JP2009297669A - Solid basic catalyst for manufacturing bio-diesel fuel, manufacturing method of the catalyst, device for manufacturing bio-diesel fuel using the catalyst and manufacturing method of bio-diesel fuel using the device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid basic catalyst suitable for manufacturing a bio-diesel fuel (BDF) from raw material fats and oil, to provide a manufacturing method thereof, to provide a device for manufacturing BDF using the catalyst and to provide a manufacturing method of BDF. <P>SOLUTION: The catalyst consists of calcium oxide having a particle size that does not pass a mesh textile of 1.0 mm apertures and passes the mesh textile of 10 mm apertures. The surface is modified to calcium diglyceroxide. The catalyst can be prepared by calcining crushed limestone with a predetermined particle size and then immediately dipping it into a C<SB>2</SB>or C<SB>3</SB>alcohol solution of glycerol at a temperature of 20-60°C for 10-60 min. It is preferable that the catalyst is mixed with at least two types of dispersive mediums of a different particle size when used. The BDF with high quality can be manufactured by supplying a mixed solution having 70-150 pts.vol of methanol added per 100 pts.vol of the raw material plant oil to the reaction tube where the mixture is stored. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a solid catalyst (solid catalyst for producing biodiesel fuel) suitable for producing biodiesel fuel (BDF) from raw oils and fats, and a reaction for producing biodiesel fuel in which the solid catalyst is accommodated in a pipe body. The present invention relates to a pipe and a method for producing biodiesel fuel using the reaction pipe.

Biodiesel fuel, which is extremely important for the construction of an “energy-recycling society” that reduces emissions of global warming gases and air pollutants, is obtained by the alcoholysis reaction of various triacylglycerides that constitute oils and fats.
In the current biodiesel production, the “alkali hydroxide catalyst method” is used. However, since alkali is mixed into the produced biodiesel (about 300 ppm), water washing purification is indispensable. For this reason, a large amount of alkaline waste water is generated, and a large amount of cost is required for its disposal.
Research and development activities for solid-base catalysts to realize a new method for producing environmentally friendly biodiesel fuel that does not discharge harmful alkaline wastewater are thriving, but none have been put to practical use. A method using a strongly basic ion exchange resin as a solid base catalyst is the only one that is close to practical use, and its catalytic performance is evaluated by a one-through flow reaction system (for example, Non-Patent Document 1 below). However, this method has a problem that the solid base catalyst must be frequently regenerated and the regeneration operation is complicated.
N. Shibasaki-Kitagawa, et al., Bioresour. Technol., 98 (2007) 416-421

In order to solve these problems, the present inventors have proposed a solid base catalyzed reaction method using highly active calcium oxide in which the preparation operation is devised in the following Patent Document 1. In practical use, a biodiesel fuel can be obtained by simply storing the solid base catalyst in a reaction tube and passing raw material vegetable oil and methanol through the reaction tube. Therefore, the catalyst accommodated in the reaction tube must be shaped so as to achieve both smooth flow of the reactant and good contact. However, a technology for processing a solid base catalyst using calcium oxide into a desired shape has not been established, and has not been put into practical use as a method for producing biodiesel fuel.
WO2006 / 134845

In addition, in the Japanese Patent Application No. 2007-49729, the present inventors found that calcium diglyceroxide (Ca (C ₃ H ₇ O ₃ ) ₂ ), which is a reaction product of calcium oxide and glycerin, is a substantially active species. It was pointed out that there was no practical catalyst that could be accommodated in the reaction vessel. In addition, in the method described in Japanese Patent Application No. 2007-49729, it was not possible to prepare a solid base catalyst having a property that can withstand practical use in the production of biodiesel fuel.

An object of the present invention is to provide a solid catalyst and a reaction apparatus (reaction tube) suitable for efficiently producing high-quality biodiesel fuel. It is also an object of the present invention to provide a production method suitable for efficiently producing high-quality biodiesel fuel.
As a result of intensive studies, the present inventors have surface-modified (modified) a crushed limestone having a specific size by a practical solid base catalyst having a shape that achieves both smooth flow and good contact of reactants. And the present invention was completed. This practical catalyst has undergone a production process in which the inventions described in Patent Document 1 and Japanese Patent Application No. 2007-49729 are improved. The solid base catalyst for producing biodiesel fuel according to the present invention is characterized in that a special shape processing is unnecessary and the preparation operation is very simple. In addition, since limestone as a raw material can be procured at low cost in Japan, one of the major advantages of this catalyst is that it is excellent in mass productivity. In the present invention, this practical solid base catalyst fully exhibits its original performance and claims the reaction operation conditions for efficiently producing biodiesel fuel.

The solid base catalyst for producing biodiesel fuel of the present invention used for producing biodiesel fuel has a particle size that passes through a mesh fabric having an opening of 10 mm without passing through the mesh fabric having an opening of 1.0 mm. It is characterized by comprising calcium oxide, and the surface of the calcium oxide is modified with calcium diglyceroxide.

In addition, the production method of the present invention for producing a solid base catalyst useful for producing biodiesel fuel,
Screening the crushed limestone having a particle size that passes through a mesh fabric having an opening of 10 mm without passing through the mesh fabric having an opening of 1.0 mm;
After calcining the crushed limestone obtained in the above step, the obtained calcined product is immediately immersed in a glycerin C ₂ or C ₃ alcohol solution at a temperature of 20 to 60 ° C. for 10 to 60 minutes. And the step of modifying the surface of the product with calcium diglyceroxide.

