Kinetics Modeling of Anaerobic Fermentative Production of Methane from Kitchen Waste Solid Residual

Abstract

A series of batch mesophilic anaerobic digesntion were conducted using an automatic methane potential test system (AMPTS) and the kinetics of methane production was also discussed using modified Gompertz equation, Logistic function, First-order kinetics model and Transference function, respectively. The results showed that the kitchen waste solid residual was of high biomethane potential, and the maximum specific methane yield was obtained 585 NmL/g TS at inoculums substrate ratio (ISR) 2:1. All of the four models could appropriately fit the accumulative methane production in steady state (R2>0.95), where the 1st-ordre model and Transference function were relatively much better (R2>0.99) than the other two models. The maximum methane production and maximum methane production rate obtained from the Transference function were 569.32 NmL/g TS and 150.22 NmL/g TS day; the maximum kinetics constant obtained from the 1st-order model was 0.272/day; the lag time (λ) was basically negligible in all the cases. These parameters were quite close to the experimental results.