Crude methanol rectification process includes single-column process, two-column process, three -column process and energy-saving three-column process. The feature of Four processes are as follows:
| No. | Crude methanol rectification process | Feature |
| 1 | single-column process | 1.Methonal-water regroup, separate in one column 2.Advatange: investment saving, reduce heat energy consumption 3.Disadvantage: the purity of refined methonal is not very pure. |
| 2 | two-column process | 1.The combination of pre-recification column and main rectification column 2.Refine crude methonol including dimethyl ether and other light components and reducing impurities 3.Advantage: simple process ,user friendly, less investment 4.Disadvange: high energy consumption, low purity |
| 3 | three -column process | 1.Three rectification column work under the same pressure. The third rectification column produces 2.Advantage: high purity 3.Disadvantage: high investment. Need more area |
| 4 | energy-saving three-column process | 1.Two main rectification columns and final rectification column, the first main rectification column is pressure-increasing column. The second one is normal pressure column. Two columes produce 50%-50% 2.Advantage: envery saving, reduce the ethanol content of the purified methanol, product quality is better; methanol yield is higher, low operating costs 3.Disadvantage: high one-time investment |
Our company's crude methanol distillation technology is based on the fourth energy-saving three-tower process, the main feature is to fully optimize the heat transfer network, so that the use of steam and circulating water to a minimum, in order to achieve energy conservation and investment optimization.
(1) High yield of the process: fine methanol recovery rate of 99.86% (refined methanol production and feed the amount of methanol contained in the ratio)
(2) Using a mature double-effect distillation method: the use of pressurized overhead gas phase for the atmospheric tower reboiler heat source.
To 300,000 tons / year 90.82% methanol distillation as an example.
