcohol, that is, an esterification process, is performed (step 112).

After the pretreatment, the alcohol and water removal process is performed (step 114), and raw oil for biodiesel is prepared, and biodiesel is produced by transesterifying the biodiesel raw oil (step 116).

Here, the transesterification step is a reaction in which 1 mole of triglycerides and 3 moles of alcohol (for example, methanol) react to produce 3 moles of fatty acid methyl ester and 1 mole of glycerol.

In the case of an oil consisting only of triglycerides, as shown in FIG. 2, three molecules of methanol and one molecule of triglycerides are esterified in the presence of a base or an acid catalyst to produce three molecules of fatty acid methyl ester and one molecule of glycerol. Is called a trans-esterification reaction.

Base catalysts have been reported to have faster reaction rates at lower temperatures and pressures than acid catalyzed transesterification reactions. Hydrolysis by adding water to triglycerides produces free fatty acids or free fatty acids (FFA), and fatty acid methyl esters are also synthesized by acid-catalyzed esterification of these free fatty acids with methanol. In this case, when the base catalyst is used, the esterification reaction does not occur, and the fatty acid salt is produced by the neutralization reaction with the free fatty acid and the base catalyst.

In cooking oil refining plant, sodium hydroxide (NaOH) is added to neutralize free fatty acid to produce fatty acid salt (soap), followed by centrifugation to remove fatty acid salt and additional washing with water to remove caustic soda and fatty acid components. do. This is a technique commonly avoided in the biodiesel production process because free fatty acids that can be converted into biodiesel are generated as solid waste. In the case of cooking oil refining, since the purpose is to prepare a relatively expensive edible oil, the removal of free fatty acids by the neutralization method has economic feasibility. In general, cooking oil manufacturing plants select oil seeds, such as soybeans, from soil and other miscellaneous substances, milking for obtaining crude oil, phospholipids or phophatides, and other test substances. Degumming for removal, removal of free fatty acids by Alkali-refining or Neutralization, water washing, vacuum drying, bleaching with white earth or activated carbon, unpleasant odor when edible Deodorization to remove is performed sequentially. When using edible oil prepared in this way as raw material oil, biodiesel can be produced relatively easily by transition esterification, but the amount of oil finally obtained in the process of producing edible grade high quality raw oil is small. The price of crude oil is very high, greatly reducing the economics of biodiesel production.

On the other hand, according to the prior art, the water-soluble degumming, acid degumming and washing degumming process for the removal of free fatty acids and phospholipids, the phospholipids are removed during these processes, but biodiesel raw material because it goes through a multi-step process There is a problem that the yield of milk production is lowered.

On the other hand, if the phospholipid is 40ppm or more in the biodiesel raw material oil, glycerol and fatty acid methyl ester are not separated after the transesterification reaction for biodiesel production, making it difficult to commercially produce large quantities. There is a problem. On the other hand, in the final quality of biodiesel produced through reaction purification, the phosphorus content regulation level is specified as 10ppm, and the reason why phosphorus content is regulated to 10ppm or less is that it adversely affects the catalyst of the vehicle exhaust aftertreatment device. This is because a lot of pollutants are emitted.

In addition, PA (Phosphatidic Acid), a type of phospholipid, contains not only phosphorus (P) but also metal components (Ca, Mg, Fe). When included, they must be removed as they will adversely affect the vehicle as shown in Table 1 below.

Table 2 below is a domestic biodiesel quality standard, as shown in Table 2, biodiesel should be less than 5ppm content of Ca and Mg in addition to phosphorus content.

The present invention to solve the problems of the prior art, a method of producing a biodiesel raw material oil that can effectively remove the phospholipid from the oil obtained by milking in the biomass while increasing the biodiesel raw oil yield and using the biodiesel raw oil A biodiesel manufacturing method is proposed.

Another object of the present invention is to provide a biodiesel raw material production method capable of significantly reducing phosphorus content and preventing environmental pollutant emissions and a biodiesel production method using the biodiesel raw material oil.

