SA01220385B1 - Process for producing the ester of a carboxylic acid lower aliphatic acid - Google Patents

Abstract

Abstract: The invention relates to a process for producing an ester of a lower aliphatic carboxylic acid by an esterification reaction in the gas phase starting from a lower aliphatic carboxylic acid and a lower olefin, comprising the addition of a corresponding lower alcohol to the hydrate hydrate of a lower olefin to the gas phase reaction product, condensation of lower aliphatic carboxylic acid and lower alcohol and during further conversion to ester of lower aliphatic carboxylic acid, the ester of aliphatic carboxylic acid is separated lower aliphatic carboxylic acid . The productivity is increased due to the improvement of loweraliphatic carboxylic acid conversion.

Description

Y _ _ Process for producing an ester of a lower aliphatic carboxylic acid Full Description

background of the invention

The present invention relates to the production of an ester of a small aliphatic carboxylic acid

Lower alcohol Cua is added - with high efficiency; Jower aliphatic carboxylic acid

Corresponding to a hydrate of a lower olefin to a Jeli product containing a lower aliphatic carboxylic acid and an ester of a carboxylic acid

lower aliphatic carboxylic acid; It is obtained by an acid reaction

lower aliphatic carboxylic acid and lower olefin in

gaseous phase in the presence of an acidic catalyst; catalyst 2010; to convert aliphatic carboxylic acid

The lower aliphatic carboxylic acid in the reaction product is converted into an ester of 0 lower aliphatic carboxylic acid ¢ and the ester of the acid is separated

Lower aliphatic carboxylic acid and its extraction.

Esters are considered to be lower aliphatic carboxylic acids.

40 useful chemicals used in different fields as different industrial materials and solvents. And used

Specifically, ethyl acetate has been widely used as an organic solvent alternative to solvents based on benzene or toluene. Based on this, various production processes have been proposed and implemented.

Fat - the process of producing an ester of a small aliphatic carboxylic acid can be classified as lower aliphatic carboxylic acid; Especially the process of producing ethyl acetate in terms of the starting material to (1) a method that uses acetaldehyde (Y) acetaldehyde a method that uses ethanol and acetic acid; (Y) a method that uses Ethylene and acetic acid.

Specific examples of method (1) using acetaldehyde include the method described in Unexamined Japanese Patent Publication No. 11-1 E+ NT (19-2-11-140016). Specific examples of method (7) include Which uses ethanol and acetic acid, the method mentioned in the unexamined Japanese patent publication No. 0464?1-lah-a.

(©) But the cls method has a high yield of ethyl acetate, according to this method it is possible to produce ethyl acetate 0 attention ester acetic acid and ethylene acetic acid, which uses ethylene recently as a more effective method Lower aliphatic relates to a process for the production of a small aliphatic carboxylic acid, Lad, that is specifically performed with the initiation of gas phase esterification by carboxylic acid esterification.

Vo with aliphatic carboxylic acid:©1097 and lower olefin; Such as lee production using a heterogeneous polybasic acid w/0 salt thereof as a catalyst and which were disclosed in JP Unexamined Patent Publication No. 174144-; - A and No. 134149-4-A and No. 167448-H - A and No. 1-1-4404; and no

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PE lower aliphatic is a small aliphatic carboxylic acid ester in these ester production processes; Therefore, gas phase must be introduced; The reaction is carried out in the carboxylic acid gas phase on the reactor in lower aliphatic carboxylic acid as gas. Accordingly; And in light of the efficient use of the energy required for fumigation; It is important to raise the evaporator. lower aliphatic carboxylic acid The degree of conversion of the small aliphatic carboxylic acid It is suggested to use olefin esterification to achieve this purpose; It is generally done in the esterification reaction with an amount equivalent to or greater than a small aliphatic carboxylic acid and that of a small lower olefin. lower aliphatic carboxylic acid to try to raise the conversion of the small aliphatic carboxylic acid in this case the process mentioned in the Japanese patent publication is generally used which is done only lower olefin where the feed stream is separated with small olefin ¢ © -1 456077 Its examination No. 0 lower aliphatic carboxylic acid ester reacted from an ester or something “lower aliphatic carboxylic acid or a small aliphatic carboxylic acid + lower aliphatic carboxylic acid and the like”; using a lower aliphatic carboxylic acid as an absorbent liquid and then recycling it in an equivalent amount of lower olefin by this method; More specifically, a method that uses a small VO olefin and thus esterification of a small or greater aliphatic carboxylic acid in the esterification reaction shows that the lower aliphatic carboxylic acid can raise the conversion of the small aliphatic carboxylic acid successfully lowering the energy cost required to evaporate the carboxylic acid the small aliphatic, but it is accompanied by an increase in the percentage of the increase in the olefin “lower aliphatic carboxylic acid”; An increase in the amount recycled as well as an increase in the energy needed. That is, lower olefin is small ©

that -

The lower olefin increase percentage has an appropriate range in light of the balance between these two

The two starting materials and the proportion in which an excess of the lower olefin can be used as a limit

Maximum.

Accordingly; By the previous method can only reduce the improvement of carboxylic acid conversion

Low aliphatic power aliphatic carboxylic acid as well as reducing energy cost savings

The lower aliphatic carboxylic acid needed to evaporate the small aliphatic carboxylic acid.

General description of the invention

Gas The present invention is an improvement of a process for the production of an ester of a small aliphatic carboxylic acid

lower aliphatic carboxylic acid by esterification reaction in the gas phase 01 starting with a lower aliphatic carboxylic acid and an olefin

small lower olefin » and the conversion of the aliphatic carboxylic acid L-small

lower aliphatic carboxylic acid ¢ which is difficult to obtain by the method

304 dually lower olefin is used for aliphatic carboxylic acid.

the little one; Thus, it provides an effective production method for the lower aliphatic carboxylic acid ester.

In order to achieve the previous goal; The inventors made extensive studies of the process as a whole

For the process of producing an ester of a lower aliphatic carboxylic acid

By esterification reaction in the gas phase, starting with an acid

lower aliphatic carboxylic acid and lower olefin 0 .

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0 + - As a result of this it has been found that when a lower alcohol corresponding to a hydrate of a lower olefin is added to the zie reaction during; or in the middle; or independent of a process to separate the lower aliphatic carboxylic acid ester from a reaction product containing the lower aliphatic carboxylic acid ester july acid © of lower aliphatic carboxylic acid at The outlet of the Cus reactor, the Jeli esterification is carried out in the gas phase of the small aliphatic carboxylic acid and the small tower olefin, where the lower aliphatic carboxylic acid is condensed with the alcohol to convert them into an ester ester of lower aliphatic carboxylic acid 0 is separated and the ester yield of lower aliphatic carboxylic acid is improved. This and the present invention has been accomplished on the basis of this result. more specifically; The present invention (1) is a process for producing an ester of a lower aliphatic carboxylic acid; comprising the reaction of a lower aliphatic carboxylic acid and a lower olefin in the gas phase. Gas phase Vo in the presence of an acidic catalyst Cus «acid catalyst. The production process includes the first, second and third steps: The first step: is the step of adding a lower alcohol corresponding to a small olefin hydrate of a lower olefin to a reaction product containing a lower aliphatic carboxylic acid

_ for _

carboxylic acid after the gas phase reaction, thus obtaining a reaction product

A little alcohol was added to it.

