JP2010229351A - Method for producing fatty acid alkyl ester and/or glycerine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method that increases yield and quality of a finally obtained fatty acid alkyl ester while achieving extension of a catalyst life in a reaction at a later stage. <P>SOLUTION: The method for producing a fatty acid alkyl ester and/or glycerine includes a first phase separation step of performing phase separation of a first reaction liquid, obtained by reacting fats and oils with alcohols in the presence of a solid catalyst, into a first fatty acid alkyl ester phase and a first glycerine phase using an oil water separation film. A size of pores formed in the oil water separation film used in the first phase separation step is 20 μm or less. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a fatty acid alkyl ester and / or glycerin. More specifically, the present invention relates to a phase separation step in producing a fatty acid alkyl ester and / or glycerin.

  Fatty acid alkyl esters are widely used in fields such as cosmetics and pharmaceuticals, in addition to those obtained from animal and vegetable oils and fats. In recent years, the use as a fuel added to light oil or the like has attracted attention. In other words, this is a biodiesel fuel derived from animal and vegetable oils and fats that is being developed for the purpose of reducing carbon dioxide emissions, and is a fuel that can be used directly as an alternative to light oil or added to light oil at a certain ratio. Use as Glycerin is mainly used as a raw material for producing nitroglycerin, and is also used in a wide range of fields such as raw materials for alkyd resins, pharmaceuticals, foodstuffs, printing inks and cosmetics.

  As a method for producing such fatty acid alkyl ester and glycerin, a method for producing triglyceride, which is a main component of fats and oils, by transesterification with alcohols is widely known.

  Note that in the above reaction formula, R represents an alkyl group having 6 to 22 carbon atoms or an alkenyl group having 6 to 22 carbon atoms having one or more unsaturated bonds.

  In a production method using a transesterification reaction between fats and oils and alcohols, a method using a homogeneous alkali catalyst is widely used industrially. Recently, solid catalysts that do not require the separation and removal of the catalyst that are required when using a homogeneous alkaline catalyst have also been developed (see, for example, Patent Documents 1 to 5). Furthermore, Patent Document 6 discloses a method for producing a fatty acid alkyl ester and / or glycerin using a solid catalyst.

  When a solid catalyst is used in the production of fatty acid alkyl esters and glycerin, not only can the complexity of operation in the production process be avoided, but also wastewater and waste salts generated in the reaction than when using a homogeneous alkali catalyst. Waste can be reduced.

  In the production of the fatty acid alkyl ester and glycerin, the resulting reaction liquid is phase-separated into a fatty acid alkyl ester phase and a glycerin phase to obtain the fatty acid alkyl ester and glycerin. However, in the production of fatty acid alkyl esters and glycerin using a solid catalyst, it is necessary to stand for a very long time in order to completely separate the obtained reaction solution into the fatty acid alkyl ester phase and the glycerin phase. It is a factor that reduces the production efficiency of fatty acid alkyl esters and glycerin.

  In the production of fatty acid alkyl ester and glycerin using a solid catalyst, the cause of the time required for the phase separation step is that the viscosity of the reaction solution obtained by the reaction increases, and unreacted alcohols are removed from the reaction solution. When removing by operations such as flash evaporation, glycerin is finely dispersed in the fatty acid alkyl ester phase and the fatty acid alkyl ester is finely dispersed in the glycerin phase.

Japanese Patent Laying-Open No. 2005-200398 (published July 28, 2005) JP 2006-225352 A (published August 31, 2006) Japanese Patent Laying-Open No. 2005-177722 (published July 7, 2005) Japanese Patent Laid-Open No. 7-173103 (published July 11, 1995) French Patent Publication No. 2752242 JP 2005-206575 A (published August 4, 2005) US Patent Publication No. 2004/0034244 JP 2007-169355 A (published July 5, 2007)

  Conventionally, various devices have been made in order to rapidly and reliably phase-separate a fatty acid alkyl ester phase and a glycerin phase. However, in a gravity sedimentation tank generally used as a phase separation apparatus in the production of fatty acid alkyl esters and glycerin, it is necessary to stand for a long time in order to completely separate the two phases. That is, in order to increase the residence time, the size of the gravity sedimentation tank must be enlarged, which is not realistic. Similarly, when a centrifuge is used, an increase in the size of the equipment is unavoidable, and it is not preferable from the viewpoint of utility cost.

  Patent Document 7 discloses a technique using a coalescer in a final phase separation step in a production method for producing a fatty acid alkyl ester and glycerin by a two-step reaction process. According to the method disclosed in Patent Document 7, it is possible to easily reduce the glycerin concentration in the fatty acid alkyl ester obtained as the final product and the fatty acid alkyl ester concentration in the product glycerin, thereby improving the product quality. Become.

  However, with respect to the previous phase separation process, there is no description on the influence of the quality of the separation on the product quality, and there is no description on the use of the coalescer in the previous phase separation process. Further, in Patent Document 7, details such as separation accuracy in the coalescer are not examined, and there is room for improvement.

  On the other hand, Patent Document 8 discloses a method of using a coalescer in the preceding phase separation step in a production method of producing a fatty acid alkyl ester and glycerin by a two-step reaction process characterized by using an acid catalyst in the latter stage. Has been. According to the method disclosed in Patent Document 8, the amount of glycerin brought into the downstream reactor can be reduced to some extent, and methoxy is known to be by-produced when glycerin is brought into contact with an acid catalyst. Production of propanediol and the like can be suppressed. The method disclosed in Patent Document 8 is an effective technique that can improve the quality of product glycerin as long as it is limited to a process that uses an acid catalyst in the subsequent reaction step.

