JP2006137824A - Etbe mixture, method for producing the same and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an ETBE (ethyl-tert-butyl ether) mixture useful as a high-performance fuel having a high octane number. <P>SOLUTION: The ETBE mixture is composed of a reaction product obtained by reacting hydrated ethanol with isobutene and comprises 60-90 vol.% of ethyl-tert-butyl ether, 5-20 vol.% of tert-butyl alcohol, 5-20 vol.% of ethanol and 0-3 vol.% of water. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ETBE (ethyl-tert-butyl ether) mixture, a process for producing the mixture, and an apparatus therefor, and in particular, ETBE that can be advantageously used as a high-performance fuel instead of MTBE (methyl-tert-butyl ether). The present invention relates to a mixture, a method for producing it advantageously, and an apparatus suitably used in the production thereof.

Conventionally, internal combustion engines have been widely used as power sources in various fields such as automobiles, agricultural machines such as tractors, cultivators, chainsaws, and various industrial machines and construction machines. . As a high-performance fuel for such an internal combustion engine, gasoline, which is a fossil fuel, is used. With the recent increase in awareness of global environmental problems, an effective alternative fuel to replace such gasoline has emerged. It is requested. In order to meet such a demand, as shown in the following chemical reaction formula (1), IB (isobutene) and MeOH (methanol) are directly reacted as an oxygen-containing octane improver for automobile gasoline. MTBE (methyl-tert-butyl ether) obtained in this manner has been used in large quantities.
IB + MeOH = MTBE (1)

Various physical properties of MTBE produced in this way are as shown in Table 1 below. Table 1 also shows various physical properties of gasoline, and other substances such as ETBE (ethyl-tert-butyl ether), TBA (tert-butyl alcohol), EtOH (ethanol), H ₂ O (water). Various physical properties of IB (isobutene) are also shown.

  By the way, it is understood that MTBE, ETBE, TBA, and EtOH are substances having a high octane number in any of them, as is clear from the comparison of various physical properties shown in Table 1. Among them, MTBE is a colorless and transparent strong odor liquid at room temperature, and is easily dissolved in water, and the drinking water in which it is dissolved has a problem of exhibiting an unpleasant odor and taste. Furthermore, MTBE is concerned about carcinogenicity, and there is a problem that environmental pollution is caused by its discharge.

  For this reason, non-toxic bioethanol, which can be produced by fermentation and distillation operations of renewable biomass, has been attracting attention and used instead of the above-described MTBE as a gasoline alternative fuel. However, EtOH becomes an azeotrope with water in a simple distillation operation, and it is possible to obtain only water-containing ethanol having a concentration of about 95 vol% at most. And in order to obtain absolute ethanol, it is necessary to add a solvent such as benzene or cyclohexane as the third component to such water-containing ethanol and perform azeotropic distillation. Has the problem of becoming high. Moreover, ethanol has inherent problems such as high flash point and low fuel consumption (see Table 1).

Therefore, in order to solve such a problem, as shown in the following chemical reaction formula (2), ETBE (ethyl-tert-) produced by directly reacting IB (isobutene) and EtOH (ethanol). The use of butyl ether) is considered. This ETBE has the advantages of reducing vapor pressure or lowering volatility, and also has the characteristics of almost no toxicity (see Table 1).
IB + EtOH = ETBE (2)

  By the way, Patent Document 1 clearly discloses a method of producing ETBE by reacting a C4 fraction containing IB with EtOH using a reactive distillation column equipped with a fixed bed reactor filled with an ion exchange resin. Has been. In addition, in many other literatures, methods for synthesizing ETBE have been studied (see, for example, Non-Patent Document 1). However, in these conventional techniques, expensive anhydrous ethanol is used as a raw material, and no literature that mentions the use of inexpensive hydrous ethanol as in the present invention has yet been found.

