吸收塔是采用低揮發(fā)或不揮發(fā)性溶劑對VOCs進行吸收，再利用VOCs和吸收劑物理性質(zhì)的差異進行分離。

含VOCs的氣體自吸收塔底部進入塔內(nèi)，在上升過程中與來自塔頂?shù)奈談┠媪鹘佑|，凈化后的氣體由塔頂排出。

吸收VOCs的吸收劑通過熱交換器后，進入汽提塔頂部，在溫度高于吸收溫度或壓力低于吸收壓力的條件下解吸。解吸后的吸收劑經(jīng)過溶劑冷凝器冷凝后回到吸收塔。解吸出的VOCs氣體經(jīng)過冷凝器、氣液分離器后以較純的VOCs氣體離開汽提塔，被回收利用。

吸附塔是用多孔性固體物質(zhì)處理流體混合物時，流體中的某一組分或某些組分可被吸表面并濃集其上，此現(xiàn)象稱為吸附。吸附處理廢氣時，吸附的對象是氣態(tài)污染物，氣固吸附。被吸附的氣體組分稱為吸附質(zhì)，多孔固體物質(zhì)稱為吸附劑。

固體表面吸附了吸附質(zhì)后，一部被吸附的吸附質(zhì)可從吸附劑表面脫離，此現(xiàn)附。而當(dāng)吸附進行一段時間后，由于表面吸附質(zhì)的濃集，使其吸附能力明顯下降而吸附凈化的要求，此時需要采用一定的措施使吸附劑上已吸附的吸附質(zhì)脫附，以協(xié)的吸附能力，這個過程稱為吸附劑的再生。

因此在實際吸附工程中，正是利用吸附一再生一再吸附的循環(huán)過程，達到除去廢氣中污染物質(zhì)并回收廢氣中有用組分。

The absorption tower uses low volatile or nonvolatile solvent to absorb VOCs, and then uses the difference of physical properties between VOCs and absorbent for separation.

The gas containing VOCs enters the tower from the bottom of the absorption tower, contacts with the absorbent from the tower top countercurrent in the rising process, and the purified gas is discharged from the tower top.

After passing through the heat exchanger, the absorbent absorbing VOCs enters the top of the stripper and desorbs when the temperature is higher than the absorption temperature or the pressure is lower than the absorption pressure. The desorbed absorbent returns to the absorption tower after being condensed by the solvent condenser. After passing through the condenser and gas-liquid separator, the desorbed VOCs gas leaves the stripper as pure VOCs gas and is recycled.

Adsorption tower is a phenomenon that a component or some components in the fluid can be absorbed and concentrated on the surface when the fluid mixture is treated with porous solid substances. This phenomenon is called adsorption. When treating waste gas by adsorption, the object of adsorption is gaseous pollutants and gas-solid adsorption. The adsorbed gas component is called adsorbate, and the porous solid material is called adsorbent.

After the adsorbate is adsorbed on the solid surface, a part of the adsorbate can be separated from the adsorbent surface. When the adsorption is carried out for a period of time, due to the concentration of surface adsorbate, its adsorption capacity decreases significantly, and the requirements of adsorption purification, at this time, certain measures need to be taken to desorb the adsorbate on the adsorbent to improve the adsorption capacity. This process is called adsorbent regeneration.

Therefore, in the actual adsorption engineering, the circular process of adsorption regeneration and repeated adsorption is used to remove the pollutants in the waste gas and recover the useful components in the waste gas.