Pirólise lenta da cama de aviário: modelagem, simulação e análise de um reator de forno rotativo em escala piloto

Abstract

The valorization of agro-industrial waste, such as poultry litter, through thermochemical processes is a sustainable alternative for generating value-added products, such as biochar. However, the phenomenological modeling of slow pyrolysis in pilot-scale rotary kiln reactors is still a poorly explored area. In this context, this study aimed to model, simulate, and analyze the slow pyrolysis of poultry litter, using operational data from a pilot-scale reactor operated by the startup Terraxy, incubated by King Abdullah University of Science and Technology (KAUST). Two steady-state models were developed and evaluated: one with constant heating throughout the reactor (MAS) and another with a central heating zone (MAC), more faithfully representing the experimental configuration. Batch simulations aided in the selection of the first-order kinetic model with three parallel reactions, formulated by THURNER e MANN (1981), to represent the biomass decomposition. The results indicated a biochar yield of approximately 30% for both models, below the experimental value of 39,4%. However, the MAC exhibited more realistic thermal behavior, with temperature profiles that captured the heat regeneration phenomenon and showed a difference of only 20 K (less than 1 standard deviation) compared to the temperature measured on the drum wall. Through a parametric sensitivity analysis, it was possible to correlate the influence of operational parameters, such as the heat supplied and the solids feed flow rate, with the process stability, identifying conditions that can lead to the extinction of pyrolysis. This work demonstrates the applicability of phenomenological models for the analysis and optimization of pilot-scale pyrolysis reactors, providing valuable support for process control and scalability.