Abstract: Method for treating production wastewater from the preparation of propylene oxide by co-oxidation. The wastewater includes a first portion of wastewater having a peroxide content of 2000 mg/L or more and a second portion of wastewater having a peroxide content of 50 mg/L or less.

Abstract: Method for treating production wastewater from the preparation of propylene oxide by co-oxidation. The wastewater includes a first portion of wastewater having a peroxide content of 2000 mg/L or more and a second portion of wastewater having a peroxide content of 50 mg/L or less.

Abstract: Provided in the invention are a catalyst for preparing phosgene and a preparation method therefor, and a method for the preparation of phosgene and the comprehensive utilization of energy thereof. The preparation method comprises the following steps: 1) stirring and soaking activated carbon in a modifying solution, then adding dimethyltin dichloride and chromium oxide powders and carrying out a reaction, and then adding a nickel oxide fine powder and ultrasonically oscillating same to prepare a pre-modified activated carbon; 2) drying the pre-modified activated carbon; and 3) heating and calcinating the dried pre-modified activated carbon from step 2) to prepare the catalyst.

Abstract: A catalyst for catalytic oxidation treatment of organic wastewater, comprising aluminum oxide, and nickel, ferrum, manganese, and cerium supported on the aluminum oxide in oxide form. Based on the weight of aluminum oxide, the contents of the following components in the catalyst are: nickel: 5.0-20 wt %; ferrum: 0.5-5.5 wt %; manganese: 0.5-3.5 wt %; and cerium: 1.5-3.0 wt %. The present invention has a good effect in catalytic oxidation for degrading COD organic pollutants in wastewater and has high reactivity.

Abstract: Disclosed is a light colored modified isocyanate mixture and a preparation method thereof. The method comprises the following steps: a) reacting isocyanate groups of a raw material isocyanate under the action of a phospholenecatalyst, and finally obtaining a modified isocyanate reaction solution containing carbodiimide and/or uretonimine derivatives; and b) adding a compounded terminator of a halosilane organic and a sulfonic anhydride to the reaction solution obtained in step a so as to terminate the reaction of carbodiimidization. The modified isocyanate prepared by the method has the characteristics of a liquid state at room temperature, being stable in storage at room temperature and high temperature, and low color number.

Abstract: A catalyst for preparing chlorine gas by hydrogen chloride oxidation, comprising the following components calculated according to mass content based on the total weight of the catalyst: 0.5-20 wt % copper; 2-10 wt % manganese; 0.05-2 wt % boron; 0.01-3 wt % chromium; 0.1-10 wt % rare earth metal; 0.1-10 wt % potassium; and 3-15 wt % titanium; also comprising 0.02-1.1 wt % phosphorus; and 0.03-1.9 wt % iron; the carrier content is 55-90 wt %. In the case of a fluidized bed reactor, the present catalyst can achieve a one-way hydrogen chloride conversion rate of 80-85%. Almost all of the 0-1000 mg/kg of chlorinated benzene contained in hydrogen chloride gas can be converted into CO2 and H2O without generating polychlorinated benzene.

Abstract: Disclosed is a light colored modified isocyanate mixture and a preparation method thereof. The method comprises the following steps: a) reacting isocyanate groups of a raw material isocyanate under the action of a phospholenecatalyst, and finally obtaining a modified isocyanate reaction solution containing carbodiimide and/or uretonimine derivatives; and b) adding a compounded terminator of a halosilane organic and a sulfonic anhydride to the reaction solution obtained in step a so as to terminate the reaction of carbodiimidization. The modified isocyanate prepared by the method has the characteristics of a liquid state at room temperature, being stable in storage at room temperature and high temperature, and low color number.

Abstract: A method for treating reverse osmosis concentrated water, comprises adding precipitant and oxidant to reverse osmosis concentrated water for treatment, filtering to obtain clear liquid, and adding catalyst for water treatment to clear liquid for catalytic oxidation to obtain a first-stage treated water. Optionally, the liquid may be subjected after catalytic oxidation to an adsorption treatment; performing reverse osmosis treatment on first-stage treated water to obtain second-stage reverse osmosis product water and second-stage reverse osmosis concentrated water; and adding oxidant to second-stage reverse osmosis concentrated water for oxidation treatment to obtain directly discharged effluent water. The obtaining of effluent water may further comprise subjecting liquid after oxidation treatment to adsorption treatment. The above method can recycle 75-85 wt % of water, and operates easily.

