Novel process of absorption and stabilization unit and comprehensive utilization method of products therefrom

A novel process of an absorption-stabilization unit, comprising the following steps of:

• S1 performing a primary compression of a rich gas:
• compressing the rich gas from a catalytic fractionation unit by a first compressor to a pressure of 0.6±0.2 MPa, wherein the compressed rich gas is directly fed into a de-heavy tower for separation by rectification;
• condensing the overhead fraction of the de-heavy tower at the top of the de-heavy tower and subjecting it to a gas-liquid separation inside a first reflux tank, obtaining a liquid phase mainly containing C3 and C4, and a gas phase mainly containing C3, wherein the liquid phase mainly containing C3C4 is partially refluxed and partially discharged to a tank farm or a C3 removal tower;
• S2 performing a secondary compression of the rich gas:
• introducing the gas phase mainly containing C3 from the top of the first reflux tank to an inlet of a second compressor, where it is compressed to 1.4±0.3 MPa by a second compressor;
• after the secondary compression, condensing the gas phase and subjecting it to a gas-liquid separation inside a second reflux tank, with the separated liquid phase being discharged to a C3 removal tower, and the gas phase being sent to the bottom of an absorption tower;
• S3 performing an absorption of dry gases:
• injecting the crude gasoline from the catalytic fractionation unit into the top of the absorption tower, wherein the crude gasoline is contacted with the gas phase materials from the bottom of the absorption tower, and wherein the crude gasoline absorbs C3 and C4 components from the gas phase materials to form a rich-absorption oil, while the unabsorbed components, i.e., the dry gases, are drawn off from the top of the absorption tower;
• S4 performing a gasoline stabilization:
• feeding the materials from the bottom of the de-heavy tower and the rich-absorption oil from the bottom of the absorption tower respectively into a stabilization tower, wherein a liquefied gas fraction is drawn off from the top of the stabilization tower, and a gasoline fraction is drawn off from the bottom of stabilization tower.