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579 results about "Glyoxylic acid" patented technology

Glyoxylic acid or oxoacetic acid is an organic compound. Together with acetic acid, glycolic acid, and oxalic acid, glyoxylic acid is one of the C₂ carboxylic acids. It is a colourless solid that occurs naturally and is useful industrially.

Productive technology of vanlillin by glyoxylic acid method

The invention discloses a productive technology of vanlillin by a glyoxylic acid method. The productive technology comprises a synthesis process, a fractionation process and a purification process, wherein the synthesis process comprises condensation treatment, oxidation treatment and decarboxylation treatment of methyl catechol and glyoxylic acid. The productive technology particularly comprisesthe following steps: respectively converting the methyl catechol and the glyoxylic acid into guaiacol sodium and sodium glyoxylate in a sodium hydroxide system; carrying out condensation treatment onthe guaiacol sodium and the sodium glyoxylate; after recovering the unreacted methyl catechol in a condensation liquid, carrying out oxidation treatment, namely carrying out catalytic oxidation on anethanol group in 4-hydroxy-3-methoxybenzene sodium glycolate by using copper oxide in the sodium hydroxide system to form a ketone group, thereby generating a corresponding ketonic acid compound; after separating red copper oxide particles from an oxidation liquid, carrying out decarboxylation treatment, namely using sulfuric acid to acidize the oxidation liquid, and simultaneously converting an acid group in the ketonic acid compound into carbon dioxide so as to generate 4-hydroxy-3- methoxybenzaldehyde; and carrying out the fractionation process and the purification process to obtain the vanlillin.
Owner:喜孚狮王龙香料(宁波)有限公司

Treatment method and treatment system of tail gas from glyoxylic acid production by nitric acid oxidation of glyoxal

A treatment method and a treatment system of tail gas from glyoxylic acid production by nitric acid oxidation of glyoxal belong to the fields of environmental protection, energy saving and consumption reduction. The method comprises the following steps: introducing air to oxidize NO in tail gas generated by nitric acid oxidation of glyoxal into NO2; performing six-grade water absorption continuously to absorb gas of NOx and HCl in the tail gas; absorbing the tail gas after six-grade water absorption by a NaOH or Na2CO3 solution to remove residual NO2 and HCl gas and to generate an alkaline solution containing NaNO3, NaNO2, and trace NaCl; discharging the treated tail gas by an induced draft fan; performing neutralization, concentration, crystallization, centrifugation and separation of the generated alkaline solution to obtain a mixed sodium salt containing NaNO3, NaNO2, and trace NaCl, returning the mixed sodium salt to an oxidation vessel to be used as a catalyst for recycle. The treatment system comprises: an oxidation reaction vessel, water absorbing towers from grade one to grade six, a seventh grade alkaline solution absorbing tower, a concentration and crystallization vessel, a centrifuge, and a induced draft fan.
Owner:HUBEI HONGYUAN PHARMA

Colloid palladium activation solution, preparation method thereof and non-metal surface activation method

The invention provides colloid palladium activation solution which comprises colloid palladium, sodium chloride, glyoxylic acid, hydrochloric acid, stannous chloride and stabilizer for stabilizing the stannous chloride, wherein the glyoxylic acid has strong reducibility and can avoid that divalent tin ions in the activation solution are oxidized, and prolong the service life of the action solution; simultaneously, the glyoxylic acid is adsorbed on the periphery of colloid palladium particles, thereby leading the dispersion of the colloid palladium to be more uniform, avoiding the gel coagulation among the colloid particles and enhancing the activity of the activation solution. The invention provides a preparation method of the colloid palladium, and the process is simple. In addition, the adoption of the colloid palladium activation solution for activating the surface of a non-metal substrate can firstly adsorb the glyoxylic acid in the activation solution on the surface of the non-metal substrate, enhance the bonding force between the colloid palladium particles and the non-metal substrate, leading a plated coating after chemical plating to have uniform thickness and flat surface, and leading the adhesion between the plated coating and the substrate to be very high.
Owner:深圳市新合富力科技有限公司

