Enhanced Carbonization of Sawdust and Leather Waste for Fuel Use in Pyrolysis Pilot Furnace: A Taguchi Experimental Design Approach

Pyrolysis furnaces are an efficient means of carbonizing biomass, yielding biochar, and facilitating organic waste recovery. This study aimed to refine the carbonization process of biomass waste by employing the Taguchi method to assess the influence of biomass type (sawdust and leather waste), furnace filling rate (33% and 100%), and fuel type (cardboard waste and plastic waste) on carbonization yields. Four trials were conducted, with each factor systematically varied, and the results were analyzed using an L4(2^3) design replicated thrice. The parameters evaluated included gross, net, and weighted mass yields; energy yield; technological yield; and the characteristics of the resultant coals. Taguchi analysis revealed that fuel type, notably cardboard waste, exhibited the most significant impact on all yields studied, followed by a filling rate of 100%, favoring most outcomes. In comparison, a 0.196 m3 pilot pyrolysis furnace carbonizing sawdust and leather waste demonstrated superior average mass yields of 47.8% and weighted mass yields of 44.4% compared with traditional charcoal pits, yielding 26% and 25.8%, respectively. Sawdust charcoal exhibited superior energy quality, boasting a higher percentage of fixed carbon and elevated Lower Calorific Value, with 85% of energy yield with a standard deviation of 3.5%, in contrast with 70.9% of energy yield and a higher standard deviation of 7.8% for leather waste. While the findings showcase promise, further exploration into alternative biomass types, comprehensive modeling of the entire process within the pyrolysis pilot furnace, and an assessment of large-scale profitability remain imperative.