  However, in Patent Document 8, details such as the separation accuracy in the coalescer are not examined, and there is room for improvement. Further, there is no description regarding the relationship between the amount of moisture brought into the subsequent reaction process and the life of the catalyst at the latter stage, and the influence of the moisture brought in on the product quality is not taken into consideration. That is, phase separation conditions for suitably removing moisture have not been sufficiently studied, and there is still room for improvement when using a catalyst that is affected by moisture in the subsequent reaction step.

  The present invention has been made in view of the above problems, and improves the yield and quality of a fatty acid alkyl ester and a catalyst in a subsequent reaction when producing a fatty acid alkyl ester and glycerin by a plurality of reaction steps. The main purpose is to prolong the life of the product.

  The present inventors diligently studied why the fatty acid alkyl ester having satisfactory quality cannot be obtained when the techniques described in Patent Documents 7 and 8 are used. As a result, it was clarified that the glycerin concentration in the liquid used in the subsequent reaction affects the quality and yield of the fatty acid alkyl ester obtained as the final product.

  More specifically, the transesterification reaction for producing a fatty acid alkyl ester and glycerin from fats and alcohols and alcohols is a sequential equilibrium reaction as shown in FIG. 2 (in FIG. 2, the alcohols are methanol). As an example). Therefore, when the glycerin is distributed to the fatty acid alkyl ester phase and the concentration of glycerin in the fatty acid alkyl ester is high in a plurality of reaction steps as in Patent Documents 7 and 8, the equilibrium condition is determined in the reaction in the subsequent reaction step. Is a disadvantageous condition. The present inventors have increased the unconverted glycerides (triglyceride, diglyceride, monoglyceride) in the reaction solution obtained by the latter reaction due to disadvantageous equilibrium conditions in the latter reaction step, and the fatty acid alkyl ester obtained. It was found that the quality deteriorates with the decrease in the yield.

  In addition, as a result of intensive studies on the reason why the life of the catalyst used in the subsequent reaction is shortened when the techniques described in Patent Documents 7 and 8 are used, the present inventors have found that glycerin is present in the fatty acid alkyl ester phase. In the case of distribution, it has been clarified that water is supplied to the subsequent reaction step together with glycerin distributed to the fatty acid alkyl ester phase, thereby shortening the life of the catalyst used in the subsequent reaction step. In Patent Documents 7 and 8, the water content of the fatty acid alkyl ester phase obtained in the preceding reaction step, the water content supplied to the subsequent reaction step, and the life of the catalyst in the subsequent reaction step are described. Is not disclosed.

  As described above, the inventors of the present invention have found that when the fatty acid alkyl ester and glycerin are produced by a plurality of reaction steps, the yield of the fatty acid alkyl ester and the life of the catalyst used in the subsequent reaction are reduced. It is found that it is caused by the glycerin concentration and water content in the liquid used in the process, and newly includes a process for simultaneously and sufficiently reducing the glycerin concentration and water content in the liquid used in the subsequent reaction step. The invention has been completed. The present invention has been completed by such new knowledge and includes the following inventions.

In the method for producing a fatty acid alkyl ester and / or glycerin according to the present invention,
A first reaction step in which fats and alcohols are reacted in the presence of a solid catalyst, and a first reaction liquid obtained in the first reaction step are converted into a first fatty acid alkyl using an oil-water separation membrane. A first phase separation step of phase-separating into an ester phase and a first glycerin phase, and a second reaction in which fats and oils contained in the first fatty acid alkyl ester phase and alcohols are reacted in the presence of a solid catalyst. The pore size formed in the oil-water separation membrane is 20 μm or less.

  In the method for producing a fatty acid alkyl ester and / or glycerin according to the present invention, in the first phase separation step of phase-separating the first reaction liquid obtained in the first reaction step, pores having a size of 20 μm or less are used. The formed oil / water separation membrane is used.

  Thereby, complete separation of each phase is achieved, and the water concentration supplied to the second reaction step in the subsequent stage can also be effectively reduced. Therefore, the lifetime of the solid catalyst in the second reaction step in the subsequent stage There is an effect that can extend the life.

  By prolonging the life of the solid catalyst, the frequency of replacing the solid catalyst in the reactor (reaction tower) can be reduced, so that productivity can be improved and the complicated work of replacing the catalyst can be achieved. The number of processes can also be reduced.

  Moreover, according to said structure, while being able to isolate | separate a 1st fatty-acid alkylester phase and a 1st glycerol phase rapidly, it suppresses that glycerol distributes to a 1st fatty-acid alkylester phase. Can do.

  Therefore, since the glycerin concentration in the first fatty acid alkyl ester phase can be reduced, the equilibrium conditions for the transesterification reaction in the second reaction step in the subsequent stage can be suitably maintained. That is, according to said structure, there also exists an effect which can improve the quality and yield of the fatty-acid alkylester obtained in a 2nd reaction process.

  In the method for producing a fatty acid alkyl ester and / or glycerin according to the present invention, the second reaction liquid obtained in the second reaction step is further converted into a second fatty acid alkyl ester phase using an oil-water separation membrane. It is preferable to further include a second phase separation step for phase separation into a second glycerin phase.

  According to said structure, the 2nd reaction liquid obtained in the 2nd reaction process can also be phase-separated rapidly and reliably like the 1st reaction liquid. This produces an effect that the quality of the finally obtained fatty acid alkyl ester can be further improved.

  In the method for producing a fatty acid alkyl ester and / or glycerin according to the present invention, the water content contained in the first fatty acid alkyl ester phase is preferably 0.1% by mass or less.

  By setting the water content contained in the first fatty acid alkyl ester phase within the above range, the solid catalyst used in the second reaction step has an effect of sufficiently extending the life.

