909results about "Preparation from carboxylic acid salts" patented technology

A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. An amine and CO₂ are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and the amine. The acid/amine complex is thermally dissociated, or “cracked”, in the presence of a water immiscible solvent in which the amine is selectively soluble and in which the acid is not appreciably soluble. The organic acid may then be recovered from the water by any suitable means such as distillation, reactive distillation, extraction, or reactive extraction.

The invention discloses a method for separating and purifying DHA (docosahexaenoic acid) and saturated fatty acid from schizochytrium limacinum oil. The method includes: firstly, saponifying, salting out and acidizing the schizochytrium limacinum oil under protection of nitrogen so as to obtain free mixed fatty acid, and separating the fatty acid different in degree of saturation by urea adduction fractionation so as to obtain filtrate and solids after filtration; concentrating and extracting the filtrate so as to obtain polyunsaturated fatty acid rich in DHA and DPA (docosapentenoic acid); and allowing the solids to leach by means of acidolysis, extracting the saturated fatty acid (mainly comprising palmic acid) and recovering urea, wherein the urea is recyclable. The method is performedat a low temperature, oxidization of the unsaturated fatty acid is avoided, biological activity and nutrition of the unsaturated fatty acid are kept intact, and the problem of residual solvent is avoided. Products are high in purity, and the obtained polyunsaturated fatty acid mainly comprises the DHA and the DPA and hardly comprises EPA (eicosapentaenoic acid), the content of the DHA and the DPAis higher than 93%, and the content of the palmic acid of the saturated fatty acid is higher than 82%.

Disclosed herein are methods for the recovery of an organic acid, such as a heat stable lactic acid, from a feed stream which contains at least one of an organic acid amide, an organic acid ammonium salt, or an alkylamine-organic acid complex. The feed stream is mixed with at least one azeotroping agent. The azeotroping agent is a hydrocarbon capable of forming at least one azeotrope with the organic acid that is produced by the thermal decomposition of the amide, ammonium salt, or complex in the feed stream. Preferably the azeotrope is a heteroazeotrope. The mixture of the feed stream and the azeotroping agent is heated to produce a vapor stream. The azeotrope is a component of the vapor stream. The vapor stream can be condensed to a liquid stream, and the organic acid is recovered in the liquid stream that is produced. When the azeotrope is a heteroazeotrope, the vapor stream can be condensed into a liquid stream, which can be separated into a first phase and a second phase. The first phase contains the highest concentration of organic acid and the second phase contains azeotroping agent. The organic acid can be further purified and/or concentrated from the separated first phase or from the liquid stream.

A process for the preparation of free carboxylic acids including: A) preparation of carboxylic acid by a biological cell located in an aqueous medium with addition of an amine of formula (I)

where R¹, R² and R³, independently of one another, are identical or different, branched or unbranched, optionally substituted hydrocarbon radicals or H; B) for cases where the added amine A) is water-soluble, addition of a water-insoluble amine of formula (I), where, in A) or B), a multiphase system is obtained and the corresponding ammonium carboxylate is formed from the water-insoluble amine and the carboxylic acid; C) removal of the water-insoluble phase; and D) heating of the water-insoluble phase with release of free carboxylic acid.

The present invention relates to a process for chemical recycling of PET waste that comprises, among other stages, a saponification reaction stage, wherein PET waste particles are reacted with stoichiometric or excessive amounts of a strong base metal in an alcoholic reaction media, the reaction being brought to the boiling temperature of the alcoholic reaction media, preferably at atmospheric pressure, thereby obtaining as reaction products a salt of terephthalic acid with the base metal and ethylene glycol, the latter being incorporated to the alcoholic reaction media. From this reaction it is possible to afford ethylene glycol, terephthalic acid and salts thereof, which are products with a high commercial value.

