1217 results about "Azeotrope" patented technology

Disclosed herein are azeotrope or near-azeotrope compositions comprising 2,3,3,3-tetrafluoropropene (HFC-1234yf) and hydrogen fluoride (HF). These compositions are useful in processes to produce and purify HFC-1234yf. Additionally, disclosed herein are processes for the manufacture of HFC-1234yf.

Provided are azeotrope-like compositions comprising pentafluoropropene (HFO-1225) and a fluid selected from the group consisting of 3,3,3-trifluoropropene (“HFO-1243zf”), 1,1-difluoroethane (“HFC-152a”), trans-1,3,3,3-tetrafluoropropene (“HFO-1234ze”), and combinations of two or more thereof. Also provided are uses thereof including as refrigerants, blowing agents, sprayable compositions, flame suppressant, and the like.

An azeotrope-like mixture consisting essentially of chlorotrifluoropropene and at least one component selected from the group consisting of a C₁-C₃ alcohol, a C₅-C₆ hydrocarbon, a halogenated hydrocarbon, methylal, methyl acetone, water, nitromethane, and combinations thereof.

Low water-containing biomass-derived pyrolysis oils and processes for preparing them are provided. Water-containing biomass-derived pyrolysis oil is distilled in the presence of an azeotrope-forming liquid to form an azeotrope. The azeotrope is removed at or above the boiling point of the azeotrope and low water biomass-derived pyrolysis oil is obtained.

Provided are azeotropic and azeotrope-like compositions of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and hydrogen fluoride (HF). Such azeotropic and azeotrope-like compositions are useful as intermediates in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

Provided are azeotrope-like compositions consisting essentially of 1,1,1,2-tetrafluoropropene and 1,1,1,2-tetrafluoroethane and uses thereof, including use in refrigerant compositions, refrigeration systems, blowing agent compositions, and aerosol propellants.

Provided are azeotropic and azeotrope-like compositions of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb). Such azeotropic and azeotrope-like compositions are useful as intermediates in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

An azeotrope-like mixture consisting essentially of chlorotrifluoropropene and at least one component selected from the group consisting of pentane, hexane, methanol, and trans-1,2-dichloroethene.

Provided are ternary azeotropic and azeotrope-like compositions of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), and hydrogen fluoride (HF). Such azeotropic and azeotrope-like compositions are useful as intermediates in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

Disclosed is a process for the purification of a mixed diol stream. The mixed diol stream comprising two-, three-, and four-carbon diols is separated into component diols by extraction with a hydrophobic solvent mixture. The diols recovered in the extractant may be removed from the extractant stream by back extraction with water or by distillation with an azeotrope-forming agent present, preferably an azeotroping agent already present in the extractant mixture.

The invention relates to a method for preparing sec-butyl acetate, which includes steps as follows: (1) with the existence of a catalyst and under the condition of addition reaction, C4 olefin contacts and reacts with acetic acid for a plurality of times; (2) the reaction products obtained in Step (1) are rectified and separated, C4 light components are obtained from the top of a tower and tower bottoms are obtained from the bottom of the tower; (3) the tower bottoms obtained in Step (2) and water are boiled and rectified, sec-butyl acetate and C8 olefin are obtained from the top of the tower in the form of azeotrope and acetic acid is obtained from the bottom of the tower; (4) the azeotrope obtained in Step (3) is condensed, oil and water separation is carried out and aqueous phase products and oil phase products containing C8 olefin and sec-butyl acetate are obtained; and (5) the oil phase products obtained in Step (4) and water are boiled and rectified, C8 olefin is obtained from the top of the tower in the form of azeotrope and sec-butyl acetate is obtained from the bottom of the tower. The method provided by the invention can obtain relatively high yield of sec-butyl acetate and can obtain sec-butyl acetate and recycle acetic acid at a relatively high purity.

