Energy Utilization of Yellow Phosphorus Tail Gas: Simultaneous Catalytic Hydrolysis of Carbonyl Sulfide and Carbon Disulfide at Low Temperature

The CO in yellow phosphorus tail gas can be used as energy source in the one-carbon chemical industry, but the harmful gases carbonyl sulfide (COS) and carbon disulfide (CS2) are in co-existence with CO and so must be removed. Modified microwave coal-based activated carbon (Fe/MCAC) loaded with different metal oxides was manufactured by a sol-gel process, and used for the simultaneous catalytic hydrolysis of COS and CS2 at low temperature (30-70 degrees C). The influences of Cu-Ni doping and reaction conditions on catalytic hydrolysis reaction were investigated. The results showed that the optimum addition agents are copper and nickel, and the best mole ratio of Fe/Cu/Ni was 10:2:0.5. The X-ray diffractometry results show that the doping agent could control the generation of sulfate, which can suppress the hydrolysis activity of the catalysts. Further characterization revealed that larger specific surface areas and pore volumes are favorable and enhance the catalytic hydrolysis activities. The products of simultaneous catalytic hydrolysis (S/SO42- species) could block the pore structure and surface active sites, which leads to a decline of the catalytic hydrolysis activity. Excessively high reaction temperatures (>50 degrees C) could enhance the catalytic hydrolysis of COS but inhibit catalytic hydrolysis of CS2. Excessively high relative humidity (RH) and O-2 content could lead to formation of more sulfates, and decrease the catalytic efficiencies towards simultaneous hydrolysis of COS and CS2.