Application field
Background technique
Tetrahydrofuran is widely used as a solvent, a raw material for organic synthesis and a pharmaceutical solvent, such as the preparation of Grignard reagents. Tetrahydrofuran can form an azeotropic mixture with water (water content 5.3%) during production and use, and desiccant is generally used for dehydration recovery (such as adding alkali, salt water absorption), complicated operation, high energy consumption, serious pollution, and low yield. And it is difficult to obtain high-purity solvents.
technical comparison
|
|
membrane dehydration |
Calcium chloride dehydration |
pressure swing distillation |
|
Number of distillation columns |
0 |
1~3 |
2 |
|
Operating pressure MPa(G) |
0.15~0.25 |
Atmospheric pressure |
High pressure tower: ≥0.4 |
|
Steam consumption t/t raw material |
0.32 |
0.3 |
1.5 |
|
Circulating water (32℃) consumes m 3 /t/raw material |
19 |
15 |
80 |
|
Low temperature water (15℃) consumes m 3 /t/raw material |
3 |
2 |
6 |
|
Consumption of chilled water (-3°C) m 3 /t/raw material |
18 |
- |
- |
|
Power consumption kWh/t raw material |
10 |
2 |
6 |
|
Calcium chloride consumption yuan/t raw material |
- |
170 |
- |
|
Processing cost yuan/t raw material |
97.3 |
236 |
325 |
|
Operational complexity |
Continuous operation, high degree of automation, one person operation |
Intermittent operation, labor-intensive, regular cleaning of the tower kettle is required |
Continuous operation, complex start-up and parking process, heavy workload |
|
safety |
Self-controlled chain, safe |
safer |
The pressure of the high-pressure tower is high, and the concentration of tetrahydrofuran in the tower kettle is high, and the safety is low |
|
equipment requirements |
no special requirements |
Equipment and pipelines need to be resistant to chloride ion corrosion |
The operating pressure of the high-pressure tower is high, and the requirements for equipment and sealing are high |
|
Process disadvantages |
none |
Produce more chlorine-containing waste liquid and waste residue |
The process of starting and stopping is complicated, the safety is low, the circulation of material and liquid is large, and the energy consumption is high |