Disclosed herein are azeotrope and near-azeotrope compositions comprising 1,1,3,3,3-pentafluoropentene (HFC-1225zc) and hydrogen fluoride. These compositions are useful in processes to produce and purify HFC-1225zc. Also disclosed are processes comprising pyrolyzing CF₃CH₂CF₃ to CF₃CH═CF₂. Also disclosed herein are processes for the manufacture of HFC-1225zc comprising pyrolyzing 1,1,1,3,3,3-hexafluoropropane (HFC-236fa) in the absence of dehydrofluorination catalyst in a reactor having a reaction zone.

The utility model relates to a method which utilizes a vapour permeation membrane to separate dimethyl carbonate from methanol azeotrope. Saturated vapour at the temperature of 64 to 120 DEG C and with the pressure of 0.10 to 0.6 MPa is sent into a membrane separator and is contacted with a separation membrane, the downstream side of the membrane separator keeps the vacuum degree at 4 to 200 mmHg by vacuum pumping, the dimethyl carbonate first passes through a concentration membrance filter at the permeation side of the membrane and is condensed into liquid under the condition of vacuum and low pressure, the liquid mixture directly enters into an atmospheric rectifying column, dimethyl carbonate with more than or equal to ninety nine point five percent of content is produced from the bottom of the column, and high-concentration methanol is produced from the interception side of the membrane separator and enters into next technique unit. The separation membrane is an organic composite membrane, an organic and mineral composite membrane or a mineral membrane which can preferentially permeate dimethyl carbonate, and the method has the advantages of simple technique and low energy consumption; the throughput of the permeation of the membrane is increased, and the area of the membrane is reduced; safety and reliability are increased, and the purity of dimethyl carbonate is increased as well.

The invention discloses a method for continuously extracting, rectifying and separating mixed alcohols from water, relates to a chemical separating method, and in particular to a method for continuously extracting, rectifying and separating mixed alcohols such as aqueous mixtures of ethanol, n-propyl alcohol, isobutyl alcohol and the like. According to the method, extractive distillation and common rectifying are combined together, and a multi-column combined step-by-step separating method is adopted to separate mixed alcohols from water step by step and recycle components with high purity. The method comprises steps of: with ethylene glycol as an extraction agent, separating the mixed alcohols from water in an extractive rectifying column B1, wherein the column B1 adopts normal pressure rectification, the reflux ratio is 1:1-10:1, the mixed alcohols can be get from the column top, and a mixture of a solvent and water can be get from the column bottom; recovering most of the solvent from a solvent recovering column B4 and recycling the solvent; and effectively separating the mixed alcohols through columns B2 and B3. According to the method, extractive distillation and common rectifying are combined together, the extraction agent is used to avoid the azeotrope of alcohols and water, and continuous separation of multiple columns are adopted to recover the components with high purity step by step, so that the method has high economic and environmental benefits.

Foam-forming compositions containing azeotropic or azeotrope-like mixtures containing cis-1,1,1,4,4,4-hexafluoro-2-butene are disclosed. The foam-forming composition contains (a) an azeotropic or azeotrope-like mixture of cis-1,1,1,4,4,4-hexafluoro-2-butene with methyl formate, 1,1,1,3,3-pentafluorobutane, trans-1,2-dichloroethylene, pentane, isopentane, cyclopentane, HFC-245fa, or dimethoxymethane; and (b) an active hydrogen-containing compound having two or more active hydrogens. Also disclosed is a closed-cell polyurethane or polyisocyanurate polymer foam prepared from reaction of an effective amount of the foam-forming composition with a suitable polyisocyanate. Also disclosed is a process for producing a closed-cell polyurethane or polyisocyanurate polymer foam by reacting an effective amount of the foam-forming composition with a suitable polyisocyanate.

Provided are azeotropic and azeotrope-like compositions of 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and hydrogen fluoride (HF). Such azeotropic and azeotrope-like compositions are useful as intermediates in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf).