JPH10245586A - Production of diesel fuel oil from used edible oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vegetable diesel fuel oil by separating a reaction product obtained by reacting a used edible oil from which a solid substance, water and an odorant have been removed with a catalyst-containing alcoholic solution into a light liquid and a heavy liquid and removing the impurities such as a residual catalyst, odorants, colored substances and water from the light liquid by adsorption by an solid adsorbent. SOLUTION: A catalyst containing at least one alkali substance selected among KOH, K2 CO3 and potassium alcoholate is dissolved in an alcohol to obtain a catalyst-containing alcoholic solution. Used edible oils produced from restaurants, food plants, etc., are filtered to removed solid substances and heated to remove water and odorants therefrom. Such a used edible oil is mixed with the alcoholic solution under agitation to obtain a reaction product of the used edible oil with the alcohol. The reaction product is separated into a light liquid and a heavy liquid. The light liquid is mixed with a solid adsorbent to remove impurities such as a residual catalyst, odorants, colored substances and water, and the mixture is separated into the light liquid and the solid adsorbent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cetane index of 45 to 70 from waste cooking oil such as rapeseed oil, sesame oil, soybean oil, corn oil, sunflower oil, palm oil, palm kernel oil, coconut oil, corn oil and safflower oil. , kinematic viscosity at flash point 80 ° C. to 210 ° C. and 30 ℃ 2.0mm ₂ /s~10.0mm ₂ / s
The present invention relates to a method for producing diesel fuel oil from waste cooking oil, which obtains a so-called vegetable diesel fuel oil having the following properties.

[0002]

2. Description of the Related Art At present, Japan uses edible oils such as about 700,000 tons of soybean oil, 80,000 tons of coconut oil, 50,000 tons of cottonseed oil, and 700,000 tons of rapeseed oil. Ninety percent of the used cooking oil is discarded as garbage without being recovered. A part of the discarded waste cooking oil is mixed with other waste and transported to the landfill, where it is incinerated with combustible waste, and a part of the waste cooking oil is mixed with non-combustible waste. Has been landfilled. On the other hand, the remaining 10% of waste cooking oil is reused as a raw material for soap and the like.
Soap production techniques by continuous boiling method, continuous saponification method and other continuous methods have been established, and these soap production techniques basically consist of each step of saponification, salting out, washing and finish cooking. I have.

It has been known for a long time to obtain fatty acid alkyl esters by subjecting monoglyceride, diglyceride and triglyceride, which are the main components of vegetable oil, to a transesterification reaction with an alkyl alcohol (Handbook of Organic Chemistry, Gihodo Publishing, 1988). , P.
1407-1409). Some proposals have conventionally been made on a technique for producing diesel fuel oil from vegetable oil or waste cooking oil using this reaction. For example, Japanese Unexamined Patent Publication (Kokai) No. 7-97047 discloses waste cooking oil 10
For 0 parts, 15 to 25 parts of methyl alcohol and 1 to 2 parts of caustic soda were heated to a reaction temperature of 45 ° C to 65 ° C,
A method is disclosed in which a reaction product is obtained, and then the diesel fuel oil is finally obtained through respective steps of separation by standing, washing with warm water, and dehydration and drying with a desiccant.

Japanese Patent Application Laid-Open No. Hei 7-310090 discloses that a fat raw material contains 15% by weight with respect to 100% by weight of a fat or oil.
0.2% to 1.5% by weight of alkali is added to 100% by weight of the above methyl alcohol and fats and oils,
A first step of stirring at a temperature of 0 ° C. to 64 ° C., a second step of removing the formed precipitate after standing the product obtained in the first step or by centrifugation, and a second step of A third step of heating the supernatant obtained in the above to a temperature higher than the boiling point of methyl alcohol to evaporate and remove methanol,
Water is added to the product obtained in the third step.
After neutralization by adding an acid while heating to 90 ° C., the phase is separated into an oil phase and an aqueous phase, and a fourth step of separating and removing an aqueous phase of the two phase-separated phases, A fifth step of adding water to the obtained oil phase and washing with water at a temperature of 70 ° C to 90 ° C, and then separating and removing the aqueous phase, and adding the oil phase obtained in the fifth step to a temperature of 100 ° C A manufacturing method comprising adding a clay while heating to 140 ° C., stirring, and then filtering to obtain a purified fatty acid methyl ester is disclosed.

[0005]

However, except that a small amount of waste cooking oil is reused as a raw material for soap, most of the waste cooking oil is discarded without being used from the viewpoint of resource saving. It is irrational from the point of view. Moreover, when the discarded waste cooking oil is incinerated together with combustible waste, SOx, NOx, CO ₂ , CO, suspended particulate matter, etc., which are air pollutants, are generated in large quantities, and highly toxic dioxin is also generated. It has been reported that this would occur. On the other hand, if the discarded waste cooking oil is landfilled together with non-combustible waste, it will cause soil contamination. In addition, some of the waste cooking oil discarded from restaurants, food factories, and general households is directly drained to rivers and lakes via sewers, which is one of the major causes of water quality deterioration. .

[0006] In recent years, social interest in global environmental issues has increased, and new philosophy and various policy measures for environmental conservation have been shown. In November 1993, the Ori Declaration was adopted at the International Environmental Development Council, A guideline has been issued to break away from a mass consumption society, with the aim of building a society that develops sustainably by minimizing the environmental impact of activities. In response, the Government of Japan decided on a basic plan for environmental administration in December 1994 by the Cabinet. In order to promote this plan, as a concrete action plan for environmental conservation that should be incorporated in the next five years, (1) ) 25% reduction of waste, (2) 30% reduction of combustible waste in waste,
(3) Targets such as a 10% reduction in fuel consumption of energy supply facilities were set. In addition, as means for achieving these target values, recycling of plastic, containers and packaging waste, and life cycle assessment have been adopted, and research and development have been promoted. For example, plastic liquefaction technology, CO ₂ fixation technology, automobile lubricating oil regeneration technology, exhaust gas removal NOx technology, and the like have already been developed. However, as for waste cooking oil, only a small part is used as a raw material for soap, and most of the waste cooking oil is discharged to the global environment without being used.

[0007] Further, as disclosed in Japanese Patent Application Laid-Open Nos. 7- 197047 and 7-310090, attempts have been made to produce diesel fuel oil from waste cooking oil. Has the following problems.

(1) Since pretreatment of waste cooking oil as a raw material is not performed, water and free fatty acids contained in the waste cooking oil reduce the activity of alkali acting as a catalyst for the transesterification reaction, and The conversion of edible oil is low. In addition, a large amount of water will remain in the fatty acid methyl ester used as a product, and waste cooking oil that has undergone high-temperature heating history contains odorous substances generated by thermal decomposition and oxidation of vegetable oils. Odorous substances eventually remain in the product, resulting in poor quality of the product. In addition, waste cooking oil contains a large amount of foreign substances such as garbage, lard, and solids.These foreign substances can cause clogging of pipelines and valves of manufacturing equipment, and can reduce the quality of products. It also leads to bringing. Further, when water is present in the waste cooking oil, fatty acid soap is produced in the chemical reaction formula (where R, R ₁ , R ₂ , and R _{3 are} alkyl groups and M is a metal) shown in Chemical formula ₁ . The side reaction (saponification reaction) easily proceeds, and a part of the produced fatty acid soap remains in the fatty acid methyl ester to be produced, causing turbidity, and it is difficult to separate the fatty acid soap. There is a problem that the quality of the product is reduced.

[0009]

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(2) As a catalyst, sodium hydroxide is used in any of the methods. However, the activity of sodium hydroxide for transesterification is not sufficient, and the conversion of waste cooking oil is increased to 90% or more. In order to
It is necessary to add an excess of methyl alcohol (the stoichiometric alcohol requirement is about 3 moles per mole of vegetable oil) and a catalyst, but these excess added alcohols and catalysts Subsequent steps must be removed from the product, which complicates the process, and the alcohol and catalyst removed from the product cannot be reused, resulting in higher costs. Further, when sodium hydroxide is used as a catalyst, a side reaction (saponification reaction) for producing a fatty acid soap easily proceeds in the chemical reaction formula shown in Chemical Formula 1 above. For this reason, a part of the produced fatty acid soap remains in the product and causes turbidity,
It is difficult to separate the fatty acid soap, and there is a problem that the quality of the product is reduced.

