Abstract: A method for producing an alkenyl or alkynyl-containing organosilicon precursor composition, the method comprising the steps of distilling at least once a composition comprising an alkenyl or alkynyl-containing organosilicon compound having the formula RnSiR14?n wherein R is selected a linear or branched C2 to C6 alkenyl group, a linear or branched C2 to C6 alkynyl group; R1 is selected from hydrogen, a linear or branched C1 to C10 alkyl group, and a C3 to C10 cyclic alkyl group; and n is a number selected from 1 to 4, wherein a distilled alkenyl or alkynyl-containing organosilicon precursor composition is produced after distilling; and packaging the distilled alkenyl or alkynyl-containing organosilicon precursor composition in a container, wherein the container permits transmission into the container of no more than 10% of ultraviolet and visible light having a wavelength of between 290 nm to 450 nm.

Abstract: The present invention provides methods comprising washing or, preferably, washing and neutralizing a sulfur acid containing crude MMA stream to generate a two phase stream containing at least methacrylic acid, methacrylamide (MAM), water and methanol, and an organic component containing methyl methacrylate and thereby form an aqueous component; including in any of the organic component, the aqueous component of a neutralized sulfur acid containing crude methyl methacrylate (MMA) stream or the organic component of a neutralized sulfur acid containing crude methyl methacrylate (MMA) stream one or more N-oxyl compound polymerization inhibitor; followed by separating the aqueous component from the organic component, thereby forming a treated crude MMA stream and an aqueous stream to remove residual (meth) acrylic acid.

Abstract: Polymerization inhibitor compositions are provided. The polymerization inhibitor compositions may include at least one hydroxylamine of a nitroxide and at least one phenylenediamine. Methods of inhibiting the unwanted polymerization of monomers are also provided. The methods include adding the presently disclosed polymerization inhibitor compositions to a fluid containing the monomers. The monomers may be ethylenically unsaturated monomers, such as acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, acrolein, methacrolein, acrylate, methacrylate, acrylamide, methacrylamide, vinyl acetate, butadiene, ethylene, propylene, and styrene.

Abstract: Polymerization inhibitor compositions are provided. The polymerization inhibitor compositions may include at least one hydroxylamine of a nitroxide and at least one phenylenediamine. Methods of inhibiting the unwanted polymerization of monomers are also provided. The methods include adding the presently disclosed polymerization inhibitor compositions to a fluid containing the monomers. The monomers may be ethylenically unsaturated monomers, such as acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, acrolein, methacrolein, acrylate, methacrylate, acrylamide, methacrylamide, vinyl acetate, butadiene, ethylene, propylene, and styrene.

Abstract: The present invention relates to a process for purifying monomers, by evaporating at least a portion of the monomers present in a starting composition and then condensing it, which is characterized in that at least a portion of the starting composition is evaporated in a short-path evaporator, the mass flow density of the vapors {dot over (m)} being selected according to the relation (I) m . ? 1800 ? kg · K mbar · m 2 · h · kg kmol · p i · ( M ~ T ) 0.5 ( I ) in which {tilde over (M)} is the average molar mass of the vapors in the short-path evaporator in kg/kmol T is the temperature of the vapors in K pi is the pressure in the short-path evaporator in mbar {dot over (m)} is the mass flow density of the vapors in kg/(m2·h). A further aspect of the present invention is a plant for performing the process.

Abstract: High temperatures and oxygen exposure during extractive distillation can result in polymerization of vinyl aromatic compounds. In various embodiments, the present disclosure relates to methods for inhibiting polymerization of vinyl aromatic compounds during extractive distillation. In various embodiments, the methods include a) providing a mixture containing at least one vinyl aromatic compound, b) adding at least one dinitrophenol inhibitor to the mixture, and c) after step b), performing an extractive distillation on the mixture to isolate the at least one vinyl aromatic compound. Purified styrene can be isolated by the methods described herein. In some embodiments, the dinitrophenol inhibitor is 2-sec-butyl-4,6-dinitrophenol (DNBP).

Abstract: For the distillation of temperature-sensitive liquids, in particular acrylic acid and its esters, the liquid is heated in a column and at least partly evaporated. The vapor is guided through a condenser provided inside the column, in which the vapor is at least partly condensed. The condensed liquid is at least partly withdrawn from the column. The distillation is characterized in that the vapor not condensed yet is guided through the condenser cocurrently to the condensed liquid.

