KR830002476B1 - Method for preparing methyl t-butyl ether - Google Patents

Abstract

No content.

Description

Method for preparing methyl t-butyl ether

1 is a manufacturing process of methyl t- butyl ether according to the present invention.

The present invention relates to a process for the continuous production of methyl t-butyl ether. That is to say a method for producing methyl t-butyl ether (hereinafter referred to as MTBE) from a hydrocarbon mixture containing isobutylene and methanol in a two step process under certain reaction conditions.

In recent years, lead contained in waste gas discharged from internal combustion engines has been highlighted as a pollution problem. As a result, gasoline currently contains no lead at all and high-end gasoline will soon not contain lead.

However, in order to obtain lead-free gasoline without significantly changing the mixing ratio of the basic gasoline while maintaining the octane number of the conventional gasoline, it is necessary to increase the octane number by adding an additive. Many additives for increasing the octane number are known. Among them, ether having a branched alkyl group is Sec. M. 397 (1951). For example, it is known that methyl t-butyl ether (MTBE), ethyl t-butyl ether and isopropyl t-butyl ether have very high octane numbers.

Methyl t-butylether is known in the process for preparing methanol by isobutylene in the presence of an acid catalyst. In particular, a method of using a strongly acidic cation exchange resin as a catalyst has been proposed. (For example, Japanese Patent Publication No. 1973-34,803, Japanese Patent Publication No. 1974-61,109 and 1975-58,006, US Patent No. 2,480,940).

However, these conventional methods require a heating step in the distillation process that separates the reaction products because acidic substances extracted from the strongly acidic cation exchange resin used during the reaction are incorporated into the reaction products.

However, this heating process is undesirable because of the presence of tertiary carbon atoms in the product, which causes the reverse reaction of decomposing the methyl t-butyl ether once formed into methanol and isobutylene. Moreover, products containing acidic substances cannot be mixed with gasoline fuels by themselves.

The present inventors use a particulate acid neutralizer to remove unnecessary acid and then flash and distillate to prepare tertiary alkyl ethers from lower primary alcohols and tertiary olefins in industrially high yields. The invention has been invented and already filed (Japanese Patent Application No. 140,479 / 1976). The inventors also reacted olefins with excess lower alcohols on the olefins used, followed by removal of the acidic substance with a granular acid neutralizer, followed by flashing. After removing the unreacted hydrocarbon, the reaction mixture is distilled to produce an azeotropic mixture of methyl t-butyl ether and methanol at the top of the distillation column, which is recycled to the first reactor in which the olefin and the lower alcohol are reacted, and the bottom of the distillation column is The method of obtaining methyl t-butyl ether of high purity is also invented and filed (Japanese special Hewha No. 123, 154 (1977).

It is an object of the present invention to provide a method for continuously preparing methyl t-butyl ether in high yield.

It is an object of the present invention to recycle some of the reaction mixture of isobutylene and methanol to the first reactor in which the reaction is carried out, and to send the remaining reaction mixture to the second reactor to increase the production of t-methylbutylether. It relates to a process for continuously producing butyl ether.

Still another object of the present invention is a method for continuously producing methyl t-butyl ether by reacting isobutylene and methanol in two reactors each filled with strongly acidic cation exchange resins having different physical properties.

In particular, the present invention relates to isobutylene hydrocarbon and methanol at a liquid space velocity of 0.1 to 50 (1 / hour) at a molar ratio of isobutylene and methanol at a ratio of 1: 0.6-1.4 at 60 to 100 ° C. and 1 to 50 atmospheres. The isobutylene-containing hydrocarbon is reacted with methanol by continuously passing through a first reactor packed with strongly acidic cation exchange resin particles having an average particle diameter of 0.2 to 10 mm, and the reaction product mixture is subjected to a flow rate of the first stream of the second stream. Divided into two streams of arbitrary 3 to 15 times by weight, the first stream is recycled to the first reactor filled with the above-mentioned cation exchange resin, and the second stream is 20 to 55 ° C., 1 to 50 atm. Through a second reactor packed with strongly acidic cation exchange resin particles having an average particle diameter of 0.2 to 10 mm at a liquid space velocity of 0.1 to 50 (1 / hour), and average streams from the second reactor at 0 to 55 ° C. A water-insoluble acid neutralizer solid particle having a diameter of 0.1 to 10 mm is passed through a fixed bed packed, the resulting reaction mixture is sent to a distillation column to remove unreacted hydrocarbons, and a mixture containing MTBE is collected from the bottom of the column. In this regard, the present invention relates to a method for continuously producing MTBE.