Furthermore, the device of the present invention for producing biodiesel fuel comprises:
A raw material liquid supply tank for storing and supplying the raw material liquid;
A reaction tube containing a solid base catalyst for producing biodiesel fuel,
A feed pump for supplying the raw material liquid from the raw material liquid supply tank to the reaction tube and circulating the reaction liquid after passing through the reaction tube to the raw material liquid supply tank;
A raw material liquid supply unit is provided at one end of the reaction tube, and a product take-out unit is provided at the other end. The solid base catalyst accommodated in the reaction tube has an opening of 1.0 mm. It consists of calcium oxide having a particle size that passes through a mesh fabric having an opening of 10 mm without passing through the mesh fabric, and the surface of the calcium oxide is modified with calcium diglyceroxide. And

Further, the present invention provides the apparatus for producing biodiesel fuel having the above-described characteristics, wherein the reaction is performed in a state where the solid base catalyst for producing biodiesel fuel is mixed with at least two kinds of dispersion media having different particle diameters. It is also characterized by being housed in a tube.
In addition, the present invention provides a biodiesel fuel production apparatus having the above-described features, wherein the maximum particle diameter of the solid base catalyst is 1 to 4 times the 10 parts by volume of the biodiesel fuel production solid base catalyst. 10 to 50 parts by volume of a dispersion medium (large diameter dispersion medium) having a size of 1 to 0.25 times the minimum particle diameter of the solid base catalyst (small diameter dispersion medium) It is also characterized in that 10 to 50 parts by volume are mixed. Specifically, when a solid base catalyst having a particle size of 1 to 2 mm is used, a large diameter dispersion medium having a particle size of about 2 to 8 mm is used, and a small diameter dispersion medium having a particle size of about 1 to 0.25 mm is used. used.

In addition, the production method of the present invention for producing biodiesel fuel has an opening of 1.0 mm inside a reaction tube having a raw material liquid supply part on one end side and a product liquid extraction part on the other end side. Solid base catalyst for biodiesel fuel production comprising calcium oxide having a particle size that passes through a mesh fabric having an opening of 10 mm without passing through the mesh fabric, and the surface of the calcium oxide is modified with calcium diglyceroxide And a mixture obtained by adding 70 to 150 parts by volume of methanol with respect to 100 parts by volume of the raw vegetable oil. Is supplied to the reaction tube.

In addition, the present invention is characterized in that, in the method for producing biodiesel fuel having the above characteristics, the mixed liquid is supplied at a flow rate at which a liquid space velocity with respect to the reaction tube is 40 to 160 h ^−1. It is also what you do.

In the case of the solid base catalyst for biodiesel fuel production according to the present invention, a high-quality biodiesel fuel with a smooth flow of reactants and less residual inorganic content can be efficiently produced without special shape processing. The preparation operation is very simple.
The present invention is based on the inventions described in Patent Document 1 and Japanese Patent Application No. 2007-49729 proposed by the present inventors, but exhibits effects that cannot be achieved by these conventional techniques. That is, in Japanese Patent Application No. 2007-49729, it is pointed out that calcium diglyceroxide, which is a reaction product of calcium oxide and glycerin, is a substantially active species. No catalyst has been obtained, and a practical solid base catalyst could not be prepared by the method described in this specification. A solid base catalyst having excellent resistance to atmospheric contact) is provided. Also, the method of using the practical catalyst (reaction operation conditions) could not be optimized only by the results of the tests using the internal forced stirring type batch reactor so far. A simulated reactor can be used, and mass production of biodiesel fuel becomes possible.

(1) Properties and production method of solid base catalyst of the present invention The solid base catalyst for producing biodiesel fuel of the present invention does not pass through a mesh fabric having an opening of 1.0 mm, but passes through a mesh fabric having an opening of 10 mm. A compound of calcium and glycerin, which is mainly composed of calcium oxide having a particle size (particle size of about 1.0 to about 10 mm) and is formed only on the surface layer by a modification (surface modification) treatment. There is a layer of some calcium diglyceroxide (Ca (C ₃ H ₇ O ₃ ) ₂ ). The crushed limestone used as a raw material is a crushed product obtained by pulverizing the raw stone, and the pulverized product in a certain particle size range is selected by sieving, and is used for the production of cement and steel. Any chemical composition can be used. Further, in the present invention, a commercially available 16 mesh stainless steel mesh can be used as the mesh fabric having an opening of 1.0 mm, and a commercially available 2 mesh stainless mesh can be used as the mesh fabric having an opening of 10 mm. However, the mesh fabric material is not limited to this.

In order to obtain the solid base catalyst of the present invention, the crushed limestone is calcined by the method using an inert gas described in Patent Document 1, whereby the base strength is 15.0 or more and the base amount is 0.1 mmol. It is preferable to convert to calcium oxide of / g or more. That is, by firing at a temperature of 300 ° C. or higher in an air flow substantially free of carbon dioxide and moisture, the base strength (maximum base strength) of the limestone after firing is the discoloration strength of 2,4-dinitroaniline. PKa of 15.0 or higher, and the basic strength of calcium oxide obtained by firing in a general atmosphere containing carbon dioxide and water (a little over pKa 9.3 corresponding to the discoloration strength of phenolphthalein) Of the base strength). The base amount of limestone after firing (base amount per unit weight) is 0.1 mmol / g or more, and this value is also the base amount of calcium oxide (about 0.03 mmol) obtained by firing in the air. / G). However, as long as carbonation and hydration of the surface are prevented to some extent, firing in the air may be performed. For example, calcium oxide suitable for the solid base catalyst of the present invention can also be obtained by circulating an inert gas from a temperature range where carbonation (hydration) is likely to occur in the cooling process after firing. The apparatus for firing is not particularly limited, but a fluidized bed firing furnace is suitable considering the particle size. Moreover, when transporting from the baking apparatus to the immersion of the organic solvent in the next step, it is necessary to devise operations such as an operation as quickly as possible so that the surface of calcium oxide is not contaminated with carbon dioxide gas or moisture.

