Abstract
The presence of bio-oil distillation sludge (DS) disrupts biomass refining and poses health risks. This study investigates DS utilization in industrial bio-oil refining through co-pyrolysis with walnut shell (WS). Char characterization elucidates structural changes induced by co-pyrolysis. Observations show increased DS ratios smoothened the pleated structure of W3D1, with heightened graphitized structure observed at higher DS ratios through Raman analysis. Gasification indices (R0.5 and R0.9) indicate significant enhancements through co-pyrolysis. Mineral composition analysis revealed silicon in DS reduced ash deposition, while WS blending increased deposition risks due to potassium and calcium content. Investigation into the synergistic relationship between biochar’s carbonaceous structure parameters and gasification indices emphasized stronger correlations with R0.9, indicating pronounced synergy in later gasification stages.