(3) A method for purifying fatty acid methyl esters produced by reacting waste cooking oil with methyl alcohol is to remove sodium hydroxide remaining in the fatty acid methyl esters by washing with warm water or neutralizing with an acid. However, not only is the process complicated, but also in the presence of warm water and sodium hydroxide, the saponification reaction is further accelerated, and it is difficult to completely remove water after washing. (4) A method for treating or reusing glycerin, which is a by-product of the transesterification reaction between waste edible oil and methyl alcohol, has not been established, and glycerin eventually becomes waste, and the problem of environmental pollution still remains. (5) No report has been reported on equipment and industrial methods for mass-producing diesel fuel oil from waste cooking oil, and diesel fuel oil that meets the current JIS standard for light oil is obtained from waste cooking oil. The industrial manufacturing techniques that can be used are not yet established.

The currently established technology for producing soap from waste cooking oil comprises the steps of saponification, salting-out, washing and finish-simmering. It cannot be used for the production of diesel fuel oil. In addition, although the reaction of synthesizing fatty acid alkyl esters from edible oil by alcoholysis reaction has been successful on a laboratory scale, the technology and equipment for industrially producing diesel fuel oil have not yet been developed.

[0013] Diesel fuel oil has been subjected to reforming, desulfurization, denitrification, etc., if necessary, mainly from the products of catalytic cracking or thermal cracking of petroleum gas oil fractions or residual oils. It is manufactured by doing. Therefore, this technology cannot be applied to the production of diesel fuel oil from waste cooking oil.

The present invention has been made in view of the above circumstances, and is based on petroleum-derived waste cooking oil as a raw material, which is discarded from restaurants, food factories, general households and the like and is hardly used. It is possible to obtain vegetable diesel fuel oil that can be used as it is without modification of conventional diesel vehicles that use light oil, and to make effective use of food resources and greatly contribute to global environmental protection. To provide a method for producing diesel fuel oil from waste cooking oil, and, in addition, glycerin, a by-product of the transesterification reaction between waste cooking oil and alcohol, as a fuel for boilers and heat recovery incinerators. It can be reused as a raw material in the case of recovering and manufacturing industrial glycerin through a decomposition / purification process,
An object of the present invention is to provide a method for producing diesel fuel oil from waste cooking oil, which can further contribute to global environmental protection.

[0015]

The invention according to claim 1 is
Restaurants, food factories, from waste cooking oil discarded from general households, a step of removing solid substances contained therein by a filter, and heating the waste cooking oil from which solid substances have been removed to a predetermined temperature, from waste cooking oil A step of evaporating and removing water and odorous substances contained therein, and a catalyst comprising, in an alcohol, at least one or two or more alkaline substances selected from the group consisting of potassium hydroxide, potassium carbonate and potassium alcoholate Is dissolved, and a step of preparing a catalyst-containing alcohol solution in advance, and mixing and stirring the waste edible oil and the catalyst-containing alcohol solution from which solid substances and water and odorous substances have been removed, the waste edible oil and alcohol A step of accelerating a catalytic reaction to obtain a reaction product of waste cooking oil and alcohol; and And a step of mixing the light liquid obtained in this separation step with a solid adsorbent, and adsorbing residual catalyst, odorous substances, coloring substances, moisture and other impurities contained in the light liquid onto the solid adsorbent. And a step of separating and removing the solid adsorbent from the mixture of the light adsorbent and the solid adsorbent adsorbing impurities to obtain diesel fuel oil from waste cooking oil.

According to a second aspect of the present invention, in the manufacturing method according to the first aspect, the heavy liquid obtained in the step of separating the light liquid and the heavy liquid is mixed with a neutralizing agent, and the alkaline liquid contained in the heavy liquid is mixed. The method further includes a step of neutralizing the catalyst made of the substance.

According to a third aspect of the present invention, in the manufacturing method according to the first or second aspect, the above-described series of steps are performed in a semi-continuous manner.

According to a fourth aspect of the present invention, in the method according to any one of the first to third aspects, in the step of removing water and odorous substances from the waste edible oil, the heated waste edible oil is reduced under reduced pressure. It is characterized by being placed in.

According to a fifth aspect of the present invention, there is provided the method according to any one of the first to fourth aspects, wherein the reaction product is separated into a light liquid and a heavy liquid, and the solid is a solid substance having impurities adsorbed thereon. The solid adsorbent is separated from the mixture of the adsorbent and the light liquid by a centrifugal separation method.

According to a sixth aspect of the present invention, there is provided the manufacturing method according to any one of the first to fifth aspects, wherein solid substances and water contained in waste cooking oil discarded from a restaurant, a food factory, a general household, or the like. And removing odorous substances such that the solid substance content is 0.05% or less, the water content is 0.03% or less, and the odorous substance content is 10 ppm or less.

According to a seventh aspect of the present invention, in the method according to any one of the first to sixth aspects, the alcohol is selected from alkyl alcohols having 1 to 10 carbon atoms such as methyl alcohol, ethyl alcohol and isobutyl alcohol. One or more alcohols selected from the group consisting of: a stoichiometric quantity based on the amount of glyceride in waste cooking oil or 10% greater than a stoichiometric quantity of alcohol in waste cooking oil; It is characterized by the following.

According to an eighth aspect of the present invention, in the production method according to any one of the first to seventh aspects, the amount of the catalyst added to the alcohol is 0.3% by weight to 3.0% by weight.
It is characterized by the following.

According to a ninth aspect of the present invention, in the production method according to any one of the first to eighth aspects, the reaction between the waste cooking oil and the alcohol is carried out at a temperature within the range of 25 ° C. to 240 ° C. Is carried out within a range from atmospheric pressure to 78.5 kg / cm ₂ .

According to a tenth aspect of the present invention, in the method according to any one of the first to ninth aspects, phosphoric acid is used as a neutralizing agent for neutralizing a catalyst comprising an alkaline substance contained in the heavy liquid. , Sulfuric acid or carbon dioxide.

According to an eleventh aspect of the present invention, there is provided the method according to any one of the first to tenth aspects, wherein the solid adsorbent for adsorbing impurities contained in the light liquid includes activated carbon, activated carbon fiber, and activated carbon fiber. It is characterized by using one kind of adsorbent selected from the group consisting of clay, acid clay, bentonite, diatomaceous earth, silica gel, activated alumina and molecular sieve or a mixture of two or more kinds of adsorbents.

According to the manufacturing method of the first aspect,
Waste edible oil is reacted with alcohol by a catalyst, that is, a reaction product is obtained by a transesterification reaction between waste edible oil and alcohol, followed by separation and purification steps. Property values such as flash point and kinematic viscosity reach the standard of current diesel fuel oil, that is, cetane index 45-70, flash point 80 ° C-
Kinematic viscosity at 210 ° C. and 30 ° C. 2.0 mm _{2 / s to} 10.0 m
m ₂ / s, can operate any diesel engine, and has a much lower content of sulfur and nitrogen compounds than conventional diesel fuel derived from petroleum. can get.

In the production method of the present invention, before the waste edible oil is reacted with the alcohol, solid substances, water and odorous substances are removed from the waste edible oil, so that the activity of the alkaline substance serving as a catalyst for the transesterification reaction is reduced. It does not mean that the conversion rate of waste cooking oil decreases
In addition, there is no possibility that a large amount of water remains in the fatty acid alkyl ester to be a product, an odorous substance remains, or a foreign substance remains, thereby deteriorating the quality of the product. In addition, foreign substances such as dust, lard, and solid matter do not cause clogging of pipelines and valves of the manufacturing apparatus. Furthermore, since there is no water in the waste cooking oil during the transesterification reaction, the progress of the side reaction (saponification reaction) for producing fatty acid soap is suppressed, and therefore, a part of the fatty acid soap becomes a product. There is no need to worry that it remains in the fatty acid alkyl ester and is difficult to separate, which causes turbidity and lowers the quality of the product.

Further, in the production method of the present invention, since sodium hydroxide is not used as a catalyst, the activity of the catalyst for the transesterification reaction is sufficient, and an excess alcohol is used to increase the conversion of waste cooking oil to 90% or more. It is not necessary to add and a catalyst. Therefore, a complicated process for removing the excessively added alcohol and catalyst from the product is not required, and the production cost can be reduced. In addition, since sodium hydroxide is not used as a catalyst, the progress of a side reaction (saponification reaction) for producing a fatty acid soap is suppressed, and a part of the fatty acid soap remains in the fatty acid alkyl ester as a product, causing turbidity. There is no reduction in product quality.