TBA (tert-butyl alcohol) is also valuable as an octane number improver for gasoline (see Table 1), which is synthesized from IB and H ₂ O as shown in the following chemical reaction formula (3). Also regarding this, many documents are recognized (for example, refer nonpatent literature 2 etc.).
IB + H ₂ O = TBA (3)

On the other hand, the present inventors are concerned about the shortage of supply of IB used in the chemical reaction formula as described above, and as a substitute, conduct research on TBA, and publish the results as a report ( Non-patent documents 3 and 4). Such TBA is a by-product during the production of propylene oxide. In a reactive distillation column in which the TBA and bioethanol having a high water content are packed with a strong acidic cation exchange resin as a catalyst, the following chemical reaction formula (4 ).
TBA + EtOH = ETBE + H ₂ O (4)

The IB component is normally used as a C4 fraction obtained by refining crude oil, but can also be synthesized from biomass as follows. That is, first, CH ₄ and CO ₂ are generated by biomass methane fermentation. Methane can also be obtained from underground resources such as natural gas or methane hydrate. Then, as shown in the following chemical reaction formula (5), carbon monoxide (CO) and hydrogen (H ₂ ) are formed by a methane reforming reaction with carbon dioxide (for example, Non-Patent Document 5), Furthermore, isobutene (IB) is synthesized from carbon monoxide and hydrogen (for example, Non-Patent Documents 6 and 7).
CH ₄ + CO ₂ = 2CO + 2H ₂ (5)

US Pat. No. 5,248,836 Y-C.Tian, F.Zhao, B.H.Bisowarno, M.O.Tade, "Pattern-based predictive control for ETBE reactive distillation", J. Process Control, Vol. 13, pp. 57-67 (2003) C.M.Zhang, A.A.Adesina, M.S.Wainwright, "Isobutene hydration in a countercurrent flow fixed bed reactor", Chem. Eng. Processing, Vol. 43, pp. 533-539 (2004) A.Quitain, H.Itoh, S.Goto, "Reactive Distillation for Synthesizing Ethyl tert-Butyl Ether from Bioethanol", J.Chem.Eng.Japan, Vol.32, No.3, pp.280-287 (1999) A.Quitain, H.Itoh, S.Goto, "Industrial-Scale Simulation of Proposed Process for Synthesizing Ethyl tert-Butyl Ether from Bioethanol", J.Chem.Eng.Japan, Vol.32, No.4, pp.539 -543 (1999) A. Takano, T. Tagawa, S. Goto, "Carbon Dioxide Reforming of Methane on Supported Nickel Catalysts", J. Chem. Eng. Japan, Vol. 27, No. 6, pp. 727-731 (1994) K.Maruya, T.Komiya, T.Hayakawa, L.Lu, M.Yashima, "Active sites on ZrO2 for the formation of isobutene from CO and H2", Journal of Molecular Catalysis A: Chemical, Vol.159, pp. 97-102 (2000) Y.Li, D.He, Q.Zhang, B.Xu, Q.Zhu, "Influence of reactor materials on i-C4 synthesis from CO hydrogenation over ZrO2 based catalysts", Fuel Process. Technol., Vol.85, pp .401-411 (2004)

  The present invention has been made in the background of such circumstances, and the problem to be solved is to provide an ETBE mixture useful as a high-performance fuel having a high octane number (first). And a method capable of producing such an ETBE mixture at a low cost (second problem), and further providing an apparatus that can advantageously produce such an ETBE mixture. (Third issue)

  And in this invention, in order to solve such a 1st subject, it consists of the reaction product obtained by making water-containing ethanol and isobutene react, and ethyl-tert- butyl ether: 60-90 vol%, The gist is an ETBE mixture characterized by containing tert-butyl alcohol: 5 to 20 vol%, ethanol: 5 to 20 vol%, and moisture: 0 to 3 vol%.

  In addition, according to one of the desirable embodiments of the ETBE mixture according to the present invention as described above, at least one of the hydrous ethanol and the isobutene is produced using biomass as a raw material.

  In addition, the gist of the present invention is a high-octane fuel for an internal combustion engine comprising such an ETBE mixture.

  Further, in the present invention, in order to solve the second problem described above, hydrous ethanol and isobutene are used as raw materials, and they are reacted using a fixed bed reactor filled with a solid catalyst, and at least ethyl The gist of the method is a process for producing an ETBE mixture characterized in that a reaction product containing tert-butyl ether, tert-butyl alcohol and unreacted ethanol is obtained.

