819 results about "Azeotropic distillation" patented technology

The invention relates to a figured sea-island super-fine fiber, and a preparation method and a synthetic leather preparing process method using the same, which belong to the technical field of leather and leather manufacture methods. The figured sea-island super-fine fiber is characterized in that the weight percentage ratio of island components of the fiber to sea components of the fiber is 50 percent to 80 percent/50 percent to 20 percent, wherein the island components are polyamide (PA) 6 or polyethylene terephthalate (PET), and the sea components are polyolefins or phospholamban (PLB) or polyvinyl alcohol (PVOH). The preparation method comprises the steps of slice drying and melting, composite spinning, oiling and falling into a barrel, drafting curling and drying cutting. The synthetic leather preparing method comprises the following steps that: 1. the components are sequentially prepared into a single-layer fiber net, a composite layer fiber net, needle-punched non-woven cloth and needle-punched non-weaving cloth; 2.soakage and coagulation are sequentially carried out on the non-weaving cloth, the non-weaving cloth is washed, so that a synthetic leather impregnated substrate is formed, repeated soaking squeezing, azeotropic distillation and drying are sequentially carried out, so the synthetic leather is obtained. The synthetic leather produced by the invention has the advantages of excellent mechanical performance, excellent dyeing performance, excellent dyefastness, better production controllability, economy and environment protection. Compared with natural leather and products of the natural leather, the synthetic leather has the advantages that use performance such as durability, weatherability, antibacterium mothproofing, dyefastness and the like of products is much superior to that of the natural leather and the products of the natural leather.

A process for preparing the biological diesel oil from the animal fat or vegetative oil with high acid number includes esterifying by glycerine under existance of strong acid catalyst, distilling in azeotropic solvent for removing water, mixing with methanol, transesterifying reacting to remove glycerine, water washing, and low-temp treating for removing high-smelting-point substances to obtain methyl ester of fatty acid, which is just the biological diesel oil.

It is an object of the present invention to provide a process for producing aliphatic carboxylic acid, which can stabilize operation of a distillation column upon production of aliphatic carboxylic acid by reducing a water content in an aqueous aliphatic carboxylic acid solution by a distillation column, and can shorten a time during the non-steady state such as at starting up of distillation column operation. The present invention is directed to a process for producing aliphatic carboxylic acid, which comprises an azeotropic distillation step of supplying an aqueous aliphatic carboxylic acid solution and an azeotropic solvent to an azeotropic distillation column to perform distillation, separating an azeotrope containing the azeotropic solvent and water as a distillate, and recovering aliphatic carboxylic acid with a reduced water content as bottom liquid, characterized in that a target value of an amount of the azeotropic solvent to be supplied is set depending on an amount of water in the aqueous aliphatic carboxylic acid solution supplied to the azeotropic distillation column, and the amount of the azeotropic solvent to be supplied is controlled at the target value.

The invention relates to an energy-saving and emission-reducing technique for producing propane epoxide by using hydrogen peroxide epoxidation propylene, belonging to the field of petrochemical technology. The technique comprises a reaction part, a separation part and a tail gas treatment part, and is characterized in that propylene and hydrogen peroxide have an epoxidation reaction through a Ti-Si molecular sieve at medium pressure and low temperature; the propylene and solvent have higher recovery rate, the propane epoxide meeting the requirement of commercial-grade purity can be obtained by extractive distillation, and the joint product of propylene glycol monomethyl ether can be prepared by azeotropic distillation and purification; after part of tail gas is condensed and absorbed and the propylene is recovered, the tail gas reaches the standard and is discharged; extracting agent, absorbing agent and entrainer which are needed by the technique are in closed cycle in the process flow; and medium-pressure operation is adopted by a propylene tower to ensure water-cooling on the top of the tower, and thermal energy can be recovered by multiple-effect rectification and matching of streams. The technique has the effect and the advantage that the new energy-saving and environment-friendly technique for producing the propane epoxide can generate remarkable economic and social benefits.

A process for the production of very high quality base oils optionally with simultaneous production of high quality middle distillates comprises the stages for hydrotreatment, preferably hydrocracking, on Y or beta zeolite, and atmospheric distillation. The effluent is subjected to a catalytic dewaxing on the ZSM-48 catalyst. The process then comprises a hydrofinishing stage for hydrogenating the aromatic compounds, preferably on a catalyst that comprises at least one noble metal of group VIII, chlorine and fluorine, and the stages of atmospheric and vacuum distillation. The hydrofinishing stage is conducted at a temperature lower by 20-200° C. than the catalytic dewaxing stage.