With regard to calcium hydroxide, which is a hydrated product, alcohol is adsorbed between the particle layers and is converted to calcium glyceride by the action of substitution of —OH groups and —OR groups. When most of the surface is calcium hydroxide, the treatment efficiency of the dipping operation is deteriorated. The carbonated surface is removed by peeling when the hydrated surface and glycerin generated at the same time react. However, when most of the particle surface is carbonated, calcium glyceroxide is not generated.

In the organic solvent immersion step, it is desirable to prepare a dilute glycerin solution using a reagent grade solute (glycerin) and a solvent (propanol or ethanol). If a low-grade material with a high water content is used, the surface of the catalyst to be hydrated increases, and there are concerns about various problems such as a reduction in processing efficiency. The solvent is preferably isopropanol in consideration of the reactivity with the catalyst and the solubility of glycerin. When methanol, which is a C ₁ alcohol, is used, calcium methoxide (Ca (OCH ₃ ) ₂ ) is generated on the surface, but deterioration due to atmospheric contact is significant. Furthermore, since the production rate of calcium methoxide is high, the original shape tends to collapse and become powdery. As long as the organic solvent used for the immersion has a chemical composition in which the solvent C ₂ or C ₃ alcohol is 65 parts by volume or more and the solute glycerin concentration is 15 parts by volume or less, acetone, methanol, hexane, etc. These organic solvents may be mixed. In the present invention, it is desirable to immerse 10 to 50 parts by volume of the calcined limestone with respect to 100 parts by volume of the organic solvent.
The reaction vessel for modifying the surface of calcium oxide has a sealed structure in order to avoid solvent volatilization and moisture absorption. When the liquid phase is heated, it is preferable to equip a cooling pipe for condensing and recovering the volatile solvent. The temperature at the time of immersion shall be 20-60 degreeC. If it exceeds 60 ° C., the reaction between calcium oxide and glycerin proceeds rapidly, making it difficult to maintain a shape suitable for practical use. The immersion time should be 10 to 60 minutes in the same way. In the present invention, only the particle surface can be converted to calcium diglyceroxide under the above-mentioned mild operating conditions, and practical shape collapse (pulverization) due to rapid reaction with glycerin can be easily prevented. can do.

The solid base catalyst for producing biodiesel fuel of the present invention thus obtained has greatly improved atmospheric contact resistance, which was a drawback of the solid base catalyst, and is easy to handle for storage / transport. Moreover, this solid base catalyst has a practical shape that achieves both smooth flow and good contact of a mixed liquid that is a raw material for biodiesel fuel.

The most important point regarding the solid base catalyst of the present invention is that a baked crushed limestone is immersed in an organic solvent to form a chemical core / shell structure. Specifically, the catalyst surface is converted to calcium diglyceroxide, and the inside remains calcium oxide. Calcium diglyceroxide is a substantially active species for the transesterification reaction of vegetable oil and methanol that produces biodiesel fuel, and is characterized by low elution of calcium to the reaction field. In addition, calcium diglyceroxide is found to have very good atmospheric contact resistance, and if the catalyst surface is converted to calcium diglyceroxide in advance, storage and handling operations can be performed rather than using the surface as calcium oxide. It becomes extremely easy. For example, Patent Document 1 proposes a method of storing and storing calcium oxide used as a catalyst in a reaction vessel sealed in an inert atmosphere, but according to the present invention, it is transported in a simple bag state and biodiesel. It can be accommodated in the reaction vessel without worrying about contact between the catalyst and the atmosphere at the fuel production site. In addition, by coating with calcium alkoxide in advance, fine lime particles adhering to the crushed limestone of the catalyst raw material can be removed, so that troubles such as blockage in the reaction operation, pump damage, or contamination of generated oil can be solved. When the particle size of the crushed limestone exceeds 10 mm, the contact between the catalyst and the reaction fluid is deteriorated, the deterioration of the unit processing capacity due to the decrease in the reaction efficiency is remarkable, and when it is less than 1 mm, the blockage of the stream is a problem. It becomes.

When forming a chemical core-shell structure in the catalyst of the present invention, it is most important to prevent calcium oxide and glycerin from reacting rapidly. Calcium diglyceroxide is obtained as solid particles by precipitation of a reaction product of calcium oxide and glycerin in a liquid phase reaction field. For this reason, when the baked crushed limestone reacts rapidly, it cannot maintain a practical shape that achieves both smooth flow and good contact of the reactants, and most of it will be pulverized. The operation must be carried out. Further, the solvent to dilute the glycerol to react with the calcium oxide, it is necessary to use a C ₂ or C ₃ alcohol. At this time, if C ₁ alcohol (methanol) is used, the catalyst surface is covered with calcium methoxide having no atmospheric contact resistance. C ₄ glycerin less soluble in alcohol, not withstand use herein dipping operation. Here, it is desirable to control the chemical composition of the immersed organic solvent. If the solute glycerin is 15 parts by volume or less and the solvent C ₂ or C ₃ alcohol is 65 parts by volume or more, the effect of preventing a rapid reaction is high in combination with mild operation conditions. The input amount of the baked crushed limestone is preferably 10 to 50 parts by volume with respect to 100 parts by volume of the immersed organic solvent from the viewpoint of processing efficiency.