  Then, according to one of the desirable embodiments of the method for producing the ETBE mixture according to the present invention, as the reaction proceeds, the reaction temperature of the reaction system is reduced so that the reaction temperature at the end of the reaction is lower than the reaction temperature at the beginning of the reaction. Cooling will be performed.

  According to another desirable embodiment of the production method according to the present invention, a strongly acidic cation exchange resin is used as the solid catalyst, and an azeotropic mixture of ethanol and water is used as the hydrous ethanol. It will be.

  Furthermore, in the present invention, in order to solve the third problem, at least ethyl-tert-butyl ether, tert-butyl alcohol, and unreacted ethanol are reacted by reacting hydrous ethanol with isobutene. An apparatus for producing a reaction product, a multitubular multistage fixed bed reactor equipped with heating / cooling means for reacting hydrous ethanol and isobutene, and a reaction crude product flowing out from the reactor And a distillation column for taking out the bottoms containing unreacted ethanol together with ethyl-tert-butyl ether and tert-butyl alcohol produced in the reaction, and an apparatus for producing an ETBE mixture Is the gist of this.

  In addition, according to a desirable aspect of the ETBE mixture production apparatus according to the present invention, a plurality of reaction units including the reactor and the distillation column are used, and the reaction units are arranged and connected in series. The isobutene supply means is connected to the reactor in the first reaction unit of the plurality of reaction units arranged in series, and the hydrous ethanol supply means is connected to the reactor in the final reaction unit. At the same time, the bottoms taken out by the distillation tower in a predetermined reaction unit are refluxed to the reactor in the previous reaction unit.

  According to another desirable aspect of the apparatus for producing an ETBE mixture according to the present invention, the distillation column performs distillation of the reaction crude product and proceeds reaction of unreacted products present in the reaction crude product. In the reactive distillation column, the construction is advantageously made.

  Thus, in the present invention, the IB component in the C4 fraction synthesized from methane and carbon dioxide or produced from a petroleum plant, or MTBE is decomposed (reverse reaction of the above formula (1)). In accordance with the above formulas (2) and (3), a liquid phase under pressure is obtained by using a component obtained by liquefying pure IB (hereinafter abbreviated as C4 component) and water-containing ethanol as raw materials. The reaction was performed to synthesize TBA together with ETBE, and unreacted EtOH was simultaneously made one component of the ETBE mixture.

  For this reason, in the present invention, EtOH as a raw material is used in a hydrated product, so there is no need to dehydrate hydrated ethanol or use a highly rectified product. Inexpensive raw materials can be used, and the employed liquid phase reaction can be performed under moderate conditions of medium temperature and medium pressure (100 ° C. or less, 2 MPa or less). Manufacturing costs can be further reduced.

  Moreover, TBA synthesized (by-product) together with ETBE and unreacted EtOH both have a high octane number as shown in Table 1 above. Therefore, in the present invention, these components are separated. Therefore, it was used as it is as an ETBE mixture, and as a result, it could be advantageously used as a high-octane fuel for internal combustion engines such as automobile fuel. In addition, such an ETBE mixture can be used as a good fuel regardless of the ratio of gasoline mixed with gasoline. Furthermore, it can be used not only for automobiles but also for other mechanical devices such as chainsaws. It can be advantageously used as a fuel for the internal combustion engine used.

  Hereinafter, in order to clarify the present invention more specifically, some representative embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 shows a conceptual diagram of an example of a reactor that is advantageously used to produce an ETBE mixture according to the present invention. The design concept of this reactor is that the ETBE synthesis reaction in the formula (2) is an exothermic reaction of 35 kJ / mol, and the TBA synthesis reaction of the formula (3) is also an exothermic reaction of 38 kJ / mol, It is necessary to remove heat, and furthermore, these reactions are reversible, and the lower the temperature, the more ETBE and TBA are produced. However, if the temperature is too low, the reaction rate itself increases rapidly. Therefore, it is based on the fact that temperature control is important, and that the method of decreasing the temperature is optimal as the reaction proceeds, and for this reason, a multitubular multistage fixed bed reaction is performed. It is designed as a container.