  In the method for producing a fatty acid alkyl ester and / or glycerin according to the present invention, the concentration of glycerin contained in the first fatty acid alkyl ester phase is preferably 0.1% by mass or less.

  By setting the concentration of glycerin contained in the first fatty acid alkyl ester phase within the above range, the quality and yield of the fatty acid alkyl ester obtained in the second reaction step can be sufficiently improved. .

In the apparatus for producing fatty acid alkyl ester and / or glycerin according to the present invention, in order to solve the above problems,
A first reactor for reacting oils and fats in the presence of a solid catalyst, and a first reaction liquid obtained in the first reactor, the first fatty acid alkyl ester phase and the first A first phase separator including an oil / water separation membrane for phase separation into a glycerin phase, an oil and fat contained in the first fatty acid alkyl ester phase, and an alcohol are reacted in the presence of a solid catalyst. 2, and the size of the holes formed in the oil-water separation membrane is 20 μm or less.

  According to said structure, there exists an effect similar to the manufacturing method of the fatty-acid alkylester and / or glycerol which concerns on this invention.

  In the method for producing a fatty acid alkyl ester and / or glycerin according to the present invention, in the first phase separation step of phase-separating the first reaction liquid obtained in the first reaction step, pores having a size of 20 μm or less are used. The formed oil / water separation membrane is used.

  As a result, the water concentration supplied to the second reaction step in the latter stage can be made very low, and the life of the solid catalyst in the second reaction step in the latter stage can be extended. In addition, since the equilibrium condition of the transesterification reaction in the second reaction step in the subsequent stage using the first fatty acid alkyl ester phase can be suitably maintained, the quality of the fatty acid alkyl ester obtained in the second reaction step and There exists an effect which can improve a yield.

It is a schematic diagram which shows typically the manufacturing apparatus of fatty-acid alkylester and / or glycerol. It is a figure which shows the production | generation reaction of a fatty-acid alkylester and / or glycerol.

  An embodiment of the method for producing a fatty acid alkyl ester and / or glycerin according to the present invention will be described. In the present specification and the like, “fatty acid alkyl ester and / or glycerin” has the same meaning as “at least one of fatty acid alkyl ester and glycerin”.

  The method for producing a fatty acid alkyl ester and / or glycerin according to the present invention mainly includes a reaction step, a purification step, and a phase separation step. Details of these steps will be described below.

(Process for producing fatty acid alkyl ester and / or glycerin)
Here, the manufacturing process of the fatty acid alkyl ester and / or glycerin including each step described above will be described below with reference to FIG. FIG. 1 is a schematic view schematically showing an apparatus for producing a fatty acid alkyl ester and / or glycerin according to the present invention.

  As shown in FIG. 1, a manufacturing apparatus 1 for producing a fatty acid alkyl ester and / or glycerin mainly includes an oil and fat storage tank 2, an alcohol storage tank 3, a waste storage tank 4, a fatty acid alkyl ester storage tank 5, and a glycerin storage. Tank 6, first reactor 10, first pressure flash tower 11, first atmospheric pressure flash tower 12, alcohol purification tower 13, first separator 14, second reactor 20, second pressure flash tower 21, A second atmospheric flash tower 22, an alcohol distillation tower 23, a second separator 24, and a line connecting them are provided.

  As shown in FIG. 1, alcohol is supplied from the alcohol storage tank 3 to the first reactor 10, and fats and oils are supplied from the fat storage tank 2 to the first reactor 10. At this time, oils and fats and alcohols are heated and pressurized, and then supplied to the first reactor 10 filled with the solid catalyst. The first reactor 10 and the first reaction step in the first reactor 10 will be described in detail below.

  The reaction liquid containing the fatty acid alkyl ester and glycerin obtained by passing through the first reactor 10 is sent to the first pressure flash tower 11. The first pressure flash tower 11 distills unreacted alcohols from the reaction solution, and the unreacted alcohols that have been distilled off are sent to the heat exchanger 30. The reaction liquid from which unreacted alcohols have been distilled off is supplied to the first atmospheric pressure flash tower 12. The first atmospheric flash tower 12 again distills off unreacted alcohols contained in the reaction solution, and the unreacted alcohols distilled off are supplied to the alcohol purification tower 13. In the first atmospheric pressure flash tower 12, the reaction solution from which unreacted alcohols have been distilled off is supplied to the first separator 14. Details of the first purification step in the first pressurized flash tower 11 and the first atmospheric flash tower 12 will be described in detail below.

  Subsequently, the alcohol purification tower 13 regenerates alcohols from unreacted alcohols. The regenerated alcohol is sent to the alcohol storage tank 3 and used again as a raw material. Further, substances (wastes) other than alcohols contained in the unreacted alcohols are discharged out of the apparatus and stored in the waste storage tank 4. In addition, when regenerating alcohols from unreacted alcohols, the amount of heat recovered from unreacted alcohols using the heat exchanger 30 and the heat exchanger 31 may be used.

  On the other hand, the first separator 14 supplied with the reaction liquid obtained by distilling off the unreacted alcohols separates the supplied reaction liquid into a fatty acid alkyl ester phase (upper phase) and a glycerin phase (lower phase). The first phase separation step in the first separator 14 will be described in detail below.

  The upper fatty acid alkyl ester phase is mixed with the alcohol supplied from the alcohol storage tank 3 and supplied to the second reactor 20. Thereby, the unreacted fats and oils contained in the fatty acid alkyl ester phase are completely reacted. The second reactor 20 and the second reaction step in the second reactor 20 will be described in detail below.