Raw materials used in the process of the invention are isobutylene hydrocarbons and methanol. Although high purity isobutylene may be used as the isobutylene hydrocarbon, a hydrocarbon mixture containing isobutylene may be used. That is, the mixture may include n-butane, isobutane, butene-1, butene-2, butadiene, and the like in addition to isobutylene. For example, C ₄ hydrocarbon fractions (usually including 10 to 50% by weight of isobutylene), which can be obtained by pyrolysis, steam cracking, catalytic cracking of petroleum, can be used effectively. Although methanol can use a commercial item, it is preferable that moisture content is less than 1 weight%.

In the present invention, it is not necessary to use a solvent. However, when using a solvent, a solvent inert to the reaction may be used in an amount less than 1/10 of the reactant.

When using the C ₄ hydrocarbon mixture as a starting material, it is conceivable to C ₄ hydrocarbons other than isobutylene in the solvent.

Isobutylene hydrocarbons and methanol are preheated close to the reaction temperature, either individually or in mixtures, and then introduced into a reactor filled with a strong acid cation exchange resin.

The present invention is characterized by the use of two reactors, where the first reactor, whose temperature is higher than the second reactor, increases the disclosure rate of the reaction product even though the chemical equilibrium is somewhat impaired, and the first reactor is lower than the first reactor. The reactor serves to increase the total conversion rate, based on the fact that chemical equilibrium interferes with the reaction rate but favors the reaction product.

According to the present invention, the emulsion of the reaction mixture obtained by reacting methanol and isobutylene in a first reactor filled with a strong acid cation exchange resin is divided into two, the first stream is recycled to the first reactor, and the second stream is the first reactor. We choose to send to reactor 2. The flow rate of the first stream recycled to the first reactor is 3 to 15 times, preferably 5 to 10 times the flow rate of the second stream passed to the second reactor.

In the present invention, the reason for choosing the recycling method is attributable to the following grounds. That is, the reaction of methanol and isobutylene according to the present invention is exothermic and 95% of the heat generated during the entire reaction process is generated in the first reactor. Therefore, when the method without the recirculation system is taken, the temperature difference between the inlet and outlet of the first reactor is very large, especially the temperature around the outlet is very high. Such high temperatures must be avoided because they increase side effects and degrade the performance of the catalyst being used. Therefore, in this case, a special cooling device must be installed in the reactor, and the cooling device should be in the form of a multi-pipe, cooler because the thermal conductivity of the ion exchange resin in the reactor is poor. This method requires a complicated process for the exchange of catalysts, and furthermore, a high temperature is often localized in the exchange resin. However, by choosing the recycle method, the temperature can be maintained almost uniform throughout the reaction phase.

The reaction product stream of the first reactor is introduced into the second reactor. In the second reactor, since only 5% of the heat generated through the entire reaction is generated, the temperature difference between the inlet and the outlet is not large so that the piston outlet system may be selected unlike the recirculation system.

According to the present invention, the reaction temperature of the first reactor is 60 ℃ to 100 ℃ while the reaction temperature of the second reactor is 20 ℃ to 55 ℃. When the reaction temperature of the first reactor is 60 ° C. or less, the reaction rate is too slow, and sufficient disclosure yield cannot be expected.

It is not preferable to exceed 100 DEG C, since side effects such as low molecular polymerization of isobutylene increase.

The preferred reaction temperature of the first reactor is 65 ° C to 80 ° C.

If the reaction temperature in the second reactor is 20 ° C. or less, the reaction does not proceed well. If the temperature is 55 ° C or higher, the equilibrium value is not favorable to the product, and thus, high level conversion such as 96 ° C or higher is not achieved. Therefore, the preferred reaction temperature of the second reactor is 30 ° C to 50 ° C.

The pressure range applied to the present invention is 1 to 50 atm, but preferably 5 to 30 atm for the first and second reactors. If the pressure is less than 1 atm, the reaction does not proceed well, and if the pressure exceeds 50 atm, the reactor and its auxiliary facilities must be pressure-resistant, which is disadvantageous industrially.

