WO2010058487A1

WO2010058487A1 - Process for producing fatty acid ester from fat as raw material

Info

Publication number: WO2010058487A1
Application number: PCT/JP2008/071482
Authority: WO
Inventors: 潔小坂田; 昭一伊東; 稔守田; 勝彦苫篠; 正男神岡
Original assignee: アイシーエス株式会社
Priority date: 2008-11-19
Filing date: 2008-11-19
Publication date: 2010-05-27

Abstract

A process for fatty acid ester production which comprises steps connected to each other through a closed circulatory pipe line for a superheated vaporized alcohol. The process renders efficient heat utilization possible and facilitates a treatment of the raw-material alcohol used in excess. In this process, a noncatalytic ordinary-pressure reaction can be conducted with a simple apparatus. A reduction in apparatus/operation cost and an improvement in safety are hence attained. The reaction product is collected as a gas phase, whereby a product having high quality which is not influenced by the quality of the raw material is obtained without any special purification step. Part of the raw material/product and the residue resulting from the reaction are utilized as fuel to render energy self-sufficiency possible.

Description

Process for producing fatty acid ester from fats and oils

The present invention relates to a useful method for producing a fatty acid ester by transesterification by reacting triglyceride contained in fats and oils with alcohol.

As one of the efforts to comply with carbon dioxide emission regulations, there are many attempts to use plant-derived fuel instead of fossil fuel. Palm oil, rapeseed oil, etc. that are usually obtained from plants are mainly composed of triglycerides, so the viscosity is higher than that of light oil. Not always appropriate. For this reason, a transesterification reaction is performed with triglycerides using an alkyl alcohol to produce a diesel fuel equivalent to light oil by using a fatty acid alkyl ester, and most commonly an alkali catalyst is used. The method is in practical use. However, in this method, the catalyst is contained in glycerin as a by-product and is difficult to separate, so it is usually recovered as a low-value added by-product, and metal soap is produced if there are free fatty acids in the raw material. As a result, problems such as subsequent steps are hindered, and a considerable number of extra steps are required due to problems such as the need for removal. For this reason, a method using a solid catalyst, a method using a high activity of a chemical species in a supercritical state without a catalyst, and the like have been proposed, but are widely put into practical use in terms of cost, operability or safety. It has not reached. On the other hand, when the reaction is carried out at normal pressure and without a catalyst, the reaction rate is slow, so a considerably high temperature is required compared to the catalytic method, and it has been difficult to put it to practical use in terms of energy cost.

In the present invention, in order to solve the above-mentioned problems, an attempt is made to provide a plant-derived alkyl ester fuel that is comparable to light oil in terms of performance and price, and that is pressureless and non-catalytic. Specifically, as a plant, a. Be able to respond flexibly to fluctuations in the required throughput (a system capable of both continuous and semi-continuous production); b. The quality of the product is not affected by fluctuations in the quality of the raw materials, c. A high quality product can be obtained as a fuel without a special purification step, and by-product glycerin can be collected as a product; d. The safety of operation is high due to atmospheric pressure reaction, and energy consumption is low, e. We propose a manufacturing method that can realize self-sufficiency without pollution.