The second step:

It is the step of condensation of a lower aliphatic carboxylic acid and a lower alcohol A lower alcohol product of the reaction to which a lower alcohol has been added; been obtained

it in the first step; During conversion to ester of an aliphatic carboxylic acid

small, lower aliphatic carboxylic acid; The ester of the aliphatic carboxylic acid is separated

,. lower aliphatic carboxylic acid

The present invention (Y) is a process for producing an ester of a small aliphatic carboxylic acid

1 lower aliphatic carboxylic acid 0 comprising the reaction of a lower aliphatic carboxylic acid and a lower olefin in the gas phase in the presence of an acid catalyst 41 to 201 dua 1 The production process includes the first steps To the third third: the first step:

lower aliphatic carboxylic acid is the step of adding the same lower aliphatic carboxylic acid1 used in the previously mentioned reaction to a reaction product containing an aliphatic carboxylic acid and thus the gas phase after the gas phase reaction lower aliphatic carboxylic acid Small Sad carboxylic acid a) A product of the reaction is obtained by adding ¢ lower aliphatic carboxylic acid

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—_A —

Second step:

It is the step of adding a lower alcohol corresponding to a small olefin hydrate

hydrate of a lower olefin to a reaction product to which a small aliphatic carboxylic acid has been added

lower aliphatic carboxylic acid ¢ was obtained in the first step; Thus it is obtained

¢ lower alcohol on a reaction product to which a lower alcohol 0 has been added

Third step:

It is the step of condensation of a lower aliphatic carboxylic acid and an alcohol

small lower alcohol in a reaction product to which a lower alcohol was added » Done

get it in the second step; And during the conversion to an ester of a carboxylic acid Ve, a small aliphatic carboxylic acid; The ester of the carboxylic acid is separated

,. lower aliphatic carboxylic acid

The present invention (¥) is a process for producing an ester of a small aliphatic carboxylic acid

lower aliphatic carboxylic acid; It contains a small aliphatic carboxylic acid reaction

gas phase in the gas phase lower olefin and lower aliphatic carboxylic acid where the production process includes the first steps to ¢ acid catalyst in the presence of an acid catalyst Vo

the following fourth:

The first step:

It is the step of separating a reaction product after the reaction in the gas phase containing an acid

lower aliphatic carboxylic acid and ester of a carboxylic acid

Ah

q _ _ lower aliphatic carboxylic acid into a moiety containing mainly lower aliphatic carboxylic acid as the main component and a moiety containing mainly ester iu of a lower aliphatic carboxylic acid acid cmco J prime 0 © Step two:

It is the step of adding a lower alcohol corresponding to a hydrate of a lower olefin to a moiety containing mainly lower aliphatic carboxylic acid as the main component; obtained in the first step; Thus, a product to which a lower alcohol ¢ has been added is obtained

- The third step: is the step of condensing a lower aliphatic carboxylic acid and a lower alcohol present in a product to which a lower alcohol was added »obtained in the second step; to cause conversion to an ester of a lower aliphatic carboxylic acid;

The fourth step: It is a step to separate the ester of a lower aliphatic carboxylic acid 40 obtained in the third step, thus obtaining an ester of a lower aliphatic carboxylic acid.

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1 and.

Brief description of the drawings

Each figure shows a practical example of the present invention (3). Each figure from (1) to (;) shows a place

Perform the first to fourth steps mainly in succession.

Figure:(1) shows an example of the case in which steps one to four are performed in a tower

: distillation as a single device.‎ 0

Figure: (1) shows an example of the case in which the first step takes place in a first distillation tower and then thereafter

The second step; The third and fourth steps are conducted in a second distillation tower.

Figure (*): An example of a case in which the first step is performed in the first distillation tower

Introduce the portion containing mainly lower aliphatic carboxylic acid 0 from the bottom into a mixing apparatus; And the second step is made to add

lower alcohol in the mixing device; The mixture containing is then fed

a lower aliphatic carboxylic acid and a small alcohol

lower alcohol to a reaction device; The small aliphatic carboxylic acid is condensed

ester and convert it to the ester of lower alcohol and lower alcohol lower aliphatic carboxylic acid reaction apparatus; 8 lower aliphatic carboxylic acid is a small aliphatic carboxylic acid 1

Finally he separated the ester of the lower aliphatic carboxylic acid

carboxylic acid from the mixture in the second distillation tower.

Alya

Detailed description:

The present invention (1) is a process for producing an ester of a small aliphatic carboxylic acid

lower aliphatic carboxylic acid ¢ has a small aliphatic carboxylic acid reaction

gas phase lower olefin and small olefin 1007©: aliphatic carboxylic acid 0

in the presence of an acidic catalyst 8010; Cua The production process includes the first steps

And the next second and third: The first step:

The step of adding a lower alcohol corresponding to a hydrate of a lower olefin hydrate to a reaction product containing a lower aliphatic carboxylic acid

aa carboxylic acid is a gas phase reaction and thus a reaction product is obtained

A little alcohol was added to it.

The second step:

It is the step of condensing a lower aliphatic carboxylic acid and a lower alcohol Vo into a reaction product to which a lower alcohol was added.

get it in the first step; During the conversion to ester of a carboxylic acid

lower aliphatic carboxylic acid; The ester of the carboxylic acid is separated

,. lower aliphatic carboxylic acid 1

17- — The acid catalyst used for the esterification of lower aliphatic carboxylic acid and lower olefin in the gas phase was first described in the present invention (1). The catalyst in particular takes on a particular form as long as it is an acid catalyst that is generally used Preferred examples include heterogeneous polybasic acids and/or their salts A heterogeneous polybasic acid preferred for use as an acid catalyst process Production of a lower aliphatic carboxylic acid ester of the present invention (1) which comprises a central element and terminal elements to which an oxygen is attached. The central element is usually silicon or 0-phosphorus but is not limited to Accordingly, any element chosen may be from elements belonging to groups (1) to (VY) of the periodic table. The use of 'periodic table' in this application means the periodic table according to: Kokusai Junsei Ovobi Oyo Kagaku Rengo Muki Kagaku Meimeiho, Kaitei-Ban (Revised Nomenclature in Inorganic Chemistry by International Pure and Applied

Science Association) (1989). Vo : Specific examples of a central element include cupric ion; divalent beryllium, zinc, cobalt and nickel ions; trivalent boron, aluminum, gallium, iron, cerium, arsenic, antimony, phosphorus, bismuth, chromium and rhodium ions; tetravalent silicon, germanium, tin, titanium, zirconium, vanadium, sulfur, tellurium, manganese, nickel, platinum, thorium, hafnium and cerium ions and other rare Y. yy

Y _ 3 _ earth element ions; pentavalent phosphorus, arsenic, vanadium and antimony ions; and heptavalent iodide ion, however, the present invention is not limited to them only. Specific examples of a terminal element include: tungsten, molybdenum, vanadium, niobium and tantalum ° » However, these polybasic heterogeneous acids are not defined by the present invention as 'polyoxo anion 00170010' or 'polyoxometallate' or 'metal oxide group' metal oxide cluster. The structural formulas of some well-known anions are well-known, such as the Keggin, Wells-Dawson and Anderson-Evans-Perloff structures joa. They are described in detail in Poly-san no Kagaku.

Kikan Kagaku Sosetsu (Chemistry of Polyacids, Introduction of Chemistry Quarterly), No. 20, edited by Nippon Kagaku Kai (1993) A polybasic heterocyclic acid usually has a large molecular weight; It ranges, for example, 1 _ for example, between 700 and 8500, and it not only includes its monomers, but also includes dimeric complexes. yay

Particularly favored examples of a polybasic heterocyclic acid which are preferred as an acid used in the ester production process of a lower aliphatic carboxylic acid of the present invention include: (1) tungstosilicic acid : H4[SiW 5040] X H,0O tungstophosphoric acid : H;[PW 2040].x H,O ' saul sa phosphoric acid molybdophosphoric acid : H; [PM 2040] X H, O 0 molybdosilicic acid : X HO 511/0200 [b vanadotungstosilicic acid : X H,; vanadomolybdophosphoric acid : 3-nOyg] X H,0 \o and tomato vanadomolybdophosphoric acid : yany

- — and 1 -— Hi4,[PVnM 2.1040] X 110 vanadomolybdosilicic acid : X H,0 and H511 [mel saul ga tungstosilicic acid : Ha[SiMo [W, 13-004] X H,O Q tungstophosphoric acid : [Oso] X H,O D slurry] line where © is an integer from 1 to 11 and Ax is an integer from 1 and more 0 and of course the present invention is not limited to this.

