Design and Simulation of a Sieve Tray Column for Removal of H2S from a Refinery Flue Gas

Abstract

Many commercial processes are available for the removal of H2S from gaseous streams. The presence of H2S in refinery flue gas caused dangerous effect on the environment. Hence, H2S must be removed from the refinery flue gas, and the relievable mechanism of mass transfer with chemical reactions in a sieve tray column have to be studied. In this study, the chemical absorption of hydrogen sulfide into aqueous ferric sulfate solution Fe2(SO4)3 has been studied. Designed calculations for a sieve tray column have been done and the effective operation parameters on this process have been investigated. Mass transfer was carried out theoretically by developing a mathematical model of mass transfer phenomena with chemical reaction of H2S into Fe2(SO4)3 solution in a sieve tray column. The mass transfer process was described by film model, that yielding a second order differential equation solved numerically by orthogonal collocation to estimate enhancement factor. The mass balance model in plate column consists of differential mass balance of H2S in gas phase and Fe2(SO4)3 in liquid phase giving system of non-linear first order differential equations that were solved numerically by Fourth order Runge-Kutta method under MATLAB Software. This study assumed steady state and isothermal conditions. In the system studied the refinery flue gas flow rate was, 2.401Ton/h, liquid flow rate was 10000 cm3/s, pressure P is 1atm, temperature 30oC and the concentration of Fe2(SO4)3 in inlet absorbent was 0.002 mol/cm3. It was found that the percentage of absorbed H2S can be enhanced by increasing the temperature, liquid flow rate, and Fe2(SO4)3 concentration, decreasing the flow rate of gas.