The present invention relates to a process for preparing polyoxymethylene dimethyl ethers, comprising the following steps: reaction of formaldehyde and methylal (OME.sub.1) in a reactor R1 to obtain a product mixture, distillative separation of the product mixture in a distillation unit D1 into a top stream which contains OME.sub.1, OME.sub.2, formaldehyde, methanol and water, and a bottom stream which contains OME.sub.≥3, mixing of the top stream drawn off from the distillation unit D1 with a methanol-containing stream, treatment of the mixture in a reactive distillation unit RD2 to form a top stream containing methylal and a water-containing bottom stream, introduction of the bottom stream drawn off from the distillation unit D1 into a distillation unit D3 and distillative separation of the polyoxymethylene dimethyl ethers.

The present invention relates to a process for preparing polyoxymethylene dimethyl ethers, comprising the following steps: reaction of formaldehyde and methylal (OME.sub.1) in a reactor R1 to obtain a product mixture, distillative separation of the product mixture in a distillation unit D1 into a top stream which contains OME.sub.1, OME.sub.2, formaldehyde, methanol and water, and a bottom stream which contains OME.sub.≥3, mixing of the top stream drawn off from the distillation unit D1 with a methanol-containing stream, treatment of the mixture in a reactive distillation unit RD2 to form a top stream containing methylal and a water-containing bottom stream, introduction of the bottom stream drawn off from the distillation unit D1 into a distillation unit D3 and distillative separation of the polyoxymethylene dimethyl ethers.

The present invention relates to a method for preparing a perfluorodialkyl ether, comprising the steps of: (A) preparing a perfluorodialkyl ether from a compound represented by Formula 1 in the presence of a metal fluoride; and (B) isolating the perfluorodialkyl ether, and to an apparatus for preparing perfluorodialkyl ether, comprising: a reactor for preparing a perfluorodialkyl ether from a compound represented by Formula 1 in the presence of a metal fluoride; a reactant supplier for introducing the compound represented by Formula 1 into the reactor; and a discharge unit for discharging the perfluorodialkyl ether from the upper portion of the reactor.

The present invention relates to a method for preparing a perfluorodialkyl ether, comprising the steps of: (A) preparing a perfluorodialkyl ether from a compound represented by Formula 1 in the presence of a metal fluoride; and (B) isolating the perfluorodialkyl ether, and to an apparatus for preparing perfluorodialkyl ether, comprising: a reactor for preparing a perfluorodialkyl ether from a compound represented by Formula 1 in the presence of a metal fluoride; a reactant supplier for introducing the compound represented by Formula 1 into the reactor; and a discharge unit for discharging the perfluorodialkyl ether from the upper portion of the reactor.

The present invention relates to a process for the preparation of 2-isopentyl-2-isopropyl-1,3-dimethoxypropane, said process comprising the steps of: i) contacting iso-valderaldehyde with an aqueous solution of a hydroxide base selected from the group consisting of sodium hydroxide (NaOH), potassium hydroxide (KOH) or a combination thereof, said solution having an amount of said hydroxide base of at least 20% w/v, and (m)ethanol; to form (2Z)-2-isopropyl-5-methyl-2-hexenal; step ii) contacting (2Z)-2-iso-propyl-5-methyl-2-hexenal with a reducing system to form 2-isopropyl-5-methylhexanal; step iii) contacting 2-isopropyl-5-methylhexanal with formaldehyde and an inorganic base to form 2-isopentyl-2-isopropylpropane-1,3-diol; and step iv) contacting 2- isopentyl-2-isopropylpropane-1,3-diol with a methylation agent and a base to form 2-isopentyl-2-isopropyl-1,3-dimethoxypropane.

The present invention relates to a process for the preparation of 2-isopentyl-2-isopropyl-1,3-dimethoxypropane, said process comprising the steps of: i) contacting iso-valderaldehyde with an aqueous solution of a hydroxide base selected from the group consisting of sodium hydroxide (NaOH), potassium hydroxide (KOH) or a combination thereof, said solution having an amount of said hydroxide base of at least 20% w/v, and (m)ethanol; to form (2Z)-2-isopropyl-5-methyl-2-hexenal; step ii) contacting (2Z)-2-iso-propyl-5-methyl-2-hexenal with a reducing system to form 2-isopropyl-5-methylhexanal; step iii) contacting 2-isopropyl-5-methylhexanal with formaldehyde and an inorganic base to form 2-isopentyl-2-isopropylpropane-1,3-diol; and step iv) contacting 2- isopentyl-2-isopropylpropane-1,3-diol with a methylation agent and a base to form 2-isopentyl-2-isopropyl-1,3-dimethoxypropane.

A method can be used for preparing 1,2-propanediol, dipropylene glycol, and tripropylene glycol. The method involves reacting propene with hydrogen peroxide containing nitrate, in the presence of a catalyst mixture containing a phase transfer catalyst and a heteropolytungstate, in a liquid reaction mixture containing an aqueous phase with a maximum apparent pH of 6 and an organic phase. The method then involves separating the reaction mixture into an aqueous phase containing 1,2-propanediol, dipropylene glycol, tripropylene glycol, and nitrate and an organic phase. The method further involves recycling at least part of the separated organic phase to the reaction; hydrogenating the separated aqueous phase using a heterogeneous hydrogenation catalyst to provide a hydrogenated aqueous phase with a reduced nitrate content; and recovering 1,2-propanediol, dipropylene glycol, and tripropylene glycol from the hydrogenated aqueous phase by a sequential multiple-step distillation.

A method can be used for preparing 1,2-propanediol, dipropylene glycol, and tripropylene glycol. The method involves reacting propene with hydrogen peroxide containing nitrate, in the presence of a catalyst mixture containing a phase transfer catalyst and a heteropolytungstate, in a liquid reaction mixture containing an aqueous phase with a maximum apparent pH of 6 and an organic phase. The method then involves separating the reaction mixture into an aqueous phase containing 1,2-propanediol, dipropylene glycol, tripropylene glycol, and nitrate and an organic phase. The method further involves recycling at least part of the separated organic phase to the reaction; hydrogenating the separated aqueous phase using a heterogeneous hydrogenation catalyst to provide a hydrogenated aqueous phase with a reduced nitrate content; and recovering 1,2-propanediol, dipropylene glycol, and tripropylene glycol from the hydrogenated aqueous phase by a sequential multiple-step distillation.

Systems and processes for the efficient conversion of high concentration isoolefin streams to tertiary alkyl ethers are disclosed. The systems and processes may include a feed system to advantageously divide the high concentration isoolefin feed to multiple fixed bed reactors and a catalytic distillation reactor to control the reaction exotherm and achieve a high isoolefin conversion.

Systems and processes for the efficient conversion of high concentration isoolefin streams to tertiary alkyl ethers are disclosed. The systems and processes may include a feed system to advantageously divide the high concentration isoolefin feed to multiple fixed bed reactors and a catalytic distillation reactor to control the reaction exotherm and achieve a high isoolefin conversion.