0 The method for the synthesis of these polybasic hetero-acids is not specifically limited to a specific form but any method can be used. For example, a polybasic heterogeneous acid can be obtained by heating an acidic aqueous solution (pH -1 pH approximately) containing a salt of molybdic acid or tungstic acid and a simple oxygen acid For an atom of heterogeneity or a salt thereof. To isolate the acid compound,

1 Polybasic homogeneous from the produced aqueous polybasic heterogeneous acid solution.” The method of crystallization and separation of the compound as a metal salt can be used. Examples are described in:

—_ \ = —_

Shin Jikken Kagaku Koza 8, Muki Kagobutsuno Gosei (III) (New Experimental)

Chemistry Course 8, Synthesis (III) of Inorganic Compounds), 3rd ed., edited by Nippon

Kagaku Kai, published by Maruzen, page 1413 (Aug. 20,1984) indicates that the present invention is not limited to it. The structural formula of Kegen can be characterized by 0 or 18 diffraction in addition to chemical analysis. UV or oxo-ray measurement is not particularly limited to the polybasic heterocyclic acid salt which is preferred as a catalyst used in the production of an acid ester A lower aliphatic carboxylic acid of the present invention (1) on a metallic or onium salt resulting from the substitution of part or all of the hydrogen atoms in the aforementioned polybasic heterocyclic acid. Specific examples of these include Salts of metals such as: lithium a gill ¢, sodium, potassium, cesium 6, magnesium, barium, copper, and gold. and gallium + and Jie onium salts ammonia for the polybasic heterocyclic acids mentioned before but the present invention is not limited to them. Polybasic heteropolyacid; lithium salts; sodium salts; potassium salts; cesium ¢ and magnesium salts; Barium ¢ salts, copper salts copper ¢, gold salts 2010, gallium salts ER gallium ammonium salts for heterogeneous polybasic acids. Preferably in more detail among the above

17 For cesium tungsto acid and lithium cesium salt These salts are the lithium salt of cesium tungsto acid, cesium salt lithium, and lithium salt 010850511616 acid . tungstophosphoric acid A polybasic heterogeneous acid shows relatively high solubility in a polar solvent such as, especially when the acid is not oxygen water or other oxygen-containing solvents 0 The polybasic homogeneous is a free acid or a certain type of salt; The solubility of the antagonist can be controlled by the appropriate selection of the ion. Examples of the starting material for the element forming a polybasic heterogeneous acid salt in the invention include: lithium nitrate, lithium acetate, lithium sulfate, lithium sulfite, lithium carbonate, lithium Vo phosphate, lithium oxalate, lithium nitrite, lithium chloride, lithium citrate, sodium nitrate, sodium acetate, sodium sulfate, sodium carbonate, monosodium phosphate, disodium phosphate, sodium oxalate, sodium nitrite, sodium chloride, sodium citrate, magnesium nitrate hexahydrate, magnesium acetate tetrahydrate, magnesium sulfate, magnesium carbonate, magnesium phosphate tricosahydrate, magnesium oxalate Ve dihydrate, magnesium chloride, magnesium citrate, barium nitrate, barium acetate, barium sulfate, barium carbonate, barium hydrogenphosphate, barium oxalate monohydrate, barium sulfite, barium chloride, barium citrate, copper nitrate, copper acetate, copper sulfate, copper carbonate, copper diphosphate, copper oxalate, copper chloride, copper citrate, aurous chloride, chloroauric acid, auric oxide, auric hydroxide, Y. yy

- 18 auric sulfide, aurous sulfide, gallium dichloride, gallium monochloride, gallium citrate, gallium acetate, gallium nitrate, gallium sulfate, gallium phosphate, ammonium acetate, ammonium carbonate, ammonium nitrate, ammonium dihydrogenphosphate, ammonium hydrogencarbonate, ammonium citrate, ammonium nitrate, diammonium phosphate, monoammonium phosphate and ammonium sulfate °

However, the present invention is not limited to them in any way.

Among these salts, prefer: lithium nitrate, lithium acetate, lithium carbonate, lithium oxalate, lithium citrate, sodium nitrate, sodium acetate, sodium carbonate, sodium oxalate, sodium citrate, copper nitrate, copper acetate, copper carbonate , copper citrate, aurous chloride, \ chloroauric acid, gallium citrate, gallium acetate and gallium nitrate, and more preferred are lithium nitrate, lithium acetate, lithium carbonate, lithium oxalate, lithium citrate, sodium nitrate, sodium acetate , sodium carbonate, sodium oxalate, sodium citrate, copper nitrate, copper acetate, copper carbonate and copper citrate. Jats ve selected optimal salts of polybasic heterocyclic acids that can be used in the ester production process of aliphatic carboxylic acid Small lower aliphatic carboxylic acid of the present invention (1) the lithium salt of tungstosilicic acid 0, the sodium salt of tungstosilicic acid, and gold salt of tungstosilicic acid ¢ and gallium salt tungstosilicic acid 0 and the lithium salt of tungstophosphoric acid yay |

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tungstophosphoric acid ¢ and the sodium salt of tungstophosphoric acid

tungstophosphoric acid; And the copper salt of tungstophosphoric acid

tungstophosphoric acid; and salt 01 of tungstophosphoric acid

tungstophosphoric acid ¢ and the gallium salt of tungstophosphoric acid

tungstophosphoric acid 0 ¢ and the lithium salt of molybdophosphoric acid; The sodium salt of molybdophosphoric acid

molybdophosphoric acid + and the copper salt of molybdophosphoric acid

molybdophosphoric acid; Loy = gold salt 8010 of molybdenum phosphoric acid

Loy « molybdophosphoric acid = gallium salt of molybdophosphoric acid 0 » and the lithium salt of molybdophosphoric acid 200175005111616 » and the sodium salt of molybdophosphoric acid

molybdosilicic law Lis sad ga for copper salt acid; copper salt molybdosilicic acid gallium salt molybdosilicic acid gold salt gold salt ¢ acid

lithium salt, molybdosilicic acid, gallium salt sodium salt, ¢ vanadotungstosilicic acid, 1 tungstosilicic acid, copper salt; and the copper salt, vanadotungstosilicic acid, of gallium salt; and gallium salt vanadotungstosilicic acid (ia wal lithium salt) and lithium salt vanadotungstosilicic acid sodium salt and sodium salt » vanadomolybdophosphoric acid copper tungstophosphoric acid; copper salt vanadomolybdophosphoric acid Thanado-tungstophosphoric acid

The gold and the gold salt, “vanadomolybdophosphoric acid” of the “vanadomolybdophosphoric acid” salt

salt of vanadomolybdophosphoric acid; las = gallium

gallium salt of galls tungsto-phosphoric acid vanadomolybdophosphoric acid » and salt

lithium salt of vanadomolybdophosphoric acid

Huh, sodium salt, you smell it.” of vanadomolybdophosphoric acid » and the copper salt of vanadomolybdophosphoric acid; the gold salt of vanadomolybdophosphoric acid, the gallium salt of vanadomolybdophosphoric acid, and the lithium salt of vanadomolybdophosphoric acid.

0 lustrous vanadomolybdosilicic » the sodium salt of vanadomolybdosilicic acid » and the copper salt of ganadomolybdosilicic acid

vanadomolybdosilicic acid ¢ and the gold salt of molybdosilicic acid

vanadomolybdosilicic acid; and the gallium salt of gl molybdosilicic acid

vanadomolybdosilicic acid ¢ and the lithium salt of tungsto-molybdosilicic acid

molybdotungstosilicic acid 0 ¢, the sodium salt of molybdotungstosilicic acid; and the copper salt of molybdotungstosilicic acid; and the gold salt of molybdo tungstosilicic acid

molybdotungstosilicic acid » and the gallium salt of molybdotungstosilicic acid

molybdotungstosilicic acid ¢ and the lithium salt of tungsto-molybdotung acid

0 tungstophosphoric acid ; The sodium salt of tungstophosphoric acid ¢ and the copper salt of tungsto-molybdo acid

1 — tungstophosphoric acid; the gold salt of tungstophosphoric acid; And the gallium salt of tungstophosphoric acid. Among these salts; Preferably Lol = the lithium salt of tungstosilicic acid 0 ¢ and the sodium salt of tungstosilicic acid 40 ; copper salt of tungstosilicic acid ¢ gold salt of tungstosilicic acid ¢ gallium salt of tungstosilicic acid ¢ and lithium salt of tungstosilicic acid tungstophosphoric acid; the sodium salt of tungstophosphoric acid; copper salt of tungstophosphoric acid » gold salt 8011 of tungstophosphoric acid » gallium salt of tungstophosphoric acid » and lithium salt of molybdo acid molybdophosphoric acid “and the sodium salt of molybdophosphoric acid” and the copper salt of molybdophosphoric acid; gold salt cad J) for molybdophosphoric acid; Los = gallium salt of molybdophosphoric acid » and lithium salt of molybdosilicic acid » and sodium salt of molybdosilicic acid 1. ; copper salt of molybdosilicic acid 42 + gold salt of molybdosilicic acid and gallium salt

dl lithium salt and lithium salt » molybdosilicic acid gallium salt sodium salt ¢ vanadotungstosilicic acid soil copper salt ; and the copper salt, vanadotungstosilicic acid, of the gold salt of vanadotungstosilicic acid; the gold salt, vanadotungstosilicic acid (alls) of gallium salt, and gallium salt, “vanadotungstosilicic acid (oo) of gallium salt; And the lithium salt, vanadotungstosilicic acid, sodium salt, and the sodium salt, ¢ vanadomolybdophosphoric acid, tungstophosphoric acid, copper, and the copper salt, “vanadomolybdophosphoric acid” for gold, and the gold salt, “vanadomolybdophosphoric acid” for gold. tungsten phosphoric salt; and gallium salt, vanadomolybdophosphoric acid, 6 L of 0 gandoolybdophosphoric acid.