The present invention relates to novel Ruthenium catalysts and related borohydride complexes, and the use of such catalysts, inter alia, for (1) hydrogenation of amides (including polyamides) to alcohols and amines; (2) preparing amides from alcohols with amines (including the preparation of polyamides (e.g., polypeptides) by reacting dialcohols and diamines and/or by polymerization of amino alcohols); (3) hydrogenation of esters to alcohols (including hydrogenation of cyclic esters (lactones) or cyclic di-esters (di-lactones) or polyesters); (4) hydrogenation of organic carbonates (including polycarbonates) to alcohols and hydrogenation of carbamates (including polycarbamates) or urea derivatives to alcohols and amines; (5) dehydrogenative coupling of alcohols to esters; (6) hydrogenation of secondary alcohols to ketones; (7) amidation of esters (i.e., synthesis of amides from esters and amines); (8) acylation of alcohols using esters; (9) coupling of alcohols with water to form carboxylic acids; and (10) dehydrogenation of beta-amino alcohols to form pyrazines. The present invention further relates to the novel uses of certain pyridine Ruthenium catalysts.

The invention relates to a method for coproducing high-purity methanoic acid and monobasic sodium phosphate by reaction of calcium formate and ultraphosphate. The method comprises the following steps that: carbon monoxide enters a reaction tower III; calcium hydroxide enters a reaction tower I to perform a counterflow reaction with carbon monoxide from a reaction tower II, a reaction solution overflows to the reaction tower II to perform the counterflow reaction with the carbon monoxide from the reaction tower III, the reaction solution enters the reaction tower III to perform the couterflow reaction with the carbon monoxide, the reaction solution overflows into a discharge tank from the reaction tower III to prepare a calcium formate preparation solution; the calcium formate preparation solution enters a reaction kettle, methanoic acid is dripped into the reaction kettle, sulfureted hydrogen is introduced into the reaction kettle, the mixture is separated and filtered through a filter I, a filtrate enters a continuous crystallizer, a crystalline liquid enters a filter II, and the filtered calcium formate is prepared into a finished product calcium formate through a drier; ultraphosphate, the methanoic acid and the calcium formate are conveyed into a horizontal double screw reactor to generate the methanoic acid and monobasic calcium phosphate; the methanoic acid and the monobasic calcium phosphate enter a methanoic acid distilling still for reduced pressure distillation; and the monobasic calcium phosphate is delivered to a monobasic calcium phosphate measurement receiving tank, while the monobasic acid enters a methanoic acid receiving tank. The method has high yield of the methanoic acid and low manufacturing cost.

The invention relates to a method for treating metronidazole waste water, which comprises the following steps of: concentrating the metronidazole waste water into 1/3-1/5 of total amount, and crystallizing and filtering the concentrated metronidazole waste water at 45-100 DEG C to obtain anhydrous sodium sulfate and sodium formate; adjusting the PH to 3-6 by using sulfuric acid or formic acid, and precipitating 2-methy-5-nitro imidazole; concentrating the filter liquid to anhydrous sticky state, dissolving organic matter by using methanol or ethanol, and filtering the solution to obtain anhydrous sodium sulfate and sodium formate; merging the sodium formate and the anhydrous sodium sulfate obtained in two times, successively adding formic acid and sulfuric acid, and recovering the formic acid to obtain anhydrous sodium sulfate; and rectifying and separating the organic mixture extract of methanol or ethanol to obtain methanol or ethanol and glycol. The method for treating metronidazole waste water provided by the invention is simple and convenient to operate, the content of polluting organic matter and inorganic slats in the metronidazole waste water can be obviously reduced, environmental pollution can be preveneted, various kinds of useful organic matter and inorganic matter can be recovered, raw materials are saved, and the production cost is lowered.

The invention discloses a method for preparing lactic acid with bipolar membrane electrodialysis technology. Lactic acid fermentation liquid passes through an electrodialyzer, which transforms contained lactates into lactic acid. The membrane tank configuration of the adopted electrodialyzer can be of two-cell type including an acid cell and a salt cell divided by an anion membrane or of three-chamber type including an acid cell, a salt cell and a base cell divided by a cation membrane and an anion membrane. For preparation, lactic acid fermentation liquid is transmitted into the salt cell and water is transmitted into the acid cell or the base cell. Under the effect of a circulating pump, the materials flow circularly with a current density of 80-160mA/cm2 at an operation temperature of 25-60 DEG C. The invention can completely supersede the prior calcium lactate acidifying technology without addition of acids for H+ supply and without production of waste acid, salt or base liquid. The transformation efficiency of lactic acid is higher than 98 percent, the recovery of lactic acid is higher than 90 percent and the current efficiency is higher than 70 percent, so the method can reduce environment pollution and lower consumption of chemical raw materials and energy and has remarkable industrial application value and environmental benefit.

