Application field
Background of the project
Acetonitrile is an important organic chemical raw material widely used as a solvent or a reactant. It is often necessary to separate acetonitrile from water during solvent production or recycling. Since acetonitrile and water are azeotroped, the azeotropic point is 76.3 ° C under normal pressure, and the mass of acetonitrile is 84%, which cannot be achieved by ordinary rectification. The current separation methods are mainly (salted) extractive distillation, pressure swing distillation and membrane pervaporation dehydration.
Technical comparison
|
name |
Membrane separation |
Pressure swing distillation |
|
Steam (t/t raw material) |
1.2 |
2.5 |
|
Circulating water (m3/t raw material) |
50 |
250 |
|
Low temperature water (m3/t raw material) |
4 |
20 |
|
Frozen water (m3/t raw material) |
5 |
0 |
|
Electricity (kWh/t raw material) |
30 |
20 |
|
Operating cost (yuan/t raw material) |
287 |
580 |
|
Yield (%) |
High, ≥97 |
Low, 90~93 |
|
Number of distillation towers |
1 |
2 |
|
Maximum operating pressure (MPa(G)) |
0.2 |
0.3~0.4 |
|
Required steam pressure (MPa(G)) |
≥0.4 |
0.6~0.7 |
|
Operational complexity |
Simple, automatic control |
Complex, multi-person operation |
|
Equipment investment |
Relatively high |
low |
|
Annual operating cost (measured by 10m3 per day, 250 days per year, ie 2000 tons/year) |
Energy consumption savings of 600,000 yuan; yield increase savings of >800,000 yuan / year (according to acetonitrile 10,000 yuan / ton), total savings of more than 1.4 million yuan / year |
|
|
Process selection |
recommend |
Not recommended |