. vanadomolybdophosphoric acid for gallium salt and tungstosilicic acid for lithium salt, preferably lithium salt; and copper salt 010850511616 acid of tungstosilicic acid sodium salt of gold salt and gold salt » tungstosilicic acid copper salt of gallium salt; and gallium salt tungstosilicic acid 1 Seas of lithium salt and the lithium salt ¢ tungstosilicic acid of sodium salt ¢ tungstophosphoric acid of copper salt and salt Copper » tungstophosphoric acid 8010 salt gold ~ los » tungstophosphoric acid gallium salt asl all and salt ¢ tungstophosphoric acid 0 lithium salt ¢ tungstophosphoric acid yy

a vanadotungstosilicic acid ¢ and the sodium salt of vanadotungstosilicic acid and the copper salt of vanadotungstosilicic acid; gold salt ca Jl = Ley of vanadotungstosilicic acid and gallium salt of al Sl vanadotungstosilicic acid ~~ ©; the lithium salt of vanadomolybdophosphoric acid ¢ and the sodium salt of vanadomolybdophosphoric acid ; And the copper salt of vanadomolybdophosphoric acid ¢ and the gold salt of vanadomolybdophosphoric acid ¢ and the gallium salt of vanadomolybdophosphoric acid 0 . In the acid catalyst used in the ester production process of a lower aliphatic carboxylic acid _ of the present invention (1); two or more members may also be selected from a group consisting of polybasic hetero-acids and/or salts thereof . The polybasic heterogeneous acid or a salt thereof that is preferred to be used in esterification is preferably called a lower aliphatic carboxylic acid and a lower olefin in the gas phase according to the present invention (1). with a portable catalyst where the catalytic component is carried on a carrier pala The material that can be used as a carrier is not limited to a particular form and © - a porous material commonly used as a carrier specific examples include ¢silica and diatomaceous earth

diatomaceous earth; And montmorillonite ¢ and “titania Lain” and carbon

activated carbon » and alumina or silica alumina ¢ and preferably

silica; Or silica alumina 511168 or montmorillonite.

The carrier is also not limited to a specific shape but may be powdered; or spherical; Or it looks like small 0 pellets or any other condition. Prefer ball condition or small pellets. It is not limited either

Specific particle size over a given size, although preferred particle size varies

Depending on the shape of the celal, it is preferred that the average diameter range between ? and 01 mM in Ala reaction

fixed bed and between powder to ¾ mm in the case of fluidized bed reaction.

The best carrier is a carrier of silicone material that is spherical or shaped like small pellets.

esterification Jeli _ the initiator that can be used in lower olefin small olefin 0 and « ethylene in it from? = © carbon atom. Specific examples for it include ethylene olefin is 1-pentene-1 olefin; and 2-butene; And ?- biotin I-butene biotin-1 and + propylene propylene. propylene and propylene ethylene; with preference to ethylene pentene the initiator is lower aliphatic carboxylic acid

¢ formic acid abd a carbon atom. They include 1 - 4 carboxylic acid with Vo ; and propionic acid; And propionic acid, acetic acid, and acetic acid, with a preference for acetic acid “butyric acid” and “butyric acid” acrylic acid. acrylic acid and acrylic acid

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- ve preferably in the reaction of the present invention to allow the presence of water in the starting materials to maintain catalytic activity; Except that if you find an increase in water; selectivity increases towards minor alcohols or eicers corresponding to starting minor olefins; which are produced as by-products; This is not preferred. Accordingly, the amount of water allowed to be present in the starting materials has an appropriate range. Preferred specifically

.# mol 7# and preferably more range between ? and +4 mol 01 and 1 the amount ranges from oe

The reaction form is not particularly restricted to a particular form as long as it is conducted in the gas phase and any of the reaction forms can be chosen freely Jie the second layer reaction; moving class; fluidized bed; Taking the heat of reaction removed; interaction control; Simplicity and convenience prepared in mind. If the heat of reaction is small; It found little control effect

0 interaction; A tank type fixed bed reactor is used in many cases for its simplicity and convenience. When the reaction heat leaving fixed bed reactors increases; Generally used multi-tube reactor; a mobile bed reactor; or a fluidized bed reactor to keep the catalyst bed at a uniform temperature. However, these examples are representative only and are not limited to forms of interaction.

10 that the reaction temperature is not particularly limited as long as the medium is not fed into the reactor in the gaseous state; That is, the temperature is higher than the dew point of the mixed gas. The reaction temperature is generally chosen in the range from 100 °C to You °C and preferably from 111 °C to 100 °C; because in terms of the reaction rate, it decreases when the temperature decreases »; While the rate of the side reaction greatly exceeds the increase in the rate of the main reaction when the temperature rises

© This causes a decrease in selectivity and an adverse effect on the reaction result.

a - for the reaction pressure and where the feed medium to the reactor must be in the gaseous state; As in the case of temperature; It is important to choose the preferred pressure from the temperature-vapour-pressure curve that shows the appropriate relationship of the interaction between vapor pressure and temperature and the starting material temperatures; i.e. lower olefin and lower aliphatic carboxylic acid; and water temperature. For reaction rate; if the pressure drops; reaction rate decreases; Whereas if the pressure rises; It is despite the increase in the reaction rate; the dew point of the starting material mixture of lower olefin and lower aliphatic carboxylic acid-and water rises; Thus, the reaction temperature must be set at a high temperature, but this causes a decrease in selectivity, as mentioned before. Accordingly, it is generally preferred that the reaction pressure range between 80 and 0.1 MPaG; But it may vary depending on the type of starting material. The steric velocity (hereafter simply referred to as GHSV) of the starting materials feeding the catalytic reaction is not limited to the Aims value except that if 61151 is small, the production of the lower aliphatic carboxylic acid ester is The product in vo time per unit volume of the catalyst; this is called the space-time product (hereafter simply called STY) decreases; as a result the productivity decreases. If the GHSV increases the conversion in one pass decreases and the amount of Unreacted initiators at reactor outlet STY ratio increases to 7 to be close at first however if GHSV increases greatly then STY does not increase thereafter The expected effect cannot be adequately obtained from equipment or Operating cost Ae PU 1. To increase GHSV . In light of this there is practically a suitable range for 01157 and more specifically feeding is preferred yy

L - by starting materials into the reaction system at a rate of 001 to 700 / hour; Preferably between 1 and 1 hour. The first step of the present invention (1) is described hereafter. In the first step the reaction product obtained at the outlet of the reactor is not confined to a specific form as a lower aliphatic carboxylic acid and a lower olefin are reacted olefin is in the gas phase in the presence of an acid catalyst as long as it contains an unreacted lower aliphatic carboxylic acid A Jeli product, for example, may contain an aliphatic carboxylic ester small; or water added for the purpose of maintaining the catalytic activity of the reaction The reaction product may be the reaction product itself at 0 outlet of the gas phase reactor but may also be reaction product that has been partially previously separated prior to the first step. Reaction products such as those obtained from the separation of most of the unreacted lower olefin using an absorption tower or extraction cylinder can be used in the case of the reaction of a lower aliphatic carboxylic acid and a lower olefin in the gas phase gas phase in the presence of an acid catalyst The ratio between the starting tower olefin and the lower aliphatic carboxylic acid is generally not limited to a certain range. However, as mentioned before, it is preferable to use the lower olefin with an equal molar amount or an increased molar amount for the small aliphatic carboxylic acid. Specifically preferable to be the ratio; In the sense of © the molar ratio of the lower olefin to the aliphatic dal carboxylic acid

YA - - the lower from 1 : 1 to 1: 71 (lower olefin : a small aliphatic monocarboxylic acid of lower aliphatic mono carboxylic acid and preferably more than ? : 1 to < 1 to 0 and also more preferred than *: 1 to Nive even under the circumstance mentioned before; it may be used in many cases in the first step of

0 Invention Jal (reaction product obtained from the outlet of the reactor where lower aliphatic carboxylic acid and lower olefin are reacted in a gaseous phase containing lower aliphatic carboxylic acid carboxylic acid is unreacted in many cases and this can be used in the first step in the present invention (1).

hydrate of a corresponding to a lower alcohol 0 means a hydrate of a lower alcohol fed into the first step a lower olefin hydrate when the olefin is ethanol used in the reaction. Examples include Determined ethanol -1 olefin and/or I-propanol -1 propanol and includes +etylene lower olefin lower olefin and/or a mixture thereof when the lower olefin is 2-propanol propanol

vo propylene. The lower alcohol fed into the first step may be a lower alcohol as a by-product of the present invention obtained through separation and extraction or it may be a newly fed lower alcohol. Young alcohol ©1086 of higher purity is preferred but not limited to this.