In the production method of the present invention, the catalyst is dissolved in alcohol in advance, and then the reaction is performed by mixing the catalyst-containing alcohol solution with the waste cooking oil. Thereby, the reaction speed is remarkably faster as compared with a method in which a catalyst is directly introduced into a mixed liquid of waste cooking oil and alcohol and stirred to cause reaction between the waste cooking oil and alcohol.

Further, in the production method of the present invention, in order to purify the fatty acid alkyl ester produced by the reaction between the waste edible oil and the alcohol, impurities such as residual catalyst, odor substances, coloring substances, and moisture contained in the light liquid are purified. Is adsorbed to a solid adsorbent, and the solid adsorbent that has adsorbed impurities is separated from the light liquid and removed, so that the residual catalyst in the fatty acid alkyl ester is removed by washing with warm water or neutralization with an acid. The method is simpler than that of the method, and there is no fear that the saponification reaction is accelerated, and the step of removing water after washing is unnecessary.

In the production method according to the second aspect of the present invention, the heavy liquid separated from the reaction product can be reused as a fuel and as a raw material for producing industrial glycerin. In other words, since the heavy liquid separated from the reaction product contains most of the catalyst used in the reaction in addition to glycerin as the main component, it is used as it is as a fuel or as a raw material for industrial glycerin. However, in the manufacturing method according to the second aspect of the present invention, the heavy liquid is mixed with the neutralizing agent to neutralize the catalyst composed of the alkaline substance contained in the heavy liquid. Therefore, glycerin, a by-product of the transesterification reaction between waste cooking oil and alcohol, is used as a fuel for boilers and heat recovery incinerators, etc. Further, industrial glycerin can be reused as a raw material in the case of recovering and producing industrial glycerin through a decomposition / purification process.

In the production method according to the third aspect of the present invention, diesel fuel oil is obtained by a semi-continuous operation.

In the manufacturing method according to the fourth aspect of the present invention, when the heated waste cooking oil is placed under vacuum and reduced pressure, moisture and odorous substances are quickly evaporated from the waste cooking oil, so that the water and the odor from the waste cooking oil are reduced. The removal of the substance is performed in a short time and with high efficiency.

In the production method according to the fifth aspect of the present invention, a light liquid mainly composed of a fatty acid alkyl ester and a heavy liquid mainly composed of glycerin are compared with the case of a stationary separation method using a specific gravity difference. And the separation of the solid adsorbent from the mixture of the light adsorbent and the solid adsorbent that has adsorbed impurities are performed in a short time and with high efficiency.

In the manufacturing method according to the sixth aspect of the present invention, the solid substance, moisture and odorous substances contained in the waste cooking oil are removed at a high removal rate, so that the above-described operation of the first aspect of the present invention is ensured. Is played.

According to the method of the present invention, almost all of the glyceride in the waste edible oil is converted into a fatty acid alkyl ester by a transesterification reaction with an alcohol as shown in the above chemical reaction formula. .

In the method according to the present invention, the conversion of waste cooking oil into fatty acid alkyl ester is maintained at a high level, and a side reaction for producing fatty acid soap is likely to occur due to too much catalyst. There is no such thing as. If the amount of the catalyst is too large, corrosiveness to the reactor becomes strong, but there is no such concern.

According to the production method of the ninth aspect, the conversion of waste cooking oil to fatty acid alkyl ester is kept high.

According to the tenth aspect of the present invention, a neutral heavy liquid is obtained by a neutralization reaction between a catalyst comprising an alkaline substance contained in the heavy liquid and phosphoric acid or sulfuric acid. Also, carbon dioxide is a catalyst made of an alkaline substance in the presence of water,
For example, by reacting with potassium hydroxide, potassium carbonate (K ₂ C
O ₃ ), which acts similarly to acidic substances such as phosphoric acid and sulfuric acid.

In the manufacturing method according to the eleventh aspect, the impurities contained in the light liquid are adsorbed on the solid adsorbent with high efficiency. In particular, acid clay has excellent dealkalizing, decoloring and deodorizing effects, and is a suitable adsorbent.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIGS.

First, an example of the configuration of an apparatus used to carry out the method for producing diesel fuel oil from waste cooking oil according to the present invention will be described with reference to FIGS. As shown in FIG. 1, this diesel fuel oil producing apparatus includes a pretreatment section 1, a dehydration / deodorization section 2, a catalyst-containing alcohol solution preparation section 3, a mixing reaction section 4, a liquid-liquid separation section 5, a purification processing section. 6,
It comprises a solid-liquid separation section 7 and a neutralization section 8. The configuration of the pretreatment section 1 and the dehydration / deodorization section 2 is shown in FIG. 2, the configurations of the catalyst-containing alcohol solution preparation section 3 and the mixing reaction section 4 are shown in FIG. FIG. 4 shows the structure of the purification unit 6 and the solid-liquid separation unit 7.
5 is shown in FIG.

As shown in FIG. 2, the pre-processing section 1 includes a waste cooking oil introduction chute 10 on which a filter 12 is mounted, a waste cooking oil storage tank 14, and a strainer 16 on which a cartridge type filter 18 is mounted. Waste cooking oil is
Introduced from waste cooking oil introduction chute 10, mesh number 10
The solid substances contained in the waste cooking oil are temporarily removed by passing through a filter 12 made of a stainless steel wire mesh of ~ 100, and then the solid substances contained in the waste cooking oil are further passed through a strainer 16. Removed.
Also, two waste cooking oil storage tanks 14 are installed,
While the waste cooking oil is being supplied from the one waste cooking oil storage tank 14, another waste cooking oil storage tank 14 is put on standby. When the waste cooking oil stored in the waste cooking oil storage tank 14 in the standby state is allowed to stand still, solid substances and excess moisture contained in the waste cooking oil (when the waste cooking oil contains water of a saturated water content or more, the water phase And the oil phase) naturally settles due to the difference in specific gravity, and the solid matter and excess moisture that settled out are discharged from the drain outlet at the bottom of the waste cooking oil storage tank 14 at regular intervals. Is done. Further, the waste edible oil from which the solid substances and the moisture have been temporarily removed is passed through a strainer 16 equipped with a cartridge type filter 18 having a mesh number of 100 to 600, whereby the fine solid substances contained in the waste edible oil are reduced to two. Next, a waste cooking oil is obtained which is removed and has a solid matter content of, for example, 0.05% or less. Reference numeral 9 in the figure is a valve.

The dewatering / deodorizing section 2 includes a boiler 20 for generating steam, a waste cooking oil metering pump 22, a multi-tube heat exchanger 24,
A plurality of conical perforated plates 28 and a dispersing nozzle 30
, A vacuum dehydration / deodorization tower 26, a condenser 32,
Further, the evacuation apparatus 34 is provided with a vacuum evacuation device 34 to which a vacuum gauge 36 is mounted. The waste cooking oil from which the solid substances were removed in the pretreatment unit 1 exchanged heat with steam while passing through the multitubular heat exchanger 24, and was heated to a temperature required in the subsequent vacuum dehydration and deodorization process. After that, it is introduced from the dispersion nozzle 30 into the vacuum dehydration / deodorization tower 26. Vacuum dehydration / deodorization tower 26
The waste cooking oil introduced therein is dehydrated and deodorized while sequentially flowing down onto the plurality of conical perforated plates 28. That is, the water and the odorous substance having a low boiling point contained in the waste cooking oil heated to the predetermined temperature are quickly evaporated (vaporized) under a vacuum state of 1 to 100 mmHg and discharged from the upper outlet of the vacuum dehydration / deodorization tower 26. After that, it is cooled in the condenser 32, becomes a liquid again, and is discharged out of the system. Thereby, the waste cooking oil has, for example, a water content of 0.0
It is dehydrated and deodorized so that the odorant content is 3% or less and the odorant content is 10 ppm or less.