In order to achieve the above object, the present inventors have made the following invention.
(1) When producing a fatty acid ester from fats and oils and a monohydric alcohol (hereinafter simply referred to as alcohol), the reaction product is mixed with superheated vaporized vapor (gas phase reaction product and superheated vaporized alcohol In the method of obtaining as a mixture of the above or a droplet-like reaction product), an excess of alcohol (hereinafter referred to as excess alcohol) exceeding the theoretical chemical equivalent required at the time of reaction is superheated and vaporized alcohol (pressure of the alcohol). It is used in the state of alcohol kept at a temperature higher than the boiling point corresponding to, and the required process (reaction process mainly consisting of equipment for reaction of fats and oils with monohydric alcohol, reaction by heat exchange) The process mainly consists of equipment for cooling products and raising the temperature of raw alcohol and raw oils and fats, and equipment for separating and acquiring reaction products. The superheated vaporized alcohol circulation path connecting all of the above is provided, the circulation path is a closed system including a raw material supply means and a product acquisition means, and the capacity of the circulation path is an excess alcohol required for the reaction. A method for producing a fatty acid ester, which is sufficient to supply
(2) In the step for cooling the reaction product and raising the temperature of the raw material by heat exchange, the superheated vaporized alcohol (hereinafter referred to as reaction gas) containing the reaction product, taken out from the reaction step, and the raw material In the heat exchange, the sensible heat part and the latent heat part of the reaction gas are separated and heat exchange is performed, The method for producing a fatty acid ester according to (1),
(3) A process for performing sensible heat exchange between the reaction gas and the raw material (hereinafter referred to as a high temperature heat exchange process) and / or a process for performing heat exchange between the latent heat of condensation of the reaction product and the raw material (hereinafter referred to as condensation). A heat recovery step) and / or a step for separating the condensed reaction product from the superheated vaporized alcohol (hereinafter referred to as a reaction product separation step) and / or a superheated vaporized alcohol separated from the reaction product (hereinafter referred to as a reaction product). A process for performing sensible heat exchange between the recycle alcohol and the raw alcohol and / or cooling water (hereinafter referred to as a temperature control heat exchange process) and / or a process for adiabatic cooling of the recycle alcohol with the raw alcohol. (Hereinafter referred to as an adiabatic cooling step). The method for producing a fatty acid ester according to (1).
(4) The method for producing a fatty acid ester according to (1), wherein a step for raising the temperature of the raw material (hereinafter referred to as a final preheating step) is provided immediately before the reaction step.
(5) Superheated vaporized alcohol is circulated through the superheated vaporized alcohol circulation path, and supply of raw materials or a part of the raw materials to the production process and acquisition of reaction products from the production process are referred to as the recirculated superheated vaporized alcohol (hereinafter referred to as “circulated alcohol”). ), The method for producing a fatty acid ester according to (1).
(6) The method for producing a fatty acid ester according to (1), comprising means for giving latent heat of vaporization to the reaction product during the reaction step, vaporizing the reaction product and transferring it to superheated vaporized alcohol. .
(7) In the method for producing a fatty acid ester from fats and oils and alcohol, the fats and oils are heated in a plurality of stages, and the temperature is raised to a required reaction temperature immediately before the reaction, A method for producing a fatty acid ester.
(8) In any stage of the temperature rise of the raw fats and oils, liquid and / or vaporized alcohol is allowed to coexist with the raw fats and oils, and the temperature rise of the raw fats and oils after the soot is coexisting with the alcohol (the raw material of the alcohol In a state of being dissolved in fats and oils and / or in a droplet dispersion state and / or in a bubble dispersion state and / or in a gas phase and / or liquid phase of a raw oil and fat in alcohol) The method for producing a fatty acid ester according to (7).
(9) The method for producing a fatty acid ester according to (7), wherein the heating immediately before the reaction of the fats and oils is performed in a reducing atmosphere of superheated vaporized alcohol.
(10) In the process for cooling the reaction product and raising the temperature of the raw material by heat exchange, the reaction product and / or the circulating alcohol taken out of the reaction apparatus, the raw oil and fat and / or the raw alcohol and / or Or a means for performing heat exchange with circulating alcohol, condensing reaction products in a lump, and separating / collecting fatty acid ester and glycerin from the obtained condensate, (1) A method for producing a fatty acid ester.
(11) A first high temperature heat exchanger in which a high temperature side is a circulating alcohol (hereinafter referred to as a reaction raw material alcohol) in which a high temperature side is accompanied by a reaction gas and a low temperature side is accompanied by a raw material alcohol; The manufacturing method of the fatty acid ester as described in (1) characterized by providing the 2nd high temperature heat exchanger which is a kind.
(12) The condensation heat recovery step is provided with a first condensation heat exchanger in which the high temperature side is the reaction gas and the low temperature side is the reaction raw material alcohol, and a second condensation heat exchanger in which the high temperature side is the reaction gas and the low temperature side is the raw material fats and oils. (1) The manufacturing method of the fatty acid ester characterized by the above-mentioned.
(13) The method for producing a fatty acid ester according to (1), wherein a temperature control heat exchanger is provided in the temperature control heat exchange step, wherein the high temperature side is a circulating alcohol and the low temperature side is a raw oil or fat.
(14) The method for producing a fatty acid ester according to (1), wherein the adiabatic cooling step is provided with an adiabatic cooler in which the high temperature side is circulating alcohol and the low temperature side is raw alcohol.
(15) In the process for cooling the reaction product and preheating the raw material by heat exchange, the high temperature heat exchange step includes a first high temperature heat exchanger in which the high temperature side is the reaction gas and the low temperature side is the reaction raw material alcohol; A second high-temperature heat exchanger having a reaction gas on the side and a raw oil and fat on the low-temperature side is provided, and in the condensation heat recovery step, the first condensation heat exchanger in which the high-temperature side is the reaction gas and the low-temperature side is the reaction raw material alcohol, The gas is provided with a second condensing heat exchanger whose low temperature side is raw material fats and oils, and in the temperature control heat exchanging step, a high temperature side is provided with a circulating alcohol and the low temperature side is raw material fats and oils, and a heat insulating cooling step is provided. , A heat recovery system provided with an adiabatic cooler in which the high temperature side is circulating alcohol and the low temperature side is raw alcohol, and the first and second high temperature heat exchangers are divided by bifurcating the high temperature reaction gas from the reaction step. put in The reaction gas at the intermediate temperature of each branch exiting each high-temperature heat exchanger is placed in the first and second condensation heat exchangers, and the low-temperature reaction gas exiting each condensation heat exchanger is merged to produce a reaction product. In the separation step, the reaction product is separated as a condensate, and the obtained circulating alcohol is sequentially put into a temperature control heat exchanger and an adiabatic cooler to further lower the temperature, and the required raw alcohol is added in the adiabatic cooler. Reacting raw material alcohol is sent to the low temperature side of the first condensing heat exchanger and the first high temperature heat exchanger, heated and heated to be used for the reaction, while the raw fats and oils are sequentially heated to the temperature controlled heat exchanger and the second heat exchanger. The method for producing a fatty acid ester according to (1), comprising a heat exchange step of heating and raising the temperature through the low temperature side of the condensation heat exchanger / second high temperature heat exchanger and using it for the reaction.
(16) The method for producing a fatty acid ester according to (1), wherein in the high-temperature heat exchange step, heat exchange is performed between the reaction gas and the reaction raw material alcohol using the raw material fats and oils as a heat medium.
(17) In the high-temperature heat exchange step, a high-temperature heat exchanger in which the high-temperature side is the reaction gas and the low-temperature side is the heat medium (raw oils), and alcohol heating in which the high-temperature side is the heat medium (raw oils and fats) and the low-temperature side is the reaction raw material alcohol High-temperature heat exchanger, high-temperature heat exchanger low-temperature side heat medium outlet and alcohol heating high-temperature heat exchanger high-temperature side heat medium inlet, alcohol heating high-temperature heat exchanger high-temperature side heat medium outlet and high-temperature heat The heat exchanger inlet on the low temperature side of the exchanger is connected by a conduit to form a circulation circuit of the heat medium, and a circulation pump and a high-temperature heat medium (raw oil and fat) take-out means are provided in the middle of the circulation circuit. The method for producing a fatty acid ester according to (16), wherein the reaction raw material alcohol is heated by heat.
(18) A mixed adiabatic cooler provided with raw material alcohol (liquid) supply means and gas stirring means is provided in the middle of the superheated vaporized alcohol circulation path from the temperature control heat exchange step to the condensation heat recovery step. The recovered alcohol is subjected to adiabatic cooling according to (1).
(19) In the condensation heat recovery step, the reaction products in the reaction gas are condensed at one time, and the superheated vapor containing the condensate is sent to the reaction product separation step, and the reaction product is provided with a condensate separation means such as a filter medium. The condensate and the superheated alcohol are separated through a product separation device, the collected condensate is sent to a product separation process, and put into a product separation device equipped with product separation means such as specific gravity separation, and fatty acid ester and glycerin And the method for producing a fatty acid ester according to (1).
(20) The reaction residue generated in the reaction step is sent to a step (hereinafter referred to as a reaction residue incineration step) where incineration is performed by an incinerator such as a heat medium boiler, and the heat medium is heated by heat generated during the incineration. A method for producing a fatty acid ester according to (1), wherein a high-temperature heat source is obtained.
(21) Production of fatty acid ester according to (1), wherein the high-temperature heat source (heat medium) obtained in the reaction residue incineration step is sent to the final preheating step and heat exchange is performed with the reaction raw material alcohol and raw material fats and oils Method.
(22) Reaction process, high temperature heat exchange process, condensation heat recovery process, reaction product separation process, temperature control heat exchange process, adiabatic cooling process, final preheating process, superheated vapor circulation means, product separation process and reaction residue incineration process A superheated alcohol circulation path that connects all of the reaction process, the high-temperature heat exchange process, the condensation heat recovery process, the reaction product separation process, the temperature control heat exchange process, the adiabatic cooling process, and the final preheating process. The heat generated by the reaction gas is recovered by heat exchange, the raw material is preheated and the reaction products are condensed at once, and the fatty acid ester and glycerin are separated and collected from the resulting condensate, and the reaction that occurs in the reaction process The residue is sent to the reaction residue incineration process, used as a fuel for heating the heating medium used in the final preheating process, and the shortage of the fuel is compensated with a part of the raw oils and fats. It is characterized by constructing a system that generates electricity from a part of the acid ester and can operate the entire plant without obtaining fuel and power supply from the outside, and does not discharge hazardous waste outside the plant. (1) The manufacturing method of the fatty acid ester of description.

It is a conceptual diagram of a fatty acid ester manufacturing process. It is a conceptual diagram of a fatty acid ester manufacturing process. It is a conceptual diagram of a reaction process. It is a conceptual diagram of a reaction process. It is a schematic diagram of an example (gas suction type) of a reaction apparatus. It is a schematic diagram of an example (oil spray gas suction type) of a reaction apparatus. It is a schematic diagram of an example of a reaction apparatus (packed tower / oil external heating type). It is a schematic diagram of an example (dip pipe type) of a reaction apparatus. It is a schematic diagram of an example (dip pipe type) of a reaction apparatus. It is a schematic diagram of an example (multi heat pipe type) of a reaction apparatus. It is a schematic diagram of an example (single reaction tube type) of a reaction apparatus. It is a schematic diagram of an example (fluidized bed type) of a reaction apparatus. It is a schematic diagram of an example (multi reaction tube type) of a reaction apparatus. It is a conceptual diagram of a heat exchange system. It is a conceptual diagram of the heat exchange system which uses a heat medium. It is a schematic diagram of an example of an adiabatic cooler. It is a schematic diagram of an example of a product separation apparatus. It is a schematic diagram of an example of a product separation apparatus. It is a conceptual diagram of a plant structure.