  The reaction liquid containing the fatty acid alkyl ester and glycerin obtained by passing through the second reactor 20 is sent to the second pressure flash tower 21. The second pressure flash tower 21 distills off unreacted alcohols from the reaction solution. The reaction liquid from which unreacted alcohols have been distilled off is supplied to the second atmospheric pressure flash tower 22. The second atmospheric flash tower 22 again distills off the unreacted alcohol contained in the reaction solution, and the unreacted alcohol that has been distilled off is sent to the alcohol storage tank 3 and reused as a raw material. The In the second atmospheric pressure flash tower 22, the reaction liquid from which unreacted alcohols have been distilled off is supplied to the alcohol distillation tower 23. Note that the glycerin phase, which is the lower phase separated in the first separator 14, is also supplied to the alcohol distillation column 23. Details of the second purification step in the second pressurized flash tower 21 and the second atmospheric flash tower 22 will be described in detail below.

  Subsequently, the reaction liquid obtained by distilling off the unreacted alcohol and the alcohol distillation column 23 supplied with glycerin separated in the first separator 14 are used to remove the unreacted alcohol contained in the supplied reaction liquid and glycerin. Further distill off. The unreacted alcohols distilled off are supplied to the alcohol purification tower 13 and regenerated as alcohols.

  The reaction liquid from which unreacted alcohols have been distilled off in the alcohol distillation column 23 is supplied to the second separator 24. The second separator 24 phase-separates the supplied reaction liquid into a fatty acid alkyl ester phase (upper phase) and a glycerin phase (lower phase). The fatty acid alkyl ester phase that is the upper phase is sent to the fatty acid alkyl ester storage tank 5, and the glycerin phase that is the lower phase is sent to the glycerin storage tank 6. The second phase separation step in the second separator 24 will be described in detail below.

  The series of steps in the “reaction system” refers to the entire series of processing steps described above. That is, all the process steps other than the above-described process steps are “outside the reaction system”.

  Next, the details of the first reaction step, the second reaction step, the first purification step, the second purification step, the first phase separation step, and the second phase separation step described above will be described below. To do.

(Details of first phase separation step and second phase separation step)
In the present embodiment, first, the first phase separation step and the second phase separation step, which are features of the present invention, will be described. In the first phase separation step, in the first separator 14, a solution obtained by distilling off unreacted alcohols from the first reaction solution obtained in the first reaction step is used as the first fatty acid alkyl ester phase. This is a step of phase separation into the first glycerin phase.

  At this time, in the first phase separation step, a liquid obtained by distilling off unreacted alcohols from the first reaction liquid is phase-separated using an oil / water separation membrane (coalescer). The oil-water separation membrane is a membrane that is coarsened by capturing and agglomerating glycerin finely dispersed in the fatty acid alkyl ester phase with an ultrafine fiber filter. As a result, glycerin finely dispersed in the micron order can be coarsened in the millimeter order, and rapid and reliable phase separation can be performed using the specific gravity difference.

  Thus, the first fatty acid alkyl ester phase and the first glycerin phase can be quickly separated, and distribution of glycerin to the first fatty acid alkyl ester phase can be suppressed. Therefore, since the glycerin concentration in the first fatty acid alkyl ester phase can be reduced, the equilibrium conditions for the transesterification reaction in the second reaction step can be suitably maintained. That is, the quality and yield of the fatty acid alkyl ester obtained in the second reaction step can be improved.

  In addition, since the water concentration supplied to the second reaction step can also be reduced, the life of the solid catalyst used in the second reaction step can be extended. By prolonging the life of the solid catalyst, the frequency of replacing the solid catalyst in the second reactor 20 can be reduced, so that the productivity of fatty acid alkyl ester and glycerin can be improved, and the catalyst The number of complicated processes of replacement work can also be reduced.

  In the second phase separation step, in the second separator 24, a solution obtained by distilling off unreacted alcohols from the second reaction solution obtained in the second reaction step is used as a second fatty acid alkyl ester. Phase separation into a phase and a second glycerin phase. In the second phase separation step, phase separation may be performed using a conventionally known gravity settling tank, but it is preferable to perform phase separation using an oil-water separation membrane as in the first phase separation step.

  Also in the second phase separation step, by performing phase separation using an oil / water separation membrane, the second reaction liquid can also be phase-separated quickly and reliably as in the first reaction liquid. Thereby, the time required for the phase separation step can be further shortened. Moreover, the quality of the fatty acid alkyl ester and glycerin finally obtained can be further improved.

  Further, in the case of obtaining fatty acid alkyl ester and / or glycerin having higher purity in the first separator 14 and the second separator 24, a purification column is further provided after the first separator 14 and the second separator 24. It may be provided.

(Details of the first separator 14 and the second separator 24)
Here, details of the first separator 14 and the second separator 24 used in the first phase separation step and the second phase separation step will be described. The first separator 14 and the second separator 24 (also simply referred to as coalescers) incorporate a coalescer element that acts as a filter. A coalescer element (also referred to as a filter element or element) is a cartridge-shaped device in which an oil / water separation membrane such as a nonwoven fabric or a support screen is inserted into a cylindrical casing.

  The form of the coalescer is preferably of a type in which the coalescer element itself can be replaced in order to facilitate maintenance and the like.

  The coalescer element may be a type that can suitably aggregate a hydrophilic fluid (for example, water, glycerin, lower alcohol) finely dispersed in a hydrophobic fluid (for example, fat, fatty acid alkyl ester, gasoline, light oil). preferable. The oil / water separation membrane used for such a coalescer element is preferably formed by processing and combining hydrophilic materials into pleats. Examples of the hydrophilic material include filter paper, glass wool, and polyethylene terephthalate (PET). Among these, PET is preferable. Moreover, only one type of hydrophilic material may be used for the oil / water separation membrane, or a plurality of types of materials may be appropriately combined.