The catalyst-containing alcohol solution preparing section 3 is shown in FIG.
As shown in the figure, the catalyst introduction chute 40 and the drive motor 42
And a screw conveyor 44, a catalyst supply device 38, an alcohol storage tank 46, an alcohol metering pump 48, a dissolution and stirring tank 50 provided with a cooling water jacket 52, and a catalyst-containing alcohol solution tank 54. The preparation of the catalyst-containing alcohol solution is performed by a batch operation. First, the alcohol is sent from the alcohol storage tank 46 into the dissolution stirring tank 50 by the measuring pump 48, and then the alcohol introduced into the dissolution stirring tank 50 is removed. While stirring, the catalyst fed from the catalyst supply device 38 is introduced into the dissolution and stirring tank 50 at a predetermined ratio with respect to the alcohol, and stirred until the catalyst is completely dissolved in the alcohol. The heat of dissolution generated when the catalyst dissolves in the alcohol is removed by flowing cooling water inside the cooling water jacket 52, thereby exchanging heat between the cooling water and the catalyst-containing alcohol solution. The supply rate of the catalyst into the dissolution stirring tank 50 is controlled such that, for example, when the alcohol is methyl alcohol, the temperature of the catalyst-containing alcohol solution does not exceed 64 ° C. If the catalyst feed rate is too high, it will be too late to remove the generated heat of dissolution.
When the temperature of the solution is higher than the boiling point of alcohol, evaporation of the alcohol becomes intense, and bumping due to local overheating of the solution occurs, which is dangerous. After a predetermined amount of catalyst has been charged into the dissolution and stirring tank 50 and the catalyst has completely dissolved in the alcohol, the valve 9 on the side of the dissolution and stirring tank 50 is opened, and the solution is transferred to the catalyst-containing alcohol solution tank 54. Subsequently, the alcohol and the catalyst are introduced into the dissolution / stirring tank 50 by the same procedure as described above, and the same dissolution / stirring operation is repeated.

The mixing reaction section 4 includes a catalyst-containing alcohol solution measuring pump 56, a dehydrating and deodorizing waste cooking oil measuring pump 58, and a stirring reaction tank 6 equipped with a multistage blade 62.
0. The stirring reaction tank 60 has a multi-stage blade 62 attached to a rotating shaft 64 installed at the center of a cylindrical vessel, and the rotating shaft 64 is rotated by a drive motor 66, so that the inside of the stirring reaction tank 60 starts from the bottom. The dehydration / deodorization waste cooking oil flowing to the upper part and the catalyst-containing alcohol solution are continuously mixed, and the waste cooking oil and the alcohol are reacted. Two stirred reaction tanks 60 are installed in a cascade system, and the vacuum dehydration / deodorization tower 2
The waste cooking oil sent from 6 and the catalyst-containing alcohol solution sent from the catalyst-containing alcohol solution tank 54 are continuously introduced into the bottom of the first stirred reaction tank 60 at a constant rate by the measuring pumps 58 and 56, respectively. After passing through the inside of the stirring reaction tank 60, it flows out of the outlet of the first stirring reaction tank 60, is further introduced into the bottom of the second stirring reaction tank 60, and passes through the inside of the stirring reaction tank 60. , Second
From the outlet of the stirring reaction tank 60. Then, in each of the stirred reaction tanks 60, the waste edible oil and the alcohol are mixed, and the transesterification reaction of the waste edible oil proceeds, and the waste edible oil is discharged at the outlet of the second stirred reaction tank 60. The rate of introduction of the edible oil and the catalyst-containing alcohol solution is controlled.

As shown in FIG. 4, the liquid-liquid separator 5 comprises a liquid-liquid centrifuge 68, a liquid feed pump 70, and a heavy liquid storage tank 72. Liquid-liquid centrifuge 68
Is installed at a position lower than the outlet of the stirred reaction tank 60, and the reaction product flowing out of the stirred reaction tank 60, due to the difference in height between the stirred reaction tank 60 and the liquid-liquid centrifuge 68, It naturally flows into the liquid-liquid centrifuge 68. Then, in the liquid-liquid centrifuge 68, the reaction product is separated into a light liquid mainly composed of a fatty acid alkyl ester and a heavy liquid mainly composed of glycerin. The heavy liquid is sent to and stored in the heavy liquid storage tank 72 by the liquid sending pump 70, while the light liquid is sent to the purification processing unit 6.

As shown in FIG. 5, the refining section 6 includes an adsorbent supply device 76 composed of a light liquid metering pump 74, an adsorbent supply chute 78, a drive motor 80 and a screw conveyor 82, and a stirring blade. It is composed of a stirring and purifying tank 84 provided with 86. Two stirring and purifying tanks 84 are installed in a parallel manner.
The operation at 4 is a batch type, but switching of a pair of valves 9 provided on the inlet side of each stirring and purifying tank 84,
And the screw conveyor 82 of the adsorbent supply device 76
The semi-continuous operation is performed by switching between the pair of inlets provided in. The adsorbent is supplied from the adsorbent supply device 76 into the stirring and purification tank 84 at a predetermined ratio with respect to the light liquid sent from the liquid-liquid separation unit 5 and introduced into the stirring and purification tank 84. Then, the light liquid is continuously stirred in the stirring and refining tank 84 until impurities such as alkali components, moisture, odorous substances, and coloring substances in the light liquid are completely adsorbed by the adsorbent. After the stirring, the valve 9 on the side of the stirring and purifying tank 84 is opened, and the contents in the stirring and purifying tank 84 are sent to the solid-liquid centrifugal separation unit 7.

The solid-liquid separation unit 7 includes a solid-liquid centrifuge 8
8, a liquid sending pump 90 and a purified light liquid storage tank 92. The solid-liquid centrifugal separator 88 is installed at a position lower than the outlet of the stirring and purifying tank 84, and the mixture of the light liquid and the adsorbent flowing out of the stirring and purifying tank 84 is mixed with the solid-liquid centrifugal separator 84. Due to the difference in height position with the separator 88,
It naturally flows into the solid-liquid centrifuge 88. Then, in the solid-liquid centrifuge 88, the used solid adsorbent is separated into a purified light liquid which is a product. The separated light liquid is sent to and stored in the purified light liquid storage tank 92 by the liquid sending pump 90, while the adsorbent is discharged out of the system and collected or disposed of.

As shown in FIG. 4, the neutralizing section 8 includes a heavy liquid measuring pump 94, an acid storage tank 96, an acid measuring pump 9
8, a neutralization processing stirring tank 100 provided with a stirring blade 102, a liquid sending pump 104, and a storage tank 106 for the neutralized heavy liquid. The neutralization of the heavy liquid is performed by a batch operation, and is sent from the heavy liquid storage tank 72 by the heavy liquid measuring pump 94 to the neutralization stirring tank 1.
A predetermined amount of acid is fed from the acid storage tank 96 into the neutralization agitation tank 100 by the acid metering pump 98 with respect to the heavy liquid introduced into the inside of 00. Then, the heavy liquid is sufficiently stirred in the neutralization treatment stirring tank 100, and after the stirring, the heavy liquid storage tank 10 is moved by the liquid feed pump 104.
The glycerin is fed into and stored in 6, and is used as a fuel for boilers or the like, or as a raw material for producing industrial glycerin.

