Characterization and adsorption performance evaluation of waste char by-product from industrial gasification of solid refuse fuel from municipal solid waste

This study investigated the effect of steam and air flowrate combinations on the syngas efflux, physicochemical properties and adsorption performances (on congo red, CR and crystal violet, CV removal) of waste char by-product from the industrial gasification of solid refuse fuel from municipal solid waste. The BET surface area (11.4 m²/g), porosity (74.7%), fixed carbon content (25.8 wt%) and hydrophilicity (0.09) were enhanced with lower steam rate and higher air supply rate combination (MSWC-L) than for the higher steam rate and lower air supply rate combination (MSWC-H). Adsorption performances were higher for MSWC-L than MSWC-H on both CR (35.7–49.7 mg/g) and CV (235 to 356 mg/g) removal, suggesting that, higher air supply rate (214 Nm³/h; at 0.36 equivalence ratio) with lower steam rate (37 kg/h) were more effective gasification process conditions. Results showed that, syngas efflux was more sensitive to air supply rate than steam supply rate. Reactions in the combustion zone were not only limited to the pyrolysis gas vapours but to the char also. In conclusion, the waste chars from municipal solid waste gasification showed good potential as adsorbents in wastewater treatment.