Feed oil is subject to atmospheric distillation, to thereby be separated into light oil or light distillate and atmospheric residue oil. The light distillate is catalytically contacted with pressurized hydrogen in the presence of a catalyst, resulting in a first hydrotreating step being executed. In this instance, various fractions of the light distillate produced in the atmospheric distillation are subject to hydrotreating in a lump. The atmospheric residue oil is then separated into a light matter and a heavy matter. The light matter is subject to second hydrotreating in the presence of a catalyst to produce refined oil (light matter), which is mixed with refined oil produced in the first hydrotreating to prepare a mixture. The mixture is used as gas turbine fuel oil.

The invention relates to method and equipment system for separating and recovering organic oxygen-containing compounds in a Fischer-Tropsch synthesis water phase. The equipment system is integrated by adopting twelve towers including a mixed acid cutting tower, an acetaldehyde rectifying tower, a methanol/ethanol dividing tower, a methanol extraction rectifying tower, a methanol rectifying tower, an acetaldehyde removing tower, an ethanol tower, a propanol concentration extracting tower, a propanol intermittent azeotropic distillation tower, a carboxylic acid extraction tower, a carboxylic acid intermittent rectifying tower and an extraction agent recovering tower matched with the carboxylic acid extraction tower for use. By applying the method and equipment system disclosed by the invention, more than ten kinds of organic oxygen-containing compounds such as acetaldehyde, acetone, methanol, ethanol, normal propyl alcohol, normal butanol, acetic acid, metacetonic acid, butyric acid, butanone and the like can be separated from raw materials; and the products can respectively reach the industrial purity. The method and equipment provided by the invention are economic, effective and reasonable; and according to the method and equipment, efficiency of Fischer-Tropsch synthesis industrial enterprises can be greatly increased, production cost is reduced and goal of clean production can be achieved.

The invention discloses a preparation method of a cellulose adsorbent for adsorbing heavy metal cations. The preparation method comprises the following steps: 1) crushing cellulose till the grain diameter is smaller than 80 meshes, putting the cellulose into 15-30% of sodium hydroxide solution, and soaking for 2 hours at 60 DEG C; 2) adding dimethyl sulfoxide, and removing excessive water through azeotropic distillation to obtain a cellulose sol; 3) in the presence of a nitrogen medium, reacting the sol with a diimidazole catalyst and dihydric or polyhydric amine sequentially; and 4) reflowing a reaction product with methylbenzene for 12 hours, filtering, and performing vacuum drying for 12 hours at 50 DEG C to obtain the cellulose adsorbent. The preparation method has the characteristics of mild catalytic reaction conditions, low cost and the like; and the prepared adsorbent is good in effect of adsorbing the heavy metal cations, wide in application range and recyclable.

The invention relates to a novel azeotropic distillation process method and a device thereof, in particular to a process method which use a septal azeotropic distillation column to produce acrylic acid, and a device thereof. The septal azeotropic distillation column is achieved by arranging a septal wall in the azeotropic distillation column in the vertical direction from the upper part to the bottom of the column, and the right side of the septal wall is sealed, and the azeotropic distillation column is divided into four areas. The acrylic acid solution containing the impurity of acetic acid enters into the column from the bottom of the rectification part (I); wherein, light components (water and acetic acid) and entrainer form azeotrope to be steamed out of the top of the column, and then the steam on the top of the column is condensed and treated by the phase separation; wherein, the organic phase (entrainer) reflows; the water phase (containing water and acetic acid) is exhaused out of the system; the material flow on the side rectification part (III) reflows to the feeding pipeline to be recycled; the acrylic acid product with the mass fraction of more than 99 percent can be obtained at the bottom of the public stripping part. With the invention, the dehydration of acrylic acid, the remove of acetic acid and the recycle of entrainer can be finished in the same column, thus the cost of the equipment and energy consumption are reduced.

