Modelación matemática del proceso de digestión anaerobia en condiciones de clima frio utilizando biodigestores tubulares
Abstract
El propósito principal de esta investigación es modelar y simular matemáticamente el proceso de digestión anaerobia en condiciones de clima frío utilizando biodigestores tubulares, considerando la variación de la temperatura ambiental, el comportamiento hidrodinámico del biodigestor, el mecanismo de reacción, la estequiometría y la cinética de la digestión anaerobia. En el modelo matemático que se propone se ha tomado en cuenta el comportamiento térmico del biodigestor a través de la obtención de correlaciones matemáticas que relacionan el tiempo con la temperatura ambiental y la temperatura de la fase gaseosa del biodigestor, además se asume que la temperatura en la fase líquida se mantiene constante. Por otro lado, se considera que el comportamiento hidrodinámico del biodigestor está representado por cuatro reactores CSTR conectados en serie. Adicionalmente el modelo ADM1 ha sido aplicado para representar el mecanismo de reacción, la estequiometría y la cinética del proceso de digestión anaerobia. El modelo matemático fue calibrado y validado utilizando información experimental recopilada durante el período de trabajo. Como resultado se obtuvo un conjunto de parámetros cinéticos que podrán ser utilizados en posteriores aplicaciones de ADM1 en el caso de la digestión anaerobia de estiércol de vaca. Los resultados de la simulación presentan un grado aceptable de concordancia con los resultados experimentales y las diferencias se deben a variaciones en el comportamiento hidrodinámico del biodigestor.
The main purpose of this research is to mathematically model and simulate mathematically the process of anaerobic digestion in cold weather conditions using tubular digesters, considering the variation of the air temperature, the hydrodynamic behavior of the digester, the reaction mechanism, stoichiometry and kinetics anaerobic digestion. In the proposed mathematical model the thermal behavior of the digester is taken into account through obtaining mathematical correlations relating time with air temperature and the temperature of the gaseous phase of the digester, in addition it is assumed thatthe temperature in the liquid phase remains constant. Furthermore, it is considered that the hydrodynamic behavior of the digester is represented by four CSTR reactors connected in series. Additionally the ADM1 model has been applied to represent the reaction mechanism, stoichiometry and kinetics of anaerobic digestion process. The mathematical model was calibrated and validated using experimental data collected during the work period. As a result, a set of kinetic parameters, was obtained as they could be used in subsequent applications of ADM1 for anaerobic digestion of cow manure. The simulation results show an acceptable degree of agreement with the experimental results and the differences are due to variations in the hydrodynamic behavior of the digester.
The main purpose of this research is to mathematically model and simulate mathematically the process of anaerobic digestion in cold weather conditions using tubular digesters, considering the variation of the air temperature, the hydrodynamic behavior of the digester, the reaction mechanism, stoichiometry and kinetics anaerobic digestion. In the proposed mathematical model the thermal behavior of the digester is taken into account through obtaining mathematical correlations relating time with air temperature and the temperature of the gaseous phase of the digester, in addition it is assumed thatthe temperature in the liquid phase remains constant. Furthermore, it is considered that the hydrodynamic behavior of the digester is represented by four CSTR reactors connected in series. Additionally the ADM1 model has been applied to represent the reaction mechanism, stoichiometry and kinetics of anaerobic digestion process. The mathematical model was calibrated and validated using experimental data collected during the work period. As a result, a set of kinetic parameters, was obtained as they could be used in subsequent applications of ADM1 for anaerobic digestion of cow manure. The simulation results show an acceptable degree of agreement with the experimental results and the differences are due to variations in the hydrodynamic behavior of the digester.
Description
Vol. 3, No. 1