Abstract: A process for inhibiting polymerization of (meth)acrylic acid and/or (meth)acrylic esters by introducing an oxygenous gas into the (meth)acrylic acid and/or the (meth)acrylic ester, in which the (meth)acrylic acid and/or the (meth)acrylic ester has a degree of purity of at least 95% and is in the liquid state.

Abstract: In a process for distilling polymerization-prone compounds from liquid mixtures of matter which, apart from the readily polymerizable compound, also contain other components and also polymerization inhibitors, the evaporator is operated in forced circulation and at a pressure which makes possible superheating of the liquid with respect to its boiling point at the pressure within the distillation column. This is achieved by transporting the superheated liquid against a flow restrictor, e.g. an orifice plate. The liquid which is expanded and partially evaporated on passage through the flow restrictor is returned to the distillation column. In this manner the formation of an open vapour space in the evaporator circuit after heating downstream of the heat exchanger is avoided in that, in the design of the evaporator of the prior art, formation of polymer deposits frequently occurs.

Abstract: Novel improved processes for the production and isolation of methylidene malonates via direct and indirect adduct processes.

Abstract: An improvement in the production of methylidene malonates is attained by use of specific reaction phase and/or separation phase polymerization inhibitors and combinations thereof.

Abstract: Process for distillatively purifying polymerizable compounds using a high-boiling, inert, thermally long-term-stable substance as a boiling oil, characterized in that the boiling oil is disposed in the bottom of a rectification column.

Abstract: The present invention provides a method for preventing polymerization, and a polymerizable monomer composition favorably used therefor that includes a (meth)acryloyl group-containing isocyanate compound and a specific polymerization inhibitor. The polymerizable monomer composition includes a (meth)acryloyl group-containing isocyanate compound and a stable free radical compound. The invention effectively prevents the polymerization of the (meth)acryloyl group-containing isocyanate compound and the occurrence of polymers due to the polymerization. Furthermore, the use of a stable free radical compound which has a vapor pressure approximate to that of the (meth)acryloyl group-containing isocyanate compound can effectively prevent polymerization in a vapor phase and a condensation phase of distillation facility.

Abstract: Accumulation of polymer on equipment, which is in contact with polymerizable material during normal process operation, is minimized by the method and apparatus of the present invention. The method involves positioning and affixing the equipment, such as a pressure relief device, to process apparatus, such as a distillation column, proximate to a wetted region comprising liquid phase fluid in the process apparatus, such that the moving liquid phase fluid is at least intermittently in contact with the equipment and one or more of accumulated polymerizable material, condensate comprising same, and polymer, is washed off of the equipment.

Abstract: A method for inhibiting the formation of fouling materials including contacting hydrocarbon media containing aldehyde compounds with an antifoulant while treating the hydrocarbon media with a basic wash. The antifoulant includes a reducing sugar.

Abstract: The present invention relates to a process for purifying monomers, by evaporating at least a portion of the monomers present in a starting composition and then condensing it, which is characterized in that at least a portion of the starting composition is evaporated in a short-path evaporator, the mass flow density of the vapours {dot over (m)} being selected according to the relation (I) m . ? 1800 ? kg · K mbar · m 2 · h · kg kmol · p i · ( M ~ T ) 0.5 ( I ) in which {tilde over (M)} is the average molar mass of the vapours in the short-path evaporator in kg/kmol T is the temperature of the vapours in K pi is the pressure in the short-path evaporator in mbar {dot over (m)} is the mass flow density of the vapours in kg/(m2·h). A further aspect of the present invention is a plant for performing the process.

Abstract: A process for debottlenecking a system for the separation of a conjugated diolefin the system including a first extraction section having an extractive distillation column and a stripping column and a second extraction section. The process includes the steps of withdrawing a first portion of an extract from the extractive distillation column, the extract having at least the first portion and a second portion, and transferring the first portion of the extract to a flash/separation vessel; separating the first portion of the extract into a vapor phase and a liquid phase by flashing in a flash/separation vessel; and combining the liquid phase of the separated first portion of the extract with the second portion of the extract to produce an extract feed for further processing. A system and process for the separation of a conjugated diolefin from a C4- or C5-hydrocarbon mixture containing the conjugated diolefin and higher acetylenes are also provided.