The invention relates to a preparation method for hollow nano metal, which comprises the following steps: a), reducing agent is dissolved into deionized water firstly, then is mixed with organic solvent and surface active agent, and stirring is performed for preparing microemulsion; b), water inside a system is evaporated through azeotropic distillation till the solution is clear and colorless, and at the moment, and the reducing agent is coated with the surface active agent and exist in the system in a state of monodispersed nano particles; c), metallic compound is added into the system after getting complexing through complexant, and metal is obtained through the reduction of the metallic compound on the surface of the reducing agent; and d), centrifugal separation is performed on the system after reduction reaction, precipitation is taken, and the hollow nano metal can be obtained through centrifugation after water washing. A micro-emulsion method is utilized for preparing the hollow nano metal in an assisting manner, and since the reducing agent is used as a hard template, the size and the appearance of the hollow nano metal can be effectively controlled. The prepared hollow nano metal has excellent monodispersity and is uniform in size.

The invention provides a method for separating acetic acid and sec-butyl acetate from reaction products for preparing the sec-butyl acetate. The reaction products contain the sec-butyl acetate, the acetic acid and C8 alkene. The method comprises the following steps: under operating condition of azeotropic distillation, allowing water and the reaction products to enter a first azeotrope tower for azeotropic distillation, obtaining an azeotrope from the tower top, and obtaining the acetic acid from the tower bottom; performing oil-water separation on the obtained azeotrope after condensation to obtain an aqueous phase product and an oil-phase product containing the C8 alkene and the sec-butyl acetate; and under the operating condition of azeotropic distillation, allowing the water and the obtained oil-phase product to enter a second azeotrope tower for azeotropic distillation, obtaining the azeotrope from the tower top, and obtaining the acetic acid from the tower bottom. The method can help obtain the high-purity sec-butyl acetate product by separating the reaction products, and recover the high-purity acetic acid; and the method has simple operation process, low energy consumption and lower investment in the whole device.

The invention relates to a method for recovering dilute acetic acid by virtue of extraction-azeotropic distillation of sec-butyl acetate. In the method, the sec-butyl acetate is an extractant of an extraction tower and an entrainer of an azeotropic distillation tower. The method is characterized in that a part of dilute acetic acid is fed into the top of a filler extraction tower, a small portion of tower top reflux liquid of the azeotropic distillation tower is used as the extratant to be fed to the bottom of the extraction tower, and is subjected to room temperature counter current contact extraction together with the dilute acetic acid; an extraction phase containing the sec-butyl acetate, acetic acid and little water is obtained on the top of the extraction tower; raffinate water containing trace acetic acid is obtained at a tower kettle, and enters into a solvent recovering tower; and the extraction phase in the extraction tower is fed to the upper half part of the azeotropic distillation tower for further concentration, and the other part of sec-butyl acetate is fed to the tower top of the azeotropic distillation tower. The method has the characteristic of high separation efficiency; and the recovery of the acetic acid is more than 95%, and the content of the acetic acid in waste water is below 0.5%. By using the method, the defects of large reflux ratio, high energy consumption and the like which are caused by using a rectification method are directly overcome, and the production capability of dilute acetic acid recovery is enlarged.

The invention discloses a preparation method of high-quality rifampicin, solving the problem that the traditional preparation method has the defects such as unfavorable product quality and high cost; the preparation method comprises the operational steps: S-BA liquid is salified by alkalescence sodium bicarbonate during a salification reaction; S is separated out by acetate acid before a cyclization reaction; then, dihydroxy is added for a reaction to obtain oxazine; after the reaction is finished, DMF is recovered by a molecular distillation method and then dissolved by other hydrophilic solvents; oxazine is separated out by an elutriation method; after a hydrolysis reaction and a condensation reaction are finished, an azeotropic distillation method is adopted to recover un-reacted side chains; pH is adjusted and temperature is lowered so that crystals are separated to obtain the crude products of rifampicin; and then the crude products are refined to obtain the high-quality rifampicin. Compared with the existing preparation technique, the preparation method significantly improves the product purity, reduces the production cost, controls the overall quantity of impurities to be lower than 1.5 percent, reduces two thirds of the general consumption of raw materials and more than a half of the usage of 1-methyl-4-aminopyrazine which is a valuable raw material, and eliminates the environmental pollution caused by strong acid and alkali.