Using a production apparatus having the structure shown in FIGS. 1 to 5, high-quality diesel fuel oil is produced from waste cooking oil discharged from restaurants, food factories, general households, etc. by reaction with alcohol by a catalyst. To manufacture
(1) Waste cooking oil is introduced into the waste cooking oil introduction chute 10 of the pretreatment unit 1, and a solid substance contained in the waste cooking oil is temporarily removed by a filter 12 formed of a wire mesh attached to the waste cooking oil introduction chute 10. Further, after the solid substance is naturally settled in the waste edible oil storage tank 14 and before the supernatant is sent to the dehydration / deodorization unit 2, the waste edible oil is removed by the strainer 16 installed on the outlet side of the waste edible oil storage tank 14. The contained solid material is secondarily removed. (2) The waste cooking oil from which the solid substances have been removed is sent to a heat exchanger 24 by a waste cooking oil metering pump 22 and heated to a predetermined temperature in the heat exchanger 24, and the moisture and low boiling point in the vacuum dehydration / deodorization tower 26. Deodorize and deodorize by evaporating odorous substances. (3) A predetermined amount of the catalyst and the alcohol are introduced into the dissolution and stirring tank 50 by the catalyst supply device 38 and the alcohol measuring pump 48, respectively, and the catalyst and the alcohol are dissolved in the alcohol by stirring the catalyst and the alcohol in the dissolution and stirring tank 50. After that, the solution is introduced and stored in the catalyst-containing alcohol solution tank 54.
(4) The dehydration / deodorization unit 2 and the catalyst-containing alcohol solution tank 5 are respectively put into the cascaded stirring reaction tanks 60.
4, the dehydrated and deodorized waste cooking oil and the catalyst-containing alcohol solution are fed at predetermined ratios by the measuring pumps 58 and 56, respectively. Then, in the stirring reaction tank 60 having the multi-stage blades 62, the dehydration / deodorization waste cooking oil heated to the predetermined temperature and the catalyst-containing alcohol solution are stirred and mixed, and the reaction between the waste cooking oil and the alcohol proceeds.
After obtaining the reaction product between the waste cooking oil and the alcohol, the reaction product is continuously transferred to the liquid-liquid centrifuge 68.
(5) In the liquid-liquid centrifuge 68, the reaction product is separated into a light liquid and a heavy liquid, the light liquid is sent to the purification processing unit 6 by the light liquid measuring pump 74, and the heavy liquid is stored in the heavy liquid storage tank 72.
Introduce and store inside. (6) A predetermined amount of adsorbent is supplied to the adsorbent supply device 7 with respect to the light liquid introduced into the stirring / purifying tank 84.
6 and the stirring blades 8
After the impurities contained in the light liquid are adsorbed on the adsorbent by vigorous stirring by 6, the mixture of the adsorbent with impurities and the light liquid is sent to the solid-liquid centrifuge 88. (7) In the solid-liquid centrifuge 88, the adsorbent and the purified light liquid are separated, the adsorbent is discharged out of the system, and the purified light liquid is introduced as a product into the purified light liquid storage tank 92. And store.
(8) The heavy liquid and the acid are fed into the neutralization processing stirring tank 100 from the heavy liquid storage tank 72 and the acid storage tank 96 at predetermined ratios by the measuring pumps 94 and 98, respectively. The heavy liquid and the acid are mixed by stirring, and the catalyst composed of the alkaline substance contained in the heavy liquid is neutralized with the acid, and the heavy liquid neutralized by the neutralization reaction is placed in the heavy liquid storage tank 106. It is sent and stored, and the heavy liquid is used as a fuel for boilers or the like or a raw material for industrial glycerin production. Above 8
Through two processes, waste edible oil can be finally used as vegetable diesel fuel oil, which can be used for diesel engines, as a fuel for boilers, etc., and as a raw material for producing industrial glycerin. A heavy liquid that can be obtained is obtained.

The waste cooking oil used as a raw material includes rapeseed oil waste oil, sesame oil waste oil, soybean oil waste oil, corn oil waste oil, sunflower oil waste oil, palm oil waste oil, palm kernel oil waste oil, coconut oil waste oil, corn oil waste oil, safflower oil waste oil, etc. And one of them or a mixture of a plurality of them is used as a raw material. There is no particular requirement for the quality of the waste cooking oil, but it is desirable that the water content and the solid content be low.

The filter 12 mounted on the waste cooking oil introduction chute 10 to remove solid substances in the pretreatment section 1
Is a stainless steel wire mesh having 10 to 100 meshes, and mainly plays a role in removing bulky dust and foreign substances contained in waste cooking oil. The strainer 16 installed on the exit side of the waste cooking oil storage tank 14 has a mesh number of 1
The cartridge type filters 18 of 00 to 600 are mounted, and mainly serve to remove minute-sized dust and foreign substances contained in the waste cooking oil.

From the waste cooking oil storage tank 14 to the measuring pump 22
The waste cooking oil fed to the heat exchanger 24 at a predetermined flow rate is heated to a temperature of 25 ° C. to 200 ° C. by exchanging heat with steam from the boiler 20, and completely dehydrated and deodorized in the vacuum dehydration / deodorization tower 26. It is adjusted to be easy. Further, in consideration of the temperature reduction of the waste cooking oil due to the heat of evaporation and heat loss of the moisture and odorous substances in the vacuum dehydration / deodorization tower 26, the dehydration / deodorization waste cooking oil and the catalyst-containing alcohol solution at room temperature are mixed in the stirring reactor 60. It is necessary to control the temperature of the waste cooking oil at the outlet of the heat exchanger 24 so that the temperature of the mixed solution after the heating is in a temperature range in which the reaction easily occurs.

The absolute pressure inside the vacuum dehydration / deodorization tower 26 varies depending on the contents of water and odorous substances contained in the waste cooking oil and the temperature of the waste cooking oil, but is 1 to 100 m.
It is adjusted within the range of mHg. If the absolute pressure inside the vacuum dehydration / deodorization tower 26 is too high, moisture and odorous substances cannot be sufficiently removed. On the other hand, if the absolute pressure is too low, even useful components in waste cooking oil will be removed. At the same time, unnecessary power is consumed.

As the alcohol to be reacted with the waste cooking oil,
One type or a mixture of two or more types selected from alkyl alcohols having 1 to 10 carbon atoms such as methyl alcohol, ethyl alcohol and isobutyl alcohol is used. There is no particular requirement for the purity of the alcohol, but it is desirable that the water content be low. As the type of alcohol, any of unsaturated or saturated alkyl alcohols having 1 to 10 carbon atoms can be used, but lower alcohols having a lower carbon number, such as methyl alcohol and ethyl alcohol, have higher quality. It is convenient to obtain vegetable diesel fuel oil.

The catalyst for the reaction between the alcohol and the waste cooking oil includes one or more alkaline substances selected from the group consisting of potassium hydroxide, potassium carbonate, and potassium alcoholate such as potassium methylate and potassium ethylate. Used. Further, a mixed catalyst obtained by adding a sodium-based catalyst to them may be used. When these catalysts are used, the conversion rate from waste cooking oil to fatty acid alkyl esters is improved as compared with the case where sodium hydroxide is used as a catalyst, and a high-quality vegetable diesel fuel oil is obtained. The saponification reaction shown in Chemical formula 1 is suppressed. For example, when a 99.8% methyl alcohol and a waste cooking oil containing 0.5% water are subjected to a transesterification reaction with sodium hydroxide, and the reaction product is separated by a centrifugal separator, the obtained light is obtained. The liquid contained fatty acid soap, and turbidity was observed, and fatty acid soap was detected in the heavy liquid. On the other hand, when the same waste cooking oil was used and reacted with 99.8% of methyl alcohol with potassium hydroxide, the obtained light liquid was transparent and no fatty acid soap was detected at all.

The amount of the catalyst dissolved in alcohol is from 0.3% by weight to 3.0% by weight in terms of the weight ratio of the catalyst to the waste cooking oil.
And preferably 0.6 to 2.0% by weight. In addition, the amount of the catalyst-containing alcohol solution added to the waste cooking oil is 100 in terms of the ratio of alcohol to waste cooking oil.
g of waste cooking oil, the amount of alcohol added is 0.15 mol to 0.75 mol, preferably 0.25 mol to
0.35 mol. The more the catalyst is added within a certain range, the more [equilibrium conversion of waste cooking oil = waste cooking oil converted to fatty acid alkyl ester / (raw waste cooking oil−
Impurity) × 100%], the equilibrium conversion of waste cooking oil becomes higher, but when it exceeds a certain range, the equilibrium conversion of waste cooking oil becomes almost constant, and the side reaction of fatty acid soap is likely to occur. Become. On the other hand, if the amount of the catalyst added is too large, corrosiveness to the reaction apparatus becomes strong, and the conditions in the step of purifying the reaction product must be strict. Therefore, it is necessary to use an appropriate amount of the catalyst.

Further, the more the alcohol is added to the waste cooking oil within a certain range, the higher the equilibrium conversion rate of the waste cooking oil becomes, but if it exceeds a certain range, the equilibrium conversion rate of the waste cooking oil becomes almost equal. It becomes constant, excess alcohol remains in the product after the reaction, and the alcohol is wasted.
This will also have a negative effect on product quality. Generally, in order to convert monoglyceride, diglyceride and triglyceride, which are the main components of waste cooking oil, to fatty acid alkyl ester, about 3 moles of alcohol is required stoichiometrically per mole of waste cooking oil. It is more convenient to obtain a higher quality diesel fuel oil if it is added slightly more than the stoichiometrically required amount, for example, an amount that is 10% greater than the stoichiometric amount or the stoichiometric amount.