Isobutylene and methanol in the raw material crab are fed to the first reactor in a molar ratio of 1: 0.6-1.4, preferably 1: 0.75-1.2. Here, the raw material system refers to the raw material supplied to the first reaction and excludes the stream recycled to the first reactor. When the methanol / isobutylene molar ratio of the raw material system is 0.6 or less, the isobutylene and isobutylene dimers in excess of the amount of methanol increases. In particular, when the butane-butene fraction obtained by naphtha decomposition is used as the raw material of isobutylene, the molar ratio is not good because the C ₄ '-1, C _{4 in the} unreacted butane-butene fraction after the reaction is not good. In order to use '-2', the reaction ratio of isobutylene should be increased as much as possible.

If the molar ratio of isobutylene to methanol is more than 1.4, the amount of unreacted methanol is too high to increase the amount of methanol in the mixture containing MTBE or to recycle the azeotropic mixture of MTBE and methanol to the raw material system. The amount of azeotropic mixture is increased, in both cases the amount of MTBE product is reduced. That is, the ratio of MTBE and methanol in the azeotropic composition is 85:15 (weight), and as the amount of unreacted methanol increases, the amount of MTBE in the azeotropic mixture also increases, so that the amount of MTBE product recovered at the bottom of the distillation column is reduced. do. The amount of MTBE in the azeotrope recycled to the raw material system should be less than 50% of the MTBE produced in the first reactor and exceeding this is marginally undesirable.

The strongly acidic cation exchange resin produced in the present invention is a strong acid cationic exchange resin, and typical ones include styrene sulfonic acid resin and phenol sulfonic acid resin. Styrene sulfonic acid type ion exchange resins are prepared by copolymerizing polyunsaturated compounds such as styrene and divinylbenzene and sulfonating the resulting resin. This type of resin can be represented by the following general formula.

Where m and n are integers.

The phenol sulfonic acid type resin may be a condensate of phenol sulfonic acid and formaldehyde and may be represented by the following general formula.

In which m is an integer.

The strongly acidic cation exchange resins mentioned above are used as catalysts in the present invention and are spherical or cylindrical particles having an average particle diameter of .2 to 10 mm.

The catalyst particles are supplied to the first reactor and the second cylindrical reactor having a pressure resistant structure and form a fixed bed. The size of the stationary phase is not limited but is usually between 0.2 and 20m in height.

The methanol and isobutylene described above can be fed continuously from the top or bottom of the stationary phase, with top feed being preferred. The liquid space velocity (m 3 / m 3 × 1 / hr = 1 / hr) of the feed is 0.1 to 50, preferably 0.5 to 15 (1 / hour).

The liquid space velocity of the first reactor may be expressed as the volume m 3 of the stream supplied to the first reactor per m 3 of time, except for the liquid recycled to the first reactor, at 20 ° C. and 2.5 kg / cm 3.

The liquid space velocity of the second reactor may be represented by the volume m 3 of the stream supplied to the second reactor per m 3 of catalyst per hour under the same conditions as the first reactor.

If the liquid space velocity of the reactant supplied as the raw material is less than 0.1 (1 / hr), the reaction proceeds well, but the amount of the product is too small to be industrially undesirable and the decomposition of the reaction product is increased. If the amount of reactants exceeds 50 (1 / hr), the reaction does not occur sufficiently. This requires further purification than usual and this is a disadvantage.

Sulfonic solvents, patented inert hydrocarbon solvents can be used. For example, C ₄ hydrocarbon fraction obtained by distilling naphtha, butane-butene fraction obtained by separating and removing butadiene from the C ₄ hydrocarbon fraction may be used as a raw material of isobutylene.

According to the present invention, first, about 90% of the raw material is converted into methyl t-butyl ether in the first reactor and the remaining unreacted raw material is reacted in the second reactor to obtain MTBE with excellent selectivity and high yield. However, this method has a problem that a small amount of strongly acidic material is continuously exported from the strong acid type cation exchange resin used as a catalyst and mixed with the reaction mixture. When the reaction mixture containing these acidic substances is introduced into a kind process stage, which itself involves separation of unreacted gas and normal heating, the main reaction product is decomposed by a reverse reaction, resulting in a decrease in yield and Corrosion problems are caused.

Therefore, this strongly acidic substance must be given to me. One method is to neutralize the acid with an aqueous solution of a strong base such as sodium hydroxide, calcium oxide or calcium hydroxide. However, this method is difficult to separate salts generated by neutralization, and since the concentration range of acidic substances is relatively wide, it is necessary to adjust them according to the catalyst, reaction temperature, amount of raw materials and reaction time using the amount of basic substances. There is difficulty. If the amount of basic substance is too small, the acidic substance is not completely removed and the above-mentioned obstacles and defects still remain. If too much basic material is added, the next step, separation of the unreacted gas, should be carried out under the conditions necessary to handle the strong base material. Thus, a process of washing the product with water, distillation, etc. before mixing with the internal combustion engine fuel is required, which is very undesirable.