Abstract: A catalyst for preparing chlorine gas by hydrogen chloride oxidation, comprising the following components calculated according to mass content based on the total weight of the catalyst: 0.5-20 wt % copper; 2-10 wt % manganese; 0.05-2 wt % boron; 0.01-3 wt % chromium; 0.1-10 wt % rare earth metal; 0.1-10 wt % potassium; and 3-15 wt % titanium; also comprising 0.02-1.1 wt % phosphorus; and 0.03-1.9 wt % iron; the carrier content is 55-90 wt %. In the case of a fluidized bed reactor, the present catalyst can achieve a one-way hydrogen chloride conversion rate of 80-85%. Almost all of the 0-1000 mg/kg of chlorinated benzene contained in hydrogen chloride gas can be converted into CO2 and H2O without generating polychlorinated benzene.

Abstract: A method for treating reverse osmosis concentrated water, comprises adding a precipitant and oxidant to reverse osmosis concentrated water for treatment, filtering to obtain clear liquid, and adding catalyst for water treatment to clear liquid for catalytic oxidation to obtain a first-stage treated water. Optionally, the liquid may be subjected after catalytic oxidation to an adsorption treatment; performing reverse osmosis treatment on first-stage treated water to obtain second-stage reverse osmosis product water and second-stage reverse osmosis concentrated water; and adding oxidant to second-stage reverse osmosis concentrated water for oxidation treatment to obtain directly discharged effluent water. The obtaining of effluent water may further comprise subjecting liquid after oxidation treatment to adsorption treatment. The above method can recycle 75-85 wt % of water, and operates easily.

Abstract: A catalyst for catalytic oxidation treatment of organic wastewater, comprising aluminum oxide, and nickel, ferrum, manganese, and cerium supported on the aluminum oxide in oxide form. Based on the weight of aluminum oxide, the contents of the following components in the catalyst are: nickel: 5.0-20 wt %; ferrum: 0.5-5.5 wt %; manganese: 0.5-3.5 wt %; and cerium: 1.5-3.0 wt %. The present invention has a good effect in catalytic oxidation for degrading COD organic pollutants in wastewater and has high reactivity.

Abstract: The present invention relates to a method for preparing catalyst used for preparing chlorine by oxidizing hydrogen chloride. The method is mixing a slurry mainly containing boron and chromium with a slurry mainly containing copper, boron, alkali-metal elements, rare-earth elements, aluminum sol, silica sol, carrier and optionally other metal elements, the mixing temperature being not more than 100° C., and the residence time being not more than 120 minutes, the mixed slurry is successively treated with spray drying, high temperature calcination, so that the catalyst is obtained. The present invention also relates to the catalyst prepared through the method, use of the catalyst used in the process of preparing chlorine by oxidizing hydrogen chloride and a method for preparing chlorine by using the catalyst. The catalyst is used for preparing chlorine by oxidizing hydrogen chloride with oxygen or air in fluidized bed reactor.

Abstract: The present invention discloses a method of quickly desorbing phosgene from a catalyst in a phosgene synthesizing tower when the catalyst in the phosgene synthesizing tower is replaced. The method is carried out by first purging out easily-desorbed phosgene from the catalyst activated carbon in the phosgene synthesizing tower with nitrogen gas, then purging with ammonia gas, and the ammonia gas is reacted with the hardly-desorbed phosgene in the catalyst of the phosgene synthesizing tower. Then the phosgene synthesizing tower is rinsed with a water gun and then dried with hot gas. The phosgene content at an outlet of the phosgene synthesizing tower after purging is below 0.5 ppm, which can significantly save the time of the phosgene synthesizing tower for purging the phosgene, greatly reduce the amount of nitrogen gas consumed, and improve the safety of the process operation.

Abstract: A solvent refining method for isocyanate prepared by the phosgene method and multistage absorbing towers used in same. Solvent to be refined which contains water, iron, and/or phosgene, hydrogen chloride and other materials with color is dealt by the present method and multistage absorbing towers, which can effectively prevent a drying agent from absorbing water and hardening, partial overheating in the tower and generating channeling. Meanwhile, the pressure drop is effectively lowered. In addition, the content of water is ?50 ppm, the content of iron is ?5 ppm, the content of phosgene and hydrogen chloride is ?20 ppm, Pt—Co chroma is ?20 in the refined solvent. Therefore, the refined solvent can be used as the solvent for preparing isocyanate in the phosgene method and remarkably improve an L color of isocyanate.

Abstract: The present invention discloses a method of quickly desorbing phosgene from a catalyst in a phosgene synthesizing tower when the catalyst in the phosgene synthesizing tower is replaced. The method is carried out by first purging out easily-desorbed phosgene from the catalyst activated carbon in the phosgene synthesizing tower with nitrogen gas, then purging with ammonia gas, and the ammonia gas is reacted with the hardly-desorbed phosgene in the catalyst of the phosgene synthesizing tower. Then the phosgene synthesizing tower is rinsed with a water gun and then dried with hot gas. The phosgene content at an outlet of the phosgene synthesizing tower after purging is below 0.5 ppm, which can significantly save the time of the phosgene synthesizing tower for purging the phosgene, greatly reduce the amount of nitrogen gas consumed, and improve the safety of the process operation.

Abstract: The invention relates to a method of circular use of waste brine produced in the manufacture process of MDI, comprising the following steps: (1) the waste brine produced in the manufacture process of MDI is subjected to a high-gravity extraction and then to a column extraction, wherein said waste brine contains aniline, diaminodiphenylmethane and polyamine; (2) the waste brine from step (1) is transmitted to a stripping tower for steam stripping; (3) the waste brine from the stripping tower of step (2) and a chemical oxidant are transmitted to an oxidation reactor to which air is blown for aeration; (4) the waste brine after the treatment of step (3) is transmitted to an absorption tower for absorption. The invention makes the salt water have TOC of less than 8 ppm and TN of less than 2.5 ppm and achieves regeneration of resources in the waste brine such as sodium chloride and water and the like for circular use.

Abstract: The present invention relates to a method for preparing branched polycarbonate with a continuous two-phase interface phosgene method. Firstly, an aqueous solution of alkali metal hydroxide with triphenol and polyphenol dissolved therein reacts with a certain amount of phosgene in the present of inert organic solvent to prepare a prepolymer, and then a coupling reaction is performed among the prepolymer, an aqueous solution of alkali metal hydroxide with bisphenol and phosgene dissolved therein to finally obtain a polycarbonate resin. The method can avoid a cross-linking reaction, reduce the cost and improve the quality of the product, while improving the conversion ratio of the branching agent and the branching degree of the product.

Abstract: A solvent refining method for isocyanate prepared by the phosgene method and multistage absorbing towers used in same. Solvent to be refined which contains water, iron, and/or phosgene, hydrogen chloride and other materials with color is dealt by the present method and multistage absorbing towers, which can effectively prevent a drying agent from absorbing water and hardening, partial overheating in the tower and generating channeling. Meanwhile, the pressure drop is effectively lowered. In addition, the content of water is ?50 ppm, the content of iron is ?5 ppm, the content of phosgene and hydrogen chloride is ?20 ppm, Pt—Co chroma is ?20 in the refined solvent. Therefore, the refined solvent can be used as the solvent for preparing isocyanate in the phosgene method and remarkably improve an L color of isocyanate.

Abstract: The present invention relates to a method for preparing catalyst used for preparing chlorine by oxidizing hydrogen chloride. The method is mixing a slurry mainly containing boron and chromium with a slurry mainly containing copper, boron, alkali-metal elements, rare-earth elements, aluminum sol, silica sol, carrier and optionally other metal elements, the mixing temperature being not more than 100° C., and the residence time being not more than 120 minutes, the mixed slurry is successively treated with spray drying, high temperature calcination, so that the catalyst is obtained. The present invention also relates to the catalyst prepared through the method, use of the catalyst used in the process of preparing chlorine by oxidizing hydrogen chloride and a method for preparing chlorine by using the catalyst. The catalyst is used for preparing chlorine by oxidizing hydrogen chloride with oxygen or air in fluidized bed reactor.

Abstract: The present invention relates to a catalyst for preparing phosgene and a method for preparing phosgene using the catalyst. Said method comprises: modifying the surface of an activated carbon coating/foamed silicon carbide structural catalyst using an alkali metal salt; filling the catalysts having different thickness of the activated carbon coating and different amount of the alkali metal salt in different sections in the axial direction of the multi-tubular reactor of the fixed bed, and preparing phosgene using Cl2 and CO. The radial and axial temperature difference of the catalyst bed is lowered by using the alkali metal salt-modified activated carbon coating/foamed silicon carbide structural catalyst and by segmental filling, so that high temperature of tube wall is obtained in the case of a larger tube diameter, and high quality of steam is obtained stably.