Pressure condition

Highest temperature/˚C

Dosage of catalyst

Reaction time/h

Dehydration

rate/%

Emulsion in condenser pipes

Normal pressure

150

1%

12

45.8%

Yellow emulsion

From normal pressure to reduced pressure

150

1%

10

74.4%

Trace amounts of yellow emulsion

Reduced pressure

150

1%

8

20.4%

A lot of yellow emulsion