The present invention provides a method for improving ultra-violet light transmittance of ethylene glycol, which includes the following steps: (1) subjecting ethylene glycol, a catalyst and water to a hydrolysis reaction at 120 C.-150 C.; and (2) adding a stabilizer into a product of the hydrolysis reaction, then conducting distillation at reduced pressure, and condensing to recover a fraction. The method of the present invention can effectively decompose impurities of carboxyl-, conjugated double bond-, aldehyde and ketone-containing complex organic compounds in the ethylene glycol which affect the ultra-violet light transmittance, obviously improve UV values of the ethylene glycol at 220 nm, 275 nm and 350 nm, give consideration to the requirements of environmental protection and safety and economic benefits, and have a broad application prospect.

A method of purifying raw methanol obtained in chemical pulping, wherein heavy oil is admixed with the raw methanol to prevent precipitation, and the methanol mixture is distilled or evaporated to recover the methanol. The heavy oil is formed by mixing and heating raw methanol obtained from a side stream of chemical hardwood pulping with an acidic aqueous solution to vaporize low boiling point sulfurous compounds and provide acidified raw methanol. The acidified raw methanol is separated into a liquid top phase, a liquid aqueous middle phase, and a liquid bottom phase. The liquid bottom phase is extracted to obtain the heavy oil.

A method of purifying raw methanol obtained in chemical pulping, wherein heavy oil is admixed with the raw methanol to prevent precipitation, and the methanol mixture is distilled or evaporated to recover the methanol. The heavy oil is formed by mixing and heating raw methanol obtained from a side stream of chemical hardwood pulping with an acidic aqueous solution to vaporize low boiling point sulfurous compounds and provide acidified raw methanol. The acidified raw methanol is separated into a liquid top phase, a liquid aqueous middle phase, and a liquid bottom phase. The liquid bottom phase is extracted to obtain the heavy oil.