Abstract: The present invention relates to a polymerization inhibitor composition and a method of inhibiting polymerization of distillable monomers in liquid and evaporated/condensed phases with the polymerization inhibitor composition. The polymerization inhibitor composition is useful for inhibiting polymerization of the distillable monomers during manufacture, purification (e.g., distillation), handling, and storage thereof.

Abstract: There is provided a method for rectifying a vinyl compound liquor. The method includes the steps of a) providing a rectification column operated at a temperature and pressure and b) feeding the vinyl compound liquor to be rectified into the rectification column, wherein the pressure of the rectification column and the temperature of the fed vinyl compound liquor are controlled, such that the temperature of the fed vinyl compound liquor ranges from its bubble point at the pressure of the rectification column to 10° C. lower than the bubble point.

Abstract: A condenser includes: a top face of a tube plate on which acrylic acid may be condensed inside the condenser; a spray for spreading a polymerization inhibitor on the tube plate; a first polymerization inhibitor supply tube for supplying the polymerization inhibitor to the spray; and a supporter for supporting the spray at a predetermined position. The supporter supports the first polymerization inhibitor supply tube outside the condenser. The condenser allows a stable continuous operation for a long period of time by preventing polymerization of an easily polymerizable compound in the condenser into which a vapor of an easily polymerizable compound is supplied with a simple structure thereof.

Abstract: A decomposition reaction apparatus or distillation apparatus for acrylic acid in which a column bottom liquid heated in a reboiler (5) is supplied from a supply port (1a) provided on a side wall of a column body (1) having: a top plate (12a) above the supply port (1a); and an impingement plate (12b) provided vertically to the top plate (12a), for preventing scattering of the column bottom liquid to a supply direction. The top plate (12a) is provided such that the top face of the top plate (12a) is inclined downward from a base end to a tip end. The present invention allows: suppression of formation of a polymerized product due to flowing of a liquid or gas heated in a reboiler into a column with a simple structure; and a stable continuous operation of column equipment over a long period of time.

Abstract: A distillation apparatus for subjecting a crude readily polymerizable compound to distillation under vacuum conditions to purify it, the distillation apparatus having a distillation column and a vacuum generator and an exhaust gas conduit of the vacuum generator connected to a connecting conduit therebetween through a pressure control valve. A method provides purifying of a readily polymerizable compound by subjecting a crude readily polymerizable compound to distillation under vacuum conditions to purify it, the method including using a distillation apparatus having a distillation column and a vacuum generator and an exhaust gas conduit of the vacuum generator connected to a connecting conduit therebetween through a pressure control valve and controlling the action of the pressure control valve based on a pressure of the distillation column.

Abstract: Disclosed are reduced pressure distillation methods for purifying siloxanyl monomers in the presence of at least one polymerization inhibitor. In further aspects, the polymerization inhibitor can be an alkylhydroquinone or a hydroxynaphthalene. Also disclosed are compounds purified by the disclosed methods and polymers produced therefrom. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

Abstract: A process for rectificatively separating fluids including (meth)acrylic monomers in a rectification column by directly cooling the vapor including (meth)acrylic monomers rising to the top of the rectification column to form top condensate including (meth)acrylic monomers, the condensation space at the top of the column being separated from the region of the rectification column containing the separating internals only by at least one chimney tray from which the top condensate formed is removed from the rectification column, which includes effecting the direct cooling of the vapor in the condensation space in at least two spray zones which are spatially successive and are flowed through by vapor by spraying supercooled top condensate including added polymerization inhibitor, and the temperature of the sprayed supercooled top condensate becoming lower from spray zone to spray zone in the flown direction of the vapor.

Abstract: It is an object of the present invention to provide a process for producing easily polymerizable substance, which can realize stable operation of a purification system, and can stably maintain a production amount by avoiding production stoppage, upon production of an easily polymerizable substance in plural reactors. The present invention is directed to a process for producing easily polymerizable substance, which comprises mixing easily polymerizable substances obtained in plural reactors in advance, and supplying the mixture to a purification apparatus.

Abstract: This invention resides in providing a method for the prevention of possible polymerization of the easily polymerizable substance during the purification thereof by a column provided with (a) at least one tray directly fixed to a support ring with a bolt and a nut and/or (b) at least one tray fixed to a support ring with a vertical clamp or a distillation column provided in the lower part thereof with a splash collision plate.

Abstract: In a thermal separating process between at least one gaseous and at least one liquid stream, of which at least one comprises (meth)acrylic monomers, in a separating column containing sieve trays as separating internals, at least some of the sieve trays are operated above an entrainment fraction of 10% by weight.

