Methods are disclosed for producing highly purified recombinant human insulin (RHI) having a purity of 99.0% (w/w) or greater, a Total Impurity (not including the related substance desamido Asn.sup.A21-RHI, as specified by USP) of 0.8% (w/w) or less, and an impurity C of 0.1% (w/w) or less. Also disclosed are API compositions of highly purified RHI having a purity of 99.0% (w/w) or greater, a Total Impurity of 0.8% (w/w) or less, and an impurity C of 0.1% (w/w) or less.

A process for manufacturing a purified aromatic carboxylic acid is provided. The process comprises purifying a crude aromatic carboxylic acid in a purification zone to form a purified aromatic carboxylic acid; crystallizing a purified aromatic carboxylic acid in a crystallization zone to form a solid/liquid mixture comprising purified aromatic carboxylic acid solids; filtering the solid/liquid mixture through a filter member of a rotary pressure filter apparatus to form a filter cake comprising the purified aromatic carboxylic acid solids; removing the filter cake from the filter member; rinsing the filter member to produce a filter rinse product, wherein the filter rinse product comprises purified aromatic carboxylic acid; and directing at least a portion of the filter rinse product downstream of the purification zone for recycle to the rotary pressure filter apparatus.

Disclosed herein is a method for producing high-purity terephthalic acid, including steps of dissolving crude terephthalic acid crystal in water and performing catalytic hydrogenation treatment, depressurizing and cooling a reaction liquid after the catalytic hydrogenation treatment in stages with two or more stages of crystallization vessels, to crystallize terephthalic acid to obtain a terephthalic acid slurry, introducing the terephthalic acid slurry into an upper portion of a mother liquor replacement tower, bringing the terephthalic acid crystal into contact with an upward flow of replacement water introduced from a tower lower compartment of the mother liquor replacement tower while making the terephthalic acid crystal settled down in the tower, withdrawing the terephthalic acid crystal as slurry with the replacement water from the tower lower compartment, subjecting the slurry withdrawn from the tower lower compartment to solid-liquid separation into water and the terephthalic acid crystal, and drying the separated terephthalic acid crystal.

The present application relates to a bisphenol A preparation apparatus and preparation method, and provides a bisphenol A preparation apparatus and preparation method, which can increase the overall energy efficiency of a process by using an internal heating source.

The present invention provides a continuous crystallization method under control of the multistage membrane modules, and belongs to the technical field of crystallization engineering. A crystallization solution is added to a crystallizer, and a stirring apparatus and a temperature control apparatus are started. After the system running stability, the loop of crystallization is started. Meanwhile, the coolant or antisolvent feed liquid loop is also started. The crystallization solution can respectively conduct crystal nucleation, growth and ripening in the multistage membrane modules, and then the crystallization solution is transported into a filter device and a drying apparatus to obtain the final crystal products. The desired crystal products can be obtained by the systematical control of the nucleation and crystal growth through the flow and the temperature of the crystallization solution, coolant or antisolvent feed liquid, and the contact time between two liquid phases.

There is disclosed a process for the separation of long chain amino acid and long chain dibasic acid, comprising: (1) adding an ammonium salt to the mixture of alkali salts of long chain amino acid and long chain dibasic acid; (2) heating to remove ammonia; and (3) separating long chain amino acid by solid-liquid separation; and (4) acidifying the salt of long chain dibasic acid with an acid to separate long chain dibasic acid.

A lithium-generating system can include a lithium-containing source feed, a hardness reduction unit, and a bipolar electrodialysis or electrolysis unit. The lithium-containing source feed can provide a lithium-containing material. The hardness reduction unit can be configured to receive the lithium-containing material and reduce the hardness thereof yet still be over 10 ppm upon processing by the hardness reduction unit. The bipolar electrodialysis unit can process the lithium-containing material and generate an aqueous LiOH product. The hardness reduction unit is configured to produce a hardness level within a given hardness-reduced lithium-containing material to be within an upper operational limit of at least one bipolar membrane, in addition to being at a given hardness level of over 10 ppm. The lithium-generating system can further include components to facilitate production of Li.sub.2CO.sub.3 and/or LiOH.Math.H.sub.2O.

The present invention relates to the extraction of lithium from liquid resources, such as natural and synthetic brines, leachate solutions from clays and minerals, and recycled products.

The present invention provides a continuous crystallization method under control of the multistage membrane modules, and belongs to the technical field of crystallization engineering. A crystallization solution is added to a crystallizer, and a stirring apparatus and a temperature control apparatus are started. After the system running stability, the loop of crystallization is started. Meanwhile, the coolant or antisolvent feed liquid loop is also started. The crystallization solution can respectively conduct crystal nucleation, growth and ripening in the multistage membrane modules, and then the crystallization solution is transported into a filter device and a drying apparatus to obtain the final crystal products. The desired crystal products can be obtained by the systematical control of the nucleation and crystal growth through the flow and the temperature of the crystallization solution, coolant or antisolvent feed liquid, and the contact time between two liquid phases.

The present invention provides a method capable of sufficiently reducing impurities with excellent separation efficiency even from a crystal-containing slurry that contains a low-purity mother liquor and has poor solid-liquid separation properties. The present invention relates to a method for producing a compound, the method including: a step of feeding a slurry containing crystals of the compound to a hydraulic wash column; a step of melting crystals in a crystal-containing circulation slurry discharged from the hydraulic wash column; and a step of returning a portion of a circulation liquid containing a melt obtained in the melting step to the hydraulic wash column, wherein the circulation liquid returned in the returning step in an amount of more than 30% by mass relative to 100% by mass of the melt serves as a washing liquid for crystals.