  The size of pores (hereinafter referred to as pore diameter) formed in the oil / water separation membrane provided in the coalescer element is preferably 20 μm or less, more preferably 10 μm or less, and more preferably 5 μm or less. More preferably. By setting the upper limit value of the pore diameter of the pores formed in the oil / water separation membrane within the above range, droplets finely dispersed with a size equal to or smaller than the pore diameter can be surely aggregated and coarsened. Accordingly, the smaller the pore diameter, the more preferable because small droplets can be aggregated. The lower limit of the hole diameter is not particularly limited as long as the pressure loss before and after the coalescer does not cause a problem in the operation of the apparatus.

  The temperature of the treatment liquid in the first separator 14 and the second separator 24 is preferably in the range of 10 to 80 ° C, more preferably in the range of 20 to 70 ° C, and in the range of 30 to 60 ° C. More preferably it is.

  By performing the phase separation treatment at a temperature equal to or higher than the lower limit of the above range, precipitation of glycerides contained in the reaction solution can be prevented and the viscosity of the solution is suitably reduced. Can be suppressed. Moreover, by performing the phase separation process at a temperature equal to or lower than the upper limit value in the above-described range, it is possible to improve the separation efficiency and to suppress the corrosion of the element and the seal member.

  The water content in the fatty acid alkyl ester phase (upper phase) phase-separated in the first separator 14 is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, and 0 It is more preferable that it is 0.05 mass% or less, and it is especially preferable that it is 0.01 mass% or less.

(Details of first reaction step and second reaction step)
Next, details of the first reaction step and the second reaction step will be described. Each of the first reaction step and the second reaction step is a step of producing a fatty acid alkyl ester and / or glycerin by mixing fats and oils and an alcohol and causing a transesterification reaction in the presence of a solid catalyst.

  In the transesterification reaction, fatty acid alkyl ester and glycerin can be obtained at the same time. Therefore, purified glycerin useful for various uses as a chemical raw material and fatty acid alkyl ester useful for biodiesel fuel are industrially simple. Can get to. Here, solid catalysts, alcohols and fats and oils that can be suitably used in the present invention will be described in detail below.

  The temperature of the mixed solution of fats and oils and alcohols in the first reactor 10 and the second reactor 20, that is, the reaction temperature is preferably in the range of 100 to 300 ° C, and in the range of 120 to 270 ° C. It is more preferable that it is in the range of 150 to 235 ° C. By setting the reaction temperature within the above range, the reaction rate can be sufficiently improved and the decomposition of alcohols can be sufficiently suppressed.

  The pressure in the first reactor 10 and the second reactor 20, that is, the reaction pressure is preferably in the range of 0.1 to 10 MPa, more preferably in the range of 0.2 to 9 MPa, and More preferably, it is in the range of 3-8 MPa. By setting the reaction pressure within the above range, the reaction rate can be sufficiently improved and side reactions can be sufficiently suppressed. When the reaction pressure exceeds 10 MPa, a special device that can withstand high pressure is required, and thus costs such as equipment costs are extra.

  The supply amount of alcohols and fats and oils supplied to the first reactor 10 and the second reactor 20 is within a range of 1 to 30 times the theoretical required amount of the supply amount of alcohols with respect to the supply amount of fats and oils. It is preferable to be within a range of 1.2 to 20 times, more preferably within a range of 1.5 to 15 times, and further preferably within a range of 2 to 10 times. Even more preferred. By making the supply amount of alcohols within the above range relative to the supply amount of fats and oils, the fats and alcohols can be sufficiently reacted, and the conversion rate of fats and oils can be sufficiently improved. In addition, the amount of alcohol recovered in the first purification step or the second purification step and the utility cost for the alcohol purification tower 13 or the alcohol distillation tower 23 can be reduced, so that the manufacturing cost can be reduced. .

  In addition, the theoretical required amount of alcohol in the present specification and the like refers to the number of moles of alcohol corresponding to the saponification value of fats and oils, and can be calculated by the following formula.

  Theoretical required amount of alcohol (g) = molecular weight of alcohol × [amount of used fat (g) × saponification value (mg (KOH) / g (fat)) / 56100].

  The form of the first reactor 10 and the second reactor 20 may be either a batch type or a fixed bed flow type, but is preferably a fixed bed flow type. By using the first reactor 10 and the second reactor 20 as fixed bed reactors filled with a solid catalyst, the step of separating the catalyst can be eliminated. Thereby, since a complicated work process can be omitted, industrial production can be facilitated. Conventionally known conditions can be used for conditions such as reaction time when the first reactor 10 and the second reactor 20 are fixed bed reactors and when batch reactors are used.

  In addition, when fats and oils contain impurities, such as phospholipid and protein, you may provide the degumming reaction tank for adding the mineral acid and performing the degumming process which removes an impurity. The degumming reaction tank is preferably installed in front of the first reactor 10, and more preferably before mixing with fats and oils and alcohols.

(Details of the first purification step and the second purification step)
Then, the detail of a 1st refinement | purification process and a 2nd refinement | purification process is demonstrated. The first purification step and the second purification step are steps for distilling off unreacted alcohol from the reaction liquid obtained in the first reaction step and the second reaction step, respectively.

  The first purification step and the second purification step are preferably performed by at least two different pressures. Referring to FIG. 1, the first stage purification is the purification in the first pressure flash tower 11 and the second pressure flash tower 21, and the second stage purification is the first atmospheric flash tower 12 and the second pressure flash tower 21. Purification is performed in the atmospheric flash tower 22.

  The first stage purification in the first purification step and the second purification step, that is, the pressure in the first pressure flash tower 11 and the second pressure flash tower 21 is within the range of 0.15 to 1.5 MPa. It is preferable that it is within a range of 0.20 to 1.0 MPa. Moreover, it is preferable that the pressure in the 1st normal pressure flash tower 12 or the 2nd normal pressure flash tower 22 is a normal pressure.