Explanation of symbols

1 reaction process 1a reactor 2 high temperature heat exchange process 2a high temperature heat exchanger 2b high temperature heat exchanger 2c high temperature heat exchanger 2d high temperature heat exchanger 3 condensation heat exchange process 3a condensation heat exchanger 3b condensation heat exchanger 3c condensation heat exchange 3d Condensation heat exchanger 4 Reaction product separation step 4a Reaction product separation device 4b Product sorting device 5 Temperature control heat exchange step 5a Temperature control heat exchanger 6 Adiabatic cooling step 6a Adiabatic cooler 7 Final replacement step 7a Final Heating device 7b Final heating device 8 Residue incineration process 8a Residual incineration device 8b Heat medium 9 Raw material storage tank (oils and fats)
10 Raw material storage tank (alcohol)
11 Raw material fats and oils 11a Raw material fats and oils preheated by a temperature control heat exchanger 11b Raw material fats and oils preheated by a condensation heat exchanger / high temperature heat exchanger 11d A conduit 11e having a high temperature heating medium (raw material fats and oils) taking out means 11e 11f Raw material fat supply port 11p High temperature heating medium (raw material fat) circulation means 11v High temperature heating medium (raw material fat) extraction means 12 Raw material alcohol 13 Reaction gas (superheated vaporized alcohol, fatty acid ester) Glycerin mixture)
14 Circulating alcohol 15 Reaction product (liquid phase)
16 Reaction raw alcohol (circulating alcohol, raw alcohol mixture)
17 Reaction residue 18 Cooling water 19 Reaction vessel 20 Reaction raw material alcohol supply means 20a Reaction raw material alcohol blowing nozzle 21 Raw material fat supply means 21a Raw material fat discharge means 22 Reaction gas discharge means 23 Residue discharge means 24 Heating means 24a Heating means 24b Heating Means 24c Heating means 24d Heating means 24e Heating means 25 Solid (catalyst) / liquid (raw oil / fat) / gas (reactive gas) contact means (contact means between raw oil / fat and reaction gas in the case of no catalyst)
26 Stirring means 27 Cylindrical container 28 Spray head 28a Sprinkling head 29 Circulating methanol introduction means 30 Liquid methanol introduction means 31 Reaction raw material methanol takeout means 32 Stirring means 33 Impeller 34 Draft tube 35 Gas-liquid contact means or catalyst 36 Drive motor 37 Oil feed Pump 38 Air supply pump 39 Gas-liquid mixing means 40 Reaction tube 41 Reaction raw material alcohol bubble 41a Reaction raw material alcohol foam 42 Separation tank 43 Collision plate 44 Filter material (glass wool, etc.)
45 Heat medium 46a Reaction product introduction means 46b Reaction product discharge means 47 Separator 48 Glycerin 49 Fatty acid ester 50 Glycerol discharge means 51 Fatty acid ester discharge means 52 Liquid level 53 Flow of bubbles / liquid mixed phase flow 54 Power supply process 55 Storage tanks 56 Diesel engine 57 Generator 58 Power supply 59 Combustion air 60 Effect of heat pipe The high heat recovery efficiency by a series of manufacturing processes equipped with the superheated vapor circulation means according to the present invention greatly increases the required heat energy. It does not require a high pressure such as a supercritical reaction, and the process is remarkably simplified as compared with the alkali catalyst method, and it can be expected that the operation safety, the equipment cost and the operation cost are reduced. In addition, the excess alcohol used in the reaction is always maintained and circulated as a constant volume in the closed system, so unlike the case of supplying excess alcohol only to the reaction process, no special recovery / reuse process is required. . In this method, since the fatty acid ester and glycerin are collected as a gas phase, high-boiling impurities are not included, no special purification process is required, and the quality is hardly affected by fluctuations in raw materials. Since all reaction residues are used as fuel for heating in the manufacturing process, there is almost no waste, and it is possible to configure an energy self-sufficiency plant by using a small part of raw oils and products (fatty acid esters) as fuel supplements. It is.