In order to achieve the above object, according to a preferred embodiment of the present invention, the step of removing solids from oil obtained by milking a biomass containing fats and oils; There is provided a biodiesel raw material production method comprising the step of esterifying the oil from which the solid is removed without esterification in the presence of an acid catalyst and an alcohol to remove phospholipids and free fatty acids contained in the oil below a predetermined content. .

The biomass is a tropical crop obtained from the rubber tree, the phospholipid content may be 40ppm or more.

The phospholipid content may be removed to 10 ppm or less through the esterification reaction.

Preferably, the acid catalyst is a homogeneous liquid acid catalyst including at least one of sulfuric acid, hydrochloric acid, and nitric acid, and the homogeneous liquid acid catalyst may be included in the reaction system at 0.4 to 1.0 percent or less by weight of the oil.

The homogeneous liquid acid catalyst may be included in the reaction system in an amount of 0.6 to 1.0 percent by weight of the oil.

The alcohol is methanol and the methanol may be included in the reaction system in an amount of 20 to 30 percent by weight of the oil.

The methanol may be included in the reaction system in an amount of 25 to 27 percent by weight of the oil.

The acid catalyst is sulfuric acid, the alcohol is methanol, and the sulfuric acid and the content of methanol may be determined through statistical analysis of data of optimization experiment results using reaction surface analysis.

The oil may be obtained through at least one of shell shell milking or non shell shell milking.

According to another aspect of the invention, the step of removing the solids from the oil obtained by milking a biomass (biomass) containing fats and oils; Esterifying the oil from which the solids have been removed without esterification in the presence of an acid catalyst and an alcohol to remove phospholipids and free fatty acids contained in the oil below a predetermined content; Removing the alcohol and water from the oil from which the phospholipid has been removed; And a transesterification reaction of the alcohol-free oil (biodiesel raw oil) under an alcohol and a base catalyst is provided.

Preferably, the step of removing alcohol and water corresponds to an upper layer and an oil layer corresponding to an alcohol layer in which the oil from which the phospholipid has been removed as a bulk phase through at least one of gravity separation and centrifugation. Separating into lower layers; And removing the alcohol and water from the lower layer through evaporation under reduced pressure.

Alternatively, the alcohol and water removal step, (a) dissolving the alcohol in the washing water; (b) separating the oil from which the phospholipid has been removed into an upper layer corresponding to an oil layer and a lower layer corresponding to an aqueous layer through at least one of gravity separation and centrifugation; And (c) removing alcohol and water from the oil layer through reduced pressure evaporation.

Steps (a) to (c) are repeated for the oil and oil layers from which water is removed, and the washing water is preferably alkaline.

According to the present invention, after the solids are removed, the pretreatment process is performed without the degumming process, thereby increasing the biodiesel raw oil yield and simultaneously removing the phospholipid.

1 is a flow chart illustrating a biodiesel manufacturing process according to the prior art.
2 shows a biodiesel synthesis route.
3 is a view showing a biodiesel raw material manufacturing process according to an embodiment of the present invention.
4 shows the types of phospholipids.
5 is a diagram showing the phospholipid composition of soybean oil, sunflower oil, rapeseed oil, rice bran oil.
6 is a view showing the type and characteristics of phospholipids according to the structure and substituents of phospholipids.
FIG. 7 is a diagram illustrating glycerin and biodiesel layer separation after biodiesel production from crude oil having different phospholipid contents.
8 is a view showing the pretreatment efficiency according to the amount of sulfuric acid catalyst and methanol according to the present invention.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

3 is a view showing a biodiesel raw material manufacturing process according to an embodiment of the present invention.

Referring to FIG. 3, a process for removing solids of oil obtained from a biomass including fats and oils is performed (step 300).

