Valorization of orange solid waste through pyrolysis: production of biochar and its potential as an enhancer of the anaerobic digestion

Resumen

Objective: To valorize orange solid waste through pyrolysis to obtain biochar and to analyze its potential application as an enhancer of anaerobic digestion.

Design/methodology/approach: Orange solid waste was conditioned and subjected to pyrolysis at 550 °C in an Auger-type reactor. The produced biochar was characterized by measuring pH, ash content, total solids, volatile solids, cation exchange capacity, electrical conductivity, and carbon content. Additionally, an anaerobic hybrid reactor was conditioned and monitored by measuring pH, total and soluble COD, TSS, VSS, and biogas production to subsequently evaluate the effect of the biochar on the reactor performance.

Results: Biochar exhibited alkaline properties pH (8.6), a carbon content of 60%, and an increase in cation exchange capacity (42.6 meq·100 g^-¹), indicating the development of a porous and conductive structure favorable for microbial adhesion and the mitigation of inhibitory compounds. Meanwhile, the anaerobic hybrid reactor was stabilized, maintaining a pH between 7.1 and 7.4, achieving 90% removal of total and soluble COD, as well as 4.6 L biogas/d, favoring a balanced biological environment.

Limitations on study/implications: The effect of biochar addition in the anaerobic hybrid reactor will be evaluated to determine its influence on anaerobic digestion performance. However, further studies are required to confirm its long-term stability and scalability.

Findings/conclusions: Biochar derived from orange solid waste represents an environmentally sustainable alternative to optimize the anaerobic digestion process and valorize agro-industrial waste within the framework of a circular economy.