60 results about "Glycolonitrile" patented technology

Various methods are provided for the enzymatic production of glycolic acid from glycolonitrile. These methods include: 1) use of Acidovorax facilis 72W nitrilase mutants having improved nitrilase activity for converting glycolonitrile to glycolic acid, and 2) methods to improve catalyst stability and / or productivity. The methods to improve catalyst stability / productivity include use of reaction stabilizers, running the reactions under substantially oxygen free conditions, and controlling the concentration of substrate in the reaction mixture.

The present invention provides a process for preparing an enzyme catalyst having nitrilase activity for hydrolysis of glycolonitrile to glycolic acid with improved retention of recovered catalyst activity in consecutive batch reactions with catalyst recycle, said process comprising pretreating the enzyme catalyst with glutaraldehyde. The glutaraldehyde-pretreated enzyme catalyst has improved specific activity when compared to non-glutaraldehyde-pretreated enzyme catalysts, and thereby, has improved overall catalyst activity and productivity.

The invention relates to a method for preparing n-phenylglycinenitrile. The method is characterized in that condensation reaction is continuously performed for aniline and glycolonitrile by a micro-channel reactor to obtain n-phenylglycinenitrile; the pH of glycolonitrile is pre-regulated to be 1.5 to 7 through a basic catalyst; the molar ratio of aniline to glycolonitrile is 1.00: 1.00-1.30. The method for preparing n-phenylglycinenitrile has the advantages that the process route is simple, and the reaction is fast, so that the working efficiency and production capacity can be ensured, and moreover, the production and operation safety of the process can also be ensured; with the adoption of the process method, the purity of a n-phenylglycinenitrile product exceeds 98.0% and the yield exceeds 99.9%.

A method for the environment-friendly clean production of high-purity ethylene diamine tetraacetic acid (EDTA) is an environment-friendly clean production method which takes sodium cyanide, formaldehyde and ethylenediamine or sodium hydroxide, glycolonitrile and ethylenediamine as main raw materials to synthesize the high-purity EDTA, and is characterized in that the acidization process of the synthetic EDTA solution is carried out by two steps, the purification decoloration treatment is carried out under the condition that a solution system is weak alkaline or approaches neutral, so the optimum effect of purification decoloration can be realized; the separation after the purification decoloration is carried out by two separation steps of centrifugal separation and fine filtration, so the relatively pure EDTA synthetic solution is obtained; the method is also characterized in that the mother solution which is produced by producing EDTA and is rich in sodium sulfate is subjected to comprehensive treatment for obtaining anhydrous sodium sulphate, the zero emission clean production method is realized, and is mainly realized through the technology that sodium sulfate hydrous crystalline solid is obtained through mother solution recovery treatment, and the byproduct of the anhydrous sodium sulphate is obtained through purification dehydration and other treatments of the sodium sulfate hydrous crystalline solid; and through recovering the sodium sulfate in the mother solution, not only can resources be saved, but also the environmental conservation of the EDTA production technology can be realized, and very good economic and social benefits are obtained.

Various methods are provided for the enzymatic production of glycolic acid from glycolonitrile. These methods include: 1) use of Acidovorax facilis 72W nitrilase mutants having improved nitrilase activity for converting glycolonitrile to glycolic acid, and 2) methods to improve catalyst stability and / or productivity. The methods to improve catalyst stability / productivity include use of reaction stabilizers, running the reactions under substantially oxygen free conditions, and controlling the concentration of substrate in the reaction mixture.

Various methods are provided for the enzymatic production of glycolic acid from glycolonitrile. These methods include: 1) use of Acidovorax facilis 72W nitrilase mutants having improved nitrilase activity for converting glycolonitrile to glycolic acid, and 2) methods to improve catalyst stability and / or productivity. The methods to improve catalyst stability / productivity include use of reaction stabilizers, running the reactions under substantially oxygen free conditions, and controlling the concentration of substrate in the reaction mixture.

The invention relates to a preparation and pre-use treatment method for glycolonitrile with cyanide-containing tail gas as the raw material. According to the method, the cyanide-containing tail gas is introduced into multiple stages of reaction stills containing formaldehyde and a catalyst to be directly subjected to an addition reaction, and a glycolonitrile product with a certain concentration is obtained; after material transferring, the glycolonitrile product is stored under the effect of a stabilizer for use, and before use, the pH is regulated with base or weak base till the glycolonitrile product is neutral. The catalyst is one of basic compounds including Na2SO3, Na2CO3, NaHCO3 and NaOH, the mass concentration of formaldehyde is 35%-37%, the mol ratio of formaldehyde to the catalyst is 1:(0.001-0.05), and the reaction temperature is 5-20 DEG C. According to the method, HCN in industrial waste gas of a steroid drug is chemically absorbed through formaldehyde, the catalyst and the stabilizer, glycolonitrile is generated through the reaction and serves as a raw material for biological preparation of glycollic acid, and therefore the cyanide-containing tail gas is fully absorbed and utilized and prevented from being directly exhausted to the atmosphere and polluting the environment.

The invention relates to a method for preparing n-phenylglycinenitrile. The method is characterized in that condensation reaction is continuously performed for aniline and glycolonitrile by a micro-channel reactor to obtain n-phenylglycinenitrile; the pH of glycolonitrile is pre-regulated to be 1.5 to 7 through a basic catalyst; the molar ratio of aniline to glycolonitrile is 1.00: 1.00-1.30. The method for preparing n-phenylglycinenitrile has the advantages that the process route is simple, and the reaction is fast, so that the working efficiency and production capacity can be ensured, and moreover, the production and operation safety of the process can also be ensured; with the adoption of the process method, the purity of a n-phenylglycinenitrile product exceeds 98.0% and the yield exceeds 99.9%.