  Note that “normal pressure” in this specification and the like means that the pressure is in the range of 0.095 to 0.105 MPa.

  In the present embodiment, the first purification process and the second purification process are two-stage purification, but the present invention is not limited to this, and may be one stage, or three or more stages. Also good. However, when the first purification step and / or the second purification step is one stage of the pressure flash tower, the amount of alcohol contained in the heavy liquid withdrawn from the bottom increases, and the latter phase There exists a possibility that the separation efficiency in a separation process may worsen. Specifically, fatty acid alkyl esters and / or monoglycerides are distributed to the glycerin phase, and the yield and purity of fatty acid alkyl esters and / or glycerin may be reduced.

  As the first pressurized flash tower 11, the second pressurized flash tower 21, the first atmospheric flash tower 12, and the second atmospheric flash tower 22, a conventionally known flash tower can be used.

(Additional notes)
In the present embodiment, the production method including two reaction steps of the first reaction step and the second reaction step is described as an example. However, the present invention is not limited to this, and the reaction step is not limited to this. There may be three or more stages. When the reaction process has three or more stages, it is preferable to phase-separate a liquid obtained by distilling off unreacted alcohols from the obtained reaction liquid using an oil-water separation membrane for each reaction process.

(Solid catalysts, alcohols and fats)
Here, solid catalysts, alcohols and fats and oils that can be suitably used in the present invention will be described.

(Solid catalyst)
The solid catalyst that can be suitably used in the present invention is a compound having a catalytic action in the transesterification reaction, being hardly dissolved in a reaction solution containing raw materials and products, and is a raw material such as fats and alcohols. And an insoluble solid catalyst that is insoluble in a reaction solution containing a fatty acid alkyl ester and glycerin as products. In the present specification and the like, “insoluble” of the solid catalyst means that the active component (for example, active metal component) is 1000 ppm or less, preferably 800 ppm or less, more preferably 600 ppm or less, more preferably in the reaction solution after the transesterification reaction. 300 ppm or less, most preferably means not detected by the analyzer. In addition, the density | concentration (elution amount) of the active component of the insoluble solid catalyst in a reaction liquid can be measured using a fluorescent X ray analysis method (XRF). In the fluorescent X-ray analysis method, the reaction solution after the reaction can be used in a solution state. Moreover, when measuring a very small amount of elution, it may be measured by a high frequency induction plasma (ICP) emission analysis method.

  As the solid catalyst that can be suitably used in the present invention, it is preferable that the solid catalyst can be easily removed from the reaction system after the transesterification reaction between fats and alcohols. The solid catalyst is an active catalyst for the esterification reaction of free fatty acids contained in fats and oils, that is, for both the ester exchange reaction of glycerides contained in fats and oils and the esterification reaction of free fatty acids. The catalyst is preferably active. Thereby, even if the fats and oils which are raw materials contain the free fatty acid, transesterification and esterification can be performed simultaneously. Thereby, the yield of fatty acid alkyl ester can be improved without performing an esterification reaction separately from the transesterification reaction.

  Specific examples of solid catalysts that can be suitably used in the present invention include alkali metal compounds, alkaline earth metal compounds, aluminum-containing compounds, silicon-containing compounds, titanium-containing compounds, vanadium-containing compounds, chromium-containing compounds, and manganese-containing compounds. Compound, iron containing compound, cobalt containing compound, nickel containing compound, copper containing compound, zinc containing compound, zirconium containing compound, niobium containing compound, molybdenum containing compound, tin containing compound, rare earth containing compound, tungsten containing compound, lead containing compound, A bismuth-containing compound or an ion exchange resin is preferred.

  Although it does not specifically limit as long as it has the said essential component as said compound, For example, it is preferable that it is a form, such as single, mixed or complex oxide, a sulfate, a phosphate, a cyanide, a halide, a complex. Among these, single, mixed, or complex oxides or cyanides are more preferable. Specifically, aluminum oxide, titanium oxide, manganese oxide, zinc oxide, zirconium oxide, and these or Mixtures and / or composite oxides with other metals, zinc cyanide, iron cyanide, cobalt cyanide, and mixtures and / or composite cyanides with these or other metals can be mentioned. These forms may be supported or immobilized on a support, and examples of the support include silica, alumina, silica / alumina, various zeolites, activated carbon, diatomaceous earth, zirconium oxide, and titanium oxide. , Tin oxide, lead oxide and the like.

  Examples of ion exchange resins include anion exchange resins. Specific examples of anion exchange resins include strong base anion resins and weak base anion resins. When anion exchange resins are classified according to the degree of crosslinking or porosity, they are gel type, porous type and high type. Examples thereof include a porous type.

(Oils and fats)
The fats and oils that can be suitably used in the present invention are those containing fatty acid esters of glycerin and can be used as starting materials for fatty acid alkyl esters and / or glycerin together with alcohols. It will not be specifically limited if it contains the fatty acid ester of glycerol called. Usually, it is preferable to use fats and oils containing triglyceride (triester of glycerin and higher fatty acid) as a main component and diglyceride, monoglyceride, free fatty acid and other minor components, but glycerin such as triolein or tripalmitin. The fatty acid ester may be used.

  Specific examples of such fats and oils include coconut oil, rapeseed oil, sesame oil, soybean oil, corn oil, sunflower oil, palm oil, palm kernel oil, coconut oil, safflower oil, linseed oil, cottonseed oil, tung oil and castor oil And vegetable oils such as beef fat, pig oil, fish oil and whale fat, and used oils (waste cooking oil) of various edible oils. In addition, these fats and oils may be used independently and may be used in mixture of 2 or more types.