If sodium hydroxide, calcium oxide or the like is used in solid form, it must be eluted, causing the above-mentioned problems.

Alternatively, the acid may be removed using an adsorbent such as activated carbon. However, the drawback is that the ability to adsorb acidic substances is significantly reduced when the concentration of acidic substances is low due to their low adsorption capacity.

In resolving these obstacles and shortcomings, and effectively and continuously reacting the methanol and isobutylene, one of the characteristics of the present invention is that the reaction mixture discharged from the second reactor in water-insoluble acid having an average diameter of 0.1 to 10mm Contacting the reaction mixture with the water-insoluble oxidant by passing the agent particles through the fixed bed filled. The above-mentioned obstacles and shortcomings are solved. Herein, the water-insoluble acid neutralizer solid particles are extremely low in solubility in water, usually 0.1 g or less per 100 g of water, and the active acid neutralization point is inorganic solid particles higher than 0.1 mmol / g.

The active acid neutralization point described above may be removed per gram of the solid substance remaining in the aqueous solution after adding a given amount of solid substance to 1 wt% aqueous sulfuric acid solution and leaving it at 50 ° C. for 10 hours to separate the solid substance from the solution. Obtained by calculating millimoles of sulfuric acid.

As a water-insoluble solid granular acid neutralizing agent usually used in the present invention, a complex oxide of magnesium oxide, alumina, silica, silica alumina, magnesium and aluminum and its hydrate, at least one element of Na, K, C, Si, Ca, Sr and Ba And composite oxides of magnesium, aluminum, and hydrates thereof.

For example MgO, MgO. mH ₂ O (m = 0 to 0.5), Al ₂ O ₃ , hydrotalcite (6MgOAl ₂ O ₃ CO ₂ 12H ₂ O), Al ₂ O ₃ mSiO ₂ nH ₂ O (m = 0.5 To 3, n = 1 to 6), Al ₂ O ₃ nH ₂ O, 2.5 MgO Al ₂ O ₃ nH ₂ O, Na ₂ O Al ₂ O ₃ , nH ₂ O, and 2 MgO. 6SiO ₂ nH ₂ O (n = 1 to 6 in each case). Of these, hydrotalcite and MgO are preferred in the present invention. Hydrotalcite, as used herein, typically has a molar ratio of 3: 1 to magnesium and aluminum. Hydrotalcite, which has a similar composition but varies greatly in the molar ratio of magnesium to aluminum, can be produced synthetically according to the process, but the molar ratio of magnesium to aluminum is 3: 1 and the molar ratio of magnesium to aluminum is 3: 1. In some cases, X-ray diffraction peaks specific to hydrotalcite may be exhibited. Thus, a hydrotalcite having a molar ratio of magnesium to aluminum of 1 to 10: 1 and exhibiting such a peak can be effectively used according to the present invention.

The solid particulate acid neutralizer according to the present invention is spherical, flaky or cylindrical with an average particle diameter of 0.1 to 10 mm, and is filled in a container to form a fixed phase.

The reaction mixture is passed through the stationary bed continuously at 0 to 55 ° C, preferably 20 to 50 ° C. When the temperature is below 0 ° C., the product properties cannot be sufficiently removed, so the reaction mixture from the reactor must be heated, which leads to high energy consumption. Temperatures above 55 ° C. do not need to cool the reaction mixture from the reactor and thus have the disadvantage of energy consumption.

Preferred temperatures are temperatures near the reaction temperature.

The reaction mixture is preferably added through a conduit between the reactor outlet and the inlet of the phase into an acid neutralizer filled bed, which is cooled to below ambient temperature. The liquid space velocity of the amount of reaction mixture passed through the stationary phase is usually between 0.1 and 20 (1 / hour).

According to the invention the reaction mixture is then passed through a distillation column where it is subjected to a separation step. The fleshing tower usually consists of a multistage type and separates unreacted hydrocarbons, i.e., other hydrocarbons mixed with unreacted isobutylene and isobutylene hydrocarbons from the top of the tower. Two or three flashing towers can be connected in a row and used in a multi-stage format. The separated isobutylene is liquefied and recycled to the first reactor.

The mixture containing MTBE is recovered from the bottom of the flashing tower. This mixture contains, as a main component, MTBE and a small amount of unreacted methanol.

