Catalyst for ester production and process for producing ester

Abstract

A catalyst for ester production which comprises zirconium oxide, copper, and at least one oxide selected from the group consisting of zinc oxide, chromium oxide, aluminum oxide and silicon oxide, and is obtainable by reducing with hydrogen a catalyst precursor prepared by the reaction of a salt containing at least one of metals constituting the oxides, a zirconium salt and a copper salt with an alkali hydroxide; and a process for producing an ester which comprises bringing either an alcohol or an alcohol and an aldehyde into contact with this catalyst in a gas phase.

Description

TECHNICAL FIELD

[0001] This invention relates to a new catalyst for ester production and a process for producing a lower ester by this catalyst. BACKGROUND ART

[0002] Lower esters represented by ethyl acetate have been used in large quantities as paint solvents, extracting solvents, intermediates for chemical products and medicines, or the like, and are important materials in the chemical industry.

[0003] Such lower esters have conventionally been produced by dehydrating esterification from carboxylic acids and alcohols or condensation of aldehydes which is called Tishchenko reaction. In recent years, a process for the production of esters from carboxylic acids and olefins using a heteropolyacid catalyst has been reported (JP-A 5-65248, etc.) and noted as a new process for producing ethyl acetate.

[0004] In prior art processes for the production of ethyl acetate, however, plural raw materials such as acids and alcohols or acids and olefins have been used and thus the procurement of ...

Examples

example 1

(Preparation of Catalyst)

[0040] In a flask, 97 g of copper nitrate, 40 g of zinc nitrate, 504 g of aluminum nitrate and 36 g of zirconyl nitrate were dissolved in 5 liters of water. To this solution was added an aqueous solution of 227 g of sodium hydroxide dissolved in 1 liter of water to prepare a precipitate. The precipitate (prepared by a so-called coprecipitation method) was washed with water, dried and baked to form a catalyst precursor.

[0041] In the normal-pressure vapor-circulating fixed-bed reaction apparatus, 15 g of the catalyst precursor were charged in the catalyst layer (17 mm in inner diameter, about 100 mm in length) and then reduced with a nitrogen-diluted hydrogen as a reducing agent at 200° C. or lower for 4 hours, and a CU—ZnO—Al2O3—ZrO2 catalyst layer for ester production was provided within this reaction apparatus.

(Production of Ester)

[0042] A nitrogen gas was flowed as a carrier gas at a constant rate of 20 ml / min from the top of the reaction apparatus p...

example 2

(Preparation of Catalyst)

[0044] In 5 liters of water were dissolved 97 g of copper nitrate, 40 g of zinc nitrate and 36 g of zirconyl nitrate. To this solution was added an aqueous solution of 64 g of sodium hydroxide dissolved in 1 liter of water to prepare a precipitate. The precipitate (prepared by a so-called coprecipitation method) was washed with water, dried and baked to form a catalyst precursor.

[0045] In accordance with the procedure of Example 1, a CU—ZnO—ZrO2 catalyst layer for ester production was provided in the normal-pressure vapor-circulating fixed-bed reaction apparatus.

(Production of Ester)

[0046] Ethyl acetate was produced by performing the reaction in accordance with the procedure of Example 1, except for using the fixed-bed reaction apparatus provided with the CU—ZnO—ZrO2 catalyst layer and 99% ethyl alcohol. The result of the reaction is shown in the following table.

TABLE 2Conversion ofSelectivity toYield ofLHSVethanolethyl acetateethyl acetate(h−1)(%)(%...

example 3

[0047] The reaction was performed under the same condition as in Example 2, except for using 95% ethanol as a reaction material. The result is shown in the following table.

TABLE 3Conversion ofSelectivity toYield ofLHSVethanolethyl acetateethyl acetate(h−1)(%)(%)(%)0.267.957.539.0

TECHNICAL FIELD

[0001] This invention relates to a new catalyst for ester production and a process for producing a lower ester by this catalyst. BACKGROUND ART

[0002] Lower esters represented by ethyl acetate have been used in large quantities as paint solvents, extracting solvents, intermediates for chemical products and medicines, or the like, and are important materials in the chemical industry.

[0003] Such lower esters have conventionally been produced by dehydrating esterification from carboxylic acids and alcohols or condensation of aldehydes which is called Tishchenko reaction. In recent years, a process for the production of esters from carboxylic acids and olefins using a heteropolyacid catalyst has been reported (JP-A 5-65248, etc.) and noted as a new process for producing ethyl acetate.

[0004] In prior art processes for the production of ethyl acetate, however, plural raw materials such as acids and alcohols or acids and olefins have been used and thus the procurement of ...

Examples

example 1

(Preparation of Catalyst)

[0040] In a flask, 97 g of copper nitrate, 40 g of zinc nitrate, 504 g of aluminum nitrate and 36 g of zirconyl nitrate were dissolved in 5 liters of water. To this solution was added an aqueous solution of 227 g of sodium hydroxide dissolved in 1 liter of water to prepare a precipitate. The precipitate (prepared by a so-called coprecipitation method) was washed with water, dried and baked to form a catalyst precursor.

[0041] In the normal-pressure vapor-circulating fixed-bed reaction apparatus, 15 g of the catalyst precursor were charged in the catalyst layer (17 mm in inner diameter, about 100 mm in length) and then reduced with a nitrogen-diluted hydrogen as a reducing agent at 200° C. or lower for 4 hours, and a CU—ZnO—Al2O3—ZrO2 catalyst layer for ester production was provided within this reaction apparatus.

(Production of Ester)

[0042] A nitrogen gas was flowed as a carrier gas at a constant rate of 20 ml / min from the top of the reaction apparatus p...

example 2

(Preparation of Catalyst)

[0044] In 5 liters of water were dissolved 97 g of copper nitrate, 40 g of zinc nitrate and 36 g of zirconyl nitrate. To this solution was added an aqueous solution of 64 g of sodium hydroxide dissolved in 1 liter of water to prepare a precipitate. The precipitate (prepared by a so-called coprecipitation method) was washed with water, dried and baked to form a catalyst precursor.

[0045] In accordance with the procedure of Example 1, a CU—ZnO—ZrO2 catalyst layer for ester production was provided in the normal-pressure vapor-circulating fixed-bed reaction apparatus.

(Production of Ester)

[0046] Ethyl acetate was produced by performing the reaction in accordance with the procedure of Example 1, except for using the fixed-bed reaction apparatus provided with the CU—ZnO—ZrO2 catalyst layer and 99% ethyl alcohol. The result of the reaction is shown in the following table.

TABLE 2Conversion ofSelectivity toYield ofLHSVethanolethyl acetateethyl acetate(h−1)(%)(%...

example 3

[0047] The reaction was performed under the same condition as in Example 2, except for using 95% ethanol as a reaction material. The result is shown in the following table.

TABLE 3Conversion ofSelectivity toYield ofLHSVethanolethyl acetateethyl acetate(h−1)(%)(%)(%)0.267.957.539.0