  Specifically, as shown in FIG. 1, the reactor 10 includes a can body having a predetermined length extending in the vertical direction into eight independent chambers 14 a to 14 h by horizontal partitions 12. The lowermost chamber 14a is partitioned as a raw material supply chamber, and the uppermost chamber 14h is a product take-out chamber. The raw material supply chamber 14a is supplied with water-containing ethanol (EtOH) and isobutene (IB) as raw materials from outside by a pump or the like, generally in a stoichiometric proportion necessary for the reaction under pressure. In the product take-out chamber 14h, the ETBE mixture according to the present invention produced by the reaction of the water-containing EtOH and IB can be collected and taken out as a product to the outside. ing.

  In the reactor 10, the intermediate chambers 14b to 14g partitioned as independent spaces by the upper and lower partitions 12 and 12 are reaction chambers for carrying out the reaction between the water-containing EtOH and IB, respectively. -ing In addition, a hot water supply path 16 and a cold water supply path 18 are connected to the independent reaction chambers 14b to 14g, respectively, and hot water or cold water is independently connected to the reaction chambers 14b to 14g. Is supplied so that the reaction temperature in each reaction chamber can be controlled. In particular, here, cold water is supplied and controlled so that the reaction temperature becomes lower as it goes to the upper reaction chamber.

  In each reaction chamber 14b-14g, as shown in FIGS. 2 (a) and 2 (b), a plurality of reaction tubes 20 are erected in parallel with each other with a predetermined gap therebetween, and The upper and lower partitions 12 and 12 are attached so as to be liquid-tight and pressure-tight from the respective reaction chambers 14b to 14g. Accordingly, hot water or cold water introduced into the reaction chambers 14b to 14g passes through the gaps between the reaction tubes 20 to heat or cool the reaction tubes 20 to a predetermined temperature, and then is discharged to the outside. It will be. Each reaction tube 20 is generally filled with a solid catalyst 22 having a predetermined shape such as a granular shape or a pellet shape, and a liquid-permeable filter 24 is attached to the upper and lower ends of the solid catalyst 22. Only the reaction liquid composed of a mixture of hydrous EtOH and IB can be allowed to flow in the vertical direction (here, from bottom to top). As a result, the reaction between the water-containing EtOH and IB is effectively advanced in the presence of the solid catalyst 22, and thus the desired ETBE and TBA are generated.

  In addition, the partition 12 between each reaction chamber can guide only the reaction liquid which distribute | circulates the inside of the reaction tube 20 from a lower chamber to an upper chamber, for example, below reaction chamber 14b-14g. When the reaction liquid is guided from one to the upper one, the reaction liquid flowing out from the reaction tube 20 arranged in the lower chamber can be directly guided into the reaction tube 20 in the upper chamber. In addition, the reaction liquid led from the plurality of reaction tubes 20 arranged in the lower chamber is once led to a common reaction liquid collecting space provided in the partition 12, and then again into the upper chamber. A structure or the like in which the reaction liquid is distributed and allowed to flow into the plurality of reaction tubes 20 arranged can be appropriately employed.

  By the way, IB (isobutene), which is one of the raw materials used in producing the ETBE mixture according to the present invention using such a reactor 10, is preferably supplied from underground resources or biomass as described above. In addition, even in hydrous EtOH (ethanol), the one obtained by fermentation of biomass is advantageously used. In particular, it is recommended to use raw materials supplied from ethanol fermentation or methane fermentation using only biomass as a renewable resource as raw materials. In general, the water content of the hydrous EtOH is preferably 30 vol% or less, and it is particularly recommended to use an azeotropic mixture of EtOH and water.

  Further, such a reaction between hydrous EtOH and IB is advantageously carried out in the liquid phase, generally at a medium temperature of 100 ° C. or less, particularly at a temperature of about 60 to 100 ° C. Further, in order to keep the reactant in a liquid phase in the reaction apparatus, specifically the reaction tube 20, generally, a pressure of about 2 MPa or less, particularly about 1.3 to 2 MPa is suitably employed as the pressure, In the reactor 10, the liquid phase reaction is allowed to proceed.