The invention provides an environmentally-friendly clean technology for producing hydrocyanic acid derivatives from coal-bed methane. The environmentally-friendly clean technology realizes production of hydrocyanic acid derivatives from low-concentration coal-bed methane. The environmentally-friendly clean technology is characterized in that hydrocyanic acid and its derivatives are prepared from concentrated methane having low content requirements; coal-bed methane is subjected to separation processes of pressure swing adsorption and the like to form relatively concentrated methane for production of hydrocyanic acid derivatives, wherein the relatively concentrated methane has relatively low concentration requirements and can retain residual nitrogen and oxygen having a large component ratio; and the relatively concentrated methane undergoes an ammoxidation synthesis reaction to produce hydrocyanic acid mixed gas, and the hydrocyanic acid mixed gas and a sodium hydroxide aqueous solution undergo a reaction to produce sodium cyanide for synthesis of downstream hydrocyanic acid derivatives, or the hydrocyanic acid mixed gas, formaldehyde and other aldehydes are synthesized into glycolonitrile and other derivatives for synthesis of downstream hydrocyanic acid derivatives, or the hydrocyanic acid mixed gas is absorbed by water or other solvents and then is purified to form high-purity liquid hydrocyanic acid for synthesis of downstream hydrocyanic acid derivatives.

A process is provided for producing glycolic acid from formaldehyde and hydrogen cyanide. More specifically, heat-treated formaldehyde and hydrogen cyanide are reacted to produce glycolonitrile having low concentrations of impurities. The glycolonitrile is subsequently converted to an aqueous solution of ammonium glycolate using an enzyme catalyst having nitrilase activity derived from Acidovorax facilis 72W (ATCC 57746). Glycolic acid is recovered in the form of the acid or salt from the aqueous ammonium glycolate solution using a variety of methods described herein.

The invention discloses a method for co-producing glycine and hydantoin, and an apparatus thereof. The method adopting hydroxyacetonitrile, ammonia, carbon dioxide and water, or hydroxyacetonitrile, ammonia, ammonium bicarbonate and water, or hydroxyacetonitrile, ammonium carbonate, carbon dioxide and water as raw materials comprises the following steps: carrying out an amidocarbonylation reaction on the raw materials at a temperature of 60-120DEG C under a pressure of 1.5-3.0MPa according to a molar ratio of hydroxyacetonitrile: ammonia: carbon dioxide: water of 1:3-5:2-4:46-50 in a reaction system to prepare an amidocarbonylation reaction solution; acidifying the amidocarbonylation reaction solution to obtain a hydantoin product, or carrying out ammonification hydrolysis on the amidocarbonylation reaction solution to prepare a glycine product The method and the apparatus can save the investment of apparatuses for prodcuign glycine and hydantoin, reduce the production cost, are convenient for adjusting the outputs of glycine and hydantoin, and especially overcome the disadvantages of incomplete hydrolysis, generation of iminodiacetic acid, many byproducts, difficult purification of glycine, and low yield of present hydantoin methods for preparing glycine.

Provided is a production method of glycolic acid having a first step of preparing glycolonitrile from formaldehyde and hydrocyanic acid and a second step of hydrolyzing the glycolonitrile into glycolic acid directly or via a glycolate salt, which method can produce glycolic acid in easy production and purification steps while consuming less energy. In the production method, by carrying out the first and second steps continuously or by storing the glycolonitrile obtained in the first step at pH 4 or less and carrying out a hydrolysis reaction of the second step at from pH 5 to 9, a production yield of glycolic acid, activity for the production of glycolic acid and accumulated concentration of glycolic acid are improved, resulting in the production of glycolic acid having an improved purity and quality.

A process to prepare substantially pure glycolonitrile in an aqueous medium is provided by reacting hydrogen cyanide and formaldehyde. The formaldehyde feed stream is heated prior to reacting with hydrogen cyanide, resulting in an aqueous glycolonitrile solution with fewer impurities, especially less unreacted formaldehyde, than is obtained by other methods. The process enables production of an aqueous glycolonitrile solution that requires less post-reaction purification (if any at all) prior to enzymatically converting the glycolonitrile into glycolic acid.

A method for preparing solid glycolic acid comprises the following steps: (1) hydrolysis reaction of glycolic acid: taking concentrated sulfuric acid, water and a glycolonitrile water solution as raw materials for hydrolysis reaction of glycolic acid; (2) neutral reaction: adding concentrated ammonia water while stirring for neutral reaction; (3) desalting: adding anhydrous isopropyl alcohol into a product of the step (2), stirring, performing suction filtration, drying filter cake obtained through suction filtration, retrieving filtrate, and adding injection carbon for decoloration to obtain a colorless transparent liquid; (4) alcohol recovery; and (5) crystallization: performing cooling crystallization, stopping cooling when the temperature of feed liquid reaches 5-20 DEG C, preserving the temperature for 1 h at the temperature, performing suction filtration, washing filter cake with 100 mL distilled water to obtain a glycolic acid wet product, and conducting vacuum drying at 30 DEG C for 6 h to obtain solid glycolic acid. The method for preparing the solid glycolic acid is simple to operate and high in product yield and purity.