© The amount of lower alcohol added is not limited to a certain amount. From the point of view of improving target carboxylic acid transformation; Overfeeding with alcohol is a little yay

and - ada lower alcohol except cad if the lower alcohol is fed in a large excess; the energy required in the second step to separate the non-residual portion from the lower alcohol feed stream will be undesirably increased. According to cll it is preferable that the amount be added in a preferred range so that the present invention is more effectively practiced. The unreacted carboxylic acid in the reaction product fed in the first step is between 1:1 to 19:1 (lower alcohol : lower aliphatic carboxylic acid ( Most preferably from 1 : 1 to .00 : 1 The second step is described later. The second step is the conversion step of Jsaslls lower aliphatic carboxylic acid lower alcohol into a reaction product To it a lower alcohol obtained in the first step was added to the ester of a lower aliphatic carboxylic acid and separated from the product. vo The reaction product to which a “lower alcohol” was added and fed in step Aull) contains a lower aliphatic carboxylic acid and a lower alcohol added in the first step. in addition to; As mentioned before with reference to the first step; The reaction product may also contain an ester of a lower aliphatic carboxylic acid and an ether as a by-product; water; 0 and a lower alcohol as reaction byproducts.

What distinguishes the second step is that at the time of separation of said product; The aliphatic carboxylic acid :106 ester is not only simply obtained from the product but is also obtained by condensation of the added lower alcohol and a lower aliphatic carboxylic acid the reaction product 0 and separating and extracting it as the ester of the lower aliphatic carboxylic acid produced by the gas phase reaction between tower aliphatic carboxylic acid and lower olefin in the presence of an acidic catalyst 0 acid catalyst The separation form used in this process is not particularly specific and common natural processes such as distillation and extraction can be used; absorption; and membranous separation. However, in the present invention a condensation reaction of a lower aliphatic carboxylic acid with a lower alcohol must be carried out during the process; Therefore both pressure and temperature must have a preferred range. When pressure and temperature in corresponding preferred ranges are taken into consideration as well as the state of separation of the ester of the lower aliphatic carboxylic acid Vo ester produced; Distillation is preferred. In the present invention; Other than temperature and pressure; Temperature has a significant effect on the reaction rate and is an important factor in the target esterification reaction between a lower alcohol and a lower aliphatic carboxylic acid. when the temperature rises; The reaction rate will increase.. However Cua the side reaction rate 0 represented by the production of ether as a by-product due to dehydration of the lower alcohol is also increasing yy

sa and that this causes a decrease in output; preferred temperature range; As the operating temperature of the separation equipment between mm mm mm and it is more preferable that it ranges between REE and mm, the operating pressure must be chosen so that it gives a suitable temperature for the reaction, but this varies depending on the location of the separation process in a gas phase or in a liquid phase. in the liquid phase; m the pressure Jef must be the saturated vapor pressure of a reaction product to which al) a lower alcohol was added at the reaction temperature; However, if the pressure rises to an excessive degree, the cost of the equipment will rise and the advantages of the present invention will not be evident. On the contrary; In the Als 0 gas phase the pressure must be less than the saturated vapor pressure of a reaction product to which a lower alcohol has been added » except that if the 0 pressure is too low; The target reaction rate and effect of the present invention cannot be obtained. Depending on cll, whether the phase is gaseous or Sb, it is preferable to perform the process near the saturated vapor pressure of the absorbent solution at the operating temperature. In particular, the operating pressure should be between 060 and 7.0 MPa, 10080 gauge; More preferably between 0 and 10 MPa, scale 11086. ve The first and second step of the present invention (1) can be performed using different devices or it can be done in the same device. It is possible to specify that the reaction product obtained by reacting a lower aliphatic carboxylic acid and a lower olefin be fed in the gas phase to a device where the first step is performed; A lower alcohol is added to it; Then the lower alcohol 00 and the lower aliphatic carboxylic acid are condensed in a different apparatus

ars where the first step is performed while the conversion to an ester of a lower aliphatic carboxylic acid ¢ is allowed to occur and is separated. Specific examples of a method for performing the first and second steps in the same apparatus include a method where a distillation apparatus is used to perform the condensation and separation in the second step; The reaction product obtained by reacting a lower aliphatic carboxylic acid 28 and a lower small olefin in the Hs Ll gas phase and a lower alcohol is added to the distillation lea; The first and second steps are made without a specific distinction between them in order. This method is a method in which the gas phase reaction product and lower alcohol are fed to the distillation apparatus in different pipelines 0 and mixed in the distillation apparatus. In dla the distillation apparatus is often a multi-stage distillation tower; From the point of view of densification can be carried out effectively; The feeding position (height) of the gas phase reaction product differs from the lower alcohol feeding position. Specifically, it is preferred that the position of feeding the lower alcohol be lower than the position of feeding the product of the gas phase reaction 0 . When the feeding positions differ in this way, it can be considered that the composition of the gas phase reaction product at the place where the lower alcohol is added differs from its composition at the outlet of the gas phase reaction device. However, it is needless to say that the present invention (1) contains this case. Even in the case of a process for the production of ester Fd of a lower aliphatic carboxylic acid 00 of the present invention 0) without a clear distinction between steps a yay

the first and second using the same device as mentioned before; The favorable conditions for the previously mentioned first and second step procedure are basically the same.

The present invention (Y) is described hereinafter. The present invention (Y) is a process for producing an ester of:© lower aliphatic carboxylic acid; It includes interaction

M lower aliphatic carboxylic acid and small olefin 10:6 in a gaseous phase in the presence of an acidic catalyst 41 2011 » Cua The production process includes the following first to three steps: The first step: is the step of adding the same acid lower aliphatic carboxylic acid

The used in the previously mentioned reaction to a reaction product that contains a lower aliphatic carboxylic acid after the gas phase reaction, thus obtaining a reaction product to which a lower aliphatic carboxylic acid was added ¢ the second step :

\o is the step of adding a lower alcohol corresponding to a hydrate of a lower olefin to a reaction product to which a lower aliphatic carboxylic acid has been added ; obtained in the first step; Thus, a reaction product is obtained to which a lower alcohol is added. The third step:

lipid is the condensation step of a lower aliphatic carboxylic acid and a lower alcohol 4 reaction product to which a lower alcohol has been added; obtained in the second step; While the conversion to an ester of a lower aliphatic carboxylic acid takes place, the ester of the lower aliphatic carboxylic acid is then separated. The first step of the present invention (7) aims to remove the lower aliphatic carboxylic acid. lower olefin efficiently from a reaction product containing a lower olefin as a starter, a lower aliphatic carboxylic acid, and an ester of a lower aliphatic carboxylic acid are produced. 0 It is important that the lower aliphatic carboxylic acid added in the first step is the same as the acid used in the reaction. This is because the present invention aims to convert the unreacted aliphatic carboxylic acid in the reaction product into an ester of a lower aliphatic carboxylic acid by adding a lower alcohol to it and extracting the lower aliphatic carboxylic acid acid 0 . If the Gilead carboxylic acid differs from the lower aliphatic carboxylic acid used in Jc, the targeted esterification of the lower aliphatic carboxylic acid can be inhibited or the amount of by-products unreasonably increased. Concerning the amount of lower aliphatic carboxylic acid© used in the first step on which the product of the gas phase reaction is based; the eg vo; di the operating temperature and working pressure; and the adsorption apparatus used; [0- A= 5- 140036. Using the method for example in the patent lower alcohol. The second step of the present invention (7) is a step of adding a little alcohol used in the reaction to a hydrate of a lower product olefin corresponding to the hydrate of a small olefin “lower aliphatic carboxylic acid” for the reaction to which a small aliphatic carboxylic acid (©alcohol al) was obtained was added in the first step; Thus, a product is obtained for the reaction, the target was added, and the means used are the same as those used in the first step. lower alcohol (1) of the present invention added in the second step the lower alcohol accordingly; the type of lower alcohol and a rated amount to the aliphatic small carboxylic acid adsorption solution could be 0 (1). ( used in the first step of the present invention Jia lower aliphatic carboxylic acid is a step for the condensation of the aliphatic carboxylic acid (Y) third step of the present invention into a reaction product of 1088© alcohol and lower aliphatic carboxylic acid small alcohol obtained in the second step, with a lower alcohol to which a lower aliphatic carboxylic alcohol of a small aliphatic carboxylic acid ester has been added to allow conversion to ester 1 and dissociation occur. This step can be performed in the same manner as the second step of the present invention ¢ acid that is, for an embodiment comprising a form of separator; an operating temperature; (1). alcohol (1) also in the present invention (7); as in the present invention lower alcohol to obtain a reaction product to which a small lower alcohol was added 0

vq - - as well as the step of condensing a lower aliphatic carboxylic acid and a lower alcohol with allowing conversion to an ester of a lower aliphatic carboxylic acid by distillation and separation. Furthermore it; Jia of the present invention) \ of it is preferable to perform separation and distillation without distinguishing between

6 The second step and the third step. That is, the procedure of the second step and the third step of the present invention (Y) in the same apparatus 0 and the lower aliphatic carboxylic acid ester can be obtained more efficiently. In Ala, perform the second step and the third step without distinguishing between them. The model including temperature can be used; The pressure and position of feeding the starting material as in the present invention. (1).