(2) Production of reaction tube (catalyst containing column) for producing biodiesel fuel The reaction tube in the apparatus of the present invention for producing biodiesel fuel is a substantially tubular reaction tube (including a container-like one). The raw material liquid supply part has one end side and the product take-out part on the other end side, and the mesh tube having an opening of 10 mm passes through the reaction tube without passing the mesh cloth having an opening of 1.0 mm. And a solid base catalyst for producing biodiesel fuel in which the surface of the calcium oxide is modified with calcium diglyceroxide. In the present invention, the solid base catalyst is preferably contained in the reaction tube in a state where it is mixed with at least two types of dispersion media having different particle sizes. In this case, three types of dispersion media having different particle sizes are used. It may be used, and the material is not limited.
When producing a reaction tube for producing biodiesel fuel having such a structure, the solid base catalyst produced after the above-mentioned immersion operation is added to at least two types of dispersion media having different particle sizes, mixed well, and reacted. House in a tube. In this case, care must be taken not only to disperse the catalyst but also to prevent the applied mechanical stress from causing the catalyst to collapse. The mixture of the catalyst and the dispersion medium can be accommodated in the reaction tube while being wetted with a diluted glycerin solution without being dried. However, if possible, the mixture should be washed several times with propanol or ethanol before starting the biodiesel fuel production reaction. This is because there is a concern that residual glycerin may reduce the equilibrium reaction rate during biodiesel production. The method for accommodating in the reaction tube is not particularly limited.

As a dispersion medium accommodated together with the solid base catalyst of the present invention, coconut shell activated carbon is desirable. However, any material that has equivalent mechanical strength and does not react with alcohol at 60 ° C. can be used as a dispersion medium in place of coconut shell activated carbon. Further, regarding the mixing ratio, 10 to 50 parts by volume of the large-diameter dispersion medium (1 to 4 times the maximum particle diameter of the catalyst) and 10 to 50 parts by volume of the small-diameter dispersion medium (minimum catalyst) with respect to 10 parts by volume of the aforementioned solid base catalyst. It is preferable to mix 10 to 50 parts by volume of 1 to 0.25 times the particle diameter. In the present invention, in order to obtain a catalyst within a predetermined particle size range, selection is performed using mesh fabrics having different numbers of meshes. The above catalyst maximum particle size is used to set the upper limit of the particle size range. This corresponds to the mesh size of the mesh fabric with the smaller mesh number (larger mesh size) used, and the above catalyst minimum particle size is used to set the lower limit of the particle size range. This corresponds to the mesh size of the mesh fabric with the larger number of meshes used (the smaller mesh size), and the particle diameters of the large-diameter dispersion medium and small-diameter dispersion medium are also used for measuring the particle diameter of the dispersion medium. It is determined from the opening size of each mesh fabric.
The reaction tube for producing biodiesel fuel according to the present invention having such a structure prevents the catalyst particles from agglomerating, maintains a good contact with the reactants and a good fluid state, thereby achieving a high reaction efficiency. Demonstrate the exceptional effect of realizing good operability.

(3) Production method of biodiesel fuel of the present invention The biodiesel fuel production method of the present invention uses 70 to 70 parts of methanol for 100 parts by volume of raw material vegetable oil using the reaction tube containing the solid base catalyst. The mixed liquid obtained by adding 150 parts by volume is supplied to the reaction tube, and when the reaction proceeds to some extent by adding 70 parts by volume or more of methanol to 100 parts by volume of the raw vegetable oil, the liquid phase becomes uniform. It changes from a cloudy state to a translucent state. Thereby, the diffusion resistance of the reactant is greatly relaxed and the reaction efficiency is improved. In addition, this phenomenon also has the advantage that the completion of the reaction can be easily determined, and an expensive analyzer is not required. On the other hand, if the amount of methanol exceeds 150 parts by volume with respect to 100 parts by volume of the raw vegetable oil, a large production apparatus that does not meet the processing capacity is obtained.

When producing biodiesel fuel using the above-mentioned solid base catalyst, it is important to control the reaction of glycerol and the catalyst by-produced by the biodiesel fuel production reaction. It is inevitable that calcium oxide inside the catalyst particles reacts with by-product glycerin. Although it does not lead to an abrupt reaction in which the shape collapses as in the preparation of the catalyst, since the catalyst is accommodated in the reaction tube, a bridge that causes bonding and aggregation between particles is formed by precipitation of calcium diglyceroxide. The This not only reduces the reaction efficiency due to a decrease in the contact surface of the catalyst, but also prevents a smooth fluid flow in the reaction tube, which in turn leads to a blockage that stops the reaction operation. One way to solve such problems is to mix the catalyst with appropriate solid particles and disperse the catalyst in the reaction tube. Substances that can be used as a dispersion medium are inert to heated alcohol, and activated carbon is suitable as a practical material. In particular, those manufactured from coconut shells are light and excellent in strength, and are preferred dispersion media. Sintered alumina or zeolite can also be used. What should be noted regarding the use of the dispersion medium is the selection of the particle size. Larger ones cannot disperse the solid base catalyst well. If smaller ones, the pressure loss during feeding increases and the operability deteriorates. Therefore, in the present invention, two types of dispersion media having the above-mentioned particle diameters, that is, 1 to 4 times the maximum catalyst particle diameter for the large dispersion medium, and 1 to 0 for the catalyst minimum particle diameter for the small dispersion medium. It is preferable to use a combination of 25 times.

