Análisis de sensibilidad del contenido de humedad en briquetas de carbón vegetal mediante simulación termodinámica

Abstract

Moisture content is a critical factor determining the energy performance of densified solid biofuels. In charcoal briquettes, even moderate variations reduce the lower heating value (LHV) and increase specific fuel consumption. This study quantifies the sensitivity of moisture content, between 5% and 23%, on the LHV and fuel consumption of briquettes using thermodynamic simulation validated with experimental data. Briquettes made from residual trimmings and fines from the Bolivian Chaco region were analyzed. Their base LHV was 38,10 MJ/kg at a moisture content of 8,87%. For each moisture scenario, representative of real-world drying, storage, and handling conditions, the effective LHV and the fuel consumption required to meet a thermal demand equivalent to industrial steam generation were determined using TermoGraf v5.7. The results were verified with manually calculated energy balances, achieving a relative error of less than 2%. The simulation showed a non-linear decrease in LHV from 38,63 to 30,55 MJ/kg when humidity increased from 5% to 23%, implying a reduction of approximately 20,9%. Consistently, fuel consumption increased from 8,88 to 11,21 kg/h, an increase of nearly 26,2%. It is concluded that maintaining humidity below 10% is an essential operational strategy for maximizing energy efficiency in industrial thermal applications.