JP6634783B2 - Method for producing biodiesel fuel and apparatus for producing biodiesel fuel - Google Patents

Description

  The present invention relates to a method for producing biodiesel fuel and an apparatus for producing biodiesel fuel.

In recent years, so-called biodiesel fuel using oils and fats produced by naturally-occurring plants, animals, fish or microorganisms has been expected as a fuel to replace fossil fuels such as light oil.
Of these fats and oils, fats and oils used for food production (edible oils) are often disposed of in the environment. It is particularly expected from the point of use.

Conventionally, there has been known a method of producing a fatty acid ester to be a biodiesel fuel by transesterifying fats and oils (waste cooking oil) with a lower alcohol such as methanol.
For example, Non-Patent Document 1 discloses a so-called batch-type manufacturing method. Specifically, first, methanol and a catalyst are added to waste cooking oil and stirred in a reaction tank to produce fatty acid methyl esters. In this method, it is considered that an alkali catalyst such as potassium hydroxide or sodium hydroxide is used.
Patent Literature 1 discloses a method for producing a fatty acid ester using a reactor having a plurality of catalytic reaction tubes filled with lipase.

International Publication No. 2009/078290

"Kyoto City Information Hall", [online], July 16, 2009, Kyoto City Hall, [searched October 30, 2015], Internet (URL: http://www.city.kyoto.lg.jp/kankyo) /page/0000065554.html)

However, in the method (batch type) disclosed in Non-Patent Document 1, after the fatty acid methyl ester is generated, the fatty acid methyl ester is allowed to stand in a reaction tank to separate glycerin as a by-product or to remove the catalyst. Since it is necessary, it is complicated and may be inferior in productivity.
Further, in the method disclosed in Patent Literature 1, since a plurality of stages of catalyst reaction tubes are arranged side by side, the device configuration becomes complicated.

  The present invention has been made in view of the above points, and it is an object of the present invention to provide a biodiesel fuel production method and a biodiesel fuel production apparatus in which a fatty acid ester serving as a biodiesel fuel can be easily obtained. .

  As a result of intensive studies, the present inventors have found that the above objects can be achieved by employing the following configuration, and have completed the present invention.

That is, the present invention provides the following [1] to [5].
[1] A method for producing a biodiesel fuel, comprising transesterifying a fat or oil with a lower alcohol using a solid catalyst to produce a fatty acid ester as a biodiesel fuel and glycerin as a by-product. The raw material containing alcohol is passed through a reaction tank in which the solid catalyst is placed, to produce glycerin while producing fatty acid ester, and unreacted while separating the by-produced glycerin at a specific gravity difference. The method for producing biodiesel fuel, wherein the raw material is repeatedly circulated together with the produced fatty acid ester so as to pass through the reaction tank, and the fatty acid ester produced by the circulation is recovered.
[2] The method for producing biodiesel fuel according to [1], wherein glycerin by-produced by the circulation is recovered.
[3] The method for producing biodiesel fuel according to [1] or [2], wherein the solid catalyst contains steel slag.
[4] The method for producing biodiesel fuel according to any of [1] to [3], wherein the solid catalyst includes converter slag.
[5] A biodiesel fuel production apparatus used in the biodiesel fuel production method according to any one of [1] to [4], wherein the reaction vessel and the raw material are passed through the reaction vessel. An apparatus for producing biodiesel fuel having a circulation mechanism for circulating liquid.

  ADVANTAGE OF THE INVENTION According to this invention, the biodiesel fuel manufacturing method and biodiesel fuel manufacturing apparatus which can obtain the fatty acid ester used as a biodiesel fuel easily can be provided.

It is a conceptual diagram which shows an example of a biodiesel fuel manufacturing apparatus.

  The method for producing a biodiesel fuel of the present invention is, in general, using a solid catalyst, transesterifying fats and oils with lower alcohols to produce glycerin, which is a biodiesel fuel fatty acid ester and by-product, This is a method for producing biodiesel fuel.

