Industrial Synthetic Ethanol (4)

4.

4.

4.

4.

4.

4.

4.

a.

b.

c.

d.

4.

Use a pipette to draw 5mL sample, place it in a 100mL volumetric flask, dilute to the mark with water, and mix well

Take 2mL of the above sample solution and place it in the colorimetric tube, and perform the determination according to the steps (b and c) of drawing the standard curve, and do a blank test at the same time

4.

Find the volume of methanol on the standard outlet line according to the absorbance of the sample

The white content of methanol x _{3 is} calculated according to formula (3):

In the formula; V ₀ -the volume of methanol in the blank test obtained from the standard curve, mL;

V ₁ —Check the volume of methanol in the sample from the standard curve , mL;

V ₂ —sample volume, mL
.

Take the arithmetic mean of the two parallel determination results as the determination result
.

4.
5.
6 Allowance

The difference between the two parallel determination results is not more than 0.
003%
.

4.
6 Determination of evaporation residue

According to the provisions of GB6324.
2
.

Take the arithmetic mean of the two parallel determination results as the determination result
.

Allowable difference; the difference between two parallel determination results is not more than 0.
0003%
.

4.
7 Determination of oxidation time of potassium permanganate

According to the provisions of GB6324.
3
.

4.
8 Determination of Fusel Oil Content

4.
8.
1 Principle

The color produced by the reaction between dimethylaminobenzaldehyde and the fusel oil in the sample was compared with the color of the standard solution with known fusel oil content
.

4.
8.
2 Reagents and solutions

4.
8.
2.
1 Isobutanol
.

4.
8.
2.
2 Isoamyl alcohol
.

4.
8.
2.
3 Sulfuric acid (superior grade pure).

4.
8.
2.
4 Para-dimethylaminobenzaldehyde developer:

Weigh 0.
1000g to 0.
001g, p-dimethylaminobenzaldehyde [(CH ₃ ) ₂ NC ₆ H ₄ CHO], place it in a 200mL volumetric flask, dissolve and dilute to the mark with sulfuric acid , and mix well
.
Transfer to a brown bottle
.

4.
8.
2.
5 Fusel oil standard solution: 0.
0080%, 0.
0150%
.

Take 1.
0 mL of isobutanol and 1.
0 mL of isoamyl alcohol, respectively place them in two 1000 mL volumetric flasks that already have part of the fusel oil-free ethanol, and dilute them to the mark with the fusel-free oil ethanol
.
Obtain 0.
1% isobutanol solution (liquid A) and 0.
1% isoamyl alcohol solution (liquid B)
.

A solution according to: B solution = 3: 1 ratio, 0.
1% of fusel oil to obtain standard solutions A
.

Use a pipette to draw 8.
0, 15.
0 mL of fusel oil standard solution A, place them in a 100 mL volumetric flask, and dilute to the mark with ethanol-free fusel oil
.

Note: Preparation of ethanol without fusel oil : take the ethanol with low fusel oil content for distillation, remove 50 mL of the first distillation and final distillation, cut off the middle distillate, and repeat the distillation twice
.

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