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427results about "Hydrazine preparation" patented technology

Method for preparing hydrazinobenzene in continuous micro-channel reactor

InactiveCN106316879AHigh mixing mass transfer effectImprove thermal conductivityHydrazine preparationToxic gasContinuous flow
The invention relates to a method for preparing highly pure hydrazinobenzene by using continuous flow micro-channel reactor. The method concretely comprises the following steps: preparing aniline hydrochloride from hydrochloric acid and aniline, respectively pumping the aniline hydrochloride and a sodium nitrite solution into the micro-channel reactor by two metering pumps to obtain a diazo salt solution, reducing the obtained reaction solution, carrying out acid separation on the reduced solution, filtering the obtained solution, neutralizing the filtered solution, and distilling the neutralized solution to obtain the highly pure hydrazinobenzene. The diazotization process is a strong exothermic reaction, and the generated diazo salt easily decomposes after standing at a high temperature for a long time, and generates toxic gases which pollute environment and even blast. The mixing effect of the heart-shaped micro-channel reactor is far better than the mass transfer effect generated by stirring, so the aniline conversion rate can reach 99%, the mixing mass transfer effect is good, and heat conduction is fast to avoid local overheating phenomenon; and the reaction can be carried out at constant temperature conditions, so the temperature runaway blast danger of general reactors is eliminated, and the safety is improved.
Owner:CHINA PETROLEUM & CHEM CORP +1

Preparation method of 4-chlorophenylhydrazine hydrochloride

The invention provides a preparation method of 4-chlorophenylhydrazine hydrochloride. The preparation method of the 4-chlorophenylhydrazine hydrochloride includes a diazotization reaction, a reduction reaction and an acidizing reaction. The diazotization reaction includes throwing 4-chlorophenylhydrazine to water; dropping hydrochloric acid to enable the 4-chlorophenylhydrazine hydrochloride to dissolve completely; and dropwise adding a sodium nitrite aqueous solution to obtain a chlorination diazonium parachloroaniline aqueous solution. The reduction reaction includes dropwise adding the chlorination diazonium parachloroaniline aqueous solution to an ammonium sulfite aqueous solution and obtaining diazonium parachloroaniline disulfonate. The acidizing reaction includes dropping the hydrochloric acid to the diazonium parachloroaniline disulfonate; filtering; washing; discharging; stoving; and obtaining a 4-chlorophenylhydrazine hydrochloride end product. The preparation method of the 4-chlorophenylhydrazine hydrochloride is easy to operate by using the sodium nitrite aqueous solution as a reducing agent; and the product seeds out late and side reactions are reduced due to the fact that ammonium chloride and ammonium bisulfate generated in the acidizing reaction have high solubility in the water; and furthermore product quality and product yields are improved effectively due to the fact that the product is incompact in crystallization, good in flow-ability and easy to discharge and wash.
Owner:天津市天川化工有限公司

Novel synthesis process of P-chlorophenylhydrazine hydrochloride

The invention discloses a preparation method of P-chlorophenylhydrazine hydrochloride. The method comprises the following steps: diazotizing chloroaniline taken as a raw material so as to prepare a corresponding diazonium salt; mixing anhydrous sodium sulfite with sodium hydrogen sulfite in a stirring manner, maintaining a pH (Power Of Hydrogen) value within 6 to 7, controlling a temperature below 40 DEG C, slowly adding the diazonium salt below a liquid surface and reacting at the temperature of 60 DEG C to 90 DEG C according to the molar ratio of the p-chloroaniline to the sodium hydrogen sulfite being 1:(1-1):3; maintaining the unchanged pH value in the step 2, slowly adding hydrochloric acid so as to maintain the pH value within 1 to 3, reacting for 1 to 3 hours at the reaction temperature of 40 DEG C to 90 DEG C, cooling to a room temperature, filtering and drying so as to obtain a reddish P-chlorophenylhydrazine hydrochloride solid. The pH value of the reaction system is maintained within 6 to 7 by taking a mixture of the sodium sulfite and the sodium hydrogen sulfite as a reducing agent, so that the phenomenon that the pH value is always regulated by NAOH (sodium hydroxide) or HCL (hydrogen chloride) in a reaction process is avoided; and the repeated heating during the reaction process is not required, so that the temperature is convenient to control; and the adding amount of water is reduced, so that the discharge of wastewater is greatly reduced, namely, the wastewater treatment at a later period is avoided. As a result, the cost is lowered.
Owner:NANJING UNIV OF SCI & TECH

