Abstract: Disclosed is a process for recovering a water-soluble complex mixture of organic compounds from an aqueous stream through extraction and/or through contact of the aqueous stream with a sorbent or sorbents selected from the group consisting of polymeric microreticular sorbent resins, zeolite-based adsorbents, clay-based adsorbents, activated carbon-based sorbents, and mixtures thereof; and including methods to recover the removed organic compounds.

Abstract: Disclosed herein are processes for removing water from organic compounds, especially polar compounds such as alcohols. The processes include a membrane-based dehydration step, using a membrane that has a dioxole-based polymer selective layer or the like and a hydrophilic selective layer, and can operate even when the stream to be treated has a high water content, such as 10 wt % or more. The processes are particularly useful for dehydrating ethanol.

Abstract: Process for preparing high-concentration gaseous formaldehyde having a molar CH2O:H2O ratio of ?0.6 from an aqueous formaldehyde solution by evaporation of at least part of the solution, in which the aqueous formaldehyde solution is heated to a vaporization temperature T and the gas phase formed is taken off, wherein the evaporation temperature T obeys the relationship: T[° C.]?T?min[° C.] where T?min(c)=A+B×(c/100)+C×(c/100)2+D×(c/100)3 and A=+68.759, B=+124.77, C=?12.851, D=?10.095, where c is the instantaneous CH2O content of the aqueous formaldehyde solution during the evaporation in percent by weight and is from 20 to 99% by weight.

Abstract: Process for preparing high-concentration formaldehyde solutions having a CH2O content of ?50% by weight from an aqueous formaldehyde solution having a lower CH2O content by evaporation of part of this solution (partial evaporation), in which the aqueous formaldehyde solution is heated to an evaporation temperature T at which the gas phase becomes enriched in water relative to the liquid phase and the gas phase formed is taken off continuously or discontinuously, wherein the evaporation temperature T obeys the relationship: T[° C.]<Tmax[° C.] where Tmax(c)=A+B×(c/100)+C×(c/100)2+D×(c/100)3 and A=+68.759, B=+124.77, C=?12.851, D=?10.095, where c is the instantaneous CH2O content of the aqueous formaldehyde solution during the evaporation in percent by weight and is from 20 to 99% by weight.

Abstract: A process for preparing a high-concentration formaldehyde solution by removing water from a lower-concentration formaldehyde solution having a formaldehyde content of from 5 to 50% by weight, in which the lower-concentration formaldehyde solution is fed to a preheater and heated in the preheater, depressurized via a pressure maintenance device and concentrated in a helical tube evaporator to give a vapor stream and the high-concentration formaldehyde solution as bottom stream, wherein the heated lower-concentration formaldehyde hyde solution is depressurized in the pressure maintenance device to give a two-phase mixture which is fed into the helical tube evaporator, is proposed.

Abstract: A formaldehyde-containing product is separated from a formalin solution containing formaldehyde, water, and methanol by distilling in the presence of a water entraining compound, especially methyl propionate or methyl methacrylate. The product contains substantially less water than in the solution and may be used, for example, in a further process which requires a source of formaldehyde containing a relatively low level of water, for example, the catalyzed reaction of methy propionate with formaldehyde and methanol to produce methyl methacrylate.

Abstract: There is provided a process for reducing formaldehyde content of a gas comprising the step of contacting the gas with an aqueous oxidizing solution comprising at least one cation, a base, and H2O2 so as to oxidize at least a part of the formaldehyde contained in the gas into formic acid. Thus, a gas having a reduced content in formaldehyde as compared to the gas before the process and a solution comprising formic acid, are so-obtained. Such a process can be particularly useful for treating various types of gases containing formaldehyde.

Abstract: Methods, compositions, and devices for alleviating the problems of toxic discharge of aldehydes present in waste streams are disclosed. The methods relate to forming neutralized aldehydes by treating aldehydes with oxidizing agents. The oxidizing agents offer a simple, effective, fast and inexpensive solution for treatment of toxic aldehydes prior to disposal into the environment.

Abstract: A method for formaldehyde production through catalytic oxidation of methanol, comprising the steps of feeding to a first oxidation catalytic bed (2) a gas flow comprising methanol and oxygen at a predetermined crossing linear flow rate, obtaining at the outlet of said first catalytic bed (2) a flow of gaseous reaction products comprising unreacted methanol, and feeding the flow of gaseous products to a second oxidation catalytic bed (6) is distinguished by the fact that the flow of gaseous reaction products comprising unreacted methanol is fed to the second catalytic bed (6) with a crossing linear flow rate substantially equal to said predetermined first catalytic bed (2) feeding flow rate.

Abstract: A process is provided for the production of formaldehyde from methyl chloride. In the process methyl chloride is oxidized with air over a catalyst to give formaldehyde and hydrogen chloride. In a preferred embodiment of the invention, a mixture of two different catalysts is used, one catalyst to promote the hydrolysis of methyl chloride to methyl alcohol, and the other catalyst to oxidize the methyl alcohol so formed to formaldehyde. The reaction kinetics can be regulated by adjusting the proportion of the two catalysts in the mixture. In this manner, the release of heat from the reaction can be controlled and excessive temperatures in the catalyst mixture can be avoided.

Abstract: Formaldehyde is removed by distillation from reaction solutions containing a methlolated alkanal which was obtained from the reaction of formaldehyde with an alkanal which has at least one acidic hydrogen atom &agr; to the carbonyl function or from the reaction of a 2-alkylacrolein or acrolein with water and formaldehyde, by a process in which this reaction was carried out in the presence of catalytic amounts of organic amine. The process permits the improved removal of formaldehyde from the reaction mixture and furthermore facilitates the hydrogenation of the alkanals thus obtained to give polyols.

Abstract: A method for absorbing formaldehyde from gaseous mixtures that contain it, and a method for regenerating the absorption compound used.

Abstract: A method wherein a sour natural gas stream can be treated to produce primarily carbon monoxide from methane, and the carbon monoxide and hydrogensulfide are reacted to produce methyl mercaptans, (primarily methanethiol (CH3SH) and a small amount of dimethyl sulfide (CH3SCH3)). The methyl mercaptans preferably are passed in contact with a catalyst comprising a supported metal oxide or a bulk metal oxide in the presence of an oxidizing agent and for a time sufficient to convert at least a portion of the methyl mercaptan to formaldehyde (CH2O), and sulfur dioxide (SO2).

Abstract: Methods, compositions, and devices for alleviating the problems of toxic discharge of aldehydes present in waste streams are disclosed. The methods relate to forming neutralized aldehydes by treating aldehydes with oxidizing agents. The oxidizing agents offer a simple, effective, fast and inexpensive solution for treatment of toxic aldehydes prior to disposal into the environment.

Abstract: A process and an apparatus for the post-purification in particular of pyrolysis gases for preparing pure formaldehyde, hemiformal being pyrolyzed in an evaporator, the resulting formaldehyde vapor being passed through a condensed liquid component collected in the bottom area of the evaporator, the condensed liquid component being passed out as a falling film situated on the inner wall through a cooled outlet tube disposed in the bottom area of the evaporator and the formaldehyde vapor being passed through the cooled outlet tube in cocurrent and the liquid component and the formaldehyde being taken off separately at the outlet tube end remote from the evaporator.

Abstract: A formaldehyde-containing product is separated from a formalin solution containing formaldehyde, water and methanol by distilling the solution in the presence of a water entraining compound, especially methyl propionate or methyl methacrylate. The product contains substantially less water than in the solution and may be used, for example, in a further process which requires a source of formaldehyde containing a relatively low level of water, for example, the catalyzed reaction of methyl propionate with formaldehyde and methanol to produce methyl methacrylate.

Abstract: The present invention provides a method of using a silica-supported 12-molybdosilicic acid catalyst consisting of 12-moloybdosilicic acid supported on silica, in which 12-molybdosilicic acid is supported in an amount not smaller than 10 mass % on silica, wherein the reaction system is heated in the presence of the silica-supported 12-molybdosilicic acid catalyst to the operating temperature of the catalyst at a rate not lower than 100° C./min.

Abstract: A process for the post-purification in particular of pyrolysis gases for preparing pure formaldehyde, hemiformal being pyrolyzed in an evaporator, the resulting formaldehyde vapor being passed through a condensed liquid component collected in the bottom area of the evaporator, the condensed liquid component being passed out as a falling film situated on the inner wall through a cooled outlet tube disposed in the bottom area of the evaporator and the formaldehyde vapor being passed through the cooled outlet tube in cocurrent and the liquid component and the formaldehyde being taken off separately at the outlet tube end remote from the evaporator.

Abstract: A process for producing methylal that involves feeding a liquid containing methanol, formaldehyde and water to an uppermost reactor of at least four solid acid catalyst-filled reactors which are each externally connected to an intermediate portion of a distillation column; and forcibly circulating a liquid containing methanol, formaldehyde, water and produced methylal in a temperature range of 80° C. to 100° C.

Abstract: In a process for preparing formaldehyde from methanol by dehydrogenation in a reactor in the presence of a catalyst at a temperature in the range from 300 to 1000° C., a carrier gas stream which has a temperature above the dehydrogenation temperature is fed to the reactor.

Abstract: The present invention provides a silica-supported 12-molybdosilicic acid catalyst comprising a silica carrier and at least 10% by weight, based on the silica amount, of 12-molybdosilicic acid supported on the carrier and a method of producing formaldehyde directly from a mixed gas of methane and oxygen in the presence of the particular catalyst. Formaldehyde can be produced at a high yield in the present invention without requiring a reforming process of methane with water vapor that consumes a large amount of energy. In addition, attentions are also paid to the air pollution and water contamination problems in the present invention.