A process for the recovery of organic acids from dilute solutions such as those produced by fermentation, when the organic acids are present as dilute salt solutions, is provided. The organic acid production process is integrated with a nitrogen fertilizer production process by utilizing wasted chemical energy from the fertilizer process for acidification of the organic acid solution.

The invention discloses a method for continuously producing herbicide 2,4-dichlorophenoxyacetic acid. According to the method, phenol and chlorine gas are used as raw materials; a continuous chlorination reaction is conducted through a micro-channel reactor to prepare 2,4-dichlorophenol, a condensation reaction is conducted through a tandem condensation reaction kettle to prepare 2,4-dichlorphenoxyacetic acid sodium salt, and then a continuous acidification reaction is conducted through a tandem acidification reaction kettle to prepare the 2,4-dichlorphenoxyacetic acid. Since continuous operation is realized in all the three reactions, the technological process is efficient, environmentally friendly, sustainable and suitable for industrial production; the method has the advantages that energy is saved, consumption is lowered, and emission of pollutants is reduced, and therefore safe and continuous industrial production is achieved.

A method of producing and purifying an organic acid by producing an aqueous solution of the ammonium salt of the organic acid through fermentation and/or bioconversion and neutralization. The solution is heated to thermally crack the ammonium salt of the organic acid producing a vapor phase of ammonia and water and organic acid which is thereafter passed in contact with a membrane permeable to water and ammonia and substantially impermeable to the organic acid vapor to concentrate the aqueous solution of organic acid, and remove the ammonia and excess water.

The invention relates to a method for extracting succinic acid from fermentation liquor, comprising the following steps: 1) degerming and decontaminating succinic acid fermentation liquor to obtain succinate solution; 2) allowing the succinate solution to react with calcium chloride to generate calcium succinate precipitate; 3) carrying out solid-liquid separation on reaction liquid to obtain a calcium succinate solid; 4) allowing the calcium succinate solid to react with hydrochloric acid, and separating out a succinic acid solid at a reduced temperature; and 5) carrying out solid-liquid separation on the reaction liquid to obtain the succinic acid. The method has high yield, good product quality, small original auxiliary material consumption, low energy consumption and applicability to large-scale production.

The invention relates to a synthesis method of a fine chemical product 2-(4-methylphenyl)propionic acid. According to the method, para-xylene is adopted as a raw material, and a chlorination reaction is carried out, such that a compound I which is p-methylbenzyl chloride is obtained; p-methylbenzyl chloride is subjected to a nitrilation reaction, such that a compound II which is p-methylbenzyl cyanide is adopted; p-methylbenzyl cyanide is subjected to methylation, such that a compound III which is 2-(4-methylphenyl)propionitrile is obtained; and 2-(4-methylphenyl)propionitrile is subjected to hydrolysis acidification, such that a compound IV which is 2-(4-methylphenyl)propionic acid is obtained. The method provided by the invention has the advantages of short process route, low three-waste discharge, low environment pollution, no solid waste production during reaction processes, relatively low production cost, less chemical substances used during reaction processes, less raw material types, easy-to-obtain raw materials, simple operation, high yield, relatively mild process conditions, and the like.

The invention belongs to the technical field of solid waste recovery and regeneration, and in particular relates to a production method of mixed binary acid with a long carbon chain. The method comprises the following steps of: with heavy constituents remained after ethanol obtained in the dodecanedioic acid refining process is recovered as raw materials, enabling the heavy constituents to react with and a superfluous alkali solution at the temperature of 95-100 DEG C to generate sodium binary acid with a long carbon chain and ethanol; recovering the ethanol in the reaction process by using an alcohol fog recovery tower; and after the reaction is ended, carrying out aftertreatment on the obtained sodium salt to obtain the mixed binary acid with the long carbon chain. According to the invention, the heavy constituents remained after the ethanol obtained in the dodecanedioic acid refining process is recovered as raw materials and reacts with the superfluous alkali solution to generate the binary acid with the long carbon chain, and thus not only are wastes utilized, but also the environment pollution is reduced, and the benefit is increased.