The invention relates to a novel azeotropic distillation technical method and a device, particularly to a technical method and a device using a bulkhead azeotropic distillation column to produce anhydrous isopropanol. The invention enables the separation between isopropanol and water, as well as the recovery of entrainer to be integrated into the same distillation column. The bulkhead azeotropic distillation column refers to a piece of bulkhead (6) which is arranged in the vertical direction inside the conventional distillation column and extended from the upper part of the distillation column to the bottom part of the distillation column; the total height of the bulkhead (6) is less than that of the distillation column; the bottom of the bulkhead is closed; the bulkhead (6) divides the distillation column into three parts: a public distillation segment (1), a dehydration segment (2) and a lateral line distillation segment (3). The isopropanol aqueous solution which needs to be separated enters into the distillation column from the lower part of the public distillation segment (1) and get the high-purity isopropanol from the bottom of the dehydration segment (2); the , ternary azeotrope is steamed out from the top of the distillation column; the steam at the top of the distillation column is condensed through a condenser (5) and then enters into a phase splitter (4) to be divided into light and heavy two-phase liquid; the light phase (entrainer) flows back, while the heavy phase enters into the lower part of the lateral line distillation segment (3) to get the water containing a small amount of isopropanol at the bottom of the lateral line distillation segment (3).

Carboxylic esters are prepared by a process, which comprises reacting dicarboxylic or polycarboxylic acids or their anhydrides with alcohols in a liquid medium with the concomitant removal of water formed by the esterification reaction by azeotropic distillation together with the alcohol in the medium, wherein the amount of liquid removed from the reaction medium by azeotropic distillation is replaced in whole or in part with the alcohol.

The invention relates to a method for refining long-carbon chain dicarboxylic acid. A long-chain dicarboxylic acid crude product prepared by a fermentation method is used as a raw material, acetic acid is used as a solvent, and the refining and purification are performed by recrystallization treatment. The method comprises the process steps of bleaching filtration, cooling crystallization, centrifugal separation, centrifugal material washing, secondary centrifugation and drying, and is characterized in that a. the long-chain dicarboxylic acid crude product to be refined does not need to be dried; b. the acetic acid solvent is recycled by an azeotropic distillation method, and isopropyl acetate is used as an azeotropic dehydrating agent; and c. the isopropyl acetate is used as a centrifugal material washing solvent for replacing the acetic acid. The purification method of the long-carbon chain dicarboxylic acid provided by the invention has the advantages of distillation equipment investment conservation, low operating power consumption, good product color, high purity, high refining yield and low production cost, the long-carbon chain dicarboxylic acid to be refined does not need to be dried and dehydrated, and the acetic acid solvent is completely recyclable. The quality of the refined product can meet the technical requirements of use of condensed monomer raw materials used by synthesis of high polymer materials.

The invention relates to a novel azeotropic distillation process method and a device thereof, in particular to a process method which use a septal azeotropic distillation column (5) to produce absolute alcohol, and a device thereof. The septal azeotropic distillation column (5) is achieved by arranging a septal wall (6) in the azeotropic distillation column in the vertical direction, and the septal wall (6) divides the space of the azeotropic distillation column into three areas with different functions; a public distillation part (1), a dehydration part (2) and a side stripper part (3). The alcohol solution to be separated is filled to the azeotropic distillation column from the upper part of the dehydration part (2), and the absolute alcohol is obtained at the bottom of the dehydration part (2); ternary azeotrope is steamed out of the top of the column, and condensed by a condenser (7) and then splitted into light phase solution and heavy phase solution in a phase splitter; the light phase solution (entrainer) reflows and the heavy phase solution is the feed stock in the side stripper part (3), and little water containing alcohol is obtained at the bottom of the side stripper part (3). The device and the process method of the invention can produce the absolute alcohol, and can simplify the process, reduce the energy consumption and the cost of the divices.

The invention discloses a method for improving the conductive thermal stability of a polyaniline/inorganic nano-conductive composite material, which comprises the following steps: a proton acid doped polyaniline/inorganic nano-conductive composite material filter cake is firstly prepared, then the obtained filter cake is carried out the azeotropic distillation treatment, water in the filter cake is removed, and the proton acid doped polyaniline/inorganic nano-conductive composite material is simultaneously transferred into an organic phase. The method easily prepares the proton acid doped polyaniline/inorganic nano-conductive composite material organic dispersion liquid with the excellent dispersion through the azeotropic distillation dehydration and the phase transfer process, thereby reducing the clustering phenomenon of the composite material, improving the dispersion of the composite material in the organic phase and improving the conductive thermal stability of the nano-conductive composite material.

Processes for making lactones and dilactones from aldaric acids, aldonic acids, and their corresponding salts by dehydrative cyclization and azeotropic distillation. The processes can be carried out in the presence of water because water is removed by azeotropic distillation.

A process for reducing the level(s) of water and/or other impurities from cyclosiloxanes by either azeotropic distillation, or by contacting the cyclosiloxane compositions with an adsorbent bed material. The purified cyclosiloxane material is useful for forming low-dielectric constant thin films having dielectric constants of less than 3.0, more preferably 2.8 to 2.0.