Treatment method for tail gas produced by reaction of sulfonyl chlorination

A treatment method for tail gas produced by reaction of sulfonyl chlorination comprises the following steps: (1), the tail gas produced by the reaction of sulfonyl chlorination is injected into a tertiary series hydrogen chloride falling-film absorption tower, and absorption liquid in a primary hydrogen chloride falling-film absorption tower becomes hydrochloric acid to enter a hydrochloric acid storage tank; (2), tail gas after the hydrogen chloride gas is absorbed by the tertiary hydrogen chloride falling-film absorption tower and then passes through a secondary series aqua ammonia absorption tower, sulfur dioxide gas in the tail gas is absorbed by aqua ammonia in a primary aqua ammonia absorption tower, and the residual tail gas enters a secondary aqua ammonia absorption tower; (3), ammonium sulfite water solution is prepared; (4), parachloroaniline and recovered hydrochloric acid in the primary hydrogen chloride falling-film absorption tower are taken as raw material, and sodium nitrite water solution is added into the raw materials to produce parachlorobenzene diazonium chloride; (5), parachlorobenzene diazonium chloride is dripped into the ammonium sulfite water solution to produce diazonium parachlorobenzene disulfonate; and (6), recovered hydrochloric acid is dripped into the diazonium parachlorobenzene disulfonate to prepare parachlorobenzene hydrazine dihydrochloride. The treatment method effectively separates the tail gas, utilizes hydrochloric acid and ammonium sulfite, which are recovered by the tail gas, to prepare the parachlorobenzene hydrazine dihydrochloride, thereby being environment-friendly and economical.
Owner:天津市天川化工有限公司

Method for gas stripping and separating hydrazine from hydrazine-containing solution using acetone and use thereof

ActiveCN101311107ASolving the Condensation Wastewater ProblemHydrazine preparationHydrazineGas phaseHydrazine compound
The invention relates to a method for obtaining pure hydrazine hydrate by isolating and purifying from solution containing hydrazine. The preparation method is that gas-phase acetone and the hydrazine which is contained in oxidation liquid are directly reacted and stripped under the boiling condition; or liquid-phase acetone and the solution are reacted first and then gas stripping is carried out, after the solution is hydrolyzed, the pure hydrazine hydrate is obtained; and the obtained product is sent into a general hydrolyzing tower, in which hydrolysis is carried out to produce the pure hydrazine hydrate solution, and acetone produced by the hydrolysis is sent back to a system for recycling, wherein, the mole ratio of the acetone and the hydrazine is 2 to 3.6 and the reaction temperature is 100 DEG C to 130 DEG C. By adopting the invention, the hydrazine produced by urea-chlorine method can be stripped by acetone azine (CH3)2C=N-N=C-(CH3)2, which causes the recycling of the inorganic materials such as sodium carbonate, sodium chloride, and the like, in the solution to be possible, thereby thoroughly solving the problem of waste water condensation of the ADC processing technique in the urea-chlorine method.
Owner:EAST CHINA UNIV OF SCI & TECH +2

Tailored control of surface properties by chemical modification

A process for producing a substrate having an adhesive surface, which process comprises: (a) contacting the substrate with a carbene precursor, which carbene precursor is a compound of the following formula (1): whose substituent groups are SP defined herein, provided that when R is aryl or heteroaryl, said aryl or heteroaryl may be substituted by one, two, three, four or five groups, which groups are independently selected from various groups including -LB-WB; and (b) either: (i) when WA or WB comprises an adhesive functional group, generating a carbene reactive intermediate from the carbene precursor so that it reacts with the substrate to functionalise the surface, thereby yielding said substrate having an adhesive surface; or (ii) when WA or WB comprises a group which is a precursor of an adhesive functional group, generating a carbene reactive intermediate from the carbene precursor so that it reacts with the substrate to functionalise the surface, and (c) converting said group which is a precursor into an adhesive functional group thereby yielding said substrate having an adhesive surface. The invention further relates to carbene precursor compounds for use in the process, substrates produced by the process and to processes for preparing certain precursor compounds.
Owner:OXFORD UNIV INNOVATION LTD

Carbene precursor compound for producing an adhesive surface on a substrate

A process for producing a substrate having an adhesive surface, which process comprises: (a) contacting the substrate with a carbene precursor, which carbene precursor is a compound of the following formula (1): whose substituent groups are defined herein, provided that when R is aryl or heteroaryl, said aryl or heteroaryl may be substituted by one, two, three, four or five groups, which groups are independently selected from various groups including -LB-WB; and (b) either: (i) when WA or WB comprises an adhesive functional group, generating a carbene reactive intermediate from the carbene precursor so that it reacts with the substrate to functionalise the surface, thereby yielding said substrate having an adhesive surface; or (ii) when WA or WB comprises a group which is a precursor of an adhesive functional group, generating a carbene reactive intermediate from the carbene precursor so that it reacts with the substrate to functionalise the surface, and (c) converting said group which is a precursor into an adhesive functional group thereby yielding said substrate having an adhesive surface. The invention further relates to carbene precursor compounds for use in the process, substrates produced by the process and to processes for preparing certain precursor compounds.
Owner:OXFORD UNIV INNOVATION LTD