Multi-effect membrane distillation device with efficient internal heat reclamation function and method

ActiveCN102085454AExcellent heat transferExcellent mass transfer effectGeneral water supply conservationEnergy based wastewater treatmentSulfolaneFiber
The invention relates to a multi-effect membrane distillation device with efficient internal heat reclamation function and a method. The middle part of a membrane shell is provided with a cavity, two ends of the membrane shell are provided with an inlet and an outlet respectively, hollow fibrous membranes and hollow fiber pipes arranged uniformly are arranged in the cavity of the membrane shell, joints at two ends of the hollow fibrous membranes and the hollow fiber pipes are connected with the inlet and the outlet respectively, the lower end of the membrane shell is provided with a distillate outlet, and an external heat exchanger is connected in series between the inlet and the outlet of the water return end of a membrane assembly. The device has compact structure, simple and mild operating condition, low energy consumption and high water making rate, and can be used for small-scale dispersed implementation and integrated application; the method can be used in the fields of sea water desalinization, bitter water desalinization, concentration treatment of aqueous solution of nonvolatile or semi-volatile solutes, environmental protection and the like; and particularly when the method is used for concentration of aqueous solution of nonvolatile and semi-volatile solutes such as sodium chloride, ammonium sulfate, ammonium nitrate, sodium nitrate, sodium carbonate, sodium hydroxide, sulfuric acid, hydrochloric acid, glucose, xylitol, urea, glycerol, ethylene glycol, lactic acid, glyoxylic acid, dimethyl sulfoxide, sulfolane and the like, normal pressure steam or hot water is used as a heat source, and the highest water making rate can reach 13.7.
Owner:天津凯铂能膜工程技术有限公司

Preparation methods of glyoxylic acid L-menthyl alcohol ester and monohydrate of glyoxylic acid L-menthyl alcohol ester

The invention relates to preparation methods of glyoxylic acid L-menthyl alcohol ester and a monohydrate of the glyoxylic acid L-menthyl alcohol ester, and belongs to the technical field of fine chemical industry. The glyoxylic acid L-menthyl alcohol ester is prepared by the following steps: reacting L-menthol with monohalogen or dihalogen acetyl halide or anhydride to generate monohalogen or dihalogen acetic acid L-menthyl alcohol ester; and reacting in the presence of a pro-oxidant to obtain the glyoxylic acid L-menthyl alcohol ester. The monohydrate of the glyoxylic acid L-menthyl alcohol ester is prepared by the following steps: cooling and diluting a reaction solution using monohalogen acetic acid L-menthyl alcohol ester as a raw material; treating by using a dimethylsulfoxide (DMSO) solution of P2O5 and triethylamine to obtain the glyoxylic acid L-menthyl alcohol ester; washing, extracting and concentrating a reaction solution using dihalogen acetic acid L-menthyl alcohol ester as a raw material to obtain the glyoxylic acid L-menthyl alcohol ester; and treating by using sodium hydrogen sulfite and formaldehyde to obtain the monohydrate of the glyoxylic acid L-menthyl alcohol ester. The total yield of the glyoxylic acid L-menthyl alcohol ester synthesized by the technology can reach over 72 percent; the total yield of the monohydrate of the glyoxylic acid L-menthyl alcohol ester can reach over 80 percent; the purity can reach over 99.5 percent; the technical process is simple and convenient; the raw materials are available; the yield is high; the product purity is high; and the process is suitable for industrial production.
Owner:ZHEJIANG XIANFENG TECH +1