Disclosed is a process for the production of higher aldehydes from lower alcohols using a two-stage vapor phase heterogeneous catalyst system. Ethanol feeds afford aldehydes such as butyraldehyde and crotonaldehyde while butanol feeds yield 2-ethylhexanal and 2-ethylhexenal. Higher product selectivities are obtained when the alcohol is first dehydrogenated in the upper catalyst stage followed by aldol condensation of the resulting lower aldehyde to a higher aldehyde.

The invention discloses a process of recycling terephthalic acid to produce DOTP (dioctyl terephthalate) by using polyester alkaline to reduce wastewater. The process comprises the following process steps: adding terephthalic acid reclaimed materials and isooctyl alcohol into a reaction kettle in a certain proportion, stirring and heating, adding a catalyst and activated carbon when water yield is obviously reduced, continuously stirring and heating the mixture, controlling the temperature of the mixture to 190-230 DEG C, carrying out dealcoholization in vacuum after reaction is ended, heating to 265-285 DEG C and distilling under reduced pressure under -0.09MPa to -0.1MPa to obtain raw ester, adding H2O2 in a certain proportion to discolor; and finally, absorbing impurities by use of activated carbon and kaolin and carrying out filter-pressing to obtain a nearly colorless DOTP finished product. According to the process, the raw materials can adopt untreated alkaline which is low in purity and chromaticity to reduce wastewater to recycle the terephthalic acid, so that a complex pretreatment process is avoided, the terephthalic acid reclaimed materials are utilized to the greatest extent, and the high ester content and the low colour and luster of the DOTP product are guaranteed while the efficiency is high and the energy consumption is low.

The invention belongs to the technical field of L-lactic acid production, and particularly discloses a method for purifying and refining L-lactic acid. The method for purifying and refining L-lactic acid comprises the following steps: removing thalli in a fermentation liquor through separation to obtain thallus residues which can be used as a feed raw material; decolorizing an acidolysis filteredclear liquid by using activated carbon, feeding the decolorized acidolysis filtered clear liquid into a first ion exchange column, carrying out cation and anion exchange to obtain a primary ion exchange liquid, filtering the primary ion exchange liquid by using a nanofiltration membrane, carrying out pre-concentration, and sequentially carrying out cation and anion exchange to obtain a secondary ion exchange liquid; decolorizing the secondary ion exchange solution by adopting an activated carbon decolorizing column, and then concentrating to obtain a lactic acid concentrate with the L-lactic acid content of 80-90%; and carrying out short-path distillation and purification on the lactic acid concentrate to obtain high-purity food-grade lactic acid or produce polylactic acid. According to the L-lactic acid purification and refining method provided by the invention, the finished product quality of the L-lactic acid is improved, and the finally obtained L-lactic acid is good in quality andhigh in yield and particularly meets the quality requirement of the L-lactic acid serving as a PLA raw material.

A method for making a carbon nanotube metal composite includes the following steps. A number of carbon nanotubes is dispersed in a solvent to obtain a suspension. Metal powder is added into the suspension, and then the suspension agitated. The suspension containing the metal powder is allowed to stand for a while. The solvent is reduced to obtain a mixture of the number of carbon nanotubes and the metal powder.

The invention relates to the field of pharmaceutical chemical synthesis, in particular to a preparation method of flurbiprofen and a preparation method of flurbiprofen axetil. The preparation method of the flurbiprofen comprises the steps of carrying out a Grignard reaction by using 4-bromine-2-fluorine biphenyl as a raw material, carrying out a coupling reaction, and acidizing to obtain the flurbiprofen; the yield is 90%, and the purity is 99.5%; then, the flurbiprofen axetil is prepared by using the flurbiprofen, obtained by the method, as a raw material, the yield reaches up to 90%, and thepurity reaches up to 99.5%. The preparation methods are high in quality controllability and industrial reproducibility.