A process by which the raw material, a gas comprising mainly hydrogen, carbon monoxide and carbon dioxide, is introduced into a first reactor together with a catalyst, in which one or more reactions take place that produce methanol or dimethyl ether or both, which are then introduced into a second reactor adding oxygen and a catalyst and producing formaldehyde and a minority of dimethyl ether, and where there may be an excess of water, such water being extracted from the process and the remaining products being introduced into the third reactor with, optionally, an additive, and such raw material is exposed to catalysts and under an atmosphere at medium temperature and pressure, in order to produce three or four groups of chemical reactions that, after extracting most of the water that is generated as a residue during the process, produces as a result a liquid multifunctional product that can be used as a solvent, a foaming agent or an oxygenated fuel; said product, normally a fluid, comprises polyoxymethylene dimethyl ethers with molecular formula CH3O(CH2O)nCH3 wherein n has a value between 1 and 7.

A process by which the raw material, a gas comprising mainly hydrogen, carbon monoxide and carbon dioxide, is introduced into a first reactor together with a catalyst, in which one or more reactions take place that produce methanol or dimethyl ether or both, which are then introduced into a second reactor adding oxygen and a catalyst and producing formaldehyde and a minority of dimethyl ether, and where there may be an excess of water, such water being extracted from the process and the remaining products being introduced into the third reactor with, optionally, an additive, and such raw material is exposed to catalysts and under an atmosphere at medium temperature and pressure, in order to produce three or four groups of chemical reactions that, after extracting most of the water that is generated as a residue during the process, produces as a result a liquid multifunctional product that can be used as a solvent, a foaming agent or an oxygenated fuel; said product, normally a fluid, comprises polyoxymethylene dimethyl ethers with molecular formula CH3O(CH2O)nCH3 wherein n has a value between 1 and 7.

Process for preparing polyoxymethylene dimethyl ethers having 3 oxymethylene units (OME.sub.n3), comprising the steps:

(i) introduction of formaldehyde, methanol and water into a reactor R and reaction to give a reaction mixture containing formaldehyde, water, methylene glycol, polyoxymethylene glycols, methanol, hemiformals, methylal (OME.sub.n=1) and polyoxymethylene dimethyl ethers (OME.sub.n>1);
(ii) introduction of the reaction mixture into a reactive distillation column K1 and separation into a low boiler fraction F1 containing formaldehyde, water, methylene glycol, polyoxymethylene glycols, methanol, hemiformals, methylal (OME.sub.n=1) and polyoxymethylene dimethyl ethers having from 2 to 3 oxymethylene units (OME.sub.n=2-3) and a high boiler fraction F2 containing polyoxymethylene dimethyl ethers having more than two oxymethylene units (OME.sub.n3).

Process for preparing polyoxymethylene dimethyl ethers having 3 oxymethylene units (OME.sub.n3), comprising the steps:

(i) introduction of formaldehyde, methanol and water into a reactor R and reaction to give a reaction mixture containing formaldehyde, water, methylene glycol, polyoxymethylene glycols, methanol, hemiformals, methylal (OME.sub.n=1) and polyoxymethylene dimethyl ethers (OME.sub.n>1);
(ii) introduction of the reaction mixture into a reactive distillation column K1 and separation into a low boiler fraction F1 containing formaldehyde, water, methylene glycol, polyoxymethylene glycols, methanol, hemiformals, methylal (OME.sub.n=1) and polyoxymethylene dimethyl ethers having from 2 to 3 oxymethylene units (OME.sub.n=2-3) and a high boiler fraction F2 containing polyoxymethylene dimethyl ethers having more than two oxymethylene units (OME.sub.n3).

Process for preparing polyoxymethylene dimethyl ethers having 3 oxymethylene units (OME.sub.n3), comprising the steps:

(i) introduction of formaldehyde, methanol and water into a reactor R and reaction to give a reaction mixture containing formaldehyde, water, methylene glycol, polyoxymethylene glycols, methanol, hemiformals, methylal (OME.sub.n=1) and polyoxymethylene dimethyl ethers (OME.sub.n>1);
(ii) introduction of the reaction mixture into a reactive distillation column K1 and separation into a low boiler fraction F1 containing formaldehyde, water, methylene glycol, polyoxymethylene glycols, methanol, hemiformals, methylal (OME.sub.n=1) and polyoxymethylene dimethyl ethers having from 2 to 3 oxymethylene units (OME.sub.n=2-3) and a high boiler fraction F2 containing polyoxymethylene dimethyl ethers having more than two oxymethylene units (OME.sub.n3).

A method for preparing methyl formate in which a raw material containing formaldehyde, methanol and/or dimethyl ether is introduced into a first reaction zone to come into contact with a catalyst A, and a component I is obtained by separation, the component I is introduced into a second reaction zone to come into contact with a catalyst B so as to obtain, by separation, methyl formate as a product, dimethyl ether that is returned to the first reaction zone and a component II that is returned to the second reaction zone, the catalysts have a long service life, the reaction conditions are mild, and the utilization rate of the raw material is high, thus enabling a continuous production for large-scale industrial application.

A method for preparing methyl formate in which a raw material containing formaldehyde, methanol and/or dimethyl ether is introduced into a first reaction zone to come into contact with a catalyst A, and a component I is obtained by separation, the component I is introduced into a second reaction zone to come into contact with a catalyst B so as to obtain, by separation, methyl formate as a product, dimethyl ether that is returned to the first reaction zone and a component II that is returned to the second reaction zone, the catalysts have a long service life, the reaction conditions are mild, and the utilization rate of the raw material is high, thus enabling a continuous production for large-scale industrial application.

The invention relates to a process for preparing chloroacetaldehyde acetals of monohydric, dihydric or higher-functionality aliphatic alcohols, in which the chloroacetaldehyde acetal is obtained from an aqueous chloroacetaldehyde solution in the presence of the alcohol to be acetalized and an acid catalyst by azeotropic removal of water with the aid of a solvent, wherein the solvent is a halogenated solvent.

The invention relates to a process for preparing chloroacetaldehyde acetals of monohydric, dihydric or higher-functionality aliphatic alcohols, in which the chloroacetaldehyde acetal is obtained from an aqueous chloroacetaldehyde solution in the presence of the alcohol to be acetalized and an acid catalyst by azeotropic removal of water with the aid of a solvent, wherein the solvent is a halogenated solvent.

The invention relates to a process for preparing chloroacetaldehyde acetals of monohydric, dihydric or higher-functionality aliphatic alcohols, in which the chloroacetaldehyde acetal is obtained from an aqueous chloroacetaldehyde solution in the presence of the alcohol to be acetalized and an acid catalyst by azeotropic removal of water with the aid of a solvent, wherein the solvent is a halogenated solvent.