Biomass (biomass) is a generic term for biological resources used as chemical energy, in the present invention, if the biomass contains fats and oils, the kinds of animals, plants, etc. are not greatly limited, and plant biomass is considered in consideration of commerciality and economic efficiency. It is preferable that it is a mass, and it is more preferable that it is an oil seed (Oil Seed). Animal biomass containing fats and oils in the present invention include fish, chickens, birds such as ducks, mammals such as pigs and cows. Oil seed refers to vegetable oil crops that can be oiled. More specifically, sunflower seeds, soybeans, rapeseed seeds, jatropha seeds, palm fruits, and rice bran and camellia fruits, which are by-products of the brown rice production process. , Gum fruits and by-products after coffee extraction.

In particular, according to a preferred embodiment of the present invention, the rubber tree fruit seeds cultivated or grown in tropical regions such as Southeast Asia and China may be used as biomass for the production of biodiesel raw oil, in the present invention It is described that the oil used is an oil milked from rubber tree fruit seeds having a content of free fatty acid in the range of 15 to 20 weight percent and a phosphorus content of 40 ppm or more.

In general, it is difficult to directly measure the content (mass%) of phospholipids or phosphatides, and the content of phospholipids (mass%) can be obtained by analyzing the phosphorus content (mass%). Phosphorus content (mass%) can be measured by AOCS Official Method Ca 12-55 as shown in Equation 1 below, and the phospholipid content is calculated by multiplying phosphorus content (mass%) by 30 on the basis of soybean oil (mass%). ) Can be calculated.

The sample analysis procedure according to AOCS Official Method Ca 12-55 is as follows.

(1) 3.0 to 3.2 ± 0.001 g of sample and 0,5 g of zinc oxide were added to the crucible and heated slowly until the sample melted, and then heated until completely burned.

(2) The crucible is placed in a muffle furnace and kept at 550 to 600 ° C. for 2 hours, then taken out and cooled to room temperature.

(3) 5 ml of distilled water 5 ml concentrated hydrochloric acid is added to the completely burned sample ash.

(4) Cover the crucible with a watch glass and heat it for 5 minutes with mild heat.

(5) Solution filtered into a 100 ml flask and cooled to room temperature

(6) Neutralize through a 50% KOH solution until a white float is formed, and then drop the hydrochloric acid dropwise to make the solution clear.

(7) Neutralize suspended solids and dilute with distilled water up to 100ml graduation

(8) In a 50 ml flask, 10 ml of the above solution, 2.0 ml of sodium molybdate, and 8.0 ml of hydrazine sulfate were mixed.

(9) heating in a water bath for 10 minutes

(10) Cool the heated solution to 25 ± 5 ° C and dilute with distilled water to the graduation of 50ml flask.

(11) Absorption measurement using a spectrophotometer (650 nm) adjusted to read 0% absorption for quartz cells containing distilled water

Where A is the mass of the sample obtained by comparison with the Phosphorus Calibration Curve

B is the phosphorus content of Blank (analysis tested without adding the sample in the above procedure (1))

W is the mass of the sample in the procedure (1)

V is the volume of solution taken in the procedure (8)

On the other hand, as shown in Figure 4, the phospholipids are largely classified into four types, of which Ca (Phospahtidic Acid) containing Ca and Mg occupies the most weight.

Figure 5 shows the phospholipid composition of soybean oil, sunflower oil, rapeseed oil, rice bran oil, Figure 6 shows the type and characteristics of phospholipids according to the structure and substituents of phospholipids (Phospholipid).

In the case of the milking oil of the rubber tree fruit seed, the phosphorus content was measured up to 280 ppm when the milk was milked, and the phosphorus content was measured up to 90 ppm when the peel was removed. Therefore, when it is used as a biodiesel raw oil, as shown in Figure 7, the biodiesel production process may cause a problem that the separation of the methyl ester / glycerin layer. Here, the raw material oil 1 shows the case where the phospholipid is high content, and the raw material oil 2 shows the case where the phospholipid is low content.

The present invention, as described above, to provide a biodiesel raw material oil that can increase the biodiesel production efficiency while reducing environmental pollution from the rubber seed fruit seeds having a high phosphorus content.

The oil described above is obtained through milking, where milking means obtaining oil from biomass.

