Preparation of hybrid porous carbon using black liquor lignin impregnated with steelmaking slag and its performance in SO2 removal
John Wiley and Sons, Inc
School of Engineering
A hybrid porous adsorbent was produced by mixing black liquor lignin (BL) with basic oxygen furnace steelmaking slag (SS) followed by carbonization at 860°C for removal of trace sulfur dioxide (SO2) from air. The effects of BL percentage, carbonization temperature, carbonization duration and the binary combined effect of each individual process parameter on the removal of SO2 have been statistically analyzed. The optimal preparation conditions were 48% = BL/(BL + SS), carbonized at 860°C for 50 minutes (labeled BL-SS-48-860-50). The crystallite CaO and MgO phases remained in the hybrid matrix. A carbonization temperature over 800°C facilitated gasification reaction between the carbon matrix and the CO2 emitted from the decomposition of calcium and magnesium carbonate, which led to the pore formation and enlargement in the carbon matrix. The prepared hybrid adsorbent showed good SO2 removal performance. The kinetic model demonstrated satisfying results in predicting SO2 adsorption kinetics with good prediction within a relative large range of SO2 inlet concentration. The mass transfer coefficient k = 537 (s−1) was obtained by fitting the model to the experimental breakthrough curve.