In order to solve the problem of the catalyst particles being bound and aggregated, it is also necessary to appropriately set the operating conditions for the biodiesel fuel generation reaction. First, the amount of methanol added to the vegetable oil is 70 parts by volume or more with respect to 100 parts by volume of the vegetable oil. This is an effect of reducing the concentration of by-product glycerin in the reaction field liquid phase. In this operation, the contact between the vegetable oil and methanol that do not mix with each other is improved, which is advantageous for improving the reaction efficiency. Furthermore, when the production rate of biodiesel fuel exceeds 80%, the emulsion liquid phase is uniform and clear. It becomes possible to judge the completion of the reaction visually. Usually, since an expensive analyzer (gas chromatograph or high-performance liquid chromatograph) is required, it derives to the advantage that the operation management of the manufacturing apparatus becomes extremely easy. In addition, when the methanol to add exceeds 150 volume parts, the deterioration of processing efficiency will become a new problem.

Another effective operation is to set the flow rate of the raw material fluid in which vegetable oil and methanol are mixed so that the liquid space velocity is 40 to 160 h ⁻¹ with respect to the capacity of the reaction vessel (catalyst layer). . Below 40 h ⁻¹ , the residence time of the raw material fluid is long, and the reaction product of calcium oxide and by-product glycerin tends to precipitate. On the other hand, if it exceeds 160 h ⁻¹ , the solid base catalyst tends to physically collapse, and there is a concern about problems such as clogging of piping due to the powdered catalyst. In addition, if a 1-through flow continuous reaction system is designed under these operating conditions, the capacity of the reaction vessel becomes enormous and the equipment cost deteriorates. For this reason, in the present invention, it is preferable to adopt a batch reaction system of circulating flow.
By adopting the above operating conditions, it is possible to prevent precipitation of a reaction product of calcium and glycerin causing aggregation of catalyst particles, and it is possible to maintain excellent catalyst performance for a long period of time.

(4) Example of production of biodiesel fuel by batch system of circulating flow The biodiesel fuel production reaction is carried out using the reaction vessel containing the above-mentioned mixture of the solid base catalyst and the dispersion medium. The raw material vegetable oil is not particularly limited, and not only edible oil but also non-edible oil derived from jatropha and used edible oil can be used. However, it is desirable to carry out pretreatment according to the properties. For example, a filtration operation is required for a raw material containing a solid material, and a drying operation is required for a raw material with a lot of moisture. Moreover, about the raw material containing many free fatty acids, the alkyl esterification process of the free fatty acid using an ion exchange resin is desirable according to description of Unexamined-Japanese-Patent No. 2008-1856. Methanol is preferred as the secondary material alcohol in terms of cost and reactivity. As for the reaction method when using a solid base catalyst, a one-through flow distribution method is used when mass production is aimed at, but a circulation flow batch method is suitable when aiming at a “local production for local consumption” type business. However, in the present invention, since the flow rate of the raw material fluid obtained by mixing vegetable oil and methanol is 40 to 160 h ⁻¹ with respect to the reaction vessel, the capacity of the reaction vessel is enormous compared to the throughput in the distribution method. This is disadvantageous in terms of equipment costs. Therefore, the present invention is preferably applied to a circulation flow batch system.

Next, a biodiesel fuel production reaction experimental apparatus simulating an actual machine suitable for carrying out the present invention will be described. FIG. 1 is a diagram showing an example of a configuration of a biodiesel fuel generation reaction experimental apparatus simulating an actual machine suitable for carrying out the present invention.
In the circulating flow batch method, as shown in FIG. 1, the reaction process includes a raw material liquid supply tank (raw material input tank), a liquid feed pump (raw material circulation pump), and a reaction tube (reactor) containing a catalyst and a dispersion medium. Equipment connected by piping is used for the reaction process. In the apparatus of FIG. 1, a cooling pipe is attached to the raw material charging tank, and a heater for controlling the reaction temperature is attached to each of the raw material charging tank and the reaction pipe.
In order to produce biodiesel fuel, a predetermined vegetable oil and the specified volume of methanol are charged into and mixed with a raw material charging tank, and supplied to the reactor at a predetermined flow rate. By continuing such a raw material fluid circulation operation at a temperature of 60 ° C. for 2 hours, the production rate of biodiesel fuel exceeds 96.5%. This production rate satisfies the European standard (EN14214) for biodiesel fuel and can be used for high-performance diesel engines for automobiles. According to the present invention, when the reaction is almost completed, the liquid phase changes from an emulsion state to a clear uniform state, so that the end of the reaction operation can be easily determined visually.

