PID (Proportional-Integral-Derivative) control on gas cleaning with methanol scrubber

We have worked on process design that includes the implementation of PID-controlled gas cleaning with a methanol scrubber. This advanced technology requires precision and expertise to ensure efficiency and compliance with environmental requirements. Here is how the process can be described:

Gas extraction and condensation

The gas produced by the pyrolysis furnaces contains a significant amount of moisture. To remove this moisture, the gas is first directed to a condenser where it is cooled sufficiently for the moisture to condense and be removed from the gas.

Cleaning through methanol scrubbing

After the condenser, the gas is passed through a methanol scrubber. Here, methanol is injected into the gas to cleanse it from further impurities and particles. The methanol acts as a ‘wash’ that enhances the purity of the gas.

Removal of remaining contaminants

After the cleansing through the methanol scrubber, the gas passes through a carbon filter to remove any remaining contaminants and particles before being released into the atmosphere.

PID på gas

Cooling and maintenance

During the process, the condenser is cooled using a water circuit and also has a cleaning circuit with methanol to ensure it continues to operate effectively and maintain optimal performance.

Control of purity level and circulation of methanol

To monitor and maintain the purity of the gas, the process is supervised by a turbidity meter. When necessary, the amount of methanol injected into the scrubber is adjusted to ensure the desired purity level. The circulation of methanol is controlled by a frequency-controlled pump regulated by flow meters to minimize unnecessary methanol usage and maintain process efficiency.

Safety and environmental protection

All tanks are equipped with level sensors and are located under an exhaust hood to ensure that any gas leaks or emissions are ventilated out, thus mitigating any risks to safety or the environment.