Abstract: Abstract A process for purifying formaldehyde in which the formaldehyde is scrubbed with alcohol in an absorption unit and in the course of this reacted virtually completely to form the hemiformal and is simultaneously separated off from gaseous impurities in a first purification step. In a desorption unit, the residual impurities are then converted into a gaseous state and separated off from the liquid hemiformal, whereupon the purified hemiformal is thermally cleaved into alcohol and formaldehyde in a pyrolysis unit. The formaldehyde thus prepared is suitable, for example, for preparing oligomers, polymers, dyestuffs and fertilizers, as well as for the treatment of seeds.

Abstract: A method wherein a gas stream containing a methyl mercaptan is passed in contact with a catalyst comprising a supported metal oxide or a bulk metal oxide in the presence of an oxidizing agent and for a time sufficient to convert at least a portion of the methyl mercaptan to formaldehyde (CH.sub.2 O) and sulfur dioxide (SO.sub.

Abstract: In a process for the preparation of aqueous formaldehyde solutions consisting of the following steps:(a) reaction of a methanol/water/air mixture in vapor form at elevated temperature over a catalyst,(b) absorption of the reaction mixture in one or more successive absorption stages with the formation of a methanol-containing aqueous formaldehyde solution and(c) removal by fractional distillation of a fraction esentially containing methanol and water,the methanol/water/air mixture which is required for the reaction is evaporated by means of heat which is withdrawn by indirect heat exchange from the formaldehyde solution being formed in the absorber and/or at least some of the vapors obtained by fractional distillation are condensed by means of liquid water. This condensate is fed together with fresh methanol and with air into the evaporator which is upstream from the catalyst stage.

Abstract: A process for producing formaldehyde having high purity is disclosed, which comprises: (A) feeding crude formaldehyde containing water and methanol to the middle or lower part of a distillation column, and feeding a polyalkylene oxide compound which is inert to formaldehyde to the upper part of the column in an amount at least 10 times the total weight of the water and methanol contained in the crude formaldehyde; (B) carrying out distillation; and (C) recovering purified formaldehyde gas from the top of the column while withdrawing a solution containing the polyalkylene oxide compound, water and methanol from the bottom of the column. Using this process, formaldehyde having stable high purity can be obtained continuously through simplified steps at low cost.

Abstract: Aqueous compositions containing organic oxygenates such as methyl isobutyl ketone are treated by pervaporation through a polyvinyl alcohol/polyacrylic acid membrane to yield retentate containing increased concentration of oxygenate.

Abstract: A process is disclosed for producing an alpha-, beta-ethylenically unsaturated monocarboxylic acid compound which comprises the aldol-type condensation of a saturated aliphatic monocarboxylic acid compound under vapor phase conditions in the presence of a hydrocarbon of 6 to 12 carbon atoms and a solid catalyst.

Abstract: Waste heat possessed by a hot formaldehyde product gas obtained by catalytic reaction of methanol with air is heat exchanged with pressurized water in a waste heat boiler, thereby generating steam, and then leading the product gas to a formaldehyde absorption column, thereby absorbing formaldehyde, into an aqueous solution, and heat exchanging a recycling solution for a feed gas humidifier with the aqueous solution withdrawn from the bottom of absorption column. The waste heat can be efficiently recovered without deposition of paraformaldehyde on the heat transfer surface of heat exchanger and the amount of additional steam can be reduced or made entirely zero.

Abstract: Aqueous formaldehyde solutions containing minor amounts of methanol are substantially stripped of methanol by a low energy process at relatively low temperature by means of recycled inert gas in a stripping column comprising at least about 1.5 theoretical transfer units for stripping methanol.

Abstract: Formaldehyde manufacture by oxidative-dehydrogenation of methanol over a silver or copper catalyst. Aqueous formaldehyde solution is obtained from the reaction and is substantially stripped of methanol by a low energy process at relatively low temperature by means of recycled off-gas in a stripping column comprising at least about 1.5 theoretical transfer units for stripping methanol.

Abstract: A method for purifying air by removing gaseous formaldehyde under ambient conditions, by bringing the air in contact with a solid shaped composition consisting essentially of one or more polyhydric water-soluble polymers and ambient moisture, in the absence and in the presence of a solid substrate.

Abstract: Formaldehyde manufacture by oxidative-dehydrogenation of methanol over a silver or copper catalyst. Aqueous formaldehyde solution is obtained from the reaction and is stripped of methanol and water by a low energy process at relatively low temperature by means of recycled inert gas in a stripping column comprising at least about 1.5 theoretical transfer units for stripping methanol.

Abstract: A mixture containing formaldehyde and water is separated effectively by contacting with adsorbents of specific type A zeolites containing exchanged cations of the elements from Group IA (4) to (6) or Group IIA (6) or mixture thereof of the Periodic Table of Elements.