0 The invention Jal (©) is described hereinafter. The present invention ( ) is a process for producing an ester of a lower aliphatic carboxylic acid ¢ comprising the reaction of a lower aliphatic carboxylic acid and a lower olefin in the gas phase in the presence of an acid catalyst; Where the production process includes the following first to fourth steps: ye The first step: is the step of separating a reaction product after the reaction in the gas phase containing a lower aliphatic carboxylic acid and an ester of a carboxylic acid lil small lower aliphatic carboxylic acid into two halves containing mainly lower aliphatic carboxylic acid as the main component and a halves containing

yy

Primarily an ester of a lower aliphatic carboxylic acid

acid as the main ingredient;

The second step:

The step of adding a lower alcohol corresponding to a hydrate of a lower olefin © to a moiety containing mainly an aliphatic carboxylic acid

lower aliphatic carboxylic acid as the main ingredient; obtained in the first step;

Thus, a product is obtained to which a lower alcohol has been added.

Third step:

It is the step of condensation of a lower aliphatic carboxylic acid and a small alcohol (sae lower alcohol) in a product to which a lower alcohol has been added.

get it in the second step; To cause conversion to an ester of an aliphatic carboxylic acid

¢ lower aliphatic carboxylic acid is small

Fourth step:

It is a step to separate the ester of a lower aliphatic carboxylic acid ve 5 obtained in the third step, thus obtaining an ester of a carboxylic acid

,. lower aliphatic carboxylic acid A small aliphatic carboxylic acid

The first step of the present invention (1) is an acid-containing reaction product separation step

a lower aliphatic carboxylic acid and an ester of a carboxylic acid

Hah

Rum - a lower aliphatic carboxylic acid after a reaction in the gas phase into a moiety containing mainly an ester of a small aliphatic carboxylic acid Tower aliphatic carboxylic acid as a main component and a moiety containing mainly an ester: © the acid lower aliphatic carboxylic acid as the main ingredient.

0 means 'lower aliphatic carboxylic acid moiety as principal constituent' and 'primarily ester moiety: lower aliphatic carboxylic acid as principal constituent' as used In this application, when the reaction product obtained after the reaction in the gas phase is divided into two or more parts, the part in which the content of

Lower aliphatic carboxylic acid About the content of lower aliphatic carboxylic acid and the ester of lower aliphatic carboxylic acid in the original product is called "a half containing mainly aliphatic carboxylic acid" lower aliphatic carboxylic xa acid as the main ingredient"; And that the part in which the ester content increases is the carboxylic acid

0 lower aliphatic carboxylic acid is called "a moiety containing mainly an ester of a lower aliphatic carboxylic acid as the main component". Accordingly; Needless to say; That these phrases include Ala in which to obtain; Depending on the method and circumstances of dismissal; On a moiety in which the aliphatic carboxylic acid is completely separated

0 lower aliphatic carboxylic acid and ester of a small aliphatic carboxylic acid

yy

dum - lower aliphatic carboxylic acid and allow partial mixing; of the corresponding component or moiety containing alcohols, minor ethers or by-products generated in the gas phase reaction and containing in addition water added. The third segment mainly contains by-products; Of course, water and the like can be separated independently from "a shat containing mainly a lower aliphatic carboxylic acid as the main component," a shat containing mainly an ester of a lower aliphatic carboxylic acid acid as the main constituent.” Specific examples of the first step include a method of performing separation using a distillation apparatus, which is preferable if the reaction product is separated into “a moiety containing mainly lower aliphatic carboxylic acid as a constituent.” main" and "a moiety containing mainly an ester of a lower aliphatic carboxylic acid as a main component" by using a distillation tower as a distillation device it is possible to obtain a "moiety containing mainly an ester of an aliphatic carboxylic acid" Small lower aliphatic carboxylic acid as the main component" from the top of the distillation tower and "a part containing mainly vo aliphatic carboxylic acid as the main component" from the bottom of the distillation tower AN in general is a point The boiling point of ST lower aliphatic carboxylic acid is from the boiling point of the ester of a lower aliphatic carboxylic acid. at this time; By-products of lower alcohols, ethers, added ©water, and the like are present in any moiety depending on the composition of the gas phase reaction product

M. - And the performance of the distillation tower, and the conditions of temperature and pressure. It is preferable, of course, to obtain a lower aliphatic carboxylic acid and/or an ester of a lower aliphatic carboxylic acid of as high a purity as possible by using a high-performance distillation apparatus or by assembling a group of distillation towers; However, this is not a basic requirement. One of the objectives of the first step is to facilitate an equilibrium shift of a mixture of a lower aliphatic carboxylic acid and a lower alcohol towards the ester jiu side of a JX lower aliphatic carboxylic acid possible in the third step following the step the second. Conditions can thus be tested freely as long as this can be achieved and the accuracy of the separation in the first step is not limited to this. In order for the third step to condensate lower aliphatic carboxylic acid and tower alcohol with good efficiency; It is preferable to exclude the lower aliphatic carboxylic acid ester 3 as possible from the obtained "biss containing mainly lower aliphatic carboxylic acid as a main component". 0 The next Aull step is the step of adding a lower alcohol to the shi "having mainly lower aliphatic carboxylic acid as the main constituent" obtained in the first step. The exact step is the same as the first step of the present invention (1) or the second step of the present invention (AY) as Lad mentioned after; In one specific example of the invention (oT) Jad the first step 0 is performed to separate the gas phase shal product into a moiety containing mainly a carboxylic acid

- 1 as a main component and “a unit that contains in the form of lower aliphatic carboxylic acid lower aliphatic carboxylic acid of a small aliphatic carboxylic acid ester on the ester using the same device Tower aloohol as a main component” and the second step is to add Small alcohol In this case, the feeding positions of the candy product, especially in a distillation tower as a distillation device, are not particularly limited to the position of the lower alcohol and the gas phase of the gas phase is reduced at a specific lower alcohol position . Preferably the feeding position of the small alcohol The best locations vary depending on the performance of the tower. gas phase Feeding with gas phase reaction product, etc. gas phase Distillation and separation conditions; And the feed rate of the gas phase reaction product is generally preferred to the aforementioned topical relationship so that the efficiency of the third step is enhanced and the lower aliphatic carboxylic acid alcohol is condensed to 0 . lower alcohol AE or step (1) Details of the third and fourth steps as the second step of the present invention. (7) of the present invention Examples of embodiment of the present invention (¥) include the case of performing all first through fourth steps Performing the Alay part using different devices; the case for performing all steps using the same device 1 of these steps using the same device and performing the others with different devices Examples include more specifically: z Case shown in Figure (1) All steps 1 to 4 are carried out in 1) one distillation tower;

“) the case shown in Fig. (7); where the first step is performed in a first distillation tower; thereafter the second, third and fourth steps are performed in a second distillation tower; “) the case shown in Figure oF) where the first step is performed in a tower first distillation and the ' moiety containing mainly lower aliphatic carboxylic acid ° as main component' obtained from the bottom is introduced into a mixer; the second step is made to add a lower alcohol in a mixer; after which the A mixture of lower aliphatic carboxylic acid and lower alcohol is fed to the reaction apparatus; lower aliphatic carboxylic acid 01 and lower alcohol are condensed to an ester ester of a lower aliphatic carboxylic acid in a reaction apparatus, and finally the ester of the lower aliphatic carboxylic acid is separated from the mixture in a second distillation tower.The procedure of the present invention (©) is preferred. In form (1) but it is not specifically limited to vo; of course the present invention (©) can also be made in the manner shown in form (Y) or form (7) and these methods are not restricted; combinations can also be used with other steps; or a recycling system not shown or the like. The present invention is described in more detail hereafter with reference to examples; However, the present invention is not to be construed as limiting them. a