The MTBE obtained by the process of the invention can be added to the fuel for internal combustion engines by themselves.

If the methanol molar ratio in the reactant system is high, the amount of methanol in the methyl t-butylether mixture discharged from the bottom of the flashing tower is also high. Therefore, to reduce the methanol content in the reaction mixture as much as possible, the reaction mixture is distilled in a distillation column to recover the high purity methyl t-butylate at the bottom of the column by midstreaming the azeotropic mixture of methyl t-butylether and methanol. Methanol can be used effectively by recycling the azeotrope to the reactant system. When the azeotrope does not need to be recycled to the reactant system, the azeotrope can be washed with water or another solvent to separate the methyl t-butyl ether and methanol.

In order to explain the manufacturing method according to the present invention in more detail, the actual manufacturing process will be described below with reference to the manufacturing process diagram. The raw material isobutylene is introduced through conduit 1 and methanol is introduced through conduit 2. If necessary, the recovered unreacted isobutylene is recycled to the raw material system via conduit 11. The feed mixture is sent to heater E ₁ through conduits 4 and 5 to preheat and then to reactor R ₁ (not shown) with a fixed bed filled with strong acid cation exchange resin particles. The reaction mixture discharged from reactor R ₁ is divided into two streams. One stream is cooled in chiller E ₂ and then via conduit 6 to conduit 5 through conduit 6 where it is recycled combined with new, raw material from conduit 4 to reactor R _{1. The} remaining stream is conduit 7 It is fed to a heat exchanger R ₂ through which it is preheated and introduced into a reactor R ₂ having a fixed bed filled with a strong acid cation exchange resin.

The emulsion discharged from reactor R ₂ is sent through conduit 8 to neutralization tower N with a fixed bed filled with water-insoluble solid acid neutralizer particles. The pressures in the reactors R ₁ , R ₂ and neutralization tower N are adjusted with a pressure regulating valve (PCV). The liquid stream passing through the neutralization tower N is depressurized and sent to the heat exchanger E ₄ (heater) through conduit 9, where the temperature is controlled and then sent to distillation tower F. The hydrocarbon mixture comprising unreacted isobutylene is discharged through conduit 11 from the top of the distillation column F and, upon reuse, is mixed with the raw material isobutylene which is introduced into conduit 1 after liquefaction.

The mixture containing methyl t-butylether is recovered via conduit 10 at the bottom of distillation column F. The following examples illustrate the features of the present invention in more detail.

Example 1

The reactors R ₁ and R ₂ were filled with 90 styrene ion exchange resins (Rohm and Haas, Co .; Amberlist-15, average particle diameter, 0.5 mm) and the neutralization tower N was 50 ι hydrotalcite (6 MgO · Al ₂ O ₃ · CO ₂ · 12H ₂ O, average particle diameter, 0.7mm). Isobutylene with a 99% purity is introduced through conduit 1 at a flow rate of 118.7 kg / hr (2.12 kg mol / hr), and conduit 2 with 99% pure methanol at a flow rate of 70.0 kg / hr (2.19 kg mol / hr). Introduce through. The liquid space velocity of each raw material compound was 3.2 (1 / hr) and the pressure was maintained at 15 kg / cm 2 G by the pressure regulating valve. One of the streams discharged from the first reactor is fed through conduit 6 to conduit 5, mixed with newly introduced isobutylene and methanol and sent to reactor R ₁ through conduit 5. The heat exchanger E ₁ is adjusted so that the reactor R _{1 has} an introduction temperature of 70 ° C., and the amount of liquid through the conduit 6 is adjusted by the recirculation pump P to be 7 times the amount of the raw material introduced through the conduit 4. The amount of liquid discharged from the reactor R ₁ and passed through the conduit 7 was 188.7 kg / hr, and the configuration included 90.0 wt% of the reaction product, 5.6 wt% of the unreacted isobutylene, and 4.4 wt% of the unreacted methanol. The reaction mixture liquid is adjusted to 40 ° C. in heat exchanger E ₃ through conduit 7 and then introduced into reactor R ₂ . The composition of the liquid discharged from the reactor R ₂ is 96.1 wt% methyl t-butylether, 1.7 wt% unreacted isobutylene and 2.2 wt% unreacted methanol. The acid concentration of the liquid is 3.0 x 10 ^-4 eq / ι. The liquid flow is introduced into neutralization tower N through conduit 8.

