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: 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: An object of the present invention is to provide a refined methionine production method capable of achieving an improvement in washing efficiency. This production method is a method for producing refined methionine from a slurry of crude methionine and comprises (1) a step of separating the slurry of crude methionine into solid and liquid by using a continuous filter, (2) a step of spraying preliminary washing water on a crude cake obtained by separating the slurry of crude methionine into solid and liquid to wash the crude cake, and (3) a step of mixing a semi-refined cake obtained by spraying preliminary washing water on the crude cake to wash the crude cake with finishing washing water to wash the semi-refined cake.

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: 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 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: 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.

Abstract: In an electrical connector to be attached to a circuit board, a terminal has a contact section on one free end side to contact with a terminal of a mating connector and has a connecting section on the other free end side to be connected by soldering to a circuit portion of a circuit board. The terminal has a holding section and a connecting section. The holding section has a face-contact section, a backside section, and a side-face section. The terminal has a low solder wetting area at least on a part of a circumferential area of the holding section in the longitudinal direction, and the contact section is formed above the upper end of the low solder wetting area on the backside section. The upper end of the low solder wetting area is provided below the upper end at the side-face sections and the contact-face section.

Abstract: In an electrical connector to be attached to a circuit board, a terminal has a contact section on one free end side to contact with a terminal of a mating connector and has a connecting section on the other free end side to be connected by soldering to a circuit portion of a circuit board. The terminal has a holding section and a connecting section. The holding section has a face-contact section, a backside section, and a side-face section. The terminal has a low solder wetting area at least on a part of a circumferential area of the holding section in the longitudinal direction, and the contact section is formed above the upper end of the low solder wetting area on the backside section. The upper end of the low solder wetting area is provided below the upper end at the side-face sections and the contact-face section.