In the subsequent purification step, residual methanol and by-product glycerin will be removed. These operations can be sufficiently handled by current technology. For the removal of methanol, an evaporation method of heating under reduced pressure is preferred. For removal of glycerin, a stationary separation method using the property of not dissolving with biodiesel fuel is easy. About these orders, it can determine suitably considering the operativity of an installation. A trace amount of catalyst component (50 to 200 ppm-calcium) is dispersed in the biodiesel fuel obtained after removing methanol and glycerin. Since quality standards in countries around the world indicate that the calcium content in biodiesel fuel should be reduced to 5 ppm or less, the dispersed catalyst components must be removed. For this method, an adsorption operation using an appropriate porous solid material is efficient. For the porous solid material used for the adsorbent, an acidic ion exchange resin described in “Japanese Patent Application No. 2007-238277” by the present inventor is suitable. For example, if biodiesel fuel is circulated at a liquid space velocity of about 0.5 h ⁻¹ through an adsorption container containing an acidic ion exchange resin having a proton type sulfone group, a trace amount of catalyst components can be completely removed. it can.
Through the above operations, biodiesel fuel can be obtained without generating alkaline wastewater, and environmentally conscious production can be realized.

1. Effect of Catalyst Chemical Composition Control <Catalyst A-1> Powdered limestone (surface area 10 m ^{2 /} g) 0.78 g was heated at 900 ° C. for 2 hours under high purity helium gas flow. While maintaining this inert atmosphere, it was cooled to room temperature and immediately subjected to a biodiesel fuel production reaction test.
<Catalyst A-2> The catalyst A-1 was left in the atmosphere for 3 minutes and then subjected to a biodiesel fuel production reaction test.
<Catalyst A-3> The catalyst A-1 was left in the atmosphere for 30 minutes and then subjected to a biodiesel fuel production reaction test.
<Catalyst A-4> The catalyst A-1 was immersed in 150 ml of an ethanol solution of glycerin (glycerin concentration: 50% by volume), and the reflux state of ethanol was maintained by heating for 2 hours. Thereafter, it was subjected to a biodiesel fuel production reaction test after filtration and drying under reduced pressure. The catalyst after immersion was calcium diglyceroxide based on powder X-ray diffraction.
<Catalyst A-5> The catalyst A-4 was left in the atmosphere for 30 minutes and then subjected to a biodiesel fuel production reaction test.

In the biodiesel fuel production reaction experiment conducted to evaluate the above five types of catalysts, a glass container having an internal volume of 500 ml was used for the reactor. To this reactor, 100 ml of edible soybean oil (acid value 0.1 mg-KOH / g or less, moisture 0.1% or less) and 50 ml of reagent-grade methanol were added together with a catalyst, and stirring was started at 500 rpm after sealing. Thereafter, the methanol reflux state was maintained for 1 hour by heating. The reaction product was separated into a light liquid composed of diesel fuel components and a heavy liquid composed of glycerin due to the difference in specific gravity in the stationary tank. The result of analyzing the separated light liquid with a gas chromatograph is shown in FIG.
As shown in FIG. 2, the surface of the active surface of calcium oxide started to stand after being left in the atmosphere for 3 minutes, and the catalytic activity was remarkably lowered after being left for 30 minutes. Calcium diglyceroxide, on the other hand, had no significant decrease in catalytic activity even after standing for 30 minutes, and was extremely excellent in resistance to atmospheric contact.

2. Control Method of Catalytic Chemical Composition <Catalyst B-1> After calcination at 900 ° C. for 2 hours while circulating high-purity helium gas to 20 ml of crushed limestone having a particle size of 1 to 2 mm, 100 ml of glycerin in methanol (glycerin immediately) The sample was immersed and stirred in a concentration of 50% by volume, and the temperature of 50 ° C. was maintained for 20 minutes by heating.
<Catalyst B-2> After calcination in the same manner as Catalyst B-1 for 20 ml of crushed limestone having a particle size of 1 to 2 mm, it was immediately immersed and stirred in 100 ml of an isopropanol solution of glycerin (glycerin concentration 10% by volume). The temperature of 50 ° C. was maintained for 20 minutes by heating.

  After the dipping operation, the catalyst B-1 did not maintain its original shape, and all was powdery. As a result of powder X-ray diffraction, the chemical species was calcium diglyceroxide. On the other hand, the catalyst B-2 retained its original shape. When chemical species were identified by powder X-ray diffraction, calcium oxide was the main component, but a weak diffraction line of calcium diglyceroxide was also observed, suggesting that only the vicinity of the surface of the crushed particles had reacted with glycerin. It was. From this result, by using a dilute glycerol isopropanol solution in the liquid phase, the rate at which calcium oxide and glycerin react can be controlled, and the chemical core-shell structure catalyst according to claim 1 can be obtained. all right.

3. Effect of mixing of dispersion medium <Catalyst C-1> After calcination at 900 ° C. for 2 hours while circulating high-purity helium gas to 20 ml of crushed limestone having a particle diameter of 1 to 2 mm, immediately 100 ml of glycerol in isopropanol (glycerin concentration 10 volume%) was immersed and stirred, and the temperature of 50 ° C. was maintained for 20 minutes by heating. Then, it accommodated in the stainless steel reaction tube (internal volume 125 ml), and the biodiesel fuel production | generation reaction test which simulated the real machine was done.
<Catalyst C-2> A solid catalyst obtained by the same operation as Catalyst C-1 was mixed with 100 ml of coconut shell activated carbon having a particle diameter of 0.5 mm and accommodated in a stainless steel reaction tube. Using this reaction tube, a biodiesel fuel generation reaction test simulating an actual machine was conducted.
<Catalyst C-3> A solid catalyst obtained by the same operation as that of the catalyst C-1 was mixed with 100 ml of coconut shell activated carbon having a particle diameter of 3 mm and accommodated in a stainless steel reaction tube. Using this reaction tube, a biodiesel fuel generation reaction test simulating an actual machine was conducted.
<Catalyst C-4> A solid catalyst obtained by the same operation as that of Catalyst C-1 was mixed with 50 ml of coconut shell activated carbon having a particle diameter of 3 mm and 0.5 mm, respectively, and accommodated in a stainless steel reaction tube. Using this reaction tube, a biodiesel fuel generation reaction test simulating an actual machine was conducted.
<Catalyst C-5> After calcination at 900 ° C. for 2 hours while circulating high-purity helium gas over 20 ml of crushed limestone having a particle size of 1 to 2 mm, the same as C-4 while maintaining this inert gas atmosphere In operation, coconut shell activated carbon was mixed and accommodated in a stainless steel reaction tube. Using this reaction tube, a biodiesel fuel generation reaction test simulating an actual machine was conducted.