The solid catalyst used in the present invention is not particularly limited as long as it promotes the transesterification reaction, and examples thereof include metal oxides and ion exchange resins, among which metal oxides such as calcium oxide are used. Solid catalysts containing are preferred.
In particular, steel slag such as blast furnace slag and converter slag is preferable because calcium oxide is abundant, and converter slag is more preferable because metal oxide is contained in a well-balanced manner.

Examples of the lower alcohol include methanol, ethanol, n-propanol, and n-butanol, and among them, methanol is preferable.
When methanol is used as a raw material, fatty acid methyl esters are generated.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. In the following embodiment, an example will be described in which waste edible oil is used as fat and oil, methanol is used as lower alcohol, and fatty acid methyl ester is generated as fatty acid ester.
However, the present invention is not limited to the following embodiments.

FIG. 1 is a conceptual diagram illustrating an example of a biodiesel fuel manufacturing apparatus.
The biodiesel fuel manufacturing apparatus 1 shown in FIG. 1 includes a methanol tank 31 containing methanol as a raw material, a waste cooking oil tank 32 containing a waste cooking oil also as a raw material, and a methanol and waste cooking oil esterified. It mainly comprises a reaction tank 11 for performing an exchange reaction, a product tank 41 for storing fatty acid methyl esters generated by transesterification, and a by-product tank 42 for storing glycerin which is a by-product of transesterification. .

  The reaction tank 11 is, for example, a cylindrical stainless steel container. Part of the reaction tank 11 is made of a transparent member such as glass, and the inside of the reaction tank 11 can be visually recognized from the outside.

Inside the reaction tank 11, a mesh-like mesh 12 is fixedly attached.
A catalyst unit 13 is arranged in a region on the upper surface side of the mesh 12. The catalyst unit 13 is a cartridge containing a plurality of solid catalysts 13a in a stainless steel mesh basket 13b. By replacing the catalyst unit 13, the solid catalyst 13a can be easily replaced. The catalyst unit 13 may be placed on the upper surface of the mesh 12 or may be suspended inside the reaction tank 11.

  The mesh 12 and the mesh basket 13b of the catalyst unit 13 have a mesh shape. And many gaps are also formed between the solid catalysts 13a in the mesh basket 13b. For this reason, inside the reaction tank 11, the liquid is allowed to flow from the upper side to the lower side while contacting the solid catalyst 13a.

When steel slag such as converter slag is used as the solid catalyst 13a, a granular steel slag larger than the mesh may be used so as not to fall off from the mesh of the mesh basket 13b.
Further, if the mesh of the mesh 12 is made finer than the mesh of the mesh cage 13b, even if the solid catalyst 13a falls off from the mesh of the mesh cage 13b, it is captured by the mesh 12.
Further, the mesh 12 also captures other impurities.
As a result, the product and by-products of the transesterification reaction do not contain the solid catalyst 13a and the like, and the trouble of removing the solid catalyst 13a later can be omitted.

  Inside the reaction tank 11, a heater 14 is disposed at a position where the catalyst unit 13 can be heated. The heater 14 is, for example, a coil heater. A heating unit 15 for driving the heater 14 is connected to the heater 14. The heating unit 15 is further connected to a personal computer (PC) 16.

  The reaction tank 11 is further provided with a thermocouple 17 and a liquid level gauge 18. The thermocouple 17 measures the temperature inside the reaction vessel 11. The liquid level gauge 18 measures the liquid amount inside the reaction tank 11. The thermocouple 17 and the liquid level gauge 18 are connected to the PC 16, and each measurement result is input to the PC 16. The PC 16 receives the measurement results of the thermocouple 17 and the liquid level gauge 18 and controls the heating unit 15 to drive the heater 14 so that the inside of the reaction tank 11 has a desired temperature.