Y _ $ _— Analysis of a bulk solution by distillation apparatus: Analysis was performed using the internal titer method; The analysis solution was prepared by adding 1 ml of 1-;- dioxane as an internal titer to 01 ml of each solution collected from the top and bottom and 0, ¥ μL of the analysis solution was injected. 0 Gas Chromatograph: GC-14B column manufactured by Shimadzu Seiskosho; Capillary column TC-WAX (length Y 0 meters, inner diameter 2 Y * mm, thickness Laat 5 microns Y). Carrier gas: 0 > nitrogen (separation ratio: (Yo rate) Column flow: ¥ ml/min).Temperature conditions: The detector and the evaporation chamber were at a constant temperature “a Yoo” and the column temperature was kept at “µm” for minutes from the start of the analysis” and then raised to 151 C; at a rate of fo Ye a minute and was agli at 1050m for 10 minutes yo Scout: FID (pressure 71 iH, kPa sg; air pressure: 001 kPa sg)

Prepare the solution to be fed to the distillation apparatus:

The reaction mile was prepared; and the reaction product to which a lower alcohol has been added;

and a lower aliphatic carboxylic acid absorption solution.

and the absorption solution to which lower alcohol and lower alcohol © have been added in the following ways.

reaction product:

The reaction product was prepared with the composition shown in Table (1) using the following Jal pall and purified water.

Acetic acid: acetic acid

7. 95.17 workers with a special quality; Purity « Wako Pure Chemical Industries, Ltd. Produced by: Ethanol Js) 0

Produced by Wako Pure Chemical Industries, Ltd. "First Class Worker; Jo purity

Joo water

Jui: Ethyl acetate acetate

7. 948.8 private; Purity de Agent « Wako Pure Chemical Industries, Ltd. Produced by: lower alcohol 0

using the same ethanol used to prepare the reaction product and water; Alcohol has been prepared

lower alcohol with the composition shown in Table (1).

o — ¢ — reaction product to which a lower alcohol has been added: Both the reaction product and the lower alcohol previously prepared were mixed with the composition given in Table (1) in a ratio of VE : 4 by weight; Thus, a reaction product was prepared to which a lower alcohol was added with the composition shown in Table (1). © Lower aliphatic carboxylic acid absorption solution: The previously prepared reaction product was mixed with the composition shown in Table (1) and acetic acid (a product of Wako Pure Chemical Industries, Ltd. “special agent; 7 7 purity) in a ratio of 117:01 by weight to prepare Tower aliphatic carboxylic acid absorbent solution With the composition shown in Table (1). 1. An absorption solution was added (4 J gas) a small lower alcohol: The absorption solution of a lower aliphatic carboxylic andl acid was previously mixed with the composition shown In Table (1) and a lower alcohol with a ratio of ?: ddl, where the absorption solution was prepared to which a lower alcohol was added with the composition shown in Table (1). Examples (rr -1) The reaction product and lower alcohol prepared each of the composition shown in Table (1) were fed into an Oldershow distillation apparatus (inner diameter 117 mm; The actual number of plates (Fo) and the distillation was carried out under the conditions shown in Table (?).

— $ 3 — The samples of the collected solutions were analyzed from above and below to indicate the components using the analysis method mentioned before. The results are shown in Table ( ). Table (1) Composition [7 by weight] Feed solution Acetic ethanol and sold “Ethanol acetic acid Reaction product Reaction product to which lower alcohol Yo,vY was added without 1 3 alcohol aliphatic carboxylic acid absorption solution ¢ YY, 77 8" small ql Y lower aliphatic carboxylic acid qt

(Y) Tan Ta schedule

Ls ed | quantity quantity degree ratio ba] | | a | Nutrition | Position solution degree! Nutrition adage Pa | condensation pe nutrition | [part | heat | al a) | Nutritional solution. Feed. ELC (m) (09) | Yellow [Jose] (tablet) MPa | 1 h] h] [G Alcohol Small Example "71 10 You 2" Y "1 Ye. Ve Reaction product lower = (0) alcohol Alcohol lower e.g. 0 Yoo £. Te Yin Vo Je lal) product lower (0) alcohol Alcohol Small example 1 Va Yeu 2 A 1. Ye. Ya Reaction product lower = (*) alcohol Reaction product |g Ar 1 10 1. YA. Ve lower added to it ‎ alcohol 0 Alcohol absorption solution : Co i » 1 6" 6 6 \ small .. ot. 0 lower aliphatic | L lower carboxylic (©) alcohol acid absorption solution eg added v8 oN YN 1. oA Va lower alcohol (7) eg 0 oO) BE 1 Ye. Ve Reaction Product Comparator 1 Absorbed Example Solution | p lower aliphatic .

Y, 8 oO) < 0 1 of Ve Comparative carboxylic 0 acid

- m/m (©) Table Upper distillate Lower distillate Flow Composition (7 wt.) Composition (7 wt.) Extraction Out Amount acetic

Acetic acetic | #52) Acetic acetic | (a part of acid water Ethanol sla Ethanol 0 Ethyl acid | by weight/ Ethyl acid | by weight/ hour) An example is the RIX TH essential TEVA | discount to give up | dissolve YL AA YY. 0) Raha | YVAY [er| Kalabakah | Qara 1 for Takla Fahz VY,YA | kk Yyo (Y)

YY,A YY, EE has £0) | TAY Eo | AVE | YA RT] Veal | For 4t (7) example each | Nakim £00 | 14, Y. wa | Hatfa | Ga Yo 8 Ex 9777 78 oY ¥,44 Yo,0) YAO Aram Ab 6 15 (°) Ex Yv,q 17 8 Lala YA vay YA YY YA,QY Mac YAA 0) Example OA AS A 1 64 RRP ve, va "174 You | Ham 7 111 | Compare (0) 1 Tal LAVAL | Ham | Turk Qart | Kat 158 | Comparator (Y)

_ 4 ¢ — Example (6): Reaction product to which a lower alcohol has been added of the composition shown in Table (1) is fed into an Oldershow distiller (inside diameter: TV mm; actual number of plates: 01”) and the distillation process was carried out under the conditions shown in Table (AY) © The samples of the collected solutions were analyzed lef and below to indicate the components using the previous analysis method. The results are shown in Table (¥) Example (0) Fed With a solution of absorption of a lower aliphatic carboxylic pra acid v and a small alcohol “©108_each of which has the composition shown in Table (1) to an Oldershow distillation apparatus (inner diameter: mm, the actual number of plates (v vol) and the distillation process was carried out under the conditions shown in Table (Y). The samples of the collected solutions were analyzed above and below to show the components using the previous analysis method. \o Then the results are shown in Table (¥)

Ce. :) (Example with the composition shown in lower alcohol was fed with an absorption solution to which a small alcohol was added) : 71 mm; Actual number of plates YY: (Inner diameter Oldershow to distiller) Table (1) | (1). Distillation under the conditions shown in Table Samples of the collected solutions were analyzed above and below for components. Using the previous 0 analysis method. (7) The results are illustrated in Table 1: (comparative example)

Oldershow to a distillation apparatus (1) was fed a reaction solution having the composition shown in Table

Cig hall and the distillation process was carried out under (Fr : mm; actual number of plates YY : (inner diameter 0 (Y) shown in the table of components using the Jind analysis method. Samples of solutions collected above were analyzed And from the previous one. (7). The results are illustrated in a comparative example table (?): Oldershow to a distillation apparatus (1) having the composition shown in Table 40 (7). The distillation process was carried out under the conditions indicated in Table Fr: actual number of plates h1

1e - The samples of the collected solutions were analyzed above and below to show the components using the previous method of analysis. The results are shown in Table (©). Industrial Applicability: © It is clear from the results listed in the previous pages that in a process to produce an ester of a lower aliphatic carboxylic acid by an esterification reaction in the gas phase starting from a lower aliphatic carboxylic acid aliphatic carboxylic acid and a lower alcohol; Cua The step of adding a lower alcohol corresponding to a hydrate of a lower olefin to a reaction product containing lower aliphatic carboxylic acid is carried out after the gas phase reaction. the condensation of alcohol and lower aliphatic carboxylic acid; Whereas the conversion to ester (iu) of a lower aliphatic carboxylic acid is allowed to occur and separated; The conversion of a lower aliphatic carboxylic acid to an asad ester 0 small carboxylic acid can be improved, which can only be achieved by a method using an excess of lower olefin relative to the lower aliphatic carboxylic acid. carboxylic acid in the gas phase reaction, as well as the lower aliphatic carboxylic acid ester can be efficiently produced. ester of a lower aliphatic carboxylic acid from the gas phase reaction product, thus complex modifications to the production equipment are unnecessary.