In the dissolving and stirring tank 50, the alcohol is first introduced into the dissolving and stirring tank 50 and then stirred to prevent boiling or bumping of the alcohol due to local overheating due to the heat of dissolution. It is necessary to add the catalyst at a predetermined rate. In order to discharge the heat of melting, the jacket 5 of the melting and stirring tank 50 is used.
Cooling water is flowed through 2 and the flow rate of the cooling water is adjusted so that the temperature of the catalyst-containing alcohol solution can be maintained at or below the boiling point of the alcohol.

The production method according to the present invention employs a method in which a catalyst for promoting the reaction between alcohol and waste edible oil is dissolved in alcohol in advance, and then the catalyst-containing alcohol solution is reacted with the waste edible oil. According to such a method, the reaction speed is significantly higher than when the catalyst is directly charged into the stirring reaction tank 60. For example, when potassium hydroxide is dissolved in methyl alcohol in advance, and then the reaction is performed by mixing the catalyst-containing alcohol solution and the waste cooking oil, the reaction temperature is 60 ° C., the stirring speed is 300 rpm, and the equilibrium conversion rate of the waste cooking oil is increased. The reaction time required to reach 99% is within 1.0 minute. On the other hand, when methyl alcohol and a catalyst are simultaneously added to and reacted with waste cooking oil, the reaction time required for the equilibrium conversion of waste cooking oil to reach 96% under the same conditions is 30 minutes. Become. in this way,
By the method according to the present invention, the reaction operation between alcohol and waste edible oil, which could be conventionally only performed by a batch operation, can now be performed in a continuous operation, and the reaction speed can be significantly improved. Was. That is, as shown in FIG. 3, two stirring reaction tanks 60 each having multi-stage blades 62 are installed in a cascade manner, and the reactants (waste cooking oil and alcohol solution containing catalyst) are placed at the bottom of the first stirring reaction tank 60. After passing through the inside of the stirring reaction tank 60 and passing through the inside of the stirring reaction tank 60, the reactant flowing out from the outlet of the first stirring reaction tank 60 is introduced into the bottom of the second stirring reaction tank 60. The stirring reaction tank 60 is controlled so that the total residence time of the reactants in the two stirring reaction tanks 60 from passing through the inside to flowing out from the outlet of the second stirring reaction tank 60 is 1.0 minute or more. Height is designed.

The reaction between the waste cooking oil and the alcohol in the stirring reaction tank 60 is carried out at a temperature ranging from room temperature (25 ° C.) to 240 ° C. and a pressure ranging from atmospheric pressure to 78.5 kg / cm ₂ , preferably 20 kg / cm ₂ . in the range of up to cm _2, in this case, the equilibrium conversion of waste edible oil reaches 10% to 99.9%. Since the reaction between waste cooking oil and alcohol is a reversible reaction, optimal temperature and pressure conditions are required to maximize the equilibrium conversion of waste cooking oil. The higher the temperature, the higher the reaction rate, but the higher the pressure in the system, the higher the pressure required for the reactor, which is disadvantageous in cost. When the temperature becomes higher than the boiling point of the alcohol, the alcohol evaporates, and a reaction between the gaseous alcohol and the liquid waste cooking oil occurs, which in turn lowers the equilibrium conversion rate.

The reaction product flowing out of the stirring reaction tank 60 is, as shown in the chemical reaction formula (1), a fatty acid alkyl ester formed by a transesterification reaction between triglyceride, which is a main component of vegetable oil, and alcohol. And glycerin as a main component. Conventionally, separation of fatty acid alkyl ester and glycerin has been performed by a stationary separation method utilizing the difference in specific gravity between fatty acid alkyl ester and glycerin. In this separation method, fatty acid alkyl ester and glycerin are completely separated. Separation takes time and productivity is poor. In this apparatus, the fatty acid alkyl ester and glycerin could be completely separated efficiently by centrifugation. The light liquid flowing out of the liquid-liquid centrifugal separator 68 contains not only the fatty acid alkyl ester as a main component but also a small amount of a catalyst, unreacted alcohol, odorous substances, colored substances, and the like. Therefore, it is necessary to send the light liquid to the purification processing unit 6 for purification. In addition, since heavy liquid contains most of the catalyst used in the reaction in addition to glycerin, which is the main component, if used directly as fuel or as a raw material for glycerin production, corrosion of the equipment due to alkali will be avoided. Will bring. For this reason, the heavy liquid is sent to the neutralization processing section 8 to perform the neutralization processing with an acid.

For the purification of the light liquid containing fatty acid alkyl ester as a main component, one kind of adsorbent selected from the group consisting of activated carbon, activated carbon fiber, activated clay, acid clay, bentonite, diatomaceous earth, activated alumina and molecular sieve Alternatively, a mixture of two or more adsorbents is used. Among them, clays, especially so-called acidic clay treated with sulfuric acid, are excellent adsorbents, decolorizing effects and deodorizing effects, and are suitable adsorbents. The particle size of the particulate adsorbent is not particularly required, but in order to shorten the treatment time as much as possible and to efficiently separate the adsorbent and the light liquid after the treatment, the particle size is 0.01 mm to 5 mm. And preferably in the range of 0.1 mm to 1.5 mm. The smaller the particle size of the adsorbent, the better the purification effect, but the more difficult it is to separate after treatment. Further, the larger the particle size of the adsorbent, the easier the separation after purification, but the worse the purification effect. In the agitation purification tank 84, the amount of the adsorbent added to the light liquid varies depending on the type of the adsorbent, the particle size, the stirring speed, the purification conditions such as the temperature, etc. When using activated clay having an average particle size of 1 mm, At room temperature, a stirring speed of 300 rpm, and a stirring time of 10 minutes, the amount of activated clay added is 0.
5% to 2.0% by weight is sufficient.

The mixture of the light liquid and the adsorbent after purification is
If left at rest, the layers separate spontaneously due to the difference in specific gravity between the light liquid and the adsorbent, but the time required for complete layer separation increases, resulting in poor productivity. In this device,
With the liquid centrifuge 88, the light liquid and the adsorbent could be completely separated efficiently. The light liquid flowing out of the solid-liquid centrifuge 88 is introduced and stored in a purified light liquid storage tank 92 as so-called vegetable diesel fuel oil as a product, and the adsorbent is either recycled or disposed of. Is processed in the following manner.

Either phosphoric acid or sulfuric acid is used for the neutralization treatment of the heavy liquid containing glycerin as a main component.
As the neutralizing agent, carbon dioxide can be used in addition to acids such as phosphoric acid and sulfuric acid. Since carbon dioxide reacts with a catalyst made of an alkaline substance, for example, potassium hydroxide in the presence of water to form potassium carbonate, it has the same action as an acidic substance of phosphoric acid or sulfuric acid. The higher the melting point or boiling point of the salt contained in the neutralized heavy liquid, the more suitable the neutralized heavy liquid is as a fuel for a boiler or the like. For example, when a heavy liquid containing potassium hydroxide is neutralized with phosphoric acid, phosphoric acid and potassium hydroxide react to form potassium phosphate. The melting point of potassium phosphate is 1,34
0 ° C., the combustion temperature of heavy liquid is 800 ° C. to 1,000 ° C.
In a furnace at 0 ° C., potassium phosphate does not dissolve but remains as ash. Therefore, there is no problem of corrosion on the furnace wall and no problem of environmental pollution due to harmful gas generated by decomposition of salt. In addition, potassium phosphate, which becomes ash, has industrial uses such as a watering agent, a desulfurizing agent for petroleum products, and an expanding agent, and also becomes an important agricultural fertilizer.

[0067]

EXAMPLES The method for producing diesel fuel oil from waste cooking oil according to the present invention will be described below with reference to more specific examples.