The liquidus temperature introduced to the neutralization tower N is 45 degreeC. The acid concentration of the liquid exiting polymerization tower N is 1.5 × 10 ⁻⁷ eq / ι. The emulsion is fed to a distillation column through conduit 9 to separate unreacted isobutylene. Methyl t-butylether of 98.0% purity is withdrawn at a flow rate of 185.2 kg / hr through conduit 10 at the bottom of the distillation column.

Example 2

Reactors R ₁ and R ₂ are charged to the catalysts obtained by sulfonating a resin 90ι having a diameter of 20 to 50 mesh produced by polymerizing styrene containing 14% divinyl benzene. Isobutylene with 99% purity was introduced through conduit 1 at a flow rate of 100.8 kg / hr (1.80 kg mol / hr) and methanol with 99% purity was passed through conduit 2 at a flow rate of 64.0 kg / hr (2.0 kg mol / hr). Introduce. The liquid space velocity of these raw materials is 2.8 (1 / hr), respectively. The introduction temperature of the reactor R ₁ and R ₂ is adjusted to 70 ℃ and heat exchanger 35 ℃ be E ₁ and E _2, respectively. The introduction temperature in polymerization tower N is 32 degreeC. Except the matter described above, it implements like Example 1. The composition of the liquid through conduit 7 is 90.2 wt% methyl t-butyl ether, 3.8 wt% unreacted isobutylene and 6.0 wt% unreacted methanol. The composition of the liquid introduced into the distillation column F through conduit 9 is 95.1 wt% methyl t-butyl, 0.7 wt% isobutylene and 4.2 wt% methanol, and the acid concentration is 2.8 × 10 ⁻⁷ eq / ι. Through conduit 10 underneath distilled coal F, a liquid containing a small amount of methanol is discharged at a flow rate of 163.6 kg / hr.

Example 3

A 90ι styrene type cation exchange resin (Rohm and Haas, Co .; H ⁺ substitutable Amberlite IR-121, aperture 0.6 mm) is charged to the reactor R ₁ as a catalyst. A C ₄ fraction containing 40% isobutylene was introduced through conduit 1 at a flow rate of 147.0 kg / hr (1.05 kg mol / hr) and 99% pure methanol was introduced at a flow rate of 32.0 kg / hr (1.00 kg mol). / hr) through conduit 2. The introduction temperatures of the reactors R ₁ and R ₂ were adjusted in the same manner as in Example 1 except that the heat exchangers E ₁ and E ₂ were adjusted to 73 ° C. and 37 ° C., respectively. The discharge temperatures of the reactors R ₁ and R ₂ are 83 ° C. and 45 ° C., respectively. The introduction temperature of the neutralization tower N is 42 degreeC. The composition of the liquid through conduit 7 is 43.3% by weight methyl t-butylether, 54.6% by weight C ₄ fractions, and 2.1% by weight methanol. The composition of the liquid introduced into distillation column F through conduit 9 is 46.7 wt% methyl t-butylether, 52.4 wt% fraction and 0.9 wt% methanol and the acid concentration is 3.0 × 10 ⁻⁷ eq / ι.

Through conduit 10 at the bottom of the distillation column F, methyl t-butyl ether having a purity of 98.1% is produced and discharged at a flow rate of 85.2 kg / hr. The only impurity is methanol.

Claims (1)

In the continuous preparation of methyl t-butyl ether by reacting isobutylene and methanol using a strong acid type cation exchange resin as a catalyst and recovering methyl t-butyl ether from the reaction mixture, the isobutylene and methanol are molar ratios. 1: 0.6-1.4 continuously passes through a first reactor filled with a strongly acidic cation exchange resin particle having an average particle diameter of 0.2 to 10 mm at a liquid space velocity of 0.1 to 50ι / hr at 60 to 100 ° C and 1 to 50 atmospheres. To react the isobutylene-containing hydrocarbon with methanol, dividing the reaction product mixture into two streams having a flow rate of the first stream of 3 to 15 times the second stream, and recycling the first stream to the first reactor, The stream was subjected to a second reactor packed with a strongly acidic cation exchange resin particle having an average particle diameter of 0.2 to 10 mm at 20 to 55 ° C. at 1 to 50 atm. The stream from the second reactor was passed through 0ι / hr, and the stream from the second reactor was passed from 0 to 55 ° C., through a fixed bed filled with a water-insoluble solid granular acid neutralizer having an average particle diameter of 0.1 to 10 mm, and the resulting reaction mixture was passed through To separate unreacted hydrocarbons and to recover a mixture containing methyl t-butyl ether from the bottom of the distillation column.

Images