Method for preparing 4-hydroxyphenyl hydantoin

The invention discloses a method for preparing 4-hydroxyphenyl hydantoin from a glyoxylic acid, phenol and urea by condensation under acid condition, which is characterized in that: the 4-hydroxyphenyl hydantoin is prepared in the presence of a sulfamic acid, the production of polymerization impurities is inhibited and simultaneously a phenylglycine byproduct is produced. The mol ratio of the reaction raw materials of the glyoxylic acid to the phenol to the urea to the sulfamic acid is 1:1.0-1.1:1-1.5:0.2-0.5. The method comprises the following steps of: adding dropwise glyoxylic acid solution at the relatively lower temperature of 50 to 60 DEG C to form a 2-ureidobenzeneacetic acid intermediate, preparing the 4-hydroxyphenyl hydantoin at the relatively higher temperature of 80 or 105 DEG C by ring formation and simultaneously producing the p-hydroxyphenylglycine byproduct, wherein reaction solution is subjected to post-treatment to obtain white 4-hydroxyphenyl hydantoin crystals with the purity of 99.6 percent and the yield of 62.7 percent; and mother solution is further treated to obtain white p-hydroxyphenylglycine crystals with the purity of 99.2 percent ad the yield of 10.1 percent. In the method, the main byproduct is p-hydroxyphenylglycine, the utilization rate of the synthesis raw materials is increased and the problems of unstable quality of product and high treatment cost of the mother solution in the prior art are solved.
Owner:TIANJIN VOCATIONAL INST

Method for achieving chemical nickel plating by activating surface of PCB

The invention discloses a method for achieving chemical nickel plating by activating the surface of a PCB and belongs to the field of printed circuit board manufacturing. The method comprises the following steps that 1, 0.01-10 g / L soluble silver salt is prepared to serve as a silver soaking solution; 2, activating liquor is prepared from 1-100 g / L pH stabilizer and 10-50 g / L reducing agent, wherein the pH stabilizer is one or more of sodium hydroxide, potassium hydroxide, ammonia water, sodium acetate and the like, and the reducing agent is one or more of formaldehyde, acetaldehyde, glyoxylic acid, methyl alcohol, vitamin C, citric acid and the like; 3, pretreatment of the PCB is conducted; 4, the PCB is soaked in the silver soaking solution for 10-120 seconds after pretreatment, washed and then soaked in the activating liquor for 10-80 seconds; and 5, the PCB obtained in the step 4 is placed in chemical nickel-plating liquor for chemical nickel-plating. According to the method for achieving chemical nickel plating by activating the surface of the PCB, no precious metal palladium is used during activating; the stability of the activating liquor is high; diffusion coating is avoided; and the production cost of the PCB is effectively reduced.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Method for synthesizing vanillin by using glyoxylic acid and guaiacol together

The invention discloses a method for synthesizing (ethyl) vanillin by using condensation, oxidation and decarboxylation reactions of glyoxylic acid and (ethyl) guaiacol. The method is characterized in that: a Y-shaped molecular sieve is used for loading copper, manganese and cobalt mixed oxide catalysts, and the condensation reaction and the oxidation reaction are simultaneously performed in a reactor. A molar ratio of the glyoxylic acid and the (ethyl) guaiacol serving as raw materials to sodium hydroxide is 1:(1.0-1.2):(2-4); the pH of solution is more than 12 by controlling the dropping speed of alkali solution; and the temperature in the reaction process is controlled to be between 40 and 80 DEG C when the raw materials are dropped, and the temperature in the reaction process is controlled to be between 80 and 100 DEG C after the raw materials are added. The acid concentration of 3-alkoxy-4-hydroxy phenethyl alcohol is below 4 percent all the time during the oxidation reaction. White (ethyl) vanillin crystals are obtained by performing acidification decarboxylation, extraction separation, and vacuum distillation refining on a reaction completing fluid with 50 percent of sulfuric acid, and the yield is 86.3 percent. By the method, an (ethyl) vanillin synthesis process is simplified, the equipment production capacity is improved, and polymerization by-products are restrained, and auxiliary raw material consumption and waste liquid are reduced.
Owner:TIANJIN VOCATIONAL INST
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