Extraction is usually divided into two types: extrusion and solvent extraction. The compression method is a method of obtaining oil by applying mechanical pressure to a biomass using an expeller such as a screw, and is used for crops having a high content. Extraction method is mainly used for crops with low biomass retention, which is obtained by dissolving oil with volatile solvent and recovering solvent again, but it is also used to extract oil from milking milk or milking by-products which have undergone mechanical milking. . Since the biomass used in the present invention is preferably a crop having a high content, the milking method is also preferably a compression method, but is not limited thereto. In addition, milking may be divided into non-shelled milking, which includes milking and peeling of the biomass, especially oilseed crops, including shelling during milking, and shelled milking, which is milked after removing the skin. Milking in the present invention is non-shelled milking and shelling. Includes all milking. After biodiesel production, the solids content standard is defined as 24 ppm in Europe and less than 0.05% as sediment containing water in Korea.

The water evaporation process may be performed such that the content of water that inhibits the esterification reaction with the removal of the solids is below a certain level (for example, 0.1%).

After removal of the solids, the pretreatment process is performed immediately without degumming (step 302).

The pretreatment is a process for removing free fatty acids and phospholipids from the oil obtained through milking, which is an esterification reaction.

In the esterification reaction, free fatty acids (FFAs) are esterified with alcohols to be converted to fatty acid alkyl esters (FAAE), or biodiesel, and the phospholipids are converted to hydrophilic and nonpolar. It is removed from the routine by moving to the polar alcohol phase (or alcohol layer). In more detail, the phospholipid shown in FIG. 6 is separated from the triglyceride structure in which the part including the substituent having the hydrophilicity (Water affinity, polar) of the phospholipid is lipophilic (Oil affinity, apolar) by alcohol and esterification reaction. Phospholipids are changed to lipophilic (oil affinity, apolar) diglycerides that do not contain phosphorus, and the part containing phosphorus is dissolved in alcohol and has a nonpolar oil phase (triglyceride, diglyceride, monoglyceride, fatty acid alkyl ester) It is separated from and is mainly present in the hydrophilic alcohol phase.

According to this embodiment, after the solids are removed, a pretreatment process (esterification reaction as a simultaneous removal process of phospholipids and free fatty acids) is performed without degumming, such as water soluble degumming and acid degumming.

The pretreatment according to the present embodiment is carried out in the presence of an acid catalyst and an alcohol. Preferably, the acid catalyst may be a homogeneous liquid acid catalyst such as sulfuric acid, nitric acid, hydrochloric acid, and more preferably a sulfuric acid catalyst.

In addition, the alcohol may have 1 to 6 carbon atoms, preferably methanol may be used.

In this case, the sulfuric acid may be 0.4 to 1.0 percent, preferably 0.6 to 1.0 percent, based on the weight of the oil from which the solids are removed.

On the other hand, methanol may be included in the reaction system in an amount of 20 to 30 percent by weight of the oil, preferably, in the reaction system in an amount of 25 to 27 percent.

Here, the amount of acid catalyst and alcohol can be obtained through statistical analysis of the results of optimization experiments using reaction surface analysis.

The tropical crop oil used in the present invention contains more than 15% of free fatty acid and a large amount of phospholipid (phosphorus content of 90 to 280 ppm), thereby preventing the reaction during biodiesel production through a trans-esterification reaction. Since the reaction yield is lowered, free fatty acid removal and phospholipid removal through the pretreatment process are essential. Free fatty acids form fatty acid salts (Fatty acid salt, metal soap) by neutralization with KOH, NaOH, NaOCH ₃ and other catalysts used in the transesterification reaction. The hydrophilic part of Na) acts as a surfactant, making it difficult to separate biodiesel and glycerin. And glycerin make the separation more difficult.

In general, it is known to go through a degumming process to remove phospholipids, but according to the present invention, compared to the case of performing the pretreatment process after the degumming process and only the pretreatment process, rather than desulphurization under sulfuric acid catalyst and methanol conditions When only pretreatment was performed, it was confirmed that not only free fatty acids but also phospholipids were lowered below a desired level, and experimentally confirmed that the yield was higher than that of the degumming process.

