The present invention discloses a composite multi-carbon
alcohol cosolvent and a preparation method thereof. The composite multi-carbon
alcohol cosolvent adopts offcuts from an
ethanol production
plant or a
winery as raw materials, wherein the offcuts comprise 40-70% of
ethanol, 5-15% of
propanol and isopropanol, 5-15% of n-
butanol,
isobutanol and
tert butyl alcohol, 1-5% of
amyl alcohol,
isoamyl alcohol, hexyl alcohol,
heptanol,
octanol, nonanol, decanol and other liquid multi-carbon alcohols, and 14-40% of water. With performing steps of the
raw material pretreatment,
pervaporation membrane
dehydration, blending and the like, the composite multi-carbon alcohol cosolvent with the
water content less than 0.5% is prepared. The composite multi-carbon alcohol cosolvent can be adopted as an alcohol oil cosolvent, and the assistant
dissolution effect of the composite multi-carbon alcohol cosolvent is high. The composite multi-carbon alcohol cosolvent provides lower
toxicity than the
aromatic alcohol oil cosolvent, and provides lower
corrosion than the
acetone alcohol oil cosolvent. In the prior art, boiling points of the
propanol, the
isobutanol, the n-
butanol and the like are close to the
boiling point of the water, and the
azeotrope effect is further generated, such that the
dehydration is difficult to perform by the
fractionation method. With the preparation method of the present invention, the
disadvantage in the prior art is overcome. The production cost for the composite multi-carbon alcohol cosolvent is significantly lower than the production cost of the composite multi-carbon alcohol cosolvent produced by blending the corresponding
monomer multi-carbon alcohol, and the assistant
dissolution effect of the composite multi-carbon alcohol cosolvent is higher than the assistant
dissolution effect of each
monomer multi-carbon alcohol.