Development and simulation of a novel oil absorption process for recovering ethylene from refinery dry gas

Oil refineries dry gases contain ethylene and other valuable raw material. However, those dry gases are often lined into the flare system to be burned directly, which results in a waste of resources. Current oil absorption methods are difficult to get polymerization grade C₂ components and that limits their range of use. A novel oil absorption method using C₅ as absorbent was developed to recover polymerization grade C₂ components. Then a single factor analysis of the recovery of C₂ components and energy consumption was analyzed for different cases according to different system pressure, temperature, absorbent flowrate and theoretical stage numbers of all columns. The appropriate range of those factors are 3-3.2 MPa, -20-10 ℃, 15-20 t/h, 20, 14, 20 for absorption column, desorption column and distillation column. Then an orthogonal analysis of temperature, pressure and absorbent flowrate was conducted,which showed that the order of influencing recovery was absorbent flowrate > temperature > pressure, the order of influencing energy consumption was pressure > temperature > absorbent flowrate.