  A methanol tank 31 and a waste cooking oil tank 32 are connected to such a reaction tank 11. The methanol tank 31 and the waste cooking oil tank 32 are, for example, drums having a capacity of 200 L.

  More specifically, the methanol tank 31 is connected to the reaction tank 11 via a pipe 61 and a pipe 63. In the middle of the pipe 61, a pump 55 and a flow meter 56 are installed. The pipe 63 is inserted into the upper surface of the reaction tank 11. On / off of the pump 55 is manually selected, and the pump 55 is electrically driven in the on state (the same applies to other pumps). By driving the pump 55, methanol is sucked up from the methanol tank 31, flows through the pipes 61 and 63, and is introduced into the reaction tank 11. The flow rate of methanol flowing through the pipe 61 is measured by the flow meter 56.

  The waste edible oil tank 32 is connected to the upper surface of the reaction tank 11 via a pipe 62 in which a pump 57 is installed on the way and the pipe 63 described above. By driving the pump 57, waste cooking oil is sucked up from the waste cooking oil tank 32, flows through the pipes 62 and 63, and is introduced into the reaction tank 11. A flow meter may be provided after the pump 57. Further, it is preferable to provide a filter in front of the pump 57 in order to remove dust contained in the waste cooking oil.

  A pipe 81 extends from a portion where the pipe 61 and the pipe 62 are connected to the pipe 63, and the pipe 81 is connected to a three-way valve 54 described later.

One end of a pipe 71 on which a pump 51 is installed is connected to a side surface of a lower region (a region lower than the mesh 12) of the reaction tank 11. The connection position between the pipe 71 and the reaction tank 11 can be freely changed in the vertical direction. Before the pump 51, it is preferable to provide a filter for removing the powdered solid catalyst 13a, a silica gel adsorption filter for adsorbing Ca ²⁺ dissolved in the produced fatty acid methyl ester, and the like.

  The other end of the pipe 71 is connected to the three-way valve 53. The three-way valve 53 can be opened and closed manually (the same applies to other three-way valves). The three-way valve 53 is connected to another three-way valve 54 via a pipe 72, and the three-way valve 54 is further connected to a pipe 73 inserted into the upper surface of the reaction tank 11. In this way, the pipe 71, the pump 51, the three-way valve 53, the pipe 72, the three-way valve 54, and the pipe 73 form a circulation mechanism that circulates the liquid so as to pass through the reaction tank 11.

  Further, one end of a pipe 82 is connected to the three-way valve 53, and the other end of the pipe 82 is inserted into the upper surface of the product tank 41. A cooler (not shown) for cooling the liquid (fatty acid methyl ester) flowing through the pipe 82 may be provided in the middle of the pipe 82.

  One end of a pipe 83 in which a pump 52 is installed is connected to the lower surface of the reaction tank 11. The other end of the pipe 83 is inserted into the upper surface of the by-product tank 42. A cooler (not shown) for cooling the liquid (glycerin) flowing through the pipe 83 may be provided in the middle of the pipe 83. Note that a stop valve 58 that can be manually opened and closed is provided between the lower surface of the reaction tank 11 and the pump 52.

  In such a configuration, first, the pump 55 is driven to suck up methanol from the methanol tank 31, and the pump 57 is driven to suck up waste cooking oil from the waste cooking oil tank 32. At this time, the three-way valve 54 is in a state where the connection with the pipe 81 is closed (that is, the state where the pipe 72 and the pipe 73 are connected). Also, the stop valve 58 is kept closed. Thus, the raw material methanol is introduced into the reaction tank 11 through the pipe 61 and the pipe 63. Similarly, waste cooking oil, which is a raw material, is introduced into the reaction tank 11 through the pipes 62 and 63. The introduction amount of the raw material (mixture of methanol and waste cooking oil) inside the reaction tank 11 can be grasped from the measurement result of the liquid level gauge 18.