In the following, methanol is used as the raw material alcohol, and the oil and fats are applied under the conditions of a pressure of 0.090 to 0.405 MPa (preferably 0.102 to 0.150 MPa) and a temperature of 350 to 150 ° C. (preferably 290 to 180 ° C.). The best mode for carrying out the present invention when using a superheated vaporized methanol in excess of the required theoretical chemical equivalent for the reaction and carrying out the reaction without catalyst will be described with reference to the drawings.
First embodiment
FIG. 1 is a conceptual diagram of a process for producing a fatty acid ester linked by a superheated vapor circulation means, which is the center of the first embodiment. As the most preferred mode, a reaction process 1, a high-temperature heat exchange process 2, The condensing heat recovery process 3, the product separation process 4, the temperature control heat exchange process 5, the adiabatic cooling process 6 and the final preheating process 7 are shown.
The superheated alcohol circulation means 14a is subjected to the reaction step 1, the high temperature heat exchange step 2, the condensation heat recovery step 3, the product separation step 4, the temperature control heat exchange step 5, and the adiabatic cooling step 6, and again the condensation heat recovery step 3, Through the high temperature heat exchange step 2 and further through the final heat preheating step 7, the catalyst reaction step 1 is reached to form a circulation path. The temperature of the circulating (superheated vaporization) methanol flowing through the circulation path is the highest in that it exits the reaction step 1 as the reaction gas 13 accompanied by the reaction product, and the temperature is lowered by sequential heat exchange, and the reaction product separation step 4 The reaction product is separated at the point of exiting and becomes the circulation (superheated vaporization) alcohol 14, and at the point of exiting the adiabatic cooling step 6, it becomes the minimum temperature as the reaction raw material (superheated vaporization) alcohol accompanied by the raw material alcohol, and the heat of condensation again. The temperature is raised through the recovery process 3 and the high-temperature heat exchange process 2, the required temperature is obtained by the final preheating process 7, and the process returns to the reaction process 1.
The raw material fats and oils 11 are sequentially heated through a temperature control heat exchange process 5, a condensation heat recovery process 3 and a high temperature heat exchange process 2, and a required temperature is obtained by a final heating process 7 and supplied to the reaction process 1.
The raw material methanol (liquid) 12 is vaporized in the alcohol adiabatic cooling step 6 and then merged with the circulating methanol 14 to become a reaction raw material methanol 16, which is further subjected to a condensation heat recovery step 3 and a high temperature heat exchange step 2. The temperature is raised successively, and a required temperature is obtained in the final preheating step 7 and supplied to the reaction step 1.
FIG. 2 is a conceptual diagram for more specifically explaining the superheated vapor alcohol circulating means of FIG. 1, and also shows the position of heat recovery by the residue incineration step 8. In the reaction step 1, methanol (superheated vaporized state) is always kept in an excess state exceeding the theoretical chemical equivalent with respect to fats and oils, and the methanol and fats and oils interact with each other under sufficient contact by contact means. In addition, some of them also react in the gas phase part above the liquid. The reaction product (fatty acid ester and glycerin) is transferred into excess superheated vaporized methanol and discharged together with the superheated vaporized methanol as a reaction gas 13 from the reaction step 1 and divided into two parts, and the reaction raw material methanol in the high temperature heat exchange step 2 respectively. 16 and after the heat exchange with the raw material fats and oils 11, it enters into the condensation heat recovery step 3 while branching, and exchanges heat with the reaction raw material methanol and the raw material fats and oils, respectively. State) and condensed into a liquid phase (droplet), followed by methanol (superheated vaporized state) and exiting the condensation heat recovery step.
The two-branched superheated vapor methanol accompanied by droplets of the reaction product joins and enters the reaction product separation step 4, and the reaction product (liquid) 15 is separated from the methanol, and further separated into fatty acid ester and glycerin. To be the final product.
On the other hand, the methanol separated from the reaction product is sent to the temperature-controlled heat exchange step 5 as circulating methanol (superheated vaporized state) 14 to exchange heat with the raw oils and fats 11 and, if necessary, the cooling water 18 to the next step. It is adjusted to a suitable temperature and enters the adiabatic cooling step 6 where it is adiabatically cooled by the mist of the raw material methanol (liquid) 12 to lower the temperature and ensure a temperature difference in return heat exchange, while the raw material methanol obtains latent heat of vaporization. Into the gas phase, and accompanied by the circulating methanol, enters the condensation heat recovery process 3 and the high-temperature heat exchange process 2 as the reaction raw material methanol 16, and countercurrently reacts with the reaction gas 13 to perform heat exchange to obtain a necessary temperature and finally The preheating step 7 and the reaction step 1 are reached to form a superheated vaporization methanol circulation path.
The raw material alcohol 12 is supplied in an amount corresponding to the amount taken out as the reaction product 15.
Raw material fats and oils supply the quantity corresponding to the part taken out as the reaction product 15 and the reaction residue 13.
The reaction residue 17 is sent to the waste liquid incineration step 8 and incinerated with a heat medium boiler or the like to produce a high-temperature heat medium used in the final heat exchange step 7.
In this embodiment, excessive superheated vaporized methanol and fats and oils are sufficiently brought into contact, a reaction product is obtained in a high yield, and each reaction product is collected in the vapor phase together with superheated vaporized methanol. By forming a closed circulation stream of superheated vaporized methanol that connects the processes and supplying only the raw material methanol consumed in the reaction to the circulation stream, a methanol excess required for the reaction with a certain amount of methanol It is possible to ensure the conditions of
In addition, the formation of the circulating flow makes it easy to perform the cooling step for condensing and separating the product and the heating step of the raw material by mutual heat exchange, and it is economical to absorb some fluctuations in the reaction efficiency. It is possible to construct a simple plant. In the present invention, no catalyst is taken into consideration, but a solid catalyst or the like can be used in the reaction step.
Second embodiment
This embodiment corresponds to the reaction process. FIGS. 3 and 4 are the main parts of the second embodiment, the superheated vaporized methanol (reaction raw material methanol) and the feed means of the raw oil and fat, the superheated vaporized alcohol (reactive gas) containing the reaction products and the discharge of the reaction residue. Means, liquid (raw fats and oils) / gas (superheated alcohol) two-phase or solid-phase contact means including solid (catalyst) and two-phase or solid (contact means and / or catalyst) included It is a basic conceptual diagram of the reaction process comprised by the heating means of 1 or 2 of 3 phases, or all the 3 phases.
FIG. 3 shows a reaction raw material methanol supply means 20, raw material fats and oils supply means 21, reaction gas discharge means 22, and reaction residue discharge means 23 outside the reaction vessel 19. The heating means 24 and the means for contacting the fats and oils with the reaction raw material methanol (contact means for the catalyst, fats and oils and reaction raw material methanol in the case of using a catalyst) 25 are installed. The contact means is provided with any stirring means 26 as required. The target of the heating means is either or both of the reaction raw material methanol and the raw material fats and oils, and if necessary, the contact means and / or the catalyst is also heated, and the contact means and / or the catalyst is used as the reaction raw material methanol and the raw material fats and oils And / or function as a heating means for the reaction product.
In this reaction step, a state in which vaporized alcohol bubbles are present in the fats and oils and a state in which vaporized fats and oils are present in the vaporized alcohol are mixed, and these are in contact with a solid (contact means or catalyst). Since the reaction takes place, local temperature changes are likely to occur. Therefore, it is difficult to ensure the required temperature during the reaction only by heating in the final preheating step prior to the reaction step, and it is necessary to perform heating immediately before the reaction in the reaction step to satisfy the set temperature condition. is there. In the reaction step according to the present invention, a heating means is provided in the reaction vessel, and necessary heating is performed immediately before methanol and / or raw oils and fats reach the contact means, and further, heating by the catalyst and / or the contact means is performed. Solved the problem. In the present invention, since the reaction product is discharged as a gas phase together with superheated vaporized methanol, the heating means provides not only the temperature required for the reaction but also the supply of latent heat of vaporization to the reaction product.
Increasing the reaction temperature of raw fats and oils is advantageous for the production of fatty acid esters, but at the same time, the deterioration of raw fats and oils is promoted. For this reason, it is necessary to shorten the time for keeping the raw fats and oils at a high temperature as much as possible. In the reaction step according to the present invention, the above-mentioned means is used to raise the temperature to a required temperature immediately before the reaction. Settled. In addition, it is effective to prevent deterioration of fats and oils by coexisting methanol at any stage (including multiple stages) of temperature rise of raw oils and fats and performing subsequent heating in a reducing atmosphere in which methanol coexists. it is conceivable that. As the coexistence form of both, dissolution and / or liquid phase (droplet) dispersion and / or gas phase (bubbles) dispersion of methanol in raw material fats and oils and / or gas phase of raw material fats and oils in methanol and / or Mixing / dispersing as a liquid phase, and using a stirring means if necessary. In particular, when the catalyst or the contact means is a heating means, heating to the maximum temperature immediately before the reaction of the raw oils and fats can be performed in an excessive superheated vaporized methanol atmosphere. The range of the temperature rise just before the reaction needs to be adjusted depending on the type of raw material fat used, etc., but in the present invention, the raw oil and fat are preheated and heated in multiple stages, and the final preheating step is provided immediately before the reaction step. Solved this.
FIG. 4 shows that the heating means is installed outside the reaction vessel because of the simplification of the apparatus or the necessity of the shape of the reaction apparatus incorporating the contact means.