After the sulfuric acid pretreatment, a methanol and water removal process is performed (step 304) and biodiesel is produced via a transesterification reaction (step 306).

In step 304, gravity separation or centrifugation may be used to remove methanol and water.

As a first method, when gravity separation or centrifugation is performed on oil (prephosphorylated oil) in which the pretreatment process is completed, the phospholipid-depleted oil has a lower layer corresponding to an oil layer and an alcohol layer (methanol layer). It can be separated into the upper layer corresponding to), and methanol and water are removed from the oil layer of the lower layer through dark evaporation.

As a second method, methanol and water removal processes can be carried out by washing.

When methanol contained in the oil pretreated by washing is dissolved in the washing water and then separated or centrifuged, the upper layer is separated into an oil layer and the lower layer is separated into a water layer containing water and methanol, and the upper layer is evaporated under reduced pressure. Water and methanol are removed from the oil layer.

Preferably, after the water and methanol are removed, the above washing, separation process and reduced pressure evaporation process may be repeatedly performed on the residual oil layer. Preferably, the methanol and water removal process is performed by washing after performing sulfuric acid pretreatment. A total of 2 to 4 times can be performed.

When the cleaning process is added to remove methanol and water from the phospholipid removed oil as described above, the acid catalyst (sulfuric acid) and the water-soluble impurities remaining in the oil can be effectively removed.

Alkali water, which is an aqueous solution of KOH or NaOH, may be used as the washing water in one or two of the above-described two to four washing procedures for effective removal of the acid catalyst.

In the transesterification reaction, a chemical catalyst, a base catalyst (KOH, NaOH, NaOCH3 catalyst) and an alcohol (methanol) having high reaction activity are generally used, and more specifically, biodiesel raw material oil prepared through pretreatment as described above. When 1 mole and 3 moles of alcohol are added to the catalyst and reacted, 1 mole of glycerin is produced as 3 moles of biodiesel and by-products. Generally, a molar ratio condition of about 4/1 to 9/1, which is an excess of theoretical molar ratio (moles of alcohol) / (moles of oil) = 3/1, is used.

According to an embodiment of the present invention, biodiesel raw material oil from which phospholipids and free fatty acids are removed may be produced only by removing solids, removing sulfuric acid, and removing methanol without water soluble degumming, acid degumming and washing degumming.

In particular, according to the present invention, phospholipid removal and free fatty acid removal can be performed simultaneously by optimizing the amount of sulfuric acid catalyst and methanol for sulfuric acid pretreatment.

[Example]

In the following, embodiments of the present invention will be described in more detail. However, the following examples are only intended to illustrate the present invention more clearly and do not limit the protection scope of the present invention.

Analysis of Physical Properties of Tropical Crop Oil (Rubber Seed Milking Oil)

Seeds of uncropped tropical crops were milked by mechanical pressing to obtain vegetable raw oils. Tropical crops used tropical crop seeds obtained from a tree named scientific name Hevea brasiliensis.

The tropical crops were subjected to shelling or non-shelling milking to obtain tropical crop oils, and the physical property analysis results of the tropical crop oils are shown in Table 3 below.

Generally, the acid value criterion that is preferably required in the biodiesel production process is 1.0 or less. In addition, the phosphorus content is 10 ppm or less. The acid value of tropical crop oil was analyzed to have an acid value of 32.8 to 40.05 for non-shelled and shelled samples, which was much higher than 10.64 of jatropha oil. Free fatty acid content ranged from 16% to 20%, 3-4 times higher than 5.3% of jatropha oil.

Example  1. Remove solids

In this embodiment, biodiesel raw material oil is prepared using shelled tropical crop oil (rubber oil) having an acid value of 38.6 mgKOH / g, water content of 0.11%, and phosphorus content of 46 ppm.

Here, the content of phospholipids is indicated by the phosphorus content.

Solids contained in tropical crop oils must be removed as they cause problems that reduce efficiency in chemical pretreatment processes.

