Beiyang Lixing Extraction Tower Pressure Distillation Unit Distillation Tower

Beiyang Lixing Extraction Tower Pressure Distillation Unit Distillation Tower

1、 Key parameters of pressurized distillation unit

1. ‌pressure control‌

• Typical operating pressure: 0.65 ± 0.05 MPa (such as methanol pressurized tower), and the ethylene distillation tower can reach 1.8-2.2 MPa.

• Pressure regulation method: By adjusting the gas phase extraction or refrigerant volume, a DCS system is required to monitor pressure fluctuations.

• Pressure fluctuation impact: Exceeding ± 5 kPa may disrupt gas-liquid equilibrium and require triggering the reflux ratio adjustment device.

2. ‌Temperature configuration‌

• Top temperature: The methanol pressurized tower has a temperature range of 119-123 ℃ (corresponding to high-quality methanol), while the top temperature of the ethylene tower is as low as -30 ℃ to -25 ℃.

• Bottom temperature: methanol tower bottom 78 ± 2 ℃, ethylene tower bottom -15 ℃ to -10 ℃.

• Control accuracy: Industrial towers typically have a temperature of ± 1 ℃, while experimental towers can reach a temperature of ± 0.1 ℃.

2、 Extraction tower process parameters

1. ‌Extraction agent requirements‌

• The concentration should be greater than 60% (such as acetonitrile separation of butadiene), and the feeding position should be located above the raw material inlet.

• The solvent recovery section should be located at the top of the tower to ensure that the solvent concentration in the distillate can be ignored.

2. ‌Operation characteristics‌

• Thermal energy consumption is mainly used to increase the temperature of the extractant, which requires maintaining a high concentration of solvent inside the tower.

• Typical process: The solvent and heavy components are discharged from the bottom of the tower and recycled through a recovery device.

Beiyang Lixing Extraction Tower Pressure Distillation Unit Distillation Tower

3、 General parameters of distillation tower

1. ‌structural parameters‌

• Tower diameter: Experimental tower with a diameter of 25mm, industrial tower with a diameter of 4-6 meters (such as ethanol tower with a diameter of 800-2000mm).

• Tower height: The industrial tower exceeds 70 meters, and the experimental tower is about 1.4 meters.

• Material: 304 stainless steel (ethanol tower), Hastelloy alloy (high corrosion environment).

2. ‌separation efficiency‌

• Theoretical plate number: 60-80 floors of industrial tower, calculated using McCabe Thiele method.

• Reflux ratio: Industrial tower 2.5-4.0, adjustable range of experimental tower 99:1-1:99.

3. ‌special working conditions‌

• Vacuum operation: The packed tower is superior (low pressure drop), with a vacuum degree of up to 60Pa.

• Energy saving design: Double effect distillation can reduce energy consumption by 6.3%.

4、 Operation precautions

• ‌pressure interlockThe pressurized tower requires gradient pressure increase (≤ 0.04 MPa per minute).

• ‌exception handlingWhen the temperature exceeds 130 ℃, it is necessary to check the heating source and adjust the reflux ratio.

• ‌environmental requirementsIf the pressure deviation of the sewage outlet exceeds 0.1 MPa, it needs to be reported.

The above parameters need to be optimized comprehensively based on material properties, separation objectives, and energy consumption.