Abstract: A perforated tray without downcomer having only a small deviation between the opening ratio based on the diameter of a column and the actual opening ratio and a perforated tray column without downcomer formed by disposing such perforated trays without downcomer are provided. The perforated trays without downcomer are characterized by having a ratio of (A)/(B) in the range of 1.1-1.5, wherein A denotes the opening ratio found from the standard pitch between centers of holes and (B) denotes the opening ratio based on the diameter of a column.

Abstract: In a process for preparing water-absorbent resins based on acrylic acid, crude acrylic acid is firstly isolated from the reaction gases from the catalytic gas-phase oxidation of propane, propylene and/or acrolein. This is treated with an aldehyde scavenger and pure acrylic acid is separated by distillation from the treated crude acrylic acid, and this pure acrylic acid can be subjected directly to a free-radical polymerization.

Abstract: (Meth)acrylic monomers are separated by a thermal separation process by ascending at least one ascending gaseous stream in a separating column containing a sequence of mass transfer trays and a liquid stream that contains dissolved polymerization inhibitor which descends in the separating column, and in at least one of the streams being (meth)acrylic monomers; and spraying the inner surface of the separating column with the descending liquid stream that contains the dissolved polymerization inhibitor, and the separating column having internals, certain areas of which are shadow regions of the sprayed descending liquid stream; and which shadow regions are equipped by covering means which prevent contact of the shadow regions with (meth)acrylic monomers and consequently undesired polymerization of monomer.

Abstract: Quinone methide derivatives such as 4-benzylidene-2,6-di-tert-butyl-cyclohexa-2,5 dienone are used to inhibit styrene monomer polymerization in the dehydrogenator portion of a styrene monomer production system. The inhibitor contacts the dehydrogenation effluent and does not partition in substantial amounts to the aqueous phase that is separated in the phase separator.

Abstract: A process for the high yield production of high purity glacial methacrylic acid (“HPMAA”) with minimization of decomposition of hydroxy isobutyric acid (HIBA). The HPMAA is substantially pure, specifically 99% pure or greater with a water content of 0.05% or less. This improved process involves the steps of providing a crude MAA stream which was formed by hydrolyzing acetone cyanohydrin and, therefore, includes HIBA which is an intermediate product of the hydrolysis reaction, and purifying that crude methacrylic acid stream in a series of successive distillation steps.

Abstract: Inhibitor blends that include both nitrosophenols and nitrosoanilines, optionally in combination with air or oxygen, reduce the premature polymerization of ethylenically unsaturated monomers. unsaturated monomers.

Abstract: A process for preparing and/or working up mixtures by (meth)acrylic acid and/or (meth)acrylic ester in the presence of at least one polymerization inhibitor and at least one oxygenous gas, which comprises metering in at least part of the oxygenous gas at an exit rate of at least 50 mm/s.

Abstract: The object of this invention to provide an improved arrangement that enables to prevent adhesion of polymer on or around the inner wall of a purification apparatus directly equipped on the outer wall thereof with an attachment such as a support by suppressing local temperature lowering inside the apparatus due to the existence of the attachment. The present invention provides a purification apparatus comprising an attachment directly mounted on an outer wall of the apparatus; and a covering material made of a low heat conductive material which partly or entirely covers the outer wall of the apparatus, and which partly or entirely covers the attachment.

Abstract: The present invention provides an industrially easy and economical method for purification of acrylic acid which enables to efficiently eliminate impurities from a crude acrylic acid containing aldehydes as the impurities while the formation of acrylic acid polymer is inhibited. The method for purification of acrylic acid includes the step of distilling a crude acrylic acid which is charged with an aldehyde treatment chemical, wherein the concentration ratio of furfural to acrolein by weight in the crude acrylic acid is adjusted so as to satisfy the following equation: (furfural concentration by weight)/(acrolein concentration by weight)?100.

Abstract: The invention concerns a method of purifying a (meth) acrylic monomer selected among (meth) acrylic acids and their esters, by distillation in the presence of at least a polymerisation inhibitor requiring input of oxygen and/or an inhibitor having better efficacy in the presence of oxygen for stabilizing the liquid phase. The invention is characterized in that the distillation is performed in the presence of a NO2 gas, with an oxygen/organic vapor (p/p) ratio ranging between 0.02 and 3%, and with a NO2 condensed organic vapor (p/p) ratio ranging between 0.01 and 50 ppm.

Abstract: Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds. Also disclosed is a composition of matter comprising: A) an ethylenically unsaturated monomer and B) an effective inhibiting amount, sufficient to prevent premature polymerization during distillation or purification of said ethylenically unsaturated monomer, of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds used together with an effective amount of oxygen or air to enhance the inhibiting activity of said inhibitor.

Abstract: An apparatus and a process for purification of an acrylic acid family.

Abstract: A method of inhibiting fouling and viscosity increase in hydrocarbon streams including ethylenically unsaturated monomers is disclosed. The method includes the step of adding to the hydrocarbon stream an effective amount of one or more quinone methides of the formula: wherein R1, R2, and R3 are independently selected from the group consisting of H, —OH, —SH, —NH2, alkyl, cycloalkyl, heterocyclo, and aryl.

Abstract: Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds. Also disclosed is a composition of matter comprising: A) an ethylenically unsaturated monomer and B) an effective inhibiting amount, sufficient to prevent premature polymerization during distillation or purification of said ethylenically unsaturated monomer, of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds used together with an effective amount of oxygen or air to enhance the inhibiting activity of said inhibitor.

Abstract: Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of: A) at least one first inhibitor selected from the group consisting of C-nitrosoaniline compounds; and B) at least one second inhibitor selected from the group consisting of quinone alkides, nitroaromatic compounds, hydroxylamine compounds, phenylenediamine compounds, quinone compounds, and hydroquinone compounds. Also disclosed is a composition of matter comprising: A) at least one member selected from the group consisting of C-nitrosoaniline compounds; and B) at least one member selected from the group consisting of quinone alkides, nitroaromatic compounds, hydroxylamine compounds, phenylenediamine compounds, quinone compounds, and hydroquinone compounds.

Abstract: A process for inhibiting a polymerization of an easily polymerizable compound purification system is disclosed. According to the present invention, the polymerization of the easily polymerizable compound such as (meth)acrylic acid and (meth)acrylate flowed into a vacuum section can be inhibited by contacting a liquid containing a polymerization inhibitor with the compound directly in the vacuum section. When the vacuum section includes a gas and liquid contact chamber (usually a condenser), the liquid containing a polymerization inhibitor may be supplied to the chamber. When the vacuum section includes a liquid ejector and/or a nash pump as a vacuuming device, the liquid containing a polymerization inhibitor may be circulated by the liquid ejector and/or the nash pump for reducing a pressure of a purifying section. Examples of easily polymerizable compounds are (meth)acrylic acid and (meth)acrylates.

Abstract: A process for the distillation of vinylaromatic monomers in the presence of 4-tert-butylcatechol (TBC) and oxygen, wherein no aromatic nitro or amino compound is present in any effective amount. The process is particularly suitable for destabilizing and purifying styrene which has been stabilized with 4-tert-butylcatechol (TBC) for transportation.

Abstract: A process for preventing undesired polymerization is conducted by maintaining an effective concentration of a stabilizer which comprises N-oxyl radicals in a mixture containing ethylenically unsaturated compounds, wherein (i) an electronic signal which correlates with the concentration of the N-oxyl radicals in the mixture is obtained periodically or continuously, (ii) the electronic signal is compared with a reference value, and (iii) addition of a stabilizer to the mixture is controlled according to the comparison (ii). The signal is preferably obtained by ESR measurement. The process permits efficient use of the stabilizer.

Abstract: In a distillation apparatus, a production process and a purification method of readily polymerizable compounds, a problem of the invention is to solve a serious plugging problem in a large-sized distillation column as in the commercial equipment and to provide an apparatus and a method for distilling and purifying a readily polymerizable compound stably over a long period of time.

Abstract: Thermal separating process between at least one gaseous and at least one liquid stream, of which at least one comprises (meth)acrylic monomers, in a separating column whose separating internals are mass transfer trays, in which the liquid stream is polymerization-inhibited and used for spraying the surface of the separating column, and internal surfaces which are in the shadow region of the spraying are removed from the shadow region by covering.

Abstract: Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds.

Abstract: Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds.

Abstract: (Meth)acrylic acid is worked up in the presence of at least one stabilizer by a process in which a stabilizer-containing mixture originating from the working-up and substantially freed from (meth)acrylic acid is passed into a distillation apparatus and a stabilizer-containing low boiler stream obtained from said apparatus is recycled to the working-up.