Development of scrubber with nano-TiO2 coated packing for H2S removal

Abstract

A pilot-scale packed-bed wet scrubber with plastic packing materials was made and experimented to control hydrogen sulfide.TiO2 nanoparticles were coated on the surface of packing to improve the hydrophilicity of scrubbing liquid to form a homogeneous liquid layer on the packing surface. Air flow rate, H2S concentration, and liquid pH were selected to evaluate their effect on scrubber removal efficiency. To evaluate and model the effects of selected variables, two separate sets of experiments were designed and conducted using response surface methodology, central composite design. The former was to model the effects of air flow rate and H2S inlet concentration on removal efficiency at natural liquid pH, and the latter was aimed at total optimization, where all three variables were evaluated. Results showed that TiO2 nanoparticles substantially increased surface hydrophilicity and hydrogen sulfide removal efficiency in natural pH and total optimization by 3.12 % and 3.63 %, respectively. Moreover, air flow rate and H2S concentration had an adverse effect on H2S removal efficiency, while liquid pH positively influenced the efficiency. The optimum removal efficiency for natural pH and total optimizations were 98.83 % and 99.93 %, respectively. The results showed that hydrophilicity of packing materials has a strong effect on hydrogen sulfide removal.