  When a predetermined amount of the raw material is introduced into the reaction tank 11, the driving of the pump 55 and the pump 57 is stopped, and the introduction of the raw material is stopped. Next, the three-way valve 53 is set to a state where the connection with the pipe 82 is closed (that is, a state where the pipe 71 and the pipe 72 are connected). Then, the pump 51 is driven to circulate the raw material introduced into the reaction tank 11. That is, by driving the pump 51, the raw material introduced into the reaction tank 11 flows through the pipe 71, the pipe 72, and the pipe 73 in this order, and is introduced again into the reaction tank 11.

Thus, the raw material is passed through the reaction tank 11 and comes into contact with the solid catalyst 13a. By contact with the solid catalyst 13a, waste edible oil and methanol in the raw material undergo a transesterification reaction, and glycerin is by-produced while fatty acid methyl esters are produced.
It should be noted that the transesterification reaction does not sufficiently proceed if the raw material only flows through the reaction tank 11 once, and the unreacted raw material remains.
Glycerin by-produced is separated on the basis of the specific gravity difference between the unreacted raw material and the generated fatty acid methyl ester, and settles on the lower surface side of the reaction tank 11.
Then, by continuously driving the pump 51, the unreacted raw material circulates together with the generated fatty acid methyl ester and repeatedly flows through the reaction tank 11, thereby continuously generating the fatty acid methyl ester. Let it.

At the time of circulation, it is preferable to drive the heater 14 for heating. More specifically, the PC 16 receives the measurement results of the thermocouple 17 and the liquid level gauge 18, controls the heating unit 15, and drives the heater 14 so that the inside of the reaction tank 11 has a predetermined temperature. Let it.
The heating temperature is, for example, in the range of 40 to 100C, and preferably about 60C.

By the above-mentioned circulation, the transesterification reaction gradually progresses, waste edible oil and methanol as raw materials are consumed, and the production amount of fatty acid methyl ester and glycerin increases. As described above, since a part of the reaction vessel 11 is formed of a transparent member, the production and the production amount of the fatty acid methyl ester and glycerin inside the reaction vessel 11 can be visually recognized from the outside.
The progress of the transesterification reaction may be confirmed using a liquid level meter or may be confirmed by sampling.

  When the amount of fatty acid methyl ester and glycerin produced reaches a desired amount, the pump 51 is stopped to stop the circulation. At this time, when the transesterification reaction has progressed completely, a glycerin layer is formed in the lower layer and a fatty acid methyl ester layer is formed in the upper layer inside the reaction tank 11.

Then, first, for example, glycerin as a by-product is recovered. Specifically, the stop valve 58 is opened, the pump 52 is driven, the lower layer of glycerin is extracted from the lower surface of the reaction tank 11, the pipe 83 is circulated, and the glycerin is introduced into the by-product tank 42. Even when the pump 51 is driven, when the glycerin has accumulated to some extent, the pump 52 may be driven to discharge the glycerin to the by-product tank 42 or may be continuously extracted.
It is necessary to control the extraction of glycerin so that the upper surface position of the lower layer (glycerin layer) is always lower than the connection position between the pipe 71 and the reaction tank 11. Of course, the whole amount of glycerin may be extracted.
Withdrawal of glycerin from the reaction tank 11 is stopped by stopping the drive of the pump 52. After the stop, the stop valve 58 is also closed.

Next, the fatty acid methyl ester is recovered. At this time, first, the three-way valve 53 is set to a state where the connection with the pipe 72 is closed (that is, a state where the pipe 71 and the pipe 82 are connected). Then, by driving the pump 51, the fatty acid methyl ester is extracted from the side surface of the reaction tank 11, passed through the pipes 71 and 82, and introduced into the product tank 41.
The removal of the fatty acid methyl ester from the reaction tank 11 is stopped by stopping the driving of the pump 51. Then, the three-way valve 53 is switched to return the connection with the pipe 82 to the closed state (the state where the pipe 71 and the pipe 72 are connected).

