The present invention relates to a 6-hydroxy-3-hexenyl alkoxymethyl ether compound of the following general formula (1): HOCH.sub.2CH.sub.2CH═CHCH.sub.2CH.sub.2OCH.sub.2OCH.sub.2R′ (1), R.sup.1 representing a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group; and also relates to a process for preparing a 3,13-octadecadien-1-ol compound of the following formula (6): CH.sub.3(CH.sub.2).sub.3CH═CH(CH.sub.2).sub.8CH═CHCH.sub.2CH.sub.2OH (6) from the 6-hydroxy-3-hexenyl alkoxymethyl ether compound (1).

The present invention relates to a 6-hydroxy-3-hexenyl alkoxymethyl ether compound of the following general formula (1): HOCH.sub.2CH.sub.2CH═CHCH.sub.2CH.sub.2OCH.sub.2OCH.sub.2R′ (1), R.sup.1 representing a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group; and also relates to a process for preparing a 3,13-octadecadien-1-ol compound of the following formula (6): CH.sub.3(CH.sub.2).sub.3CH═CH(CH.sub.2).sub.8CH═CHCH.sub.2CH.sub.2OH (6) from the 6-hydroxy-3-hexenyl alkoxymethyl ether compound (1).

A method for forming poly(dimethoxymethane) includes a step of separating a formaldehyde-containing blend into a first bottom stream and a first top stream. The first formaldehyde-containing blend includes methanol, formaldehyde, and water while the first bottom stream includes water. The first top stream includes dimethoxymethane that is produced from the reaction between methanol and formaldehyde. The first top stream is separated into a second bottom stream and a second top stream. The second bottom stream includes poly(dimethoxymethane) while the second top stream includes dimethoxymethane, methanol, and ethanol. The second top stream is separated into a third bottom stream and a third top stream. Third bottom stream includes methanol and ethanol while the third top stream includes dimethoxymethane. The third top steam can be recycled to form additional poly(dimethoxymethane). A system that implements the method is also provided.

A method for forming poly(dimethoxymethane) includes a step of separating a formaldehyde-containing blend into a first bottom stream and a first top stream. The first formaldehyde-containing blend includes methanol, formaldehyde, and water while the first bottom stream includes water. The first top stream includes dimethoxymethane that is produced from the reaction between methanol and formaldehyde. The first top stream is separated into a second bottom stream and a second top stream. The second bottom stream includes poly(dimethoxymethane) while the second top stream includes dimethoxymethane, methanol, and ethanol. The second top stream is separated into a third bottom stream and a third top stream. Third bottom stream includes methanol and ethanol while the third top stream includes dimethoxymethane. The third top steam can be recycled to form additional poly(dimethoxymethane). A system that implements the method is also provided.

The disclosure relates to a process for continuously producing polyoxymethylene dimethyl ethers at low temperature, pertains to the technical field of polyoxymethylene dimethyl ether preparation processes, and solves the technical problem of continuous production of polyoxymethylene dimethyl ether. A membrane separation element with precisely controlled pores in membrane is used to realize a direct separation of the feedstocks from the catalyst within the reactor, and effectively reduce the permeation resistance of the separation membrane tube. By oppositely switching the flowing direction of liquid reaction materials, the adhesion of the catalyst to the separation membrane tube is inhibited, and some particles stuck in separation membrane tube are removed, which ensures the continuous operation of the reaction process and allows a molecular sieve catalyst to exhibit its advantage of long catalytic life.

The disclosure relates to a process for continuously producing polyoxymethylene dimethyl ethers at low temperature, pertains to the technical field of polyoxymethylene dimethyl ether preparation processes, and solves the technical problem of continuous production of polyoxymethylene dimethyl ether. A membrane separation element with precisely controlled pores in membrane is used to realize a direct separation of the feedstocks from the catalyst within the reactor, and effectively reduce the permeation resistance of the separation membrane tube. By oppositely switching the flowing direction of liquid reaction materials, the adhesion of the catalyst to the separation membrane tube is inhibited, and some particles stuck in separation membrane tube are removed, which ensures the continuous operation of the reaction process and allows a molecular sieve catalyst to exhibit its advantage of long catalytic life.

The present invention provides a process for preparing an alkoxymethyl alkynyl ether compound having a terminal triple bond of the following formula (4): H—C≡C(CH.sub.2).sub.aOCH.sub.2OCH.sub.2R (4), wherein R represents a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group, and “a” represents an integer of 1 to 10, the method comprising subjecting an alkynol compound having a terminal triple bond of the following formula (1): H—C≡C(CH.sub.2).sub.aOH (1), wherein “a” is as defined above, to an alkoxymethylation with a halomethyl alkyl ether compound of the following formula (3): RCH.sub.2OCH.sub.2X (3), wherein X represents a halogen atom, and R is as defined above, in the presence of a dialkylaniline compound of the following formula (2): [CH.sub.3(CH.sub.2).sub.b][CH.sub.3(CH.sub.2).sub.c]NC.sub.6H.sub.5 (2), wherein b and c represent, independently of each other, an integer of 0 to 9, to form the alkoxymethyl alkynyl ether compound (4) having a terminal triple bond.

The present invention provides a process for preparing an alkoxymethyl alkynyl ether compound having a terminal triple bond of the following formula (4): H—C≡C(CH.sub.2).sub.aOCH.sub.2OCH.sub.2R (4), wherein R represents a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group, and “a” represents an integer of 1 to 10, the method comprising subjecting an alkynol compound having a terminal triple bond of the following formula (1): H—C≡C(CH.sub.2).sub.aOH (1), wherein “a” is as defined above, to an alkoxymethylation with a halomethyl alkyl ether compound of the following formula (3): RCH.sub.2OCH.sub.2X (3), wherein X represents a halogen atom, and R is as defined above, in the presence of a dialkylaniline compound of the following formula (2): [CH.sub.3(CH.sub.2).sub.b][CH.sub.3(CH.sub.2).sub.c]NC.sub.6H.sub.5 (2), wherein b and c represent, independently of each other, an integer of 0 to 9, to form the alkoxymethyl alkynyl ether compound (4) having a terminal triple bond.

A method of producing dimethoxymethane oligomers (DMMn), the method comprising: reacting a formaldehyde source and dimethoxymethane monomer (DMM1) in the presence of an acidic catalyst to produce a reaction effluent comprising DMMn and unreacted DMM1; and separating, from the reaction effluent, DMM1-2 including unreacted DMM1 and DMMn having a chain length n equal to 2 (DMM2), dimethoxymethane oligomers having a chain length n in the range of from 2-5 (DMM2-5), dimethoxymethane oligomers having a chain length n of ≥5 (DMM5+), or a combination thereof, wherein the separating comprises distillation in the presence of at least one alcohol, a distillate fuel, or both.

A method of producing dimethoxymethane oligomers (DMMn), the method comprising: reacting a formaldehyde source and dimethoxymethane monomer (DMM1) in the presence of an acidic catalyst to produce a reaction effluent comprising DMMn and unreacted DMM1; and separating, from the reaction effluent, DMM1-2 including unreacted DMM1 and DMMn having a chain length n equal to 2 (DMM2), dimethoxymethane oligomers having a chain length n in the range of from 2-5 (DMM2-5), dimethoxymethane oligomers having a chain length n of ≥5 (DMM5+), or a combination thereof, wherein the separating comprises distillation in the presence of at least one alcohol, a distillate fuel, or both.