Optimization of fishbone biochar preparation process based on adsorption performance

Food and Kitchen Waste with high organic matter poses great challenge to the living environment and ecology, which arouses great enthusiasm for suitable treatment routes. As one kind of major component of Food and Kitchen Waste, fishbone was selected as potential feedstock for high-value biochar production. The effect of major parameters controlling fishbone carbonization was investigated on biochar production performance. And with Plackett-Burman and Central Composite Design methodology, multi-factor process optimization was performed in order to achieve better biochar yield and quality. Experimental results revealed that carbonization temperature has the most significant impact on the yield and adsorption performance of biochar, especially at 2.5–5 °C·min−1 heating rate and residence time. Based on Response Surface Method, a three-dimensional surface model was constructed to evaluate the quality of biochar with varied carbonization conditions. Better biochar yield was achieved at carbonization conditions (473 °C, 6.3 °C·min−1, 1.3 h), with biochar adsorption value of methylene blue at 20.193 mg g−1 and specific surface area at 21.936 m2 g−1, which was also confirmed by biochar characterization. The established three-dimensional surface map provides theoretical basis for valued fishbone biochar conversion, and also for process optimization of Food and Kitchen waste carbonization.