  In addition, when the above-mentioned fats and oils contain impurities, such as phospholipid and protein, it is preferable to add mineral acids, such as a sulfuric acid, nitric acid, phosphoric acid, or boric acid, and to remove impurities. In the method for producing a fatty acid alkyl ester and / or glycerin according to the present invention, if a fatty acid alkyl ester and / or glycerin that is less susceptible to reaction inhibition by a mineral acid is used as a catalyst, Since it can manufacture efficiently, it is more preferable.

(Alcohols)
The alcohol that can be suitably used in the present invention is preferably an alcohol having 1 to 6 carbon atoms as the alcohol when the production of biodiesel fuel is intended. More preferably, alcohols are used. Examples of the alcohol having 1 to 6 carbon atoms include methanol, ethanol, propanol, isopropyl alcohol, 1-butanol, 2-butanol, t-butyl alcohol, 1-pentanol, 3-pentanol, 1-hexanol and 2 -Hexanol etc. can be mentioned. Among these, methanol or ethanol is preferable. Moreover, these alcohols may be used independently and may be used in mixture of 2 or more types.

  Moreover, in the manufacturing method of the fatty-acid alkylester and / or glycerol which concern on this invention, other trace components other than fats and oils, alcohols, and a solid catalyst may exist.

  In the present specification and the like, “alcohols” mean a generic name of compounds in which hydrocarbon hydrogen atoms are substituted with hydroxyl groups.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  Hereinafter, an Example is shown and it demonstrates in more detail about the form of this invention. Of course, the present invention is not limited to the following examples, and various modes are possible for details.

[Example 1]
(Method for preparing solid catalyst)
Activated alumina (74 parts, AC-12 manufactured by Sumitomo Chemical Co., Ltd.) was impregnated with and supported by a 50% by weight manganese nitrate aqueous solution (36 parts). Subsequently, the activated alumina supporting manganese nitrate was dried in an evaporating dish on a hot water bath, then dried in a dryer at 120 ° C. for a whole day and night, and calcined at 800 ° C. for 5 hours in an air stream.

(Production of fatty acid alkyl esters and glycerin)
In this example, palm oil and methanol were used as reaction raw materials. In addition, the refined palm oil which degummed palm oil was used. Further, the solid catalyst (15 mL) was packed into a SUS316 reactor (first reactor 10) having an inner diameter of 10 mm and a length of 210 mm.

  Palm oil (6.3 g / hr) and methanol (6.3 g / hr) are continuously fed using a precision high-pressure metering pump, heated to 200 ° C. and mixed with a line mixer, then the first reactor 10 It was distributed downward from the top. In the first reactor 10, 200 ° C. and 5 MPa were maintained.

  The reaction liquid obtained in the first reactor 10 was supplied to the first pressure flash tower 11. The pressure of the 1st pressurization flash tower 11 was 0.35 MPa. Next, the heavy liquid continuously extracted from the bottom of the first pressurized flash tower 11 was supplied to the first atmospheric flash tower 12. The heavy liquid continuously extracted from the first pressure flash tower 11 contained 17% by mass of methanol.

  The heavy liquid extracted from the bottom of the first atmospheric pressure flash tower 12 was separated into an upper phase and a lower phase using a coalescer (oil-water separation membrane, pore size 2 μm; first separator 14). Each phase was obtained as a homogeneous phase. The upper phase contained 0.05% by mass of glycerin.

  Subsequently, the obtained upper phase (6.3 g / hr) was continuously supplied to the second reactor 20, and methanol (6.3 g / h) was obtained under the same conditions as the first reactor 10 (200 ° C., 5 MPa). hr). In the second reactor 20, 6 mL of the solid catalyst described above was charged.

  Next, the reaction solution obtained in the second reactor 20 was supplied to the second pressure flash tower 21. The pressure of the second pressurized flash tower 21 was 0.35 MPa. Next, the heavy liquid continuously extracted from the bottom of the second pressure flash tower 21 was supplied to the second atmospheric flash tower 22. The heavy liquid continuously extracted from the second pressure flash tower 21 contained 14% by mass of methanol.

  In order to mix the heavy liquid extracted from the bottom of the second atmospheric pressure flash tower 22 and the lower phase (glycerin phase) in the first separator 14, and to dissipate unreacted methanol contained in the mixed liquid, It supplied to the thin film evaporator (alcohol distillation tower 23). The pressure inside the thin film evaporator was adjusted to 0.03 MPa, and the reboiler temperature was adjusted to 175 ° C. The residence time was 2 minutes. The heavy liquid continuously extracted from the bottom of the thin film evaporator contained 0.07% by mass of methanol.

  Next, the obtained heavy liquid was separated into an upper phase and a lower phase using a coalescer (oil-water separation membrane, pore size 2 μm; second separator 24). The obtained upper phase contained fatty acid methyl ester (purity> 99% by mass), and the lower phase contained glycerin (purity> 99% by mass). At this time, the glycerin concentration contained in the upper phase was less than 0.05% by mass. The composition of the obtained fatty acid methyl ester is shown in Table 1. The units of fatty acid methyl ester, glycerin and monoglyceride in Table 1 are all in mass% concentration.

  In the present example, the water content contained in the upper phase separated by the first separator 14 was less than 0.01% by mass. In this example, the catalyst was not deteriorated for 2000 hours or more, and no change in the composition of the reaction solution over time was observed.

[Comparative Example 1]
Fatty acid methyl ester and glycerin were obtained in the same manner as in Example 1 except that the phase separation in the first separator 14 and the second separator 24 was performed using a continuous gravity sedimentation tank without using a coalescer. Manufactured.

