Process retrofit for energy-use improvement of an absorption and stabilization process in refineries

An absorption and stabilization system is an important process, which is used to produce the industrial raw materials such as dry gas, liquefied petroleum gas, and stable gasoline. However, the existing absorption and stabilization process is heavily energy intensive with low economic benefits. In the existing process, double feeding with different temperatures and identical composition of the desorption tower results in an axial back-mixing behaviour, which weakens efficiencies of the mass and heat transfer of the desorption tower. To solve the problem, a new process with two-stage condensation section is presented in this work. The new process can eliminate the axial back-mixing and improve efficiency of energy-use. Compared with the existing process, the new process improves the separation efficiency of the absorption tower, as well as decreases its cold utility and hot utility by 19.67 % and 24.47 %, respectively.