An example of a preferable reactor equipped with contact means is as follows. FIG. 5 is a schematic diagram showing an example of a gas suction type reaction apparatus. A draft tube 34 is provided in the reaction vessel 19, and an impeller 33 for sucking the liquid in the draft tube downward is provided at the lower portion. The drive shaft and the drive motor 36 are arranged on the central axis of the tube, and the stirring means 26 is attached to the drive shaft. Contact means 35 (catalyst when using a catalyst) which is detachable for maintenance is installed between the outer upper portion of the draft tube and the reaction vessel wall. The raw material fats and oils 11 pass through the raw material fats and oils supply means 21 and the heating means 24b from the upper side to the inside of the tube, and the reaction raw material methanol 16 passes through the reaction raw material alcohol supply means 20 and the heating device 24a to the upper part of the raw material fats and oils inside the tube. Supplied. In the reaction vessel, raw material fats and oils are always stored up to the liquid level 52 higher than the upper end of the tube, and the gas-liquid mixed phase flow 53 of the raw material fats and reaction gas bubbles in the tube is lowered by the impeller and then outside the draft tube And a circulating flow is formed which passes through the contact means 35 (a catalyst when a catalyst is used) and returns from the upper end of the draft tube into the tube. The reaction raw material methanol is agitated while descending the tube in this circulating flow, becomes microbubbles, mixes with the raw material fats and oils, rises outside the tube, and passes through the contact means (catalyst when using a catalyst) The reaction product becomes a reaction gas 13 together with excess vaporized methanol, and is discharged from the reaction gas discharge means 22 to the outside.
FIG. 6 is a schematic diagram showing an example of an oil spray / gas suction type reaction apparatus. In the gas suction type shown in FIG. 4, the raw oil / fat 11 is sprayed and supplied downward as a mist through the spray head 28. In addition, the contact opportunity with the reaction raw material methanol is further increased. FIG. 5 shows an example in which a drive motor is arranged at the lower part of the reaction vessel and the contact means (catalyst when using a catalyst) 35 is also heated by the heating means 24c. Such arrangement of the heating means or the drive motor can be similarly performed in the method of FIG.
FIG. 7 is a schematic diagram showing an example of a packed tower / oil external heating type reactor, in which raw material fats and oils are stored below 35 (a catalyst layer when using a catalyst) provided in an intermediate part of the packed tower. The raw material fats and oils 11 are supplied to the raw material fats and oils through the raw material fats and oils supply means 21, taken out together with the unreacted raw material fats and oils to the outside by the liquid feed pump 37, heated by the heating means 24b and contact means ( Or, it is fed into the tower from above the catalyst packed bed). FIG. 6 shows a mold in which heated raw material fats and oils are supplied as mist through the spray head 28 to increase the chance of contact with the reaction raw material methanol. The reaction raw material methanol 16 is supplied from the bottom of the tower through the reaction raw material methanol supply means 20 and the heating means 24a through the blowing nozzle 20a, passes through the raw material fats and oils as bubbles, and then contacts with the inside of the contact means (or catalyst layer) 35. In the process of contacting the raw material fats and oils above the means (or catalyst layer), the reaction product is discharged from the discharge means 22 as the reaction gas 13 together with the superheated vaporized methanol.
FIG. 8 is a schematic view showing an example of a dip pipe type reaction apparatus, in which a plurality of gas blowing nozzles 20a are provided in a reaction vessel, and the reaction temperature is raised to a required temperature via a supply means 20 and a heating means 24a. The raw material alcohol 16 is blown into the raw material fats and oils stored in the reaction vessel, and the reaction raw material alcohol rises as the bubbles to form the foam layer 41a on the upper part of the liquid surface 52, and the foams burst. Thus, a reaction is caused in the process of entering the reaction gas above the foam layer. The generated reaction gas 13 is taken out through the discharge means 22. The raw fats and oils 11 are supplied by raising the amount lost by the reaction to a required temperature via the introducing means 21 and the heating means 24b. In FIG. 8, the reaction vessel is divided into two chambers by a separator 47, and a part of the raw material fats and oils into which the reaction raw material alcohol is blown in the left chamber enters the right chamber through the gap below the separator, and further, A two-stage apparatus receiving blow was shown. The number of reaction stages can be increased as necessary. The liquid depth at the tip of the blowing nozzle is set so that the bubble diameter of the reaction raw material alcohol to be produced is optimal for the reaction, and a bubble diameter control means is provided in the nozzle tip or in the reaction vessel as necessary. The reaction apparatus shown in FIG. 8 can also be realized by modifying an existing reaction apparatus such as a bubble tower.
FIG. 9 is a schematic diagram showing an example of a dip pipe type reactor similar to FIG. 8, in which a contact means (or catalyst) 35 is added to the apparatus of FIG. 8. In FIG. 9, the contact means (or catalyst) is provided on the top of the foam layer, and the foam (a state in which a very thin oil film is in contact with the superheated alcohol) touches the packed layer of, for example, a honeycomb or ring-shaped material (or catalyst). The case of passing while showing. It is also possible to apply a heating means to the packed bed so that the reaction raw material has a required high temperature only at the time of contact. In addition, the location of the contact means (or catalyst) is not limited to the upper part of the foam layer, but can be installed in any part of the raw oil or fat to the upper part of the foam layer as necessary, and may be installed in multiple locations. I can do it.
FIG. 10 is a schematic diagram showing an example of a multi-heat pipe type reactor, and the right portion of the figure shows the arrangement of the heat pipe 60 by a cross section perpendicular to the heat pipe. A predetermined temperature is given to the plurality of heat pipes 60 installed horizontally in the reaction vessel through the heat medium 45 heated by the heating device 24c, and raw material fats and oils are dropped from the upper spray head 28a. In the state where the liquid flows in the form of a film on the surface of the heat pipe, a reaction is caused with the reaction raw material alcohol 16 introduced from below through the supply means 20 and the heating means 24a, and the reaction product is excessive superheated vaporized methanol. At the same time, it is discharged from the discharge means 22 as a reaction gas. The reaction raw material alcohol passes through the raw material fats and oils stored in the lower part of the reaction vessel as bubbles before reaching the heat pipe. The raw material fats and oils 11 are supplied to the lower part of the reaction vessel through the supply means 21 through the supply means 21 and fed to the upper part by the liquid feed pump 37 through the discharge means 21a together with the raw material fats and oils that have fallen unreacted. The temperature is raised to the required temperature through the means 21 and the heating means 24b and supplied to the spray head 28a. When using a catalyst, a metal-based solid catalyst is added to the surface of the heat pipe.
FIG. 11 is a schematic view showing an example of a single reaction tube type reaction apparatus, in which the reaction raw material methanol 16 sent by the air feed pump 38 enters the mixing means 39 after being heated by the heating means 24a and similarly heated. Mixing with the raw material fats and oils 11 heated by the means 24b and entering the mixing means, it becomes a gas-liquid mixed phase flow, passes through the reaction tube 40 having the required length and maintained at the required temperature by the heating means 24d, The reaction gas 13 is discharged from the discharge means 22. When using the catalyst, the contact with the catalyst is carried out in the mixing means and / or in the reaction tube, if necessary. As a mixing means, in addition to simple devices such as a static mixer, other reaction devices are used to react a gas-liquid mixture of the obtained reaction gas and raw oil or fat, or a reaction gas accompanied by raw oil and fat droplets. There are ways to feed the tube.
FIG. 12 is a schematic view showing an example of a fluidized bed type reaction apparatus, in which raw material fats and oils stored in the reaction vessel 19 are held with contact means (or catalyst) 35 such as granular or flake form, The reaction raw material gas 16 and the raw material fats and oils 11 heated by the heating means 24a and 24b are respectively supplied from the lower part of the reaction vessel to generate a three-part mixed fluidized bed of the reaction gas bubbles 41, the raw material fats and oils and the catalyst particles 35. The reaction gas 13 is taken out from the discharge means 22 at the upper part of the container. The fluidized bed is maintained at a required temperature by the heating means 24e inside the reaction vessel. The flow is performed by bubbling of the reaction raw material gas, and if necessary, an appropriate stirring means is provided.
FIG. 13 is a schematic view showing an example of a multi-reaction tube type reaction apparatus, in which a contact means (or catalyst) 35 is filled in a reaction tube 40 installed in a reaction vessel 19, and the outside of the reaction tube is heated. A heating means 24c for the heating medium is provided, and the reaction raw material gas 16 heated by the heating means 24a is supplied from below, and the raw fats and oils 11 heated by the heating means 24b are supplied from above, A reaction is caused in the heated catalyst, and the reaction gas 13 is discharged from the upper part of the container.
Each of the above reactors can be adapted to batch, semi-batch and continuous production methods, and the raw oils and fats existing in the lower part of the reaction vessel or the raw oils and fats containing some reaction gas bubbles are the same or A multistage reaction apparatus can be configured by supplying raw material oils to different types of reaction apparatuses.
The reaction conditions in each reactor were mild as described above, with a pressure of 0.090 to 0.405 MPa (preferably 0.102 to 0.150 MPa) and a temperature of 350 to 150 ° C. (preferably 290 to 180 ° C.). Thus, the reactor structure and materials do not require special considerations such as supercritical reactions. During the reaction, it is advantageous to have an excess of methanol (preferably more than 3 times the theoretical chemical equivalent) with respect to the raw oil and fat. This is easily achieved by the system. In order to prevent leakage of reaction gas and the like in the path, it is effective to maintain a slight negative pressure with respect to the atmospheric pressure in the path as necessary. The above pressure is a numerical value of a liquid column type or a Purdon tube type pressure gauge installed on the reaction vessel wall, and the temperature is the temperature of the contact means by thermistor type or resistance type or the surface of the catalyst (or an internal point close to the surface). It is a measured value.
In the present invention, it is possible to construct an economically feasible manufacturing process without using a catalyst at the time of reaction, but if necessary, use a metal-based solid catalyst without making major changes to the reaction apparatus etc. I can do it. The metal in the catalyst can be lead, zinc, tin or steel containing molybdenum / chromium / nickel or vanadium, all of which do not pollute the reaction products and require special measures for recovery. And not. In addition, about the usage form of a catalyst, the related matter described in Japanese Patent Application No. 2003-436641, Japanese Patent Application No. 2004-40565, and Japanese Patent Application No. 2004-40566 is applied.
Third embodiment
This embodiment is a system for efficiently exchanging heat between a reaction gas and a raw material, and FIG. 14 shows a conceptual diagram thereof. The reaction gas 13 discharged from the reaction apparatus 1a in the reaction step 1 is divided into two parts and enters the high temperature side of the high

temperature heat exchangers

2a and 2b in the high temperature heat exchange step 2, respectively. Countercurrent heat exchange with the fats and oils 11 is performed and then introduced into the condensation heat recovery step 3 with two branches.
One of the halved reaction gases passes through the high temperature side of the condensation heat exchanger 3a to exchange heat with the reaction raw material methanol, and then enters the reaction product separation step 4. The other of the halved reaction gas enters the high temperature side of the condensation heat exchanger 3b, performs countercurrent heat exchange with the raw oils and fats 11, and then merges with the branched reaction gas that has exited 3a to produce a reaction product. The separation step 4 is entered. In the condensation heat recovery step 3, all reaction products other than methanol condense into a liquid phase and give latent heat to methanol.
In the reaction product separation step 4, the reaction product accompanying as droplets is separated from methanol by the reaction product separation device 4 a using a filter, a collision plate, etc., and the methanol is temperature-controlled heat exchange as circulating methanol 14. In Step 5, the separated reaction product 15 is sent to the product sorting device 4b using specific gravity separation to sort the fatty acid ester 49 and glycerin 48 to obtain a final product.
On the other hand, the circulating methanol 14 passes through the high temperature side of the temperature control heat exchange step 5 (temperature control heat exchanger 5a), performs countercurrent heat exchange with the raw oils and fats 11 and the cooling water 18, and is adjusted to a required temperature. It enters the adiabatic cooling step 6 (alcohol adiabatic cooler 6a) and is adiabatic cooled by the spray mist of the raw material methanol 12 (liquid), lowers the temperature to ensure the temperature difference of return heat exchange, and vaporizes in the adiabatic cooler The raw material methanol obtained by obtaining the latent heat is combined into the reaction raw material methanol 16 and sequentially enters the low temperature side of the condensation heat recovery step 3 (condensation heat exchanger 3a) and the high temperature heat exchange step 2 (high temperature heat exchanger 2a). Heat exchange is performed by counterflowing with the reaction gas, and a necessary temperature is obtained in the final heat preheating step 7 (heating device 7b) and sent to the reaction step 1. The superheated vaporized methanol is circulated by an air feed pump 38.
The amount of raw material methanol 12 taken out from the raw material storage tank 10 is supplied to the adiabatic cooling step 6 (alcohol adiabatic cooler 6a) corresponding to the amount collected as a reaction product, and the adiabatic cooling of the circulating methanol 14 as a spray mist. When the process is performed, it obtains vaporization latent heat, vaporizes, merges with the circulating alcohol 14 to become the reaction raw material alcohol 16, and is supplied to the reaction step 1 at the required temperature via the preheating path.
The raw material fats and oils 11 taken out from the raw material storage tank 9 are first put into the low temperature side of the temperature control heat exchanger 5a and counterflowed with the circulating alcohol 14 in an amount corresponding to the amount taken out as reaction products and reaction residues. Then, it is preheated, and then supplied to the reaction step 1 at the required temperature via the condensation heat exchanger 3b, the high temperature heat exchanger 2b and the heating device 7a of the final heat exchange step 7.
The reaction residue 13 is sent to the residue incineration step 8 and incinerated by a residue incinerator 8a such as a heat medium boiler, and a high-temperature heat medium 8b for the final preheating step is produced by the obtained heat.
In the present invention, methanol and fats and oils are placed under the required reaction temperature conditions in the reaction step, and heating to give latent heat of vaporization to the reaction product is necessary. In the above heat exchange system, Provide most of the heat required for the reaction by preheating raw methanol, circulating methanol and raw oils and fats in the cooling / condensation process, and using a high-temperature heating medium by incineration of the reaction residue. I can do it. Hot water obtained by the cooling water 18 is used as a plant utility.
Fourth embodiment
The present embodiment is a heat exchange system in which heat exchange by gas / gas is avoided and heat exchange efficiency is improved by using a liquid heat medium (raw oils and fats) in a high-temperature heat exchange process. The figure is shown. In this embodiment, the high temperature side is a reaction gas, the low temperature side is a liquid heat transfer medium (raw oil and fat), a high temperature heat exchanger 2c, the high temperature side is a liquid heat transfer medium (raw oil and fat), and the low temperature side is a high temperature heat exchanger 2d that is a reaction raw material gas. Condensation heat exchanger 3c in which the high temperature side is the reaction gas and the low temperature side is the reaction raw material methanol, the condensation heat exchanger 3d in which the high temperature side is the reaction gas and the low temperature side is the raw material fats and oils, liquid heat medium (raw material fats and oils) circulation means (blower) 11p, the conduit | pipe 11e provided with the raw material fats and oils supply port 11f, and the conduit | pipe 11d provided with the high temperature heating medium (raw material fats and oils) extraction means 11v.
The reaction gas 13 taken out from the reaction process enters the high temperature side of the high-temperature heat exchanger 2c, performs counter-current heat exchange with the low-temperature side liquid heat transfer medium (raw oils and fats), and is divided into two parts to each of the condensation heat exchangers 3c. Enters the high temperature side of 3d and circulates by the route described in the third embodiment.
The low temperature side of the high temperature heat exchanger 2c and the high temperature side of the high temperature heat exchanger 2d are a conduit 11d provided with a liquid heat medium (raw oil and fat) circulating means (blower) 11p and a high temperature heat medium (raw oil and fat) taking-out means 11v. And a circulation path is formed by a conduit 11e provided with a raw material fat supply port 11f, and a liquid heat medium (raw material fat) obtains a high temperature by gas / liquid heat exchange in the high temperature heat exchanger 2c, and in the high temperature heat exchanger 2d Heats the reaction raw material methanol 16 by liquid / gas heat exchange as a heat source.
The raw material fats and oils 11a preheated by the temperature control heat exchanger as in the third embodiment are heated through the low temperature side of the condensing heat exchanger 3d, and the liquid heat medium (raw material) is discharged at the outlet of the high temperature heat exchanger 2d. Oil and fat) and is heated by the high-temperature heat exchanger 2c. The necessary amount of raw material fats and oils that have obtained a high temperature is sent from the high-temperature liquid heat medium (raw material fats and oils) take-out means 11v to the final heating device 7a and then supplied to the reaction step 1.
The reaction raw material methanol 16 is sequentially heated by the condensation heat exchanger 3c and the high temperature heat exchanger 2d, and is supplied to the reaction step 1 through the final heating device 7b.
According to this embodiment, as a result of improving the heat transfer efficiency by using the liquid heat medium (raw oil and fats), the volume of the high-temperature heat exchanger can be reduced (about 20% reduction), and the temperature of the raw oil and fats is increased. The heating load in the final heating step and the reaction step can be reduced.
The state of condensation of each component of the reaction product (fatty acid ester and glycerin) in the reaction gas depends on the concentration and temperature in the reaction gas, and the thermal properties of the condensed and uncondensed parts are different. Changes drastically. Therefore, in order to perform stable heat exchange, it is necessary to separately use sensible heat and latent heat of the reaction gas. In the present invention, as shown in the above embodiments, this problem is solved by providing a high-temperature heat exchange step and a condensation heat exchange step in series, and this also applies to this embodiment. .
Fifth embodiment
This embodiment corresponds to the solving means (18). FIG. 16 is a schematic diagram of an example of the adiabatic cooler 6 a used in the adiabatic cooling step 6 of the circulating methanol 14, and an introduction means 29 of the circulating methanol 14, the raw material methanol (liquid) 12 is provided at one end of the cylindrical container 27. Introducing means 30 and a spray head 28 connected thereto, a reaction means methanol 16 take-out means 31 at the other end, a stirring means 32 (static mixer) is provided below the spray head in the container, and a temperature control heat exchange process The circulating methanol exiting the tank is introduced into a cylindrical container, and the methanol is adiabatically cooled by spraying the liquid raw material methanol into the methanol, while the liquid raw material methanol (liquid) is vaporized by obtaining latent heat of vaporization, together with the circulating methanol. Then, it is taken out from 31 as the reaction raw material methanol 16 in which the temperature difference necessary for the return heat exchange is ensured. The impingement plate 43 and the filter medium 44 (glass wool or the like) are droplet collecting means provided in the case where the reaction product is not completely removed in the preceding product separation step 4, and the collected reaction product 15. (Liquid) is taken out via the reaction product discharge means 46b. The collision plate and the filter medium can be omitted, and conversely, the product separation step 4 can be omitted and the reaction product can be collected only by this apparatus.
In the present invention, since the raw material methanol is introduced into the reaction step by the circulation flow of excess superheated vaporized methanol, it is necessary to heat and vaporize the raw material methanol. The vaporization can be performed using heat exchange accompanying adiabatic cooling, and no special heating device is required.
Since the amount of raw material methanol (liquid) sprayed is smaller than the circulation amount of superheated vaporized methanol, the raw material methanol is completely vaporized, and a mist eliminator or the like for the treatment of unvaporized droplets is not necessary.
Sixth embodiment
This embodiment corresponds to the solving means (19). FIG. 17 is a schematic diagram showing an example of a reaction product separation device for separating a reaction product from recovered methanol containing droplets of the condensation reaction product obtained in the condensation heat exchange step. In principle, it is the same as that shown in FIG. 16, and includes droplets of reaction products introduced from the reaction gas introduction means 41 by a mist eliminator composed of the filter medium 44 and the collision plate 43. The reaction product 15 is separated from the reaction gas 13, the reaction product is sent to the product fractionation device through the reaction product discharge means 46 b, and the methanol is sent as the circulating methanol 14 to the temperature control heat exchange step 5.
FIG. 18 is a schematic diagram of an example of a product sorting device that continuously sorts fatty acid esters and glycerin by specific gravity separation, and is a mixture of fatty acid esters and glycerin introduced by the reaction product introducing means. Is divided up and down by the difference in specific gravity on the left side of the separator, and the glycerin that sinks below is stored on the right side of the tank through the lower part of the separator.
In the present invention, the reaction product is collected as a gas phase, and the temperature is controlled to 350 ° C., preferably 290 ° C. Therefore, all the high boiling components remain as reaction residues in the reaction vessel, and the reaction product is separated. Since the temperature of the process is maintained at 90 ° C. or higher, methanol exists as a gas phase. Therefore, the reaction product is a mixture of only glycerin and a fatty acid ester containing a trace amount of water. The fatty acid ester with few impurities can be separated and collected from glycerin containing a small amount of water without providing it.
Seventh embodiment
This embodiment corresponds to the solving means (20) and (21). In the reaction process of the present invention, since the target reaction product is sent to the next process as a gas phase, the resulting reaction residue is a high-boiling component containing an oxidation / polymerization product of fats and oils, which is taken out from the bottom of the reaction vessel. As described above with reference to FIG. 14, it is used as fuel oil for the residue incinerator (heat medium boiler) 8a. The generated high-temperature heat medium 8b is branched into two and sent to the final heat exchange step, and is used in the final heat exchange devices 7a and 7b for heating the raw material fats and the reaction raw material methanol, respectively.
The amount of reaction residue generated and the amount of heat generated vary depending on the type of raw oil and fat. When virgin palm oil, rapeseed oil or the like is used as a raw material, the amount of residue is small, and when there is a use calendar such as waste oil, the amount generated is large and the variation in quality and quantity is large. Therefore, it is difficult to predict how much heat can be obtained. However, if the temperature of the high-temperature heating medium is estimated to be 350 ° C, the amount of heat corresponding to 2-5% of the amount used for production in terms of raw material oil If it is obtained, it is possible to cover the thermal energy of the whole plant in combination with efficient heat exchange. Since the reaction residue is of plant origin, its incineration does not lead to an increase in carbon dioxide.
Eighth embodiment
This embodiment corresponds to the solving means (22). As shown in FIG. 19, the best mode of the plant configuration according to the present invention includes a series of manufacturing processes 1 to 8, a tank group 55 such as a raw material storage tank / product storage tank, and a power supply facility 54. The amount of heat required for the plant is superheated by catalytic reaction step 1, high-temperature heat exchange step 2, condensation heat recovery step 3, reaction product separation step 4, temperature control heat exchange step 5, adiabatic cooling step 6 and final heating step 7. Since the raw material can be preheated by heat exchange with the reaction gas by the alcohol circulation means, the heat medium 8b for the final heating step by the reaction residue incineration step 8 (reaction residue incinerator 8a) can be used. It can be almost covered by acquisition. The amount of heat obtained by incineration of the reaction residue is unstable, but if necessary, stable operation is maintained by supplementing 5% or less of the raw material fats and oils. A generator 57 is operated by a diesel engine 56 using 2 to 5% of 49 to cover the power used by all plants. Hot water obtained from the cooling water 18 is used as a utility of the plant. By these measures, in the present invention, a self-sufficiency system that does not require external fuel and electric power supply is constructed. Diesel power generation using fatty acid esters does not lead to an increase in carbon dioxide.
The waste generated in the production method according to the present invention is almost only the reaction residue, and by incinerating it and recovering heat, substantially zero emission can be achieved. Such energy self-sufficiency and zero-emission plants are of course desirable in normal industrial environments, but especially in raw material production areas where sufficient utility cannot be expected, we aim to reduce raw material transportation costs. In such a case, it is particularly useful.

With respect to the dip pipe type shown in FIG. 8, an experiment for non-catalytic esterification of rapeseed oil was conducted with a simple apparatus in which only one superheated alcohol blowing nozzle was used. A glass cylindrical container with a diameter of 40 mm and a height of 400 mm is filled with rapeseed oil (purity 92%) to a height of about 100 mm from the bottom and kept at 290 ° C., and a stainless baffle plate with a diameter of 25 mm is provided at a point 20 mm from the bottom. A 1.5 mm stainless steel tube was used as a blowing nozzle and the open end was placed upward at a point 2 mm below the center of the baffle plate, and 290 ° C. superheated vaporized methanol (purity 99.8%) was blown at a flow rate of 2.6 ml / min. A foam layer having a height of about 10 to 20 mm was present on the surface of the rapeseed oil, the reaction gas was taken out from the upper end of the container, and cooled to collect the reaction product. In order to simulate the two-stage reaction, another similar apparatus was prepared, the lower ends of the containers of both apparatuses were connected with a glass tube having an inner diameter of 5 mm, and methanol was blown at a flow rate of 2.6 ml / min in the second apparatus. Similarly, the reaction gas was taken out from the upper end, cooled, and the reaction product was collected. The amount of reaction product obtained from the second device was 2 to 3 times that of the first device. The raw material rapeseed oil was supplied to the first container in an amount of about 1.7 ml / min corresponding to consumption by the reaction. The superheated methanol was recovered by cooling and condensing after separating the reaction product. This apparatus was continuously reacted for 3.9 hours to obtain about 400 ml of a reaction product, and allowed to stand to separate glycerin and esterified product to obtain about 25 ml of glycerin and about 375 ml of esterified product. The obtained esterified product was a pale yellow transparent liquid, and the kinematic viscosity was 10.4 mm ² / sec.

A bench test using a catalyst was performed by the manufacturing method of FIG. The specifications of the equipment used and the raw materials used are as follows. The reaction residue was not incinerated.
Reactor: Cylindrical, 200 mm in diameter, filled height 1000 mm, filled with steel Raschig ring 20 × 20 mm, attached with 0.5 m ² heat exchanger (circulation pump 100 l / hr).
Heat exchanger: High temperature heat exchanger 2d (reaction raw material methanol heating); 4 m ² , final heater 7a (reaction raw material methanol heating); 0.4 m ² , high temperature heat exchanger 2c (raw material fats and oils heating); 3.0 m ² , final heater 7b (heating raw material fats and oils); 0.3 m ² , condensation heat exchanger 3c; 1.0 m ² , condensation heat exchanger 3d; 0.6 m ² , temperature control heat exchanger; 0.3 m ² , Adiabatic cooler; cylindrical, diameter 80 mm, length 300 mm.
Specific gravity separation tank capacity: 10 l
Raw material methanol: Purity 99.8%
Ingredients: rapeseed oil, purity 92%
Using the above apparatus and raw materials, the amount of fatty acid ester (obtained by separating glycerin from the reaction product) 4.8 kg / hr with respect to the rapeseed oil supply amount 5 kg / hr · methanol supply amount 0.6 kg / hr, A glycerin of 0.48 kg / hr and a reaction residue of 1.2 kg / hr were obtained. As the catalyst, about 800 sheets of lead thin plate (thickness 0.3 mm) 20 × 20 mm were mixed and used in Raschig rings. The average reaction temperature was 287 ° C, the circulating superheated vaporized methanol was 19.4 kg / hr in circulation, the supply temperature to the reactor was 292 ° C, and the amount of electricity used for heating the reactor was 1.1 kW. It was.
Table 1 shows main components and properties of the obtained fatty acid ester.

The present invention produces plant-derived diesel fuel at low cost under normal pressure and safe operating conditions by an extremely heat-efficient system without producing hazardous waste such as chemical catalysts, The construction of a self-sufficient / pollution-free plant enables location in various environments, and is expected to be used on a large scale from the viewpoint of CO2 emission regulations.