In a biodiesel fuel production reaction test simulating an actual machine, an apparatus in which the above stainless steel reaction tube, a glass container having an internal volume of 500 ml, and a tubing pump were connected by a fluororubber tube having an inner diameter of 6.1 mm was used. The glass container is equipped with two supply and drainage nozzles for use as a raw material circulation tank, and the raw material fluid sent to the reaction tube by the tubing pump returns to the glass container again. Form. 270 ml of edible rapeseed oil and 200 ml of reagent grade methanol were used as raw materials, and these mixed fluids were circulated in the reaction system at 100 ml / min. At this time, the liquid space velocity is 50h- ¹ . The product was collected after maintaining the reaction temperature of 60 ° C. for 2 hours, and the production rate of biodiesel fuel was determined by gas chromatographic analysis.

As shown in Table 1 below, the results were evaluated not only with biodiesel fuel production rate (reaction rate) but also with operability.
Among the catalysts used in the experiment, C-1 had the lowest reaction rate, and when the reaction time was extended, liquid feeding with a tubing pump became impossible. After the experiment, when the reaction tube was opened, the crushed particles of the catalyst were strongly agglomerated, and it was difficult to extract out of the reaction tube. As for C-2, liquid feeding was impossible from the beginning of the experiment. When the flow rate was reduced to 1/10, liquid feeding became possible, but before the reaction time reached 2 hours, liquid feeding again became impossible. After the experiment, when the reaction tube was opened, the same strong aggregation of catalyst particles as in the case of catalyst C-1 was observed. This is because the circulation flow rate of the raw material fluid was too small and the reaction between the catalyst and the by-product glycerin and the precipitation of the product were promoted. When C-3 was used, the liquid could be delivered smoothly, but the reaction rate was slightly low, and it took 3 hours or more to complete the reaction. After that, repeated experiments were attempted, but no liquid could be delivered from the beginning. Although the catalyst particles in the reaction tube were not as large as C-1 and C-2, agglomeration was observed, suggesting that mixing was insufficient before storing in the reaction tube. In C-4, there was no problem in operability and reaction rate, and it was possible to repeat a highly efficient operation in which the reaction was completed in 2 hours. When C-5 whose particle surface remained calcium oxide was used, the liquid could not be fed before the reaction time reached 2 hours, and a large amount of white powder was mixed in the product. The reaction rates shown in the table are those at the time when liquid feeding becomes impossible (about 1.5 hours). Moreover, when the reaction tube was opened, not only the catalyst aggregation but also the outlet filter was clogged.

  From the above, if the vicinity of the surface of the calcined crushed limestone is chemically covered with calcium diglyceroxide and mixed with two kinds of large and small dispersion media, biodiesel fuel can be produced with high efficiency by easy operation. I understand that I can do it. It was also found that modifying the surface of the crushed limestone with calcium diglyceroxide is also effective in solving the operational problems of the reactor.

4). Effect of catalyst particle size <Catalyst D-1> After calcination at 900 ° C. for 2 hours while circulating high-purity helium gas over 20 ml of crushed limestone having a particle size of 1 to 2 mm, immediately 100 ml of glycerol in isopropanol (glycerol concentration) 10 volume%) was immersed and stirred, and the temperature of 50 ° C. was maintained for 20 minutes by heating. Thereafter, 50 ml each of coconut shell activated carbon having a particle diameter of 3 mm and 0.5 mm was mixed and accommodated in a stainless steel reaction tube. Using this reaction tube, a biodiesel fuel generation reaction test simulating an actual machine was conducted.
<Catalyst D-2> A solid catalyst was obtained in the same manner as D-1 with respect to 20 ml of crushed limestone having a particle diameter of 2 to 3 mm. Thereafter, 50 ml each of coconut shell activated carbon having a particle diameter of 3 mm and 0.5 mm was mixed and accommodated in a stainless steel reaction tube. Using this reaction tube, a biodiesel fuel generation reaction test simulating an actual machine was conducted.
FIG. 3 shows the results of a biodiesel fuel production reaction test, and it can be seen that a catalyst having a large particle size causes a reduction in reaction efficiency. If the amount is reduced to this extent, it is considered that the capacity of the reaction vessel does not become enormous even if the amount of the catalyst used is increased, and it can withstand practical use.