The invention discloses a preparation method of a supported nickel catalyst, which comprises the following steps of: reacting soluble nickel salt solution and a precipitator to obtain a green precipitate, wherein the precipitator is mixed solution of sodium silicate and sodium carbonate, the Na<+> concentration is 0.1-1 mol/L, the amount of the sodium silicate is calculated according to the content of SiO2 in a carrier, and the amount of the sodium carbonate is 10-30 percent more than that of nickel nitrate based on a stoichiometric ratio; washing the precipitate by distilled water and carrying out supercritical drying or azeotropic distillation drying to obtain a supported nickel catalyst precursor; roasting the supported nickel catalyst precursor for 2-5 hours under N2 atmosphere at 200-600 DEG C, changing the N2 atmosphere into H2 atmosphere, and reducing the supported nickel catalyst precursor for 2-4 hours under H2 atmosphere at 300-550 DEG C to obtain the supported nickel catalyst with the surface area of high active metal nickel. The surface area of the obtained catalyst is 250-450m<2>/g, the average aperture is 4-16nm, and the pore volume is 1.0 -1.9cm<3>/g. The surface area of the active metal nickel of the obtained catalyst is 40-70m<2>/g. The catalyst prepared by using the method can be used for catalyzing hydrogenation of a benzene ring.

Disclosed is a distillation system and method for recovering acetic acid from a feed stream containing acetic acid and water stream generated during terephthalic acid production. The invention includes a liquid-liquid extraction column and a dehydration distillation column utilizing azeotropic distillation or conventional to recover the acetic acid. The liquid-liquid extraction column is installed upstream from the dehydration distillation column. The liquid-liquid extraction column produces an extract of an extraction solvent and acetic acid which is sent to the dehydration distillation column to separate the extraction solvent and acetic acid. The dehydration distillation column may be used with or without a condenser system to recover the energy. The condenser system is a steam generator that condenses the vapor into a concentrated acetic acid stream while generating a low pressure steam. Any remaining acetic acid in water is sent to a waste water recycling facility.

The invention discloses a method for preparing preparing silicon dioxide aerogel powder, which comprises the following steps: adding acid into sodium silicate solution to make a pH value equal to 3 to 6; adding a chemical drying control agent into mixture and standing to form gel; after the gel is sufficiently aged, adding an azeotropic distillation organic solvent into the gel to distill to form a primary dried product; and drying the primary dried product to form silicon dioxide aerogel powder. The method uses the common commercial sodium silicate as the raw material to prepare the silicon dioxide aerogel powder and has the advantages that the raw material is easily obtained; the normal pressure is used for preparation; the chemical drying control agent is adopted to prolong the gelation time to promote uniformity of the gel structure; an azeotropic distillation drying process is adopted to control a stress level when the solvent is dried; a pore volume and a specific surface area of the silicon dioxide aerogel are controlled; the pore volume reaches 1.2 to 3.0ml/g; the specific surface area reaches 300m2/g to 800m2/g; and compared with the normal pressure drying, the drying time is shortened and the like. The organic solvent is easy to realize recycling. And the production process is simple and the production cost is low.

The invention discloses a wear-resisting ceramic coating for non-stick cookware and a preparation method thereof. The coating is composed of a component A and a component B, wherein the weight ratio of the component A to the component B is (2.8-3.2): (1.8-2.0); the component A is composed of silicon dioxide sol, aluminum oxide sol, zirconium oxide sol, water soluble polyester modified epoxy resin, ultrafine aluminum oxide powder processed by azeotropic distillation method, black iron oxides, ultrafine spherical ceramic powder, isopropyl alcohol, deionized water, hydroxyethyl cellulose acetate butyrate and fluorosilicon oil; and the component B is composed of methyl triethoxysilane, amino dimethyldiethoxylsilane, dimethyl dimethoxy silicane, isopropyl alcohol and alcohol. The preparation method comprises the following steps of: mixing the component A and the component B of the coating in a weight ratio of (2.8-3.2): (1.8-2.0); and hermetically stirring and curing the obtained mixture for at least 3 hours under the conditions of 35 DEG C and 800-1000 rpm, thereby obtaining the coating. According to the invention, through carrying out polycondensation reaction on metal oxide colloids and polysiloxane, the bonding strength of a film forming matter is improved.