In solids removal, heating and filtering were performed before the filter to lower the viscosity of the oil. Solids removal method was heated to 80 ℃ while stirring the oil in Crude oil vessel. The preheated oil was passed through a filter (microfiber depth filter, 1μm) using a pump to perform a filtering process and then stored in a filtered oil vessel.

Example  2. Pretreatment Catalytic amount  And Methanol amount  decision

The esterification experiment was carried out using sulfuric acid (H ₂ SO ₄ ) as a solid acid catalyst Amberlyst-15, Amberlyst-BD20 and a homogeneous catalyst as a homogeneous catalyst.

Sulfuric acid catalyst was selected for esterification because of high reactivity in order of sulfuric acid, Amberlyst-15, Amberlyst-BD20.

A pretreatment reaction experiment was performed by constructing an experimental matrix for the amount of sulfuric acid catalyst and methanol as shown in FIG. 8 using a central composite design (CCD) based on a response surface method (RSM). The variables for determining the operating conditions of the pretreatment process are the main variables such as the amount of catalyst, alcohol (methanol), reaction temperature, reaction time, and stirring speed. Has been reported to exist [Korea Institute of Energy Research, "A Process Development of Biodiesel Production from Used Frying Oil Using Chemical Catalyst,""Resource Recycling R & D Program, 2A-B-3-1, 96- 111 (2003). In addition, the operating cost and the efficiency of the pretreatment process were found to be largely dependent on the amount of catalyst and the amount of methanol. Therefore, in the present invention, the amount of catalyst and methanol is determined as an operating variable, and statistical analysis is performed using SPSS Software using the result data after the RSM experiment. Could get

[Equation 2]

F = 12.586 + 4.149x + 64.562y-0.058x2-16.698y2-1.190xy

F (Conversion,%) = 98.12

The optimum reaction conditions determined from the above equations were 26.70% methanol and 0.982% catalyst for tropical crop oils.

It has been found that the optimum catalyst input can achieve a high pretreatment reaction conversion of at least 98% with a relatively small amount of less than 1%.

Example  3. Sulfuric acid pretreatment

The solids removed solution was transferred to the preesterification reactor using a pump from the buffer tank. At the same time, sulfuric acid and methanol are transferred from the Acid-MeOH vessel to the preesterification reactor. The flow rate of the oil and sulfuric acid-methanol solution was adjusted according to the reaction time, and the free fatty acids and phospholipids contained in the oil were removed and converted. The internal temperature of the preesterification reactor was adjusted to maintain 65 ℃ and the reaction proceeded for 120 minutes.

After completion of the pretreatment reaction, the oil was passed through a check valve (2 atm) and stored in the Esterification vessel. The oil and sulfuric acid-methanol phases were separated by standing for 60 minutes. The lower valve was opened to transfer the lower pretreatment oil to the oil vessel, the sight glass was observed, the valve was closed when the interface was visible, and the sulfuric acid-methanol was transferred to the MeOH vessel. The oil in the oil vessel was transferred to the evaporation vessel for methanol removal.

After the sulfuric acid pretreatment process, the yield was 98.0%, the content of fatty acid methyl ester (FAME) was 22%, the acid value was 2.5mgKOH / g, moisture 0.41%, phosphorus content was confirmed to be less than 9ppm.

As described above, when the phosphorus content is 9ppm, PA (phospatidic acid), which occupies the largest proportion of phospholipids, is also reduced, and Ca and Mg were confirmed to be 5ppm or less.

Example  4. Methanol Removal

The temperature of the evaporation vessel was heated to 65-75 ° C. (preferably 70 ° C.), and a vacuum pump was run to remove methanol at reduced pressure (-50 to -75 mmHg) for 30 minutes. The removed methanol was passed through a condenser and stored in a sulfuric acid-methanol vessel, and the oil was stored in a product vessel.

The yield of methanol was 96.3%, the acid value was 2.6mgKOH / g, the water content was 0.05%, and the phosphorus content was 14ppm. The phosphorus content was increased by methanol and water removal.

It was confirmed that phospholipids were reduced to less than 9 ppm by the sulfuric acid pretreatment process without degumming to remove phospholipids, and biodiesel crude oil was obtained with a yield of 94.3% for tropical crop oils.