In addition, according to the present invention, various known catalysts can be appropriately used as the solid catalyst 22 filled in the reaction tube 20 in order to react hydrated EtOH with IB. Ion exchange resins, especially strong acidic cation exchange resins for catalysts, are advantageously used. As such a strongly acidic cation exchange resin, a porous type (MR type) styrene resin into which a strong acid group such as a sulfonic acid group (—SO ₃ H) is introduced as an ion exchange group can be suitably used. It is. Moreover, as such a strongly acidic cation exchange resin, any commercially available one can be adopted, for example, “Amberlyst”, “Amberlite” (USA: Rohm and Haas), “Diaion” ( Products sold under the names such as Mitsubishi Chemical), “Dowex” (US: Dow Chemical), “Duolite” (US: Diamond Shamrock) will be used as appropriate. In addition, the particle size of such a strongly acidic cation exchange resin is usually about 0.5 to 1.0 mm.

  Then, by using the reactor 10 as described above, the water-containing EtOH and IB are reacted to obtain a reaction product containing unreacted EtOH together with the generated ETBE and TBA. In such a composition that ETBE is contained in a proportion of 60-90 vol%, TBA 5-20 vol%, EtOH 5-20 vol%, and moisture 0-3 vol%, respectively. Is taken from the reaction system and made into an ETBE mixture according to the invention. In particular, by preparing it as an ETBE mixture in such a composition range, it can be advantageously used as a high-octane fuel for internal combustion engines, and as an octane improver, it can be added to gasoline to provide excellent fuel economy characteristics. To demonstrate.

  FIG. 3 is a layout diagram illustrating an example of an apparatus for producing an ETBE mixture using the reactor 10 as described above. The manufacturing apparatus shown in FIG. 3 relates to a preferred example of an apparatus when IB 100% is used as the IB raw material, and 100% IB led from the IB raw material tank 30 is IB raw material supply. Heat is exchanged and heated in the heat exchanger 32 through the flow path 31 and then supplied to the reactor 10 by the pump 34. Further, the water-containing EtOH taken out from the EtOH raw material tank 36 is supplied through the surge tank 38 in the EtOH supply flow path 39 and supplied to the reactor 10 by the pump 40 under a predetermined pressure. ing. The 100% IB and the water-containing EtOH pumped by the pumps 34 and 40 are heated to a predetermined temperature of 100 ° C. or less by the water vapor in the heater 42 and introduced into the reactor 10. ETBE and TBA production reaction is allowed to proceed.

  The reaction crude product containing a predetermined amount of ETBE and TBA generated in the reactor 10 and further containing unreacted EtOH and residual moisture is taken out through the take-out flow path 44 and supplied to the distillation column 46. The In the distillation column 46, the supplied reaction crude product is distilled by a predetermined distillation operation, and a product is taken out from the bottom as a bottoms. On the other hand, from the top of the distillation column 46, the reaction crude product is removed. The distillate composed of unreacted IB separated by distillation is liquefied by cooling with cooling water, taken out, and mixed with the 100% IB raw material supplied from the IB raw material tank 30 through the recovery channel 48. Can be used effectively. Further, the bottoms taken out from the bottom of the distillation column 46 is guided and stored in the product tank 50 through the product channel 52 as an ETBE mixture according to the present invention. The waste heat of the bottoms led to the product tank 50 is effectively used by heat exchange between the product flow path 52 and the IB raw material supply flow path 31 in the heat exchanger 32. It can be illustrated. Further, in the distillation column 46 described above, removing hydrocarbons accumulated in the reaction system from the reaction crude product is also employed as necessary.

  By the way, in the apparatus shown in FIG. 3, the mass balance of a commercial plant when 100% IB raw material is used and the monthly production is 6000 kL is summarized as shown in Table 2 below. At this time, the supply amount of 100% IB from the IB raw material tank 30 is calculated as 89 L / min, and the supply amount of 92 vol% hydrous EtOH from the EtOH raw material tank 36 is calculated as 64 L / min. Yes. From the mass balance shown in Table 2, it is well understood that the composition of the ETBE mixture meets the requirements of the present invention.