5. Influence of reaction operation conditions After calcination at 900 ° C. for 2 hours while circulating high-purity helium gas to 20 ml of crushed limestone having a particle size of 1 to 2 mm, immediately into 100 ml of glycerin isopropanol solution (glycerin concentration 10% by volume). It was immersed and stirred, and the temperature of 50 ° C. was maintained for 20 minutes by heating. Thereafter, 50 ml each of coconut shell activated carbon having a particle diameter of 3 mm and 0.5 mm was mixed and accommodated in a stainless steel reaction tube. Using this reaction tube, a biodiesel fuel generation reaction test simulating an actual machine was conducted.
<Operating condition 1> 270 ml of edible rapeseed oil and 200 ml of reagent grade methanol were mixed, and the circulation flow rate was 100 ml / min.
<Operating condition 2> 320 ml of edible rapeseed oil and 160 ml of reagent grade methanol were mixed, and the circulation flow rate was 100 ml / min.
<Operating condition 3> 270 ml of edible rapeseed oil and 200 ml of reagent grade methanol were mixed, and the circulation flow rate was 50 ml / min.
The results of the above experiment are shown in FIG. LHSV indicates liquid space velocity.

From the experimental results shown in FIG. 4, there was no problem in reaction efficiency and operability under the operating condition 1, but the reaction efficiency was low in the operating condition 2, and when the experiment was repeated, liquid feeding became impossible from the beginning. When the reaction tube was opened, some catalyst agglomeration was observed. When the extracted catalyst and the dispersion medium were mixed and accommodated again, the experiment could be repeated, but the reaction efficiency gradually decreased. Although the highly efficient reaction operation could be repeated even under the operating condition 3, the reaction efficiency gradually decreased when the number of repetitions exceeded 10, and the 17th experiment required twice the initial time to complete the reaction. did.
From the above, it can be seen that highly efficient reaction operation can be repeatedly performed for a long period of time by increasing the amount of methanol added and the circulation flow rate.

It is a figure which shows an example of a structure of the biodiesel fuel manufacturing apparatus imitating the actual machine suitable for implementing this invention. It is a graph which shows the influence which the catalyst chemical composition obtained from the experiment using five types of catalysts (catalyst A-1 to A-5) described in an Example exerts on atmospheric contact tolerance. It is a graph which shows the influence which the catalyst particle diameter obtained from the experiment using the catalyst of the catalyst D-1 and D-2 described in an Example has on reaction efficiency. It is a graph which shows the influence which the operating conditions 1-3 described in an Example exert on reaction efficiency.

Claims (7)

A solid catalyst used in the production of biodiesel fuel, the catalyst having a particle size that passes through a mesh fabric with an opening of 10 mm without passing through the mesh fabric with an opening of 1.0 mm A solid base catalyst for producing biodiesel fuel, characterized in that it is made of calcium, and the surface of the calcium oxide is modified with calcium diglyceroxide. A method for producing a solid base catalyst useful for producing biodiesel fuel, the method comprising:
Screening the crushed limestone having a particle size that passes through a mesh fabric having an opening of 10 mm without passing through the mesh fabric having an opening of 1.0 mm;
After calcining the crushed limestone obtained in the above step, the obtained calcined product is immediately immersed in a glycerin C ₂ or C ₃ alcohol solution at a temperature of 20 to 60 ° C. for 10 to 60 minutes. And a step of modifying the surface of the product with calcium diglyceroxide. An apparatus for producing biodiesel fuel, the apparatus comprising:
A raw material liquid supply tank for storing and supplying the raw material liquid;
A reaction tube containing a solid base catalyst for producing biodiesel fuel,
A feed pump for supplying the raw material liquid from the raw material liquid supply tank to the reaction tube and circulating the reaction liquid after passing through the reaction tube to the raw material liquid supply tank;
A raw material liquid supply unit is provided at one end of the reaction tube, and a product take-out unit is provided at the other end. The solid base catalyst accommodated in the reaction tube has an opening of 1.0 mm. It consists of calcium oxide having a particle size that passes through a mesh fabric having an opening of 10 mm without passing through the mesh fabric, and the surface of the calcium oxide is modified with calcium diglyceroxide. A device for producing biodiesel fuel. The biodiesel fuel according to claim 3, wherein the solid base catalyst for producing the biodiesel fuel is contained in the reaction tube in a state of being mixed with at least two kinds of dispersion media having different particle diameters. Manufacturing equipment. 10 to 50 parts by volume of a dispersion medium having a size of 1 to 4 times the maximum particle diameter of the solid base catalyst with respect to 10 parts by volume of the solid base catalyst for biodiesel fuel production, The biodiesel fuel production apparatus according to claim 4, wherein 10 to 50 parts by volume of a dispersion medium having a size of 1 to 0.25 times the minimum particle diameter is mixed. A method for producing biodiesel fuel, wherein in the production method, an opening 1 is provided inside a reaction tube having a raw material liquid supply part at one end and a product liquid take-out part at the other end. Solid for producing biodiesel fuel composed of calcium oxide having a particle size that passes through a mesh fabric having an opening of 10 mm without passing through a 0 mm mesh fabric, and the surface of the calcium oxide is modified with calcium diglyceroxide Obtained by mixing a base catalyst and at least two types of dispersion media having different particle sizes in a mixed state, and adding 70 to 150 parts by volume of methanol to 100 parts by volume of the raw vegetable oil A method for producing biodiesel fuel, characterized in that a mixed liquid is supplied to the reaction tube. The method for producing biodiesel fuel according to claim 6, wherein the mixed liquid is supplied at a flow rate at which a liquid space velocity with respect to the reaction tube is 40 to 160 h ⁻¹ .