Example 1 In a manufacturing apparatus having a processing capacity of 5 tons / day having the configuration shown in FIGS. 1 to 5,
As the filter 12 mounted on the waste cooking oil introduction chute 10 of the waste cooking oil storage tank 14, a stack of two stainless steel meshes having 120 meshes was used. In addition, the strainer 1 installed on the exit side of the waste cooking oil storage tank 14
As the cartridge type filter 18 mounted on 6, a filter made of polyester long fiber having 300 meshes was used. Waste cooking oil from food factories (acid value 3.4, saponification value 18
5, Iodine value 112, flash point 220 ° C, moisture 0.9%,
(Ash content: 1.3%) was introduced into the waste cooking oil storage tank 14 from the waste cooking oil introduction chute 10 and allowed to settle overnight, and then the supernatant was used for the reaction. Using potassium hydroxide (purity 85%) as a catalyst,
After dissolving the catalyst in methyl alcohol at a ratio of 11.5 parts by weight to 100 parts by weight of methyl alcohol (purity: 99.8%), the resulting solution was transferred to a catalyst-containing alcohol solution tank. Activated clay (average particle size: 1 mm) was used for the purification of the light liquid, and phosphoric acid (85% purity) was used for the neutralization treatment of the heavy liquid.

Removal of solid substances contained in waste cooking oil, heating and vacuum dehydration / deodorization of waste cooking oil from which solid substances have been removed, reaction of dehydrated / deodorized waste cooking oil with catalyst-containing methyl alcohol solution, and reaction Each step of the liquid-liquid separation of the product and the solid-liquid separation of the purified light liquid and the activated clay was performed under the following continuous operation conditions. Mass flow rate of waste cooking oil measuring pump 22: 842 kg / h Mass flow rate of catalyst-containing alcohol solution measuring pump 56: 1
22 kg / h Outlet temperature of the multitubular heat exchanger 24: 84 ° C. Absolute pressure in the vacuum dehydration / deodorization tower 26: 60 mmHg Inlet temperature of the first stirred reaction tank 60: 61 ° C. Stirring speed of the stirred reaction tank 60: 350 rpm Centrifugal effect of liquid-liquid centrifuge 68: 1,000 G Centrifugal effect of solid-liquid centrifuge 88: 1,000 G

The purification of the light liquid separated by the liquid-liquid centrifuge 68 with activated clay was carried out by the following semi-continuous operation. Weight ratio of activated clay to light liquid: 1% Stirring speed of stirring and purifying tank 84: 300 rpm Stirring time of stirring and purifying tank 84: 10 minutes

The neutralization of heavy liquid separated by liquid-liquid centrifugation 68 with phosphoric acid was performed under the following batch-type operating conditions. Weight ratio of 85% phosphoric acid to heavy liquid: 5.5% Stirring speed of neutralization treatment stirring tank 100: 100 rpm Stirring time of neutralization treatment stirring tank 100: 5 minutes

Under the above conditions, the removal of solid substances contained in the waste cooking oil, the heating of the waste cooking oil from which the solid substances have been removed, the vacuum dehydration and deodorization, and the reaction between the dehydrated and deodorized waste cooking oil and the catalyst-containing methyl alcohol solution , Liquid-liquid separation of reaction product and solid-liquid separation of purified light liquid and activated clay, semi-continuous step of purification of light liquid by activated clay, and neutralization of heavy liquid by phosphoric acid Perform a batch process of processing,
The obtained light liquid and the heavy liquid subjected to the neutralization treatment are respectively subjected to about 3 liters in the purified light liquid storage tank 92 and the heavy liquid storage tank 106.
Stabilized for 0 minutes. Thereafter, the purified light liquid storage tank 92
The purified light liquid (vegetable diesel fuel oil) and the neutralized heavy liquid were sampled from the inlet of the heavy liquid storage tank 106, respectively, and their properties were analyzed.

The concentration of the odorous substance in the light liquid was determined as follows. That is, a gas chromatograph (GC-14)
A, Capillary column TC-1, 0.25mmI
D, 15 mL), inlet temperature: 280 ° C., detector temperature: 250 ° C., column temperature: 40 ° C., 5 minutes; 320
15 ° C., heating rate: 10 ° C./min, sample injection amount:
Analysis was performed under the conditions of 10 μl, and in the obtained GC chart, light components having a retention time of 20 minutes or less (excluding methyl alcohol) were defined as odorous substances, their concentrations were determined from the peak areas, and the concentration of the odorous substances was determined. And Other property analysis was performed by a method specified in JIS standard of petroleum fraction or a usual method. Table 1 shows the results of the property analysis of the purified light liquid, and Table 2 shows the results of the property analysis of the neutralized heavy liquid.
Are shown below. In Table 1, "waste cooking oil conversion rate [%]"
It shows the yield of the light liquid with respect to the waste cooking oil, and is defined by the formula of [conversion rate of waste cooking oil = amount of fatty acid alkyl ester / (amount of raw waste cooking oil−amount of impurities) × 100%].

[0074]

[Table 1]

[0075]

[Table 2]

Example 2 Using the same manufacturing apparatus as in Example 1 above, under the same conditions, a light liquid purified from waste cooking oil and a heavy liquid neutralized were obtained. However, instead of the methyl alcohol used in Example 1, ethyl alcohol (purity 99.5%) was used as the alcohol,
Further, the mass flow rate of the catalyst-containing alcohol solution measuring pump 56 was changed to 170 kg / h. The properties of the obtained light liquid and heavy liquid were also analyzed in the same manner as in Example 1.
However, in the calculation of the concentration of the odorous substance in the light liquid, in the obtained GC chart, light components (excluding ethyl alcohol) having a retention time of 20 minutes or less were regarded as odorous substances. The results of the property analysis are shown in Tables 1 and 2.

Comparative Example 1 Using the same production apparatus as in Example 1 above, under the same conditions, a light liquid purified from waste cooking oil and a heavy liquid neutralized were obtained. However, in the apparatus shown in FIGS. 1 to 5, a flow path is connected between the outlet of the multi-tubular heat exchanger 24 and the outlet of the dehydration / deodorization waste cooking oil metering pump 58 by a bypass pipeline, and The waste cooking oil flowing out was allowed to flow directly into the stirring reaction tank 60 without passing through the vacuum dehydration / deodorization tower 26. The temperature of the waste cooking oil at the outlet of the heat exchanger 24 was set to 62 ° C.
The properties of the obtained light liquid and heavy liquid were also analyzed in the same manner as in Example 1. The results are shown in Tables 1 and 2.

[Comparative Example 2] A light liquid purified from waste cooking oil and a heavy liquid neutralized were obtained under the same conditions using the same production apparatus as in Example 1 described above. However, instead of the potassium hydroxide used in Example 1, sodium hydroxide (purity: 96%) was used as a catalyst, and a dissolution stirring tank was used.
In the catalyst, methyl alcohol (purity 99.8%) 10
The catalyst was dissolved in methyl alcohol at a ratio of 11.5 parts by weight to 0 parts by weight. The properties of the obtained light liquid and heavy liquid were also analyzed in the same manner as in Example 1. Table 1 shows the results.
And Table 2.

[Comparative Example 3] A light liquid purified from waste cooking oil and a heavy liquid subjected to neutralization treatment were obtained under the same conditions and using the same production apparatus as in Example 1 described above. However, in the apparatus shown in FIG. 1 to FIG. 5, the apparatus is configured such that the catalyst supply device 38 is moved from above the dissolution and stirring tank 50 to above the stirring reaction tank 60, and the catalyst can be directly introduced into the stirring reaction tank 60. Partially changed. Then, the catalyst (potassium hydroxide) is stored in the catalyst introduction chute 40 of the catalyst supply device 38, and methyl alcohol (purity 99.8%) is stored in the catalyst-containing alcohol solution tank 54, and the catalyst is preliminarily stored. Without dissolving in methyl alcohol, the catalyst is fed into the stirring reaction tank 60 from above by the catalyst supply device 38, and methyl alcohol is introduced into the stirring reaction tank 60 from the bottom by the metering pump 56, and The cooking oil was allowed to react with methyl alcohol.

