Abstract: The present invention provides a method for purifying carbon dioxide gas characterized in that carbon dioxide gas containing at least one of 3-methylmercaptopropionaldehyde and acrolein is contacted with activated carbon to remove at least one of the 3-methylmercaptopropionaldehyde and acrolein. The present invention provides also a method for producing methionine comprising the purification step of the recovered carbon dioxide.

Abstract: An object of the present invention is to provide a method for manufacturing methionine capable of achieving an improvement in ammonia removal efficiency. The manufacturing method of the present invention comprises a removal step of supplying a liquid containing a methionine salt, which is obtained by reacting 3-methylmercaptopropionaldehyde and hydrocyanic acid, or a compound obtained by reacting 3-methylmercaptopropionaldehyde and hydrocyanic acid, with carbon dioxide and ammonia to obtain a liquid containing 5-(2-methylmercaptoethyl)hydantoin and then hydrolyzing the 5-(2-methylmercaptoethyl)hydantoin, to a diffusion tower from an upper portion thereof while supplying a stripping gas to the diffusion tower from a lower portion thereof to remove ammonia contained in the liquid through stripping, and the stripping gas contains a process gas generated in a process of manufacturing methionine.

Abstract: The present provides a method for producing methionine which is characterized by a crystallization step in which carbon dioxide is introduced into a reaction solution containing an alkali salt of methionine which is obtained by hydrolyzing 5-[2-(methylthio)ethyl] imidazoline-2,4-dione in the presence of an alkali compound, thereby precipitating the methionine, and further comprises a step of adding waste methionine to the reaction solution. The method of production of the present invention can improve a yield in the production of methionine.

Abstract: The present invention addresses the problem of providing a method for producing purified methionine, the method being capable of preventing the caking of methionine. The present invention pertains to a method for producing purified methionine from crude methionine, the method comprising (1) a step for obtaining a wet cake of washed crude methionine, (2) a step for adjusting the pH of the wet cake, and (3) a step for drying the wet cake after the pH adjustment, wherein the pH of the wet cake after the pH adjustment is 5.2-6.1.

Abstract: The present invention provides a method of airflow transportation of methionine that can minimize the crushing of methionine, which is characterized in that when methionine is transported as airflow using carrier gas, the flow state of methionine is a low concentration floating flow type, and the mixing ratio of methionine and carrier gas is in the range of 4 to 10 kg-methionine/kg-carrier gas. In the method of airflow transportation of methionine of the present invention, if the D50 of methionine is in the range of 150 to 425 ?m, the increase rate of the fine powder can be suppressed to 1.5% or less by maintaining the mixing ratio at 4 to 10 kg-methionine/kg-carrier gas, and can be suppressed to 1% or less by maintaining the mixing ratio at 5 to 10 kg-methionine/kg-carrier gas.

Abstract: The present provides a method for producing methionine which is characterized by a crystallization step in which carbon dioxide is introduced into a reaction solution containing an alkali salt of methionine which is obtained by hydrolyzing 5-[2-(methylthio)ethyl] imidazoline-2,4-dione in the presence of an alkali compound, thereby precipitating the methionine, and further comprises a step of adding waste methionine to the reaction solution. The method of production of the present invention can improve a yield in the production of methionine.

Abstract: An object of the present invention is to provide a method for producing methionine enabling efficient recovery and use of ammonia from a gas generated by concentrating a mother liquor. This production method comprises a recovery step of introducing a gas generated in a mother liquor concentration step into a gas washing tower in which water is recycled and bringing the gas into contact with the water to recover ammonia contained in the gas, and a ratio of flow of the water to flow of the gas introduced into the gas washing tower is 2 or more in terms of mass ratio. The water discharged from the gas washing tower is preferably cooled before introduction into the gas washing tower.

Abstract: An object of the present invention is to provide a method for manufacturing methionine capable of achieving an improvement in ammonia removal efficiency. The manufacturing method of the present invention comprises a removal step of supplying a liquid containing a methionine salt, which is obtained by reacting 3-methylmercaptopropionaldehyde and hydrocyanic acid, or a compound obtained by reacting 3-methylmercaptopropionaldehyde and hydrocyanic acid, with carbon dioxide and ammonia to obtain a liquid containing 5-(2-methylmercaptoethyl)hydantoin and then hydrolyzing the 5-(2-methylmercaptoethyl)hydantoin, to a diffusion tower from an upper portion thereof while supplying a stripping gas to the diffusion tower from a lower portion thereof to remove ammonia contained in the liquid through stripping, and the stripping gas contains a process gas generated in a process of manufacturing methionine.

Abstract: The present invention provides a method of airflow transportation of methionine that can minimize the crushing of methionine, which is characterized in that when methionine is transported as airflow using carrier gas, the flow state of methionine is a low concentration floating flow type, and the mixing ratio of methionine and carrier gas is in the range of 4 to 10 kg-methionine/kg-carrier gas. In the method of airflow transportation of methionine of the present invention, if the D50 of methionine is in the range of 150 to 425 ?m, the increase rate of the fine powder can be suppressed to 1.5% or less by maintaining the mixing ratio at 4 to 10 kg-methionine/kg-carrier gas, and can be suppressed to 1% or less by maintaining the mixing ratio at 5 to 10 kg-methionine/kg-carrier gas.

Abstract: The present invention addresses the problem of providing a method for producing purified methionine, the method being capable of preventing the caking of methionine. The present invention pertains to a method for producing purified methionine from crude methionine, the method comprising (1) a step for obtaining a wet cake of washed crude methionine, (2) a step for adjusting the pH of the wet cake, and (3) a step for drying the wet cake after the pH adjustment, wherein the pH of the wet cake after the pH adjustment is 5.2-6.1.