As described above, the water removal process may be performed together with the methanol removal, and the layer separation and the reduced pressure evaporation may be performed for the methanol and the water removal process, or the layer separation and the reduced pressure evaporation may be performed after the cleaning process. have.

Acid value, yield, moisture content, phosphorus content according to the above process is shown in Table 4 below.

Example  5. Preparation of Biodiesel

As a catalyst, 95% KOH of JUNSEI company and anhydrous methanol of Duksan Co., Ltd. were used. The transition esterification reaction conditions for biodiesel production were 65 ° C, agitation speed 200rpm, reaction time 40min, methanol: oil mole ratio 6.2: 1, catalyst concentration (KOH) 0.8%, methanol 22.74g, 100 g oil, 0.84 g (95% assay) of KOH was used.

The experimental method quantifies the pretreated biodiesel crude oil, puts it in a reactor and heats it to 65 ° C. while stirring the reactor at 240 rpm. When the temperature is reached, stirring and heating are stopped and the raw material inlet of the reactor is left open. In a calculated amount of methanol, dissolve the catalyst in a beaker (prevent methanol evaporation as a wrap) with a magnetic bar and place it in the reactor (slowly to separate the layers).

After closing the inlet and tightening the bolts to seal, turn on the stirrer (240rpm setting), and after 40 minutes reaction, turn off the stirring and heater, stop, and then put the reaction product down into the separator funnel to separate the glycerol and Methyl Ester phase (Upper layer: Methyl Ester, Lower layer: Glycerol). The yield is determined by weighing the separated ester phase and glycerol phase and sampled for physical property analysis.

The separated fatty acid methyl ester was removed at 65 ° C. under reduced pressure for 30 minutes. In the washing, both the fatty acid methyl ester and the washing water were heated to 55-60 ° C. and stirred at 200 RPM for 1 minute. Washing water was washed twice by 10% by volume ratio of ester phase.

After washing, methanol and water contained in trace amounts in biodiesel were evaporated under reduced pressure for 30 minutes. The yield investigation was performed by measuring the mass before and after each process (Table 5).

Comparative example  One. Degum  Of biodiesel after sulfuric acid pretreatment

For yield comparison, the yield of the biodiesel production from the biodiesel crude oil from which phospholipids and free fatty acids were removed was measured by degumming and chemical pretreatment.

In the degumming process, the tropical crop oil has the same acid value, water content and phosphorus content as in Example 1, and the solid removal process was performed in the same manner as in Example 1.

For water soluble degumming, degasser used distilled water (10% by weight of oil), and water soluble degumming was performed at a degumming temperature of 50 ° C. for 5 minutes.

For acid degumming, phosphoric acid (0.01% by weight of oil) and distilled water (2%) were used, and water degumming was performed for 5 minutes at a degumming temperature of 60 ° C.

For cleaning degumming (process), distilled water (10% by weight of oil) was used as the cleaning agent, and washing was performed at a washing temperature of 50 ° C. for 5 minutes.

For water removal, the reduced pressure (-50 to -70 mmHg) was maintained for 30 minutes at a temperature of 95 ° C.

After the degumming process as described above, sulfuric acid pretreatment, methanol removal and biodiesel were prepared under the same conditions as in Examples 3 to 5. And the yield investigation was performed by measuring the mass before and after each process (Table 6).

As a result of the yield measurement, the yield of both degumming and pretreatment was 87.83%, which is lower than the yield of 98% in the process of sulfuric acid pretreatment only. The yield was 61.00% in the biodiesel sample prepared after degumming and sulfuric acid pretreatment, and 67.11% in the biodiesel sample using biodiesel raw material consisting only of sulfuric acid pretreatment.

Through the above comparison, it can be seen that the production of biodiesel raw material oil by the method according to the present invention and also the production of biodiesel using the same, the yield is greatly improved.