Claims

When producing a fatty acid ester from fats and oils and a monohydric alcohol (hereinafter simply referred to as alcohol), the reaction product is mixed with a superheated vaporized vapor (a mixture of a vapor phase reaction product and a superheated vaporized alcohol or In the method of obtaining this as a reaction product in the form of droplets, an excess of alcohol (hereinafter referred to as excess alcohol) than the theoretical chemical equivalent required at the time of reaction corresponds to superheated vaporized alcohol (corresponding to the pressure of the alcohol). (Alcohol kept at a temperature higher than the boiling point) and used in the required process (reaction process mainly consisting of equipment for reacting oils and fats with monohydric alcohols, reaction products of the product by heat exchange) The process mainly consists of an apparatus for cooling and raising the temperature of raw material alcohol and raw oils and fats, and an apparatus for separating and acquiring reaction products. Step) is provided with a circulation path for the superheated vaporized alcohol, and the circulation path is a closed system having a raw material supply means and a product acquisition means, and the capacity of the circulation path is supplied with excess alcohol necessary for the reaction. A method for producing a fatty acid ester, characterized by being sufficient.
In the process of cooling the reaction product and raising the temperature of the raw material by heat exchange, the heat exchange between the superheated vaporized alcohol (hereinafter referred to as reaction gas) containing the reaction product and the raw material taken out from the reaction process is performed. The method for producing a fatty acid ester according to 1, wherein the sensible heat part and the latent heat part of the reaction gas are separated and heat exchange is performed.
A process for performing sensible heat exchange between the reaction gas and the raw material (hereinafter referred to as a high temperature heat exchange process) and / or a process for performing a heat exchange between the condensation latent heat of the reaction product and the raw material (hereinafter referred to as a condensation heat recovery process). And / or a step for separating the condensed reaction product and the superheated vaporized alcohol (hereinafter referred to as reaction product separation step) and / or a superheated vaporized alcohol separated from the reaction product (hereinafter referred to as circulating alcohol). And a process for performing sensible heat exchange with raw material alcohol and / or cooling water (hereinafter referred to as a temperature-controlled heat exchange process) and / or a process for performing adiabatic cooling of circulating alcohol with raw material alcohol (hereinafter referred to as “temperature control heat exchange process”). 2. The method for producing a fatty acid ester according to 1, wherein the method comprises an adiabatic cooling step).
2. The method for producing a fatty acid ester according to 1, wherein a step for raising the temperature of the raw material (hereinafter referred to as a final preheating step) is provided immediately before the reaction step.
The superheated vapor is circulated in the superheated vapor circulation path, and the supply of the raw material or a part of the raw material to the production process and the acquisition of the reaction product from the production process are performed via the cyclic superheated vaporized alcohol (hereinafter referred to as the cyclic alcohol). 2. The method for producing a fatty acid ester according to 1, wherein
2. The method for producing a fatty acid ester according to 1, further comprising means for giving vaporization latent heat to the reaction product during the reaction step, vaporizing the reaction product and transferring it to the superheated vaporized alcohol.
2. The method for producing a fatty acid ester according to 1, wherein the fatty acid ester is produced from the fat and alcohol and the fatty acid is heated in a plurality of stages and heated to a required reaction temperature immediately before the reaction. .
In any stage of the temperature rise of the raw fats and oils, liquid and / or vaporized alcohol is allowed to coexist with the raw fats and oils, and the temperature rise of the raw fats and oils after the drought is coexisting with the alcohol (in the raw oils and fats of the alcohol) In a dissolved state and / or in a droplet dispersed state and / or in a bubble dispersed state and / or in a mixed and dispersed state as a gas phase and / or liquid phase of raw oils and fats in alcohol), 8. A method for producing a fatty acid ester according to 7.
8. The method for producing a fatty acid ester according to 7, wherein heating immediately before the reaction of the fats and oils is performed in a reducing atmosphere of superheated vaporized alcohol.
In the process for cooling the reaction product and raising the temperature of the raw material by heat exchange, the reaction product and / or the circulating alcohol taken out of the reaction apparatus, the raw oil and fat and / or the raw alcohol and / or the circulating alcohol The method for producing a fatty acid ester according to claim 1, further comprising means for performing heat exchange between the reaction product and the reaction product to condense the reaction product in a lump and separating and collecting the fatty acid ester and glycerin from the obtained condensate. .
In the high-temperature heat exchange step, a first high-temperature heat exchanger in which a high-temperature side is a reaction gas and a low-temperature side is a circulating alcohol accompanied by a raw material alcohol (hereinafter referred to as a reaction raw material alcohol), a high-temperature side is a reaction gas, and a low-temperature side is raw material fats and oils 2. The method for producing a fatty acid ester according to 1, wherein a second high-temperature heat exchanger is provided.
The condensing heat recovery step is provided with a first condensing heat exchanger in which the high temperature side is the reaction gas and the low temperature side is the reaction raw material alcohol, and a second condensing heat exchanger in which the high temperature side is the reaction gas and the low temperature side is the raw material fats and oils. The method for producing a fatty acid ester according to 1.
2. The method for producing a fatty acid ester according to 1, wherein the temperature control heat exchange step is provided with a temperature control heat exchanger in which the high temperature side is a circulating alcohol and the low temperature side is a raw oil or fat.
2. The method for producing a fatty acid ester according to 1, wherein the adiabatic cooling step is provided with an adiabatic cooler in which the high temperature side is circulating alcohol and the low temperature side is raw alcohol.
In the process for cooling the reaction product and preheating the raw material by heat exchange, the high temperature heat exchange step includes a first high temperature heat exchanger in which the high temperature side is the reaction gas and the low temperature side is the reaction raw material alcohol, and the high temperature side is the reaction gas. And a second high-temperature heat exchanger whose raw material is fat and oil on the low temperature side, and in the condensation heat recovery step, a first condensing heat exchanger whose high temperature side is the reaction gas and the low temperature side is the reaction raw material alcohol, and the high temperature side is the reaction gas and low temperature A second condensing heat exchanger whose side is a raw oil and fat, a temperature control heat exchange step, a temperature control heat exchanger where the high temperature side is circulating alcohol and the low temperature side is a raw material fat and oil, and the adiabatic cooling step, Establish a heat recovery system with an adiabatic cooler with circulating alcohol and low temperature side raw alcohol, split the high temperature reaction gas from the reaction process into two branches and put them in the first and second high temperature heat exchangers, respectively , Each high A reaction product separation step in which the intermediate temperature reaction gas of each branch exiting the heat exchanger is put into the first and second condensation heat exchangers, and the low temperature reaction gas exiting each condensation heat exchanger is joined. The reaction product is separated as a condensate, and the obtained circulating alcohol is sequentially put into a temperature control heat exchanger and an adiabatic cooler to further lower the temperature, and the required raw alcohol is added to the reaction raw material in the adiabatic cooler. It is made into alcohol, and it sends to the low temperature side of the 1st condensation heat exchanger and the 1st high temperature heat exchanger one by one, heats and raises temperature, and uses it for reaction, while raw material fats and oils are used for temperature control heat exchanger and 2nd condensation heat sequentially 2. The method for producing a fatty acid ester according to 1, comprising a heat exchange step of heating and raising the temperature through the low temperature side of the exchanger / second high temperature heat exchanger and using it for the reaction.
2. The method for producing a fatty acid ester according to 1, wherein in the high-temperature heat exchange step, heat exchange is performed between the reaction gas and the reaction raw material alcohol using the raw material fats and oils as a heat medium.
In the high-temperature heat exchange process, a high-temperature heat exchanger in which the high-temperature side is the reaction gas and the low-temperature side is the heating medium (raw oils), and the high-temperature heat for alcohol heating in which the high-temperature side is the heating medium (raw oils and fats) and the low-temperature side is the reaction raw material alcohol Heat exchanger outlet on the low temperature side and high temperature heat exchanger for alcohol heating High temperature heat exchanger inlet, high temperature heat exchanger for alcohol heating High temperature heat exchanger outlet and high temperature heat exchanger low temperature A heating medium circulation circuit is formed by connecting the side heat medium inlet with a conduit, and a circulation pump and a high-temperature heating medium (raw oil and fats) take-out means are provided in the middle of the circulation circuit to react with the heat of the reaction gas. 16. The method for producing a fatty acid ester according to 15, wherein the raw material alcohol is heated.
A mixed adiabatic cooler equipped with raw alcohol (liquid) supply means and gas stirring means is installed in the middle of the superheated vapor alcohol circulation path from the temperature control heat exchange process to the condensation heat recovery process. 2. The method for producing a fatty acid ester according to 1, wherein the recovered alcohol is adiabatically cooled.
Reaction product separation apparatus provided with condensate separation means such as a filter medium by condensing reaction products in the reaction gas in the condensation heat recovery step and sending superheated vapor containing the condensate to the reaction product separation step The condensate and the superheated vapor are separated through a filter, the collected condensate is sent to a product separation step, and put into a product separation apparatus equipped with product separation means such as specific gravity separation to separate fatty acid esters and glycerin. 2. The method for producing a fatty acid ester according to 1, wherein the fatty acid ester is obtained.
The reaction residue generated in the reaction process is sent to a process for incineration (hereinafter referred to as reaction residue incineration process) using an incinerator such as a heat medium boiler, and the heat medium is heated by the heat generated during the incineration to generate a high-temperature heat source. The method for producing a fatty acid ester according to 1, wherein the fatty acid ester is obtained.
2. The method for producing a fatty acid ester according to 1, wherein a high-temperature heat source (heat medium) obtained in the reaction residue incineration step is sent to the final preheating step and heat exchange is performed with the reaction raw material alcohol and the raw material fats and oils.
The main processes are reaction process, high temperature heat exchange process, condensation heat recovery process, reaction product separation process, temperature control heat exchange process, adiabatic cooling process, final preheating process, superheated alcohol circulation means, product separation process and reaction residue incineration process. A superheated vaporized alcohol circulation that connects all or multiple of the reaction process, high-temperature heat exchange process, condensation heat recovery process, reaction product separation process, temperature control heat exchange process, adiabatic cooling process, and final preheating process. It has a pathway, recovers the heat of the reaction gas by heat exchange and preheats the raw materials, condenses the reaction products at once, separates and collects fatty acid ester and glycerin from the resulting condensate, The resulting reaction residue is sent to the reaction residue incineration process and used as a fuel for heating the heating medium used in the final preheating process. Build a system that generates electricity from a part of the produced fatty acid ester, enables operation of the entire plant without obtaining external fuel and power supply, and prevents hazardous waste from leaving the plant 2. The method for producing a fatty acid ester according to 1, wherein