Abstract: The present invention provides a method for producing methionine characterized by comprising a step of hydrolyzing 5-[2-(methylthio)ethyl]imidazolidine-2,4-dione in the presence of an alkali compound to obtain a reaction solution containing an alkali salt of methionine, a step of precipitating methionine by introducing carbon dioxide into the reaction solution to obtain a first slurry containing the methionine, a step of allowing the first slurry to flow into a pressurized filter and obtaining the solid methionine and mother liquor from the first slurry, and a step of recovering carbon dioxide from the mother liquor. By the present production method, the carbon dioxide introduced in the crystallization step is suppressed from being released from the mother liquor, and the carbon dioxide can be recovered.

Abstract: An object of the present invention is to provide a method for producing methionine enabling efficient recovery and use of ammonia from a gas generated by concentrating a mother liquor. This production method comprises a recovery step of introducing a gas generated in a mother liquor concentration step into a gas washing tower in which water is recycled and bringing the gas into contact with the water to recover ammonia contained in the gas, and a ratio of flow of the water to flow of the gas introduced into the gas washing tower is 2 or more in terms of mass ratio. The water discharged from the gas washing tower is preferably cooled before introduction into the gas washing tower.

Abstract: The present invention addresses the problem of providing a method for producing purified methionine, the method being capable of preventing the caking of methionine. The present invention pertains to a method for producing purified methionine from crude methionine, the method comprising (1) a step for obtaining a wet cake of washed crude methionine, (2) a step for adjusting the pH of the wet cake, and (3) a step for drying the wet cake after the pH adjustment, wherein the pH of the wet cake after the pH adjustment is 5.2-6.1.

Abstract: The present invention provides a method for purifying carbon dioxide gas characterized in that carbon dioxide gas containing at least one of 3-methylmercaptopropionaldehyde and acrolein is contacted with activated carbon to remove at least one of the 3-methylmercaptopropionaldehyde and acrolein. The present invention provides also a method for producing methionine comprising the purification step of the recovered carbon dioxide.

Abstract: The present invention provides a method for producing methionine which is characterized by comprising (1) a reaction step: a step of hydrolyzing 5-[2-(methylthio)ethyl]imidazolidine-2,4-dione in the presence of an alkali compound to obtain a reaction solution containing an alkali salt of methionine, (2) a first crystallizing step: a step of introducing carbon dioxide into the reaction solution and precipitating methionine from the reaction solution to obtain the first crystal of methionine and the first crystal mother liquor, and (3) a second crystallizing step: a step in which after obtaining a slurry which contains precipitates containing the second crystals of methionine precipitated by introducing carbon dioxide to the first crystal mother liquor and the slurry was subjected to centrifugation to separate the second crystal of methionine and the second crystal mother liquor by a solid-liquid separation, and the precipitate remained in the obtained second crystal mother liquor is separated using a filter.

Abstract: The present invention provides a method for producing methionine characterized by comprising a step of hydrolyzing 5-[2-(methylthio)ethyl]imidazolidine-2,4-dione in the presence of an alkali compound to obtain a reaction solution containing an alkali salt of methionine, a step of precipitating methionine by introducing carbon dioxide into the reaction solution to obtain a first slurry containing the methionine, a step of allowing the first slurry to flow into a pressurized filter and obtaining the solid methionine and mother liquor from the first slurry, and a step of recovering carbon dioxide from the mother liquor. By the present production method, the carbon dioxide introduced in the crystallization step is suppressed from being released from the mother liquor, and the carbon dioxide can be recovered.

Abstract: Provided is a paper container for foods capable of being fabricated by heat sealing which does not absorb flavors, such as limonene, and capable of storing a long period at ordinary temperature. The laminated material for paper containers is composed of paper substrate layer/adhesive for paper layer/first adhesive for barrier layer/barrier layer/second adhesive for barrier layer/heat-sealable PET resin layer, has an oxygen gas barrier ability of 2.0 ml/m2·D·atm or less, and the heat-sealable PET resin layer is made having a crystal portion of less than 15%, non-crystal portion of 85% or more.

Abstract: [Problem] To provide a paper container for foods capable of being fabricated by heat sealing which does not absorb flavors, such as limonene, and capable of storing a long period at ordinary temperature. [Solving Means] The laminated material for paper containers is composed of paper substrate layer/adhesive for paper layer/first adhesive for barrier layer/barrier layer/second adhesive for barrier layer/heat-sealable PET resin layer, has an oxygen gas barrier ability of 2.0 ml/m2·D·atm or less, and the heat-sealable PET resin layer is made having a crystal portion of less than 15%, non-crystal portion of 85% or more.

Abstract: The object of the present invention is to provide a process for producing refined methionine in which the loss of methionine due to washing is reduced. The present invention relates to a process for producing refined methionine from crude methionine, comprising a step of washing crude methionine with the use of a wash water containing methionine.

Abstract: The invention provides the following method capable of producing methionine in a shorter time by making rapid progress of the hydrolysis of 5-(2-methylmercaptoethyl)hydantoin from an aqueous 5-(2-methylmercaptoethyl)hydantoin solution containing ammonia component. A method of producing methionine is the method comprising hydrolyzing 5-(2-methylmercaptoethyl)hydantoin in an aqueous 5-(2-methylmercaptoethyl)hydantoin solution containing ammonia component, wherein the hydrolysis is performed after the ammonia component is removed from the aqueous solution.