162results about How to "Improve crystallization yield" patented technology

The invention provides a refining method of C11-C18 long-chain diacids. granular long-chain diacid crystals are obtained by using methanol and ethanol as organic solvents and adopting a crystallization mode of cooling crystallization with seeding materials combined with flowing addition of dilute solvent aqueous solutions. The method has the advantages of high product purity and high crystallization yield; alcohol solvents are low in price and simple in recovery, which greatly reduces the refining cost of crude products.

The invention discloses a new process for extracting lactic acid from lactic acid fermentation liquid. The process flow comprises the following steps: preparing the fermentation liquid, deproteinizing, removing bacteria, decolorizing with activated carbon, performing plate and frame filtration, filtering with an inorganic ceramic membrane, cooling by a plate type heat exchanger, filtering with an organic nano-filtration membrane, concentrating and performing primary crystallization, performing centrifugal drying, performing resolvation, performing acidolysis, passing through an ion exchange resin column and concentrating to obtain a finished product. The process flow performs membrane filtration twice, namely the filtration with the inorganic ceramic membrane and the filtration with the organic ceramic membrane, wherein the filtration with the inorganic ceramic membrane can remove small insoluble solid impurities, bacteria, colloidal substances, macromolecular sugars and other impurities in filtrate; the filtration with the organic nano-filtration membrane can remove low-molecular weight sugars and multivalent ions in the filtrate; and the purity of the finally prepared finished product lactic acid is as high as 95%-98%, the crystallization yield of the lactic acid is improved from original 70% to above 85%, and the production cost is greatly reduced.

The invention discloses a preparation method of biapenem. The method comprises the following steps of: undergoing a catalytic hydrogenation reaction on a compound which is shown as a formula I and serves as a raw material and H2 in a mixed solvent of water and an organic solvent; adding an organic base immediately for regulating the pH value after the reaction; adding an organic solvent for precipitating biapenem crystals; and recrystallizing the crystals in water, organic acid and ethanol or ketone to obtain a refined biapenem product. The preparation method has the advantages of easiness for operating, no need of adjusting the pH value with a buffer salt during hydrogenation, no need of resin purification after hydrogenation, no need of special equipment, greatly-lowered water consumption, high yield and high product purity, and is suitable for industrial production.

The invention provides an L-tryptophan refining method. The method comprises the steps of dissolving crude products in a water and acetic acid mixed solvent; adding an antioxidant, and regulating the pH value; adding activated carbon for decoloration, and then conducting filtration; conducting cooling crystallization, centrifugal collection of crystals and drying to obtain L-tryptophan. The purity of L-tryptophan refined with the method is not lower than 99.5%. Compared with a vacuum concentration recrystallization refining method, the method has the advantages that steam consumption is reduced greatly, and yield each time is increased by over 50%.

The invention relates to a preparation method of cefdinir, which comprises the following steps: dissolving T15-AE active ester and 7-AVCA in a water system containing water-soluble organic solvent, carrying out condensation reaction at normal temperature under the action of organic alkali, and directly extracting without regulating the pH value to obtain a cefdinir intermediate; under the combined actions of mixed alkalis, efficiently removing an ester group protective agent from the cefdinir intermediate, and precipitating cefdinir compound salts; and dissolving the obtained cefdinir compound salts in water for decolorization, adding the water-soluble organic solvent, and acidifying to crystallize, thereby obtaining the cefdinir product. The invention is simple to operate, has the advantages of high product purity, low production cost and low environmental pollution, and is suitable for large-scale production.

The present invention relates to an equipment and its method for preparing vitamin C crystal by adopting fine crystal eliminating method. Said equipment nicludes crystallizer with jacket, fine crystal dissolving device, condensation device, vacuum system and distillate collecting device. Said invention also provides the concrete structure of the above-mentioned every device and their connection mode, also provides the concrete steps of said method.

The invention belongs to a preparation process of sodium gluconate and in particular relates to a novel method for extracting the sodium gluconate. The preparation process comprises the following concrete steps of: filtering and decoloring a sodium gluconate fermentation liquor; then concentrating the sodium gluconate fermentation liquor to 40-60% of the original concentration; adding an ethanol solution to the sodium gluconate fermentation liquor and stirring for 3-8h; crystallizing, sedimenting and separating; evaporating a separated clear solution; extracting ethanol; recycling raffinate into the fermentation liquor; and drying a crystal to prepare a sodium gluconate solid. By adopting the novel method for extracting the sodium gluconate, the crystallization yield of the sodium gluconate can be improved; the production cost of the sodium gluconate is lowered; a large amount of energy resources is saved; the occurrence of side reaction is reduced; the product has high purity; no wastewater is discharged in the whole production course; and a cycle process is utilized.

The invention provides an extracting process of D-xylose and L-arabinose. The extracting process comprises the following steps of: acidizing forestry and agricultural residues, carrying out steam explosion on the acidized forestry and agricultural residues to obtain the forestry and agricultural residues subjected to steam explosion, and finally carrying out aqueous extraction, separation and crystallization to obtain the D-xylose and L-arabinose. According to the technical scheme of the invention, the extracting method has the following advantages that an acid solution is recycled, and therefore the acid consumption is reduced; as the acid in an extracting solution is low in content, the load of a later-peroid purifying treatment is lightened; the peroid is short, continuous steam explosion production can be achieved, and the equipment investment is reduced when the capacity is unchanged; steam is not heated together with the acid solution in the boosting process, so that the steam consumption is greatly reduced, and energy sources are saved; and as the process of separating the D-xylose and the L-arabinose first and then respectively crystallizing is adopted, the purity of massecuite during crystallization of the D-xylose is improved, and the quality and crystallization yield of the D-xylose are improved.

The present invention discloses a secondary crystallization technique of xylose, which belongs to the techinical field of functional sugar production. The technique includes the following processes: xylose massecuite is infused into a crystallization pot, and when the infused volume reaches 80 percent to 85 percent of the capacity of the crystallization pot, infusion is stopped; when the temperature is naturally decreased to 80 DEG C, the xylose massecuite is stirred for two hours while the temperature is kept; afterwards, the temperature of the xylose massecuite is reduced at 1 DEG C per hour, and when the temperature reaches 75 DEG C, tiny crystal grains are formed in the xylose massecuite; at the moment, the residual xylose massecuite, which accounts for 20 percent to 15 percent of the capacity of the crystallization pot, is infused into the crystallization pot and uniformly mixed, so that the newly added xylose massecuite is sufficiently mixed with the xylose massecuite with the formed tiny crystal grains; then, when the temperature is naturally reduced to 75 DEG C, the xylose massecuite is stirred for three hours while the temperature is kept; the temperature is decreased again according to the speed rate of 1 DEG C per hour, and when the temperature reaches 30 DEG C to 40 DEG C, crystallization is finished; and centrifugation operation is carried out. Compared with the prior art, the secondary crystallization technique of xylose is characterized by simple operation, high crystallization yield, low production cost, and the like.

The present invention discloses a production technology of lactitol. Lactose is added into deionized water to prepare a lactose solution, pH is adjusted, a certain amount of a catalyst is added, a hydrogenation reaction is conducted under high temperature and high pressure to obtain a lactose hydrogenation solution, after the catalyst is removed, a lactitol solution is obtained, the lactitol solution is then purified, and concentration, crystallization and drying are conducted to obtain lactitol crystals. A primary crystallization yield of the lactitol relative to the lactose raw material reaches 55.0%-68.0% and a total yield of the lactitol relative to the lactose raw material reaches 92.2%-96.5%. At the same time, the technology is simplified in processes, liable for production and operation and also relatively low in production cost.