Claims (1)

Ag - Gall Elements 1-1 A process for producing an ester of a lower aliphatic carboxylic acid that includes the reaction of a lower aliphatic carboxylic acid 1 and a lower olefin in gas phase ¢ in the presence of an acidic catalyst catalyst 8010; The Cua production process comprises the following first and second ° steps: 1st step l is the step of feeding separately a lower alcohol corresponding to a hydrate of a lower olefin to a reaction product containing an aliphatic 1carboxylic acid lower aliphatic carboxylic acid sina after the gas phase 0 reaction, thus obtaining a reaction product added a) lower alcohol 1; VY Step 2: OY is the condensation step of a lower aliphatic carboxylic acid 04 and a reaction product blower alcohol to which a lower alcohol has been added. 0 – obtained in the first step; And during the conversion to 1 ester of a lower aliphatic carboxylic acid “1” the ester of the lower aliphatic carboxylic acid (YA YO) is separated according to the process For Claim (1), where the first and second steps are performed in the same device. oy — — Adee -#*1 according to claim (1); wherein the first and second steps are performed in a distilling apparatus 1.- a process to produce an ester of a small aliphatic carboxylic acid lower aliphatic carboxylic acid Y comprising the reaction of a lower aliphatic carboxylic acid 1 and a lower aliphatic carboxylic acid in a gas phase in 3 in the presence of an acid catalyst where the production process includes the steps | The first to the following third: - The first step: Z 7 is the step of adding the same lower aliphatic sad carboxylic acid A used in the aforementioned reaction to a reaction product containing q containing a lower aliphatic carboxylic acid carboxylic acid after 0 gas phase reaction, thus obtaining a reaction product to which 11 lower aliphatic carboxylic acid ¢ VY was added, the second step: VY is the feeding step separately A lower alcohol corresponds to a Vg hydrate of a lower olefin to a reaction product containing lower aliphatic carboxylic acid after the gas phase 11 reaction, thus obtaining a reaction product with a lower alcohol VY ¢ YA added The third step: 0 is the step of condensing a lower aliphatic carboxylic acid ja acid Ys and a lower alcohol into a reaction product to which a lower alcohol yay has been added ‏ duh - lower alcohol 71 « obtained in the second step; During the conversion to the YY ester of a lower aliphatic carboxylic acid ¢ YY the ester of the lower aliphatic carboxylic acid 04 is separated. 1 0—Operation according to claim of) where the first to third steps “are performed in the same machine. 1 +- operation according to claim (;); distillation apparatus. 1-1 Process for producing an ester of a lower aliphatic carboxylic acid Y comprising the reaction of a lower aliphatic carboxylic acid 1 and a lower olefin in a gas phase in ¢ Presence of an acidic cus acid catalyst The production process includes the following steps Ae to 4: 1 Step 1: 7 is the separation step of a product of the reaction after the reaction in the gas phase A containing a small aliphatic carboxylic acid lower aliphatic carboxylic acid and ester 1:© lower aliphatic carboxylic acid to 0 halves containing mainly lower aliphatic carboxylic acid 11 as a main component and a halves containing mainly an ester ester Gaal 1" lower aliphatic carboxylic acid as yay ingredient Dogen - OT main; 4 > The second step: is the step of adding a lower alcohol corresponding to a hydrate of a lower olefin 11 to a moiety containing mainly lower aliphatic carboxylic acid 11 as a main component. VA obtained in the first step; Thus, a product was obtained to which a small alcohol 4 was added, lower alcohol; 00 > Step 3: 71 is the step of condensing a lower aliphatic carboxylic acid YY and a lower alcohol present in a product to which a lower alcohol YY has been added; obtained in the second step; to cause conversion to ester Vi of Jawer aliphatic carboxylic acid ¢ © | The fourth step: YT is a step to separate the ester of a lower aliphatic carboxylic acid YY 5 obtained in the third step, thus obtaining the YA ester of a lower aliphatic carboxylic acid carboxylic acid. 1 +- operation according to claim (7); where the first step is performed in a Y distilling apparatus. distilling apparatus 1 +- process according to claim (7); Where the first step takes place in a distilling apparatus; The second step is performed in the same distilling apparatus 7 used in the first step. —_5m_ -0 1 process according to claim (4); Where the feeding position of the lower alcohol Y in the distillation apparatus is lower than the feeding position of the reaction product after YF The gas phase reaction contains a lower aliphatic carboxylic acid ¢ and an ester of a carboxylic acid lower aliphatic carboxylic acid ° to the distilling apparatus -11 1 process pursuant to any Claims -1(10); where the third step Y is performed in the same equipment as the first and/or second step. -11 1 process pursuant to any of the Claims -1(10); where the fourth step Y is performed in the same machine as step one and/or step two and/or step aay NF) operation according to claim (7); wherein the acid catalyst is obtained by "-" by synthesizing at least one member selected from a group consisting of homogeneous polybasic non-YF acids and salts thereof on a carrier. lower process of claim (7) where part or all of the lower alcohol 1-04 is (V) second step in claim Sa alcohol XY produced as a by-product when the lower alcohol acid is reacted lower aliphatic carboxylic acid acid catalyst jae in the presence of gas phase lower olefin o to -1#1 process under claim oY) where the added amount of the small alcohol Y ranges from lower alcohol mentioned in step two of claim (7); 1 in terms of the molar ratio to the lower aliphatic carboxylic acid ¢ in the reaction solution prior to the addition of the alcohol between 1 : 1 to Vo : 1 ° (alcohol 7 : minor aliphatic carboxylic acid lower aliphatic carboxylic acid 1 ). \ - process according to claim (7); where lower olefin "0 is at least one member selected from a group consisting of 1-ethylene, 1-propylene; 1-l-butene; and 7-butene 2-butene. and 1- ¢ pentene .1-pentene -17 is a process according to claim (7), where the lower aliphatic carboxylic acid Y is at least one member selected from group 7 consisting of of formic acid ¢ acetic acid g propionic acid cacrylic acid o butyric acid —VA 1 process according to claim (7"); where lower olefin Y is ethylene and lower aliphatic carboxylic acid A 7 is acetic acid. rh - Gy lee -11 -1 of claim oY) wherein the second step procedure device Y is a distilling apparatus Ye) process under protection (0+) where the third step procedure device Y is a distilling apparatus. Adee -71 1 according to any of the claims (1) and (8) wherein the Y acid catalyst is obtained by the composition of at least one member selected from the ¥ group consisting of heteropolyacids Polybasic ¢ and salts thereof on heteropolyacid salts Jala —YY 1 Process according to any of Claims (1) or (8) wherein part or all of the alcohol 7 is the lower alcohol mentioned in Step 1 of Claim (1) or all of it is Y or that mentioned in Step The second in the protection element (;) is a small alcohol; - the lower 5 is intended to be produced as a by-product upon the reaction of the lower aliphatic carboxylic acid and a lower olefin in the gas phase 1 in the presence of acid catalyst ¢ 7 and the resulting lower alcohol is obtained as a by-product through A separation and extraction. YY process ly of any of the claims (1) or (8) where the amount added is from the lower alcohol mentioned in the first step in 3 claim (1) or the second step in the claim (;); in the sense of proportion uh- ¢ Molarity to lower aliphatic carboxylic acid 48 ° in reaction solution as ddl alcohol between 1 : 1 to Voi (alcohol pra 1 :168 : lower aliphatic carboxylic acid aliphatic for carboxylic acid ( . Adee -14 -1 according to any of Claims (1) or (8) where lower olefin - “is at least one member selected from a group consisting of ethylene v ¢ and propylene ¢ and -1-butene 1-butene + and —Y butene-2 < butene ¢ and -1-pentene .1-pentene —Yo 1 process according to any of the claims (1) or (8) wherein lower aliphatic carboxylic acid Y is member 1 and at least one is selected from a group consisting of formic acid acid ¢ and acetic acid; propionic acid ¢ and cacrylic acid ell ° and butyric acid Adee -1 + 1 according to which of the claims (0) or (8) the lower olefin Y is ethylene oi ; The lower aliphatic carboxylic acid 0 is acetic acid. yy