Pt-load catalyst taking mesoporous carbon as carrier, as well as preparation method and usage thereof

The invention relates to a Pt-load catalyst taking mesoporous carbon as a carrier, which is characterized in that the mesoporous carbon is pretreated before Pt is loaded; the pretreatment method comprises one in the following steps of: (1) adding the mesoporous carbon into a 10-30% hydrogen dioxide solution, soaking for 1-24hours, washing and removing hydrogen peroxide; (2) adding the mesoporous carbon into a 1-6M hydrochloric acid or nitric acid solution, soaking for 1-24hours, washing and removing hydrochloric acid or nitric acid; and (3) adding the mesoporous carbon into a 1-6M sodium hydroxide solution, soaking for 1-24hours, washing and removing alkali, wherein the load quantity of Pt is 0.5-5%. The invention also relates to the application of the Pt-load catalyst in preparation of 2, 2'-dichloro hydroazobenzene (DHB) from ortho-nitrochlorobenzene through hydrogenation. The catalyst uses the mesoporous carbon as the carrier, so that the internal diffusion resistance can be better reduced, and the reaction speed is accelerated. The Pt-load catalyst is high in reaction activity and selectivity, and can be repeatedly used for more than eight times, so that the using cost of the catalyst is lowered.
Owner:CHANGZHOU UNIV +1

Preparation method for 4-chlorophenylhydrazine hydrochloride

InactiveCN103910650AEliminates the problem of easy agglomeration and difficult operation of feedingEasy dischargeHydrazine preparationSolubilityHydrogen Sulfate
A provided preparation method for 4-chlorophenylhydrazine hydrochloride comprises the following steps: 1) under an acidic condition, at 5-10 DEG C, dropwise adding a sodium nitrite aqueous solution with a concentration of 20% into 4-chloroaniline to perform a diazo reaction and to generate a diazo salt; 2) under a room temperature condition, dropwise adding an ammonium sulfite aqueous solution into a solution of the diazo salt obtained in the step 1, heating to 50-60 DEG C and keeping the temperature for 3-4 h; and 3) at 50-70 DEG C, dropwise adding a hydrochloric acid solution with a concentration of 20% into the solution obtained in the step 2, keeping the temperature for 1-2 h, reducing the temperature, filtering, washing, discharging the material, and drying to obtain a finished product. The beneficial effects comprise that by using ammonium sulfite aqueous solution as a reducing agent in the reduction reaction, the problems are solved that sodium sulfite solid is easy to cake during material charging in a conventional technology and material charging is not easy to operate; ammonium chloride and ammonium hydrogen sulfate which are generated in the acidification reaction have high solubility in water, and crystallization precipitation is late, thereby facilitating performing of the acidification reaction in the solution and reducing side reactions; and the product crystallizes loosely, is good in fluidity, easy for material discharging and washing, and product quality and yield are both better than conventional production levels.
Owner:TIANJIN QIDONG CHEM PLANT

Synthesis method for aromatic hydrazine sulfate

The invention discloses a synthesis method for aromatic hydrazine sulfate. The synthesis method includes the steps that firstly, aromatic amine is added in sulfuric acid with the mass fraction ranging from 15% to 65%, the temperature is lowered to -5-15 DEG C, a diazotization reagent is dropwise added in the reaction liquid, and diazonium salt is obtained after reaction; secondly, a reducing agent is prepared into a solution, a reducing solution is obtained, the diazonium salt obtained in the first step is dropwise added in the reducing solution, heating reduction is conducted after drop-by-drop addition is completed, and reducing material liquid is obtained through filtration; and thirdly, the reducing material liquid obtained in the second step is heated, dilute sulphuric acid is dropwise added in the reducing material liquid to conduct the acidolysis reaction, the temperature is lowered after the reaction is finished, the aromatic hydrazine sulfate is separated out, a filter cake and filtrate are obtained through filtration, the filter cake is washed with dilute sulphuric acid, and an aromatic hydrazine sulfate product is obtained, and sodium sulfate salt is recycled after the filtrate is preprocessed. Compared with a traditional process, the obtained aromatic hydrazine sulfate is high in yield and purity, the purity reaches 97% or above, the yield is higher than 91%, salt in the wastewater obtained through the reaction is the simplex sodium sulfate salt, and the recycling value is high.
Owner:ZHEJIANG QICAI ECO TECH CO LTD
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