Abstract: Formation of butadiene-1,3 polymer during the extractive distillation of a C-4 hydrocarbon mixture to separate and purify butadiene-1,3 using a solvent composition in which an alkoxynitrile is present in a proportion of 50-99 percent by weight, is decreased through inclusion in the solvent of a synergistic combination of 2,4-dinitrophenol and phosphoric acid, each in a proportion of 0.05 to 0.5 percent by weight.

Abstract: A method for destructive distillation of hydrocarbonaceous distilland is disclosed wherein a dienophile is introduced into the vaporous phase to reduce the production of non-distillable polymeric product. Specifically dienophiles available economically in large amounts such as maleic anhydride are disclosed. The introduction of additional sulfide to further reduce production of asphaltenic polymeric product is also described.

Abstract: The present invention relates to a method of purifying readily polymerizable high boiling vinyl monomers, in particular the acrylates and methacrylates of alkylene oxides and their ether and ester derivatives to obtain pure water white esters. The process involves flash evaporation of the preheated esters followed by condensation in the presence of polymerization inhibitors under specific conditions. The purified esters thus produced find use either as such or in the form of their copolymers in coatings, enamel paints, weather resistant finishes, adhesive compositions, as plasticizers, as lubricants for cellulose films and fibers, in magnetic tape recording media and as oil additives.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds and a new polymerization inhibitor therefor. The process comprises subjecting a vinyl aromatic compound to elevated temperatures in a distillation system in the presence of a new polymerization inhibitor comprising 2,6-dinitro-p-cresol. Also disclosed is a distillation method and apparatus for use with this inhibitor.

Abstract: A method of inhibiting the polymerization of styrene which comprises mixing with the styrene a minor but effective quantity of an inhibitor compound selected from the group consisting of 2-methylbenzoquinone-4-oxime, 2,3,5-trimethylbenzoquinone-4-oxime and mixtures thereof.

Abstract: The recovery of a hydrocarbon capable of autopolymerization from an air stream by absorbing the hydrocarbon with a plasticizer and separating the hydrocarbon from the plasticizer by vacuum and atmospheric distillation.

Abstract: Apparatus for the distillation of styrene from hydrocarbon feedstock incorporating a system for injection of gaseous polymerization inhibitor.

Abstract: Disclosed is a method for preventing the polymerization of a readily polymerizable vinyl aromatic compound during distillation at elevated temperatures within a distillation apparatus which is subject to an emergency condition, such as a power outage. This method comprises force feeding a supplemental polymerization inhibitor having a high solubility in the vinyl aromatic compound, and a long duration of efficiency, into each of the distillation vessels of a conventional distillation apparatus in an amount sufficient to prevent polymerization therein. In the preferred embodiment the supplemental polymerization inhibitor comprises 2,6-dinitro-p-cresol and meta-nitro-para-cresol.

Abstract: A method and apparatus is disclosed for the distillation of readily polymerizable vinyl aromatic compounds with polymerization inhibitors of low volatility, particularly a phenothiazine (PZ)-tertiarybutylcatechol (TBC) polymerization inhibitor combination. The method comprises introducing a feed of impure vinyl aromatic compound into a typical distillation train comprising a first fractionation column, a recycle column, and a finishing column; introducing as a separate stream into the upper portion of said recycle column and into said first fractionation column an effective amount of the PZ-TBC inhibitor in a volatile aromatic hydrocarbon diluent; and then distilling the vinyl aromatic compound in the presence of oxygen to recover an overhead product of high purity vinyl aromatic compound and a bottoms fraction.

Abstract: Use of copper ion in acrylamide solution during concentration to inhibit polymerization.

Abstract: A method for stabilizing acetylene against explosive decomposition comprising mixing together with the acetylene a chemical free radical scavenging agent chosen from the group consisting of nitric oxide, hydrogen chloride, hydrogen bromine, hydrogen iodide and vinyl bromine as well as mixtures thereof.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds which comprises subjecting such compounds to distillation conditions in the presence of an effective amount of a 4-halo-3,5-dinitrotoluene as a polymerization inhibitor.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds which comprises subjecting such compounds to distillation conditions in the presence of an effective amount of a polymerization inhibitor selected from the group consisting of 3-nitro-2, 5-cresotic acid and 3-nitro-2, 5-cresotaldehyde.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds which comprises subjecting such compounds to distillation conditions in the presence of an effective amount of a halo-6-nitro-p-cresol as a polymerization inhibitor.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds and a new polymerization inhibitor therefor. The process comprises subjecting a vinyl aromatic compound to elevated temperatures in a distillation system in the presence of a new polymerization inhibitor comprising 2,6-dinitro-p-cresol.

Abstract: A method is disclosed for stabilizing vinylbenzyl chloride and vinyltoluene against violent decomposition in the presence of iron and chlorine at ambient and above ambient temperatures which comprises contacting the vinylbenzyl chloride or vinyltoluene with an amount of a Lewis base sufficient to inhibit the decomposition during the preparation, purification or storage of said vinylbenzyl chloride or vinyltoluene.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds and a new polymerization inhibitor therefor. The process comprises subjecting a vinyl aromatic compound to elevated temperatures in a distillation system in the presence of a new polymerization inhibitor comprising m-nitro-p-cresol.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds which comprises subjecting such compounds to distillation conditions in the presence of an effective amount of a combination of phenothiazine and a phenolic compound, preferably tert-butylcatechol (TBC), as a polymerization inhibitor system in the presence of oxygen.

