12 results about "Sulfolane" patented technology

The disclosed method for recovering N-methyl pyrrolidone from complex waste liquid includes the following processes: pumping the NMP-containing waste liquid into a rectification one-effect tower after vacuum dehydration in a dehydration tower, condensing and collecting NMP at the top of the tower, and pumping the tower bottom into a rectification two-effect tower; obtaining NMP at the top of the rectification two-effect tower, sending the liquid residue to a depolymerization reactor after evaporation of the gas phase in a thin film evaporator, and condensing and condensing; performing side line extraction on the rectification two-effect tower and injecting sulfolane to extract heavy components, separating after mixing, returning the light phase to the rectification two-effect tower, and sending the heavy phase to a regeneration tower; collecting NMP-water azeotrope at the top of the regeneration tower to return to the dehydration tower, collecting sulfolane at the side line to return to the extraction cycle, and sending the concentrated residue at the bottom to the depolymerization reactor; sending the depolymerization gas obtained from the depolymerization reactor to a quenching tower, sending the cooling liquid of the quenching tower to a light-removing tower, sending the overhead product of the light-removing tower to sewage treatment, and collecting NMP at the tower bottom. The recovery treatment method has reasonable and efficient process flow, and has higher NMP yield for complex NMP-containing waste liquid.

Provided is a method for preparing lactide by one-step reaction of lactic acid, which comprises mixing lactic acid raw material with a solvent and contacting with a catalyst, wherein the solvent comprises solvent I and solvent II, the solvent I is at least one selected from polar solvents such as benzophenone, dihydrolevoglucosenone, N-methylpyrrolidone, trichloropropane and sulfolane, the solvent II is C4-C12 alkane, substituted alkane, aromatic hydrocarbon or substituted aromatic hydrocarbon, the solubility of the solvent II for lactic acid at normal temperature is not more than 1 g lactic acid / 100 g solvent; and the reaction temperature and pressure are such that the solvent I does not boil in the reaction system. The mixed solvent is used as the liquid environment for preparing lactide by one-step reaction of lactic acid, the mixed solvent can be completely miscible with lactic acid in the reaction raw material, on the one hand, it can increase the contact between lactic acid and the solid catalyst, make the reaction more complete, reduce the generation of by-product poly lactic acid, and increase the selectivity of lactide; on the other hand, since the poly lactic acid can also be dissolved in the selected solvent, the adhesion of the poly lactic acid on the catalyst can be reduced, the influence of catalyst deactivation caused by carbon deposition can be reduced, and the service life of the catalyst can be improved.

The present application provides a BOG helium extraction method and system, and a MOF slurry absorbent and a preparation method thereof. The absorbent comprises 20-40wt% of a metal organic framework material and 60-80wt% of an organic solvent; the metal organic framework material comprises at least one of HKUST-1, CALF-20, ZIF-67 and ZIF-8; and the organic solvent comprises at least one of dimethyl phthalate, 1,3-dimethyl-2-imidazolinone, N-methyl pyrrolidone, sulfolane and methylcyclohexane. The BOG helium extraction method comprises: pretreating BOG raw gas to obtain He and N2 mixed gas; and under specific temperature and pressure conditions, contacting the He and N2 mixed gas with a volume ratio of 15-30:1 with the MOF slurry absorbent to obtain He. The technical scheme of the present application realizes efficient BOG absorption-adsorption separation and helium extraction under mild temperature and pressure conditions.

This invention discloses a continuous method for preparing 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid based on a cascaded process of cyclization-de-alcoholization-scraped membrane fluorination, belonging to the field of continuous synthesis technology in fine chemicals. The method includes: cyclizing ethyl 2-ethoxymethylene-4,4-dichloroacetoacetate with methylhydrazine in a loop reactor with forced external circulation, controlling the circulation ratio boundary at 15:1 to 18:1 to improve the selectivity of the target isomer; continuously removing at least some ethanol from the cyclized liquid and adding sulfolane for solvent replacement, ensuring that the ethanol content in the system before entering the fluorination stage is no higher than 1.0% (wt) and the water content is 0.1-0.2% (wt); subsequently, the resulting intermediate material, along with anhydrous potassium fluoride and 18-crown-6 to form a heterogeneous slurry, is fed into a vertical scraped membrane reactor, with a residence time strictly controlled at 169-171°C for 80-100 seconds, and rapid cooling within 3 seconds after discharge; finally, the target product is obtained through hydrolysis and acidification. This specific combined process can achieve high 1,3-isomer selectivity, high fluorination conversion, low aldehyde byproduct levels, and good long-term continuous operation stability without separating the cyclization intermediate.

The application discloses a kind of high dispersion stability ultra-low structure carbon black material and its application.The material is prepared by the reaction of 3,4-dihydroxyphenethylamine, carbonyl coupling agent, N,N-dimethyl-1,3-propanediamine and 1,3-propane sulfolane to obtain a reactive low-melting micro-phase auxiliary agent, which is then dispersed in ethylene tar after compounding with urea and choline acetate, and is prepared by incomplete combustion, quenching, elution and homologous stabilization treatment. The application utilizes the micro-phase isolation effect of the composite micro-phase auxiliary agent during the formation of carbon black, reducing the branching degree of carbon black aggregates; and through post-treatment, a stable layer containing catechol / quinoxaline anchoring structure and sulfobetaine hydration structure is formed, improving the water-based dispersion stability of carbon black. The obtained carbon black material has the advantages of low structure, low metal residue, narrow particle size distribution and good anti-settling property, and can be used in water-based paint, water-based ink, water-based conductive paste and water-based polymer composite.

The present application provides a kind of sorbitol continuous dehydration preparation isosorbide method, belong to the preparation field of bio-based chemicals. Using solvent containing dimethyl sulfoxide, sulfolane and other compounds to dissolve sorbitol, increase the mobility of sorbitol solution, and then realize the continuous dehydration of sorbitol to prepare isosorbide. The specific steps are as follows: the solid acid catalyst is loaded into the fixed bed reactor, the preheated sorbitol solution is continuously passed through the catalyst layer for dehydration reaction, and the mixture after reaction is separated to obtain isosorbide. The present application adds polar aprotic solvent to improve the flowability of the reaction solution during the dehydration reaction stage, realizes continuous reaction, and the dehydration reaction temperature is low, and the generated pyrolysis black substance is greatly reduced; aromatic hydrocarbon is used to extract high-boiling organic solvent in the product separation stage, and the separation effect is good and the energy consumption is low; the method has important application prospect.

The application discloses a hydrophobic removing agent for nonionic surfactant and a preparation method and application thereof. The hydrophobic removing agent comprises porous polymer microspheres and sol coated on the surface of the porous polymer microspheres. The active component boric acid in the pore channel of the porous polymer microspheres can be complexed with the entering nonionic surfactant, and cannot be complexed with sulfolane, so that selective adsorption of the two is realized, deep removal of the nonionic surfactant in sulfolane is realized, and the loss rate of sulfolane is low; meanwhile, new impurities can be ensured not to be introduced after the nonionic surfactant in sulfolane is removed. Further, the sol is modified and coated to be hydrophobic, and has a repelling effect on water molecules. When the hydrophobic removing agent is applied to removal of the nonionic surfactant in a sulfoxane amine desulfurization solution, the contact probability of boric acid in the removing agent and water molecules in the desulfurization solution is greatly reduced, and the high organic molecule permeability of the colloid can ensure that nonionic surfactant molecules pass through the colloid to contact the boric acid and are removed.

The present invention relates to a process for producing dipentaerythritol from pentaerythritol in the presence of sulfolane and a heterogeneous polyacid catalyst supported on a support comprising a compound selected from the group consisting of SnO2, mesoporous silica and zeolite.

This invention discloses a silicon-carbon anode binder and its preparation method, as well as a silicon-carbon anode, belonging to the field of lithium-ion battery technology. The silicon-carbon anode binder and its preparation method include: adding a polyarylene ether resin to a polar aprotic solvent and sulfonating it to obtain a sulfonated polymer; selecting route A or route B according to the type of thermal crosslinking modifier to obtain the binder; when the thermal crosslinking modifier is an amine compound containing benzocyclobutene or a phenolic derivative substituted with maleimide, route A is selected; when the thermal crosslinking modifier is an epoxysilane coupling agent, route B is selected. This invention abandons traditional processes and uses sulfolane as the reaction medium. This solvent has good solubility and stability, can inhibit the degradation of the polymer backbone, and makes the reaction mild and controllable; at the same time, two differentiated grafting paths are designed for different crosslinking groups to ensure the activity of functional groups. During baking, a three-dimensional network structure is formed, buffering the volume expansion of silicon-carbon particles and maintaining the integrity of the electrode structure.

The application discloses a method for separating monocarboxylate end group perfluoropolyether and dicarboxylate end group perfluoropolyether by liquid-liquid extraction, which comprises the following steps: mixing a mixture containing monocarboxylate end group perfluoropolyether and dicarboxylate end group perfluoropolyether with a light-heavy two-phase solvent, separating the two phases after extraction equilibrium, removing the solvent, obtaining high-purity monocarboxylate end group perfluoropolyether product from the heavy phase, and obtaining a product containing dicarboxylate end group perfluoropolyether from the light phase; the light-phase solvent is composed of a diluent and a polar solvent containing fluorine atoms; the diluent is one or more of sulfolane, dimethyl sulfoxide, N-methyl pyrrolidone, N,N-dimethylformamide, water, ethylene glycol, acetonitrile, acetic acid, ethanol or methanol; and the heavy-phase solvent is composed of a non-polar solvent containing fluorine atoms and a polar solvent containing fluorine atoms, or composed of a non-polar solvent containing fluorine atoms and a non-polar solvent not containing fluorine atoms.

The application provides a non-water absorbent, a preparation method thereof and a CO2 capture method for dry associated gas in an oil and gas field. The raw material composition of the non-water absorbent comprises 1-40 wt% of an imidazole substance, 0.5-15% of metal organic framework compound nanoparticles and 50-98.5% of an organic solvent; the imidazole substance comprises at least one of imidazole, 1-methyl imidazole and 2-methyl imidazole; the metal organic framework compound nanoparticles comprise at least one of ZIF-8, ZIF-67 and CALF-20; and the organic solvent comprises at least one of ethylene glycol, 1,3-dimethyl-2-imidazolidinone, propylene carbonate, N,N-dimethylacetamide, polyethylene glycol dimethyl ether, isohexadecane, N-methyl pyrrolidone, 1,3-dimethylpropylene urea, dimethyl sulfoxide and sulfolane. The non-water absorbent provided by the application can realize effective separation of CO2 and C 2+ gas hydrocarbons.