  After the recovery of the fatty acid methyl ester and glycerin is completed, the above process is repeated. That is, first, methanol and waste cooking oil as raw materials are introduced into the reaction tank 11 from the methanol tank 31 and the waste cooking oil tank 32. Next, the pump 51 is driven to circulate the raw material so as to repeatedly pass through the reaction tank 11. Then, when the production amounts of the fatty acid methyl ester and glycerin reach the desired amounts, the circulation is stopped and both are collected in the product tank 41 and the by-product tank 42, respectively.

  As described above, according to the present embodiment, a fatty acid ester such as a fatty acid methyl ester serving as a biodiesel fuel can be easily obtained.

  Specifically, for example, in the method (batch type) disclosed in Non-Patent Document 1, it is necessary to allow the fatty acid methyl ester to stand after removing the fatty acid methyl ester or to remove the catalyst. In this case, no time is required to stand still, and no operation for removing the catalyst from the product is required, so that the productivity is excellent.

  Further, the method disclosed in Patent Literature 1 has a complicated apparatus configuration for arranging a plurality of stages of catalyst reaction tubes side by side, but in the present embodiment, the reaction tank 11 and the reaction tank 11 Since there is only a circulation mechanism (the pipe 71, the pump 51, the three-way valve 53, the pipe 72, the three-way valve 54, and the pipe 73) for circulating the raw material so as to pass the liquid, a simple configuration can be achieved.

1: Biodiesel fuel production apparatus 11: Reaction tank 12: Mesh 13: Catalyst unit 13a: Solid catalyst 13b: Mesh basket 14: Heater 15: Heating unit 16: PC
17: Thermocouple 18: Liquid level meter 31: Methanol tank 32: Waste cooking oil tank 41: Product tank 42: By-product tank 51, 52, 55, 57: Pump 56: Flow meter 53, 54: Three-way valve 58: Stop Valve 61, 62, 63, 71, 72, 73, 81, 82, 83: pipe

Claims (4)

Using a solid catalyst containing iron and steel slag and a reaction tank in which the solid catalyst is disposed , the oil and fat are transesterified with a lower alcohol to produce a fatty acid ester to be biodiesel fuel and glycerin which is a by-product, A method for producing biodiesel fuel,
Inside the reaction vessel, the liquid is free to flow from the upper side to the lower side while contacting the solid catalyst,
One end of a pipe arranged outside the reaction tank is connected to a side surface of the reaction tank, and a connection position between the pipe and the reaction tank is freely variable in a vertical direction. , Connected to the upper surface side of the reaction vessel,
Raw materials containing fats and oils and lower alcohols are introduced into the inside of the reaction tank, and transesterification is performed by contacting with the solid catalyst, thereby producing fatty acid esters and by-producing glycerin,
Glycerin by-produced is separated by a specific gravity difference between the unreacted raw material and the generated fatty acid ester, and settles on the lower surface side of the reaction vessel,
The unreacted starting material, together with the generated fatty acid ester, by via the pipe withdrawn from the side of the reaction vessel is repeated to introduce into the interior of the reaction vessel again from the upper surface side of the reactor, unreacted Circulating the raw materials of the reaction and the fatty acid ester produced ,
A method for producing biodiesel fuel, wherein the fatty acid ester produced by the circulation is recovered.   The method for producing biodiesel fuel according to claim 1, wherein glycerin by-produced by the circulation is recovered. Wherein the solid catalyst comprises a converter slag, method of producing a biodiesel fuel according to claim 1 or 2. A biodiesel fuel manufacturing apparatus used in the biodiesel fuel manufacturing method according to any one of claims 1 to 3 ,
The reaction vessel;
An apparatus for producing biodiesel fuel, comprising a circulation mechanism for circulating the raw material so as to pass through the reaction tank.

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