Abstract: The present invention relates to a process for the distillation of readily polymerizable ethylenically unsaturated compounds comprising subjecting such compounds to distillation conditions in the presence of nitroso methylaniline as a polymerization inhibitor and in the absence of oxygen (air) and sulfur.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds and a new polymerization inhibitor therefor. The process comprises subjecting a vinyl aromatic compound to distillation conditions in a distillation system and adding to the system the new polymerization inhibitor comprising an adduct of nitric oxide and styrene.

Abstract: The present invention relates to a process for inhibiting the polymerization of styrene monomers during the purification of crude styrene.

Abstract: In the epoxidation of propylene with tertiary butyl hydroperoxide to form propylene oxide, a by-product, tertiary butyl alcohol is formed. This alcohol can be dehydrated to form isobutylene which can be sold as a product or hydrogenated, followed by oxidation, and the resulting hydroperoxide reacted with propylene to produce propylene oxide and tertiary butyl alcohol for recycle. In this process, the operation of the tertiary butyl alcohol vaporizer is substantially improved by increasing the quantity of liquid purge to at least 15 weight percent of the input. Under such operating conditions, the organic content of the waste water effluent from the entire plant is reduced, fouling of the vaporizer heat transfer surfaces is minimized thereby increasing the on-stream time between cleanings by as much as 2-3 times the normal, and deposits are more easily removed from the vaporizer when it is shut down for cleaning.

Abstract: Styrene is inhibited against polymerization during the distillation thereof by incorporating therein, in an amount sufficient to inhibit polymerization thereof, the dinitrophenol solution recovered from styrene still residues or tars resulting from the distillation of styrene in the presence of dinitrophenol. The recovered dinitrophenol solution is a more effective polymerization inhibitor than dinitrophenol per se.

Abstract: A method for economically concentrating an acrylamide aqueous solution by catalytic hydration without substantial deterioration in the product. According to the method, an acrylamide aqueous solution obtained from catalytic hydration, is concentrated by distillation while maintaining the solution in good contact with at least 0.1 mole. or more of air per mole of water distilled from the acrylamide aqueous solution.

Abstract: The present invention relates to the use of quinone alkides as polymerization inhibitors in a styrene purification process. The inhibitors are prepared by oxidizing hindered phenols to the corresponding quinone alkide.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds and a new polymerization inhibitor therefor. The process comprises subjecting a vinyl aromatic compound to distillation conditions in a distillation system and adding to the system the new polymerization inhibitor comprising alpha, gamma-bis-diphenylene-beta-phenyl allyl.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds and a new polymerization inhibitor therefor. The process comprises subjecting a vinyl aromatic compound to distillation conditions in a distillation system and adding to the system the new polymerization inhibitor comprising a mixture of N-nitroso diphenyl amine and a dinitro-O-cresol.

Abstract: A method of distilling a polymerizable vinyl compound selected from the group consisting of acrolein, methacrolein, acrylic acid, methacrylec acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, glycidyl acrylate and glycidyl methacrylate, the method comprising distilling the polymerizable vinyl compound in the presence of a polymerization inhibitor using a distillation tower having perforated trays without downcomers and wherein the temperature of the inner wall of the tower is maintained at a temperature sufficient to prevent the condensation of the vapor being distilled, whereby the polymerizable vinyl compound is distilled without the formation of polymer.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds which comprises subjecting such compounds to distillation conditions in the presence of an effective amount of N.sub.2 O.sub.3 as a polymerization inhibitor.

Abstract: A process for the stabilization of indene against discoloration comprising adding to the indene a minor amount of an insoluble compound selected from the group consisting of neutral, acidic and basic inorganic salts, inorganic acids and organic acids.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds which comprises subjecting such compounds to distillation conditions in the presence of an effective amount of NO as a polymerization inhibitor in the substantial absence of oxygen.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds which comprises subjecting such compounds to distillation conditions in the presence of an effective amount of NO.sub.2 as a polymerization inhibitor.

Abstract: A method of inhibiting the thermopolymerization of isoprene or butadiene in the process of isolation thereof by extractive distillation from a mixture of hydrocarbons obtained in dehydrogenation of isopentane and butane. The method of inhibiting includes, prior to the introduction of said mixture of hydrocarbons and a polar extractant into an extractive distillation metal apparatus, treating the surface of the apparatus with a 1-25% aqueous solution of passivators, viz. nitrites, sulphites or phosphates of alkali metals at a temperature of 20.degree.-100.degree.C. The mixture of hydrocarbons and the polar extractant with an inhibitor of isoprene or butadiene thermopolymerization introduced into the polar extractant are then fed into said apparatus in an amount of 0.01-1% of the extractant weight. The present method makes it possible to reduce markedly the formation of isoprene and butadiene and, hence, to prevent the plugging of the extractive distillation apparatuses with the aforementioned thermopolymers.

Abstract: Disclosed is a process for the distillation of readily polymerizable vinyl aromatic compounds which comprises subjecting such compounds to distillation conditions in the presence of an effective amount of NOCl as a polymerization inhibitor in the substantial absence of oxygen.