  Furthermore, FIG. 4 shows a layout view of an example of an apparatus for producing an ETBE mixture in the case of using an IB-based material containing not only 100% IB material but also other hydrocarbons together with IB, for example, a C4 fraction. Has been. In this case, a configuration in which two sets of reaction units including the reactor 10 and the distillation column 46 shown in FIG. 3 are connected in series is employed. Here, in order to facilitate understanding, the same components as those in the apparatus of FIG.

  In the production apparatus shown in FIG. 4, a reaction unit composed of the first reactor 10a and the first distillation column 46a and a reaction unit composed of the second reactor 10b and the second distillation column 46b are connected in series. Thus, the IB raw material consisting of the C4 fraction taken out from the IB raw material tank 30 is introduced into the first reactor 10a via the heat exchanger 32. On the other hand, the water-containing EtOH taken out from the EtOH raw material tank 36 by the pump 54 is supplied with the distillate taken out from the top of the first distillation column 46a by the pump 56, Then, it is introduced into the second reactor 10b, and the reaction between the hydrous EtOH and IB is allowed to proceed further.

  And the distillate taken out from the top of the second distillation column 46b is a by-product having a low unreacted IB content, and is accommodated in the by-product tank 56, while the second distillation. The bottoms taken out from the bottom of the column 46b is pumped from the surge tank 38 to the first reactor 10a by the pump 40 so that the reaction can proceed further. In the first reactor 10a, the water-containing EtOH-rich bottoms pumped by the pump 40 reacts with the IB raw material (C4 fraction) supplied from the IB raw material tank 30 by the pump 34. The reaction crude product thus obtained is subjected to a distillation operation in the first distillation column 46a, and the bottoms taken out from the bottom thereof are used as a target ETBE mixture (product) as a product tank 50. On the other hand, since the distillate taken out from the top of the column contains unreacted IB, it is fed again into the second reactor 10b by the pump 56 and supplied to the pump 54. It can be used for the reaction with the hydrous EtOH supplied.

  In this way, a plurality of reaction units composed of the reactor 10 and the distillation column 46 are combined, and the raw material inlet of the IB raw material (C4 fraction) is used as the first reactor 10a which is the first reactor, while water-containing EtOH is contained. By supplying the raw material inlet separately as the second reactor 10b which is the last reactor, the restriction of the reversible reaction can be effectively relaxed, and the ETBE concentration The high ETBE mixture can be advantageously taken out as a product from the first distillation column 46a, which is the first distillation column. In addition, the by-product taken out as a distillate of the second distillation column 46b which is the last distillation column has a low content of IB. Therefore, the by-product thus obtained is advantageously used for other applications. It becomes possible.

  Table 3 below shows the mass balance of a commercial plant with a monthly production of 6000 kL when it is reacted with hydrous EtOH using raffinate-1, which is a C4 fraction with an IB content of 53 wt%. . In this case, the supply amount of raffinate-1 is 168 L / min, and the supply amount of 92 vol% hydrous EtOH is calculated to be 68 L / min. In addition, the symbol in Table 3 represents the following compounds. 1-B: 1-butene, C-2-B: cis-2-butene, NB: N-butane, T-2-B: trans-2-butene, IBU: isobutane, 1,3-B: 1,3-butadiene, C5 +: a hydrocarbon having 5 or more carbon atoms.

  In the production apparatus as shown in FIG. 4, between the reaction unit consisting of the first reactor 10a and the first distillation column 46a, and the reaction unit consisting of the second reactor 10b and the second distillation column 46b, It is also possible to arrange one or more reaction units and connect them in series. In that case, the bottoms taken out from the bottom of each distillation column are suitable pumps for the reactor of the upstream reaction unit, in particular the previous reactor, in order to proceed further. By means, it will be pumped.