  In both the first separator 14 and the second separator 24, the upper phase and the lower phase were not completely separated, and were obtained as a suspension. The upper phase obtained in the first separator 14 contained 2.1% by mass of glycerin. The composition of the fatty acid methyl ester finally obtained is shown in Table 1.

  In this comparative example, the water content contained in the upper phase separated by the first separator 14 was 0.12% by mass. In this comparative example, deterioration of the catalyst in the latter stage was observed after continuous use for about 1000 hours or more, resulting in a gradual increase in the concentration of glycerides in the reaction solution.

[Comparative Example 2]
Fatty acid methyl ester and glycerin were produced in the same manner as in Example 1 except that the phase separation in the first separator 14 was performed using a continuous gravity sedimentation tank without using a coalescer.

  In the first separator 14, the upper phase and the lower phase were not completely separated and were obtained as a suspension. The upper phase obtained in the first separator 14 contained 2.1% by mass of glycerin. The composition of the fatty acid methyl ester finally obtained is shown in Table 1.

  In this comparative example, the water content contained in the upper phase separated by the first separator 14 was 0.12% by mass. In this comparative example, deterioration of the catalyst in the latter stage was observed after continuous use for about 1000 hours or more, resulting in a gradual increase in the concentration of glycerides in the reaction solution.

[Comparative Example 3]
Fatty acid methyl esters and glycerin were produced in the same manner as in Example 1 except that a coalescer with a pore size of 50 μm was used in the first separator 14.

  In the first separator 14, the upper phase and the lower phase were not completely separated, and each phase was obtained as a suspension. The upper phase obtained in the first separator 14 contained 1.9% by mass of glycerin. The composition of the fatty acid methyl ester finally obtained is shown in Table 1.

  In this comparative example, the water content contained in the upper phase separated by the first separator 14 was 0.10% by mass. In this comparative example, deterioration of the catalyst in the latter stage was observed after continuous use for about 1000 hours or more, and the concentration of glycerides in the reaction solution gradually increased.

〔result〕
As shown in Table 1, by phase separation using a coalescer in the first stage phase separation process, compared to the case where no coalescer is used in the first stage phase separation process, contained in fatty acid methyl ester It has been shown that the concentration of monoglycerides being reduced can be reduced to about 1/3. That is, it was found that the effect of using the coalescer in the first stage phase separation process is about 3.3 times that when using the coalescer only in the second stage phase separation process.

  Also, as shown in Table 1, by using a coalescer with a pore size of 2 μm in the first phase separation step, compared with the case where a coalescer with a pore size of 50 μm is used in the first phase separation step, the fatty acid It has been shown that the concentration of monoglyceride contained in the methyl ester can be reduced to about 1/3. In other words, it was found that the effect of using a coalescer with a pore size of 2 μm in the first stage phase separation process is about 3.2 times that when using a coalescer with a pore diameter of 50 μm in the first stage phase separation process. .

  The concentration of monoglyceride in the case where the coalescer is used only in the second stage (Comparative Example 2) and the concentration of monoglyceride in the case where the coalescer with a pore size of 50 μm is used in the first stage (Comparative Example 3) It was almost the same as the case where no coalescer was used in any of the second stages (Comparative Example 1).

  According to the method for producing fatty acid alkyl ester and glycerin according to the present invention, glycerin that can be used as a raw material for fatty acid alkyl ester and nitroglycerin used for biodiesel fuel, etc. is produced environmentally friendly, inexpensively and industrially. be able to.

DESCRIPTION OF SYMBOLS 1 Production apparatus 2 Oil storage tank 3 Alcohol storage tank 4 Waste storage tank 5 Fatty acid alkyl ester storage tank 6 Glycerin storage tank 10 1st reactor 11 1st pressurization flash tower 12 1st atmospheric pressure flash tower 13 Alcohol purification Tower 14 First separator 20 Second reactor 21 Second pressurized flash tower 22 Second atmospheric flash tower 23 Alcohol distillation tower 24 Second separator 30 Heat exchanger 31 Heat exchanger

Claims (5)

A first reaction step in which fats and alcohols are reacted in the presence of a solid catalyst;
A first phase separation step of phase-separating the first reaction liquid obtained in the first reaction step into a first fatty acid alkyl ester phase and a first glycerin phase using an oil-water separation membrane;
A second reaction step of reacting the fats and oils contained in the first fatty acid alkyl ester phase with alcohols in the presence of a solid catalyst,
A method for producing a fatty acid alkyl ester and / or glycerin, wherein the pore size formed in the oil-water separation membrane is 20 μm or less.   It further includes a second phase separation step of phase-separating the second reaction liquid obtained in the second reaction step into a second fatty acid alkyl ester phase and a second glycerin phase using an oil / water separation membrane. The method for producing a fatty acid alkyl ester and / or glycerin according to claim 1.   The method for producing a fatty acid alkyl ester and / or glycerin according to claim 1 or 2, wherein the water content in the first fatty acid alkyl ester phase is 0.1 mass% or less.   The fatty acid alkyl ester and / or glycerin according to any one of claims 1 to 3, wherein the concentration of glycerin contained in the first fatty acid alkyl ester phase is 0.1% by mass or less. Manufacturing method. A first reactor for reacting oils and fats in the presence of a solid catalyst;
A first phase separator including an oil-water separation membrane for phase-separating the first reaction liquid obtained in the first reactor into a first fatty acid alkyl ester phase and a first glycerin phase;
A second reactor for reacting the fats and oils contained in the first fatty acid alkyl ester phase with an alcohol in the presence of a solid catalyst,
The apparatus for producing a fatty acid alkyl ester and / or glycerin, wherein the pores formed in the oil / water separation membrane have a size of 20 μm or less.

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