Removal of solid substances contained in waste cooking oil, heating and vacuum dehydration / deodorization of waste cooking oil from which solid substances have been removed, reaction of dehydrated / deodorized waste cooking oil with methyl alcohol, and reaction product Each step of liquid-liquid separation and solid-liquid separation of purified light liquid and activated clay was performed under the following continuous operation conditions. Mass flow rate of waste cooking oil metering pump 22: 842 kg / h Mass flow rate of metering pump 56: 109 kg / h Catalyst supply speed from catalyst supply device 38: 12.6 kg
/ H Outlet temperature of the multitubular heat exchanger 24: 80 ° C. Absolute pressure in the vacuum dehydration / deodorization tower 26: 55 mmHg Inlet temperature of the first stirred reaction tank 60: 57 ° C. Stirring speed of the stirred reaction tank 60: 350 rpm -Centrifugal effect of liquid centrifuge 68: 1,000G Solid-liquid centrifuge 88: Centrifugal effect: 1,000G

The properties of the obtained light liquid and heavy liquid were analyzed in the same manner as in Example 1. Table 1 and Table 2 show the results.
Shown in

[0082]

According to the method for producing diesel fuel oil from waste cooking oil according to the first aspect of the present invention, waste cooking oil discarded from restaurants, food factories, general households, etc. and hardly used until now is used as a raw material. In addition, it has sufficient quality required for fuel oil used for diesel engine vehicles such as trucks, garbage trucks, and buses, and has a lower sulfur and nitrogen compound content than conventional diesel fuel oil obtained from petroleum. A plant diesel fuel oil having a much lower content can be obtained, which can contribute to the promotion of effective use of food resources and greatly contribute to environmental protection of the earth. According to the production method of the invention according to claim 2, in addition to the above, glycerin, which is a by-product of the transesterification reaction between waste cooking oil and alcohol, is used as a fuel for boilers and heat recovery incinerators, and Because it can be reused as a raw material for industrial glycerin,
It can further contribute to environmental protection of the earth.

According to the manufacturing method of each of the third and eleventh aspects of the present invention, the above-mentioned effects of the first and second aspects of the present invention can be surely obtained.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing an example of an entire configuration of an apparatus used to carry out a method for producing diesel fuel oil from waste cooking oil according to the present invention.

FIG. 2 is a schematic diagram showing a configuration of a pretreatment unit and a dehydration / deodorization unit which constitute a part of the diesel fuel oil manufacturing apparatus shown in FIG.

FIG. 3 is a schematic view showing a configuration of a catalyst-containing alcohol solution preparation section and a mixing reaction section.

FIG. 4 is a schematic diagram showing a configuration of a liquid-liquid separation unit and a neutralization processing unit.

FIG. 5 is a schematic diagram showing the configurations of a purification processing unit and a solid-liquid separation unit.

[Explanation of symbols]

 Reference Signs List 1 Pretreatment section 2 Dehydration / deodorization section 3 Catalyst-containing alcohol solution preparation section 4 Mixing reaction section 5 Liquid-liquid separation section 6 Purification processing section 7 Solid-liquid separation section 8 Neutralization processing section 9 Valve 10 Waste cooking oil introduction chute 12 Filter 14 Waste Cooking Oil Storage Tank 16 Strainer 18 Cartridge Filter 20 Boiler 22 Waste Cooking Oil Metering Pump 24 Multi-tubular Heat Exchanger 26 Vacuum Dehydration / Deodorization Tower 28 Conical Perforated Plate 30 Dispersion Nozzle 32 Capacitor 34 Vacuum Evacuation Device 36 Vacuum Gauge 38 Catalyst supply device 40 Catalyst introduction chute 42 Drive motor 44 Screw conveyor 46 Alcohol storage tank 48 Alcohol metering pump 50 Melting and stirring tank 52 Cooling water jacket 54 Catalyst-containing alcohol solution tank 56 Catalyst-containing alcohol solution metering pump 58 Dehydration / deodorization waste cooking oil Metering pump 60 Stir Reaction tank 62 Multi-stage blade 64 Rotating shaft 66 Drive motor 68 Liquid-liquid centrifuge 70 Liquid feed pump 72 Heavy liquid storage tank 74 Light liquid measuring pump 76 Adsorbent supply device 78 Adsorbent supply chute 80 Drive motor 82 Screw conveyor 84 Stirring Purification tank 86 Stirrer blade 88 Solid-liquid centrifugal separator 90 Liquid feed pump 92 Purified light liquid storage tank 94 Heavy liquid metering pump 96 Acid storage tank 98 Acid metering pump 100 Neutralization treatment stirring tank 102 Stirrer blade 104 Liquid feed pump 106 Weight Liquid storage tank

Continued on the front page (72) Inventor Yoshio Wang 2-1026 Mibubojo 2nd complex, Mibubojo-cho 48-3, Nakagyo-ku, Kyoto (72) Inventor Hiroro Arima 1-4, Oitaimachi Kita-Shirakawa, Sakyo-ku, Kyoto-shi Parkheim Kita-Shirakawa 104

Claims (11)

[Claims] 1. A step of removing a solid substance contained in waste cooking oil discarded from a restaurant, a food factory, a general household or the like by a filter, and heating the waste cooking oil from which the solid substance has been removed to a predetermined temperature. Removing the water and odorous substances contained in the waste cooking oil by evaporating the alcohol; and adding at least one or more kinds of alcohols selected from the group consisting of potassium hydroxide, potassium carbonate and potassium alcoholate. Dissolving a catalyst containing an alkaline substance, and preparing a catalyst-containing alcohol solution in advance; mixing and stirring the waste edible oil and the catalyst-containing alcohol solution from which solid substances and water and odorous substances have been removed; A step of promoting a catalytic reaction between edible oil and alcohol to obtain a reaction product of waste edible oil and alcohol; Objects and a step of separating into a light liquid and a heavy liquid, the light liquid obtained in the separation step is mixed with a solid adsorbent,
Adsorbing impurities such as residual catalyst, odorous substances, coloring substances, and moisture contained in the light liquid onto the solid adsorbent; and Separating and removing.
A method for producing diesel fuel oil from waste cooking oil. 2. The method according to claim 1, further comprising a step of mixing the heavy liquid obtained in the separation step with a neutralizing agent to neutralize a catalyst comprising an alkaline substance contained in the heavy liquid. A method for producing diesel fuel oil. 3. The method for producing diesel fuel oil from waste cooking oil according to claim 1, wherein a series of steps are performed in a semi-continuous manner. 4. The diesel fuel oil from waste cooking oil according to claim 1, wherein the heated waste cooking oil is placed under reduced pressure in the step of removing water and odorous substances from the waste cooking oil. Manufacturing method. 5. Separation of the reaction product into a light liquid and a heavy liquid,
5. Diesel from waste edible oil according to any one of claims 1 to 4, wherein the separation of the solid adsorbent from the mixture of the light adsorbent and the solid adsorbent adsorbing impurities is performed by a centrifugal separation method. Fuel oil production method. 6. Solid substances, water and odor substances contained in waste cooking oil discarded from restaurants, food factories, general households, etc. are reduced to a solid substance content of 0.05% or less and a water content of 0.03%. The method for producing diesel fuel oil from waste cooking oil according to any one of claims 1 to 5, wherein the diesel fuel oil is removed so that the content thereof is equal to or less than 10 ppm. 7. The alcohol having a carbon number of 1 such as methyl alcohol, ethyl alcohol and isobutyl alcohol.
One or more alcohols selected from the group consisting of 10 alkyl alcohols, wherein the amount of alcohol added to the waste cooking oil is stoichiometric or stoichiometric relative to the amount of glyceride in the waste cooking oil. More than 10
The method for producing diesel fuel oil from waste edible oil according to any one of claims 1 to 6, wherein the amount is greater by%. 8. The catalyst according to claim 1, wherein the amount of the catalyst to alcohol is 0.
The amount is 3% by weight to 3.0% by weight.
The method for producing diesel fuel oil from waste cooking oil according to any one of the above. 9. The reaction between waste cooking oil and alcohol is carried out at a temperature in the range of 25 ° C. to 240 ° C. and a pressure of from atmospheric pressure to 78.degree.
The method for producing diesel fuel oil from waste cooking oil according to any one of claims 1 to 8, which is performed in a range of up to 5 kg / cm ₂ . 10. The waste according to claim 1, wherein phosphoric acid, sulfuric acid or carbon dioxide is used as a neutralizing agent for neutralizing a catalyst comprising an alkaline substance contained in the heavy liquid. A method for producing diesel fuel oil from cooking oil. 11. The solid adsorbent for adsorbing impurities contained in the light liquid is selected from the group consisting of activated carbon, activated carbon fiber, activated clay, acid clay, bentonite, diatomaceous earth, silica gel, activated alumina, and molecular sieve. The method for producing diesel fuel oil from waste cooking oil according to any one of claims 1 to 10, wherein one kind of adsorbent or a mixture of two or more kinds of adsorbents is used.