  Further, in the apparatus for producing an ETBE mixture according to the present invention shown in FIG. 5, in order to use a C4 fraction similar to the apparatus shown in FIG. 4 as a raw material, in the apparatus shown in FIG. Instead, a reactive distillation column 60 is used, and a distillate taken out from the reactive distillation column 60 is led to a by-product tank 58. In the reactive distillation column 60, a solid catalyst 22 for reacting hydrous alcohol with isobutene is accommodated in the reaction column 60, and the reaction of these components is allowed to proceed. Since the distillation operation of the crude product can be performed simultaneously, the reaction crude product taken out from the reactor 10 is further allowed to proceed in the reactive distillation column 60. is there. Thus, by using the reactive distillation column 60 instead of the simple distillation column (46), separation during the reaction becomes possible. Therefore, the reverse reaction in the reversible reaction is effectively suppressed. As a result, a predetermined composition of the ETBE mixture and a by-product with less IB can be produced.

  The exemplary embodiments of the present invention have been described in detail above. However, this is merely an example, and the present invention is not limited by the above description. Should be understood. Therefore, although not enumerated one by one, the present invention can be implemented in a mode with various changes, modifications, improvements and the like based on the knowledge of those skilled in the art. Needless to say, all are included in the scope of the present invention without departing from the spirit of the present invention.

  Hereinafter, in order to clarify the present invention more specifically, the results of carrying out the present invention in a pilot plant will be clarified.

First, as a pilot plant, a reactor having a six-stage reaction chamber as shown in FIG. 1 was manufactured. The inner diameter of the reactor was 15 cm, and the height of one stage was 30 cm. The temperature control of each reaction chamber is different from the structure shown in FIG. 2, and the reaction chambers are filled with hot water supply pipes and cold water supply pipes arranged spirally in each reaction chamber. The solid catalyst (strongly acidic cation exchange resin) was heated and cooled. The strong acid cation exchange resin used was “Amberlyst 15” (USA: Rohm and Haas), and the total amount of the strong acid cation exchange resin used as the catalyst was 22.9 L. Furthermore, the mass of the dry cation exchange resin was 4.94 kg. The ratio between the heat transfer area and the mass of the dry cation exchange resin was 0.62 m ² / kg · dry · resin.

  Further, the temperature setting in such a reactor is as follows. First stage: 80 ° C. Second stage: 90 ° C. Third stage: 85 ° C. The temperature was controlled by adjusting the supply amounts of hot water and cold water so that the stage: 80 ° C., the fifth stage: 75 ° C., and the sixth stage: 70 ° C. Note that the reaction temperature in the first-stage reaction chamber, which is the lowest stage of the reactor, was set to a temperature lower than that of the second-stage reaction chamber above it to suppress a rapid reaction near the inlet. This is to facilitate temperature control. Then, the temperature in the second stage reaction chamber above the first stage was set to the maximum temperature (90 ° C.), and thereafter, the temperature was lowered by 5 ° C. toward the upper reaction chamber.

  Of the results obtained by reacting IB with hydrous EtOH under the reaction conditions as described above, the measured values and calculated values when 100% IB is used as a raw material are compared in Table 4 below. Is shown. As is apparent from the results in Table 4, it can be recognized that the numerical values are in good agreement. The calculation was derived from the experimental equation obtained in the batch reactor, and the reaction rate equation was derived to obtain the basic equation of the tubular reactor. All other reactor simulations were determined by the same method.

Further, Table 5 below shows a comparison between measured values and calculated values when raffinate-1, which is a C4 fraction containing a lot of IB, obtained in an oil plant is used as an IB raw material. In addition, IB content in the raffinate-1 used here was 47 wt%. As is apparent from the results in Table 5, it can be recognized that the measured values and the calculated values are in good agreement.

  In any of the results of Table 4 and Table 5, the ETBE mixture is within the predetermined composition range defined in the present invention, and is suitable as a fuel for an internal combustion engine such as a high octane number automobile fuel. It is recognized that In order to clarify this fact, a fuel consumption comparison with regular gasoline was conducted using an ETBE mixture having the composition shown in Table 5, and a running experiment was conducted on a 50 cc motor bicycle and a 125 cc motorcycle. Shown in the consumption rate results. As is apparent from the results in Table 6, the fuel consumption rate is remarkably improved (20% or more) when the ETBE mixture according to the present invention is used as compared with the regular gasoline. It is recognized.

1 is a conceptual diagram showing an example of a reactor used for the production of an ETBE mixture according to the present invention. It is sectional explanatory drawing which shows an example of the reaction chamber in the reactor shown by FIG. 1, Comprising: (a) is a cross-sectional explanatory drawing of a reaction chamber, (b) is the AA cross-section part in (a). It is explanatory drawing. It is an arrangement block diagram which shows an example of the manufacturing apparatus of the ETBE mixture according to this invention. It is arrangement | positioning explanatory drawing which shows another example of the manufacturing apparatus of the ETBE mixture according to this invention. It is arrangement | positioning explanatory drawing which shows another example of the manufacturing apparatus of the ETBE mixture according to this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Reactor 12 Partition 14a-14h Reaction chamber 16 Hot water supply path 18 Cold water supply path 20 Reaction tube 22 Solid catalyst 24 Filter 30 IB raw material tank 31 IB raw material supply flow path 32 Heat exchanger 34 Pump 36 EtOH raw material tank 38 Surge tank 39 EtOH supply flow path 40 Pump 42 Heater 44 Extraction flow path 46 Distillation tower 48 Recovery flow path 50 Product tank 52 Product flow path 54, 56 Pump 58 By-product tank 60 Reactive distillation tower

Claims (10)

  It consists of a reaction product obtained by reacting hydrous ethanol with isobutene. Ethyl-tert-butyl ether: 60-90 vol%, tert-butyl alcohol: 5-20 vol%, ethanol: 5-20 vol%, and water: 0 ETBE mixture characterized by containing 3 vol%.   The ETBE mixture according to claim 1, wherein at least one of the hydrous ethanol and the isobutene is produced using biomass as a raw material.   A high octane fuel for an internal combustion engine comprising the ETBE mixture according to claim 1 or 2.   Using hydrous ethanol and isobutene as raw materials, they are reacted using a fixed bed reactor packed with a solid catalyst, and a reaction product containing at least ethyl-tert-butyl ether, tert-butyl alcohol and unreacted ethanol is obtained. A process for producing an ETBE mixture, characterized in that it is obtained.   The process for producing an ETBE mixture according to claim 4, wherein the reaction system is cooled as the reaction proceeds so that the reaction temperature at the end of the reaction is lower than the reaction temperature at the beginning of the reaction.   The method for producing an ETBE mixture according to claim 4 or 5, wherein the hydrous ethanol is an azeotropic mixture of ethanol and water.   The method for producing an ETBE mixture according to any one of claims 4 to 6, wherein the solid catalyst is a strongly acidic cation exchange resin. An apparatus for producing a reaction product containing at least ethyl-tert-butyl ether, tert-butyl alcohol and unreacted ethanol by reacting hydrous ethanol with isobutene,
A multitubular multistage fixed bed reactor equipped with heating and cooling means for reacting hydrous ethanol with isobutene;
A distillation column for distilling the crude reaction product flowing out from the reactor and taking out a bottom liquid containing unreacted ethanol together with ethyl-tert-butyl ether and tert-butyl alcohol produced in the reaction,
An apparatus for producing an ETBE mixture, comprising:   Using a plurality of reaction units comprising the reactor and the distillation column, the reaction units are arranged and connected in series, and the reactor in the first reaction unit of the plurality of reaction units arranged in series The isobutene supply means is connected to the final reaction unit, and the water-containing ethanol supply means is connected to the reactor in the final reaction unit, and the bottoms taken out in the distillation column in the predetermined reaction unit, The apparatus for producing an ETBE mixture according to claim 8, wherein the apparatus is configured to reflux the reactor in the previous reaction unit. 10. The ETBE mixture according to claim 8 or 9, wherein the distillation column is a reactive distillation column that performs distillation of the reaction crude product and promotes the reaction of unreacted substances present in the reaction crude product. apparatus.

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