Claims (17)

Removing solids from the oil obtained by milking a biomass containing fats and oils;
A method of producing biodiesel raw material oil, comprising the step of esterifying the oil from which the solids have been removed without esterification in the presence of an acid catalyst and an alcohol to remove phospholipids and free fatty acids contained in the oil to a predetermined content or less. The method of claim 1,
The biomass is a tropical crop obtained from a rubber tree, the method of producing biodiesel raw oil having a phospholipid content of 40ppm or more. The method of claim 2,
Biodiesel raw material manufacturing method that the phospholipid content is removed to 10ppm or less through the esterification reaction. The method of claim 1,
The acid catalyst is a homogeneous liquid acid catalyst containing at least one of sulfuric acid, hydrochloric acid and nitric acid,
Wherein the homogeneous liquid acid catalyst is contained in the reaction system in an amount of 0.4 to 1.0 percent or less based on the weight of the oil. The method of claim 4, wherein
Wherein the homogeneous liquid acid catalyst is contained in the reaction system in an amount of 0.6 to 1.0 percent by weight of the oil. The method of claim 1,
The alcohol is methanol,
The methanol is biodiesel raw material manufacturing method contained in the reaction system in an amount of 20 to 30 percent by weight of the oil. The method of claim 6,
The methanol is biodiesel raw material manufacturing method contained in the reaction system in an amount of 25 to 27 percent by weight of the oil. The method of claim 1,
The acid catalyst is sulfuric acid, the alcohol is methanol,
The content of the sulfuric acid and the methanol is biodiesel raw material production method is determined through statistical analysis of the results of optimization experiments using the reaction surface analysis method. The method of claim 1,
The oil is a biodiesel raw oil production method obtained by at least one of shell shell milking or non shell shell milking. The method of claim 1,
Biodiesel raw material manufacturing method further comprises the step of removing the alcohol and water from the phospholipid removed oil. The method of claim 10,
The alcohol and water removal step,
Separating the oil from which the phospholipid has been removed into an upper layer corresponding to an alcohol layer existing as a bulk phase and a lower layer corresponding to an oil layer through at least one of gravity separation and centrifugation; And
Biodiesel raw material manufacturing method comprising the step of removing alcohol and water from the oil layer through reduced pressure evaporation. The method of claim 10,
The alcohol and water removal step,
(a) dissolving the alcohol in washing water;
(b) separating the oil from which the phospholipid has been removed into an upper layer corresponding to an oil layer and a lower layer corresponding to an aqueous layer through at least one of gravity separation and centrifugation; And
(C) biodiesel raw material manufacturing method comprising the step of removing alcohol and water from the oil layer through reduced pressure evaporation. The method of claim 12,
Step (a) to (c) is repeatedly performed for the oil layer from which the alcohol and water are removed, wherein the washing water is alkaline is used. Removing solids from the oil obtained by milking a biomass containing fats and oils;
Esterifying the oil from which the solids have been removed without esterification in the presence of an acid catalyst and an alcohol to remove phospholipids and free fatty acids contained in the oil below a predetermined content;
Removing the alcohol and water from the oil from which the phospholipid has been removed; And
Bio-diesel manufacturing method comprising the step of transesterification the alcohol-free oil (biodiesel raw material oil) under a base catalyst with alcohol. The method of claim 14,
The alcohol and water removal step,
Separating the oil from which the phospholipid has been removed into an upper layer corresponding to an alcohol layer existing as a bulk phase and a lower layer corresponding to an oil layer through at least one of gravity separation and centrifugation; And
Biodiesel manufacturing method comprising the step of removing the alcohol and water from the oil layer through reduced pressure evaporation. The method of claim 14,
The alcohol and water removal step,
(a) dissolving the alcohol in washing water;
(b) separating the oil from which the phospholipid has been removed into an upper layer corresponding to an oil layer and a lower layer corresponding to an aqueous layer through at least one of gravity separation and centrifugation; And
(C) biodiesel manufacturing method comprising the step of removing alcohol and water from the oil layer through reduced pressure evaporation. The method of claim 16,
The steps of (a) to (c) are repeated for the oil layer from which the alcohol and water are removed, and the washing water is alkaline.

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