METHANE PRODUCTION KINETICS FROM RICE DRIED RESIDUE WITH PIG AND COW MANURE

Abstract

Introduction:
The anaerobic digestion is an attractive process for a grains agro-industrial enterprise where several residues are produced. Different studies show the advantages of rice straw and rice dried residue with pig manure codigestion, however the effect of the mixture rice dried residue with pig and cow manure on anaerobic digestion kinetic have not been studied.
Objective:
To evaluate the methane production kinetic from different mixtures of rice dried residue with cow and pig manure in discontinuous system.
Materials and Methods:
The anaerobic digestion process was evaluated in discontinuous system at mesophilic conditions (35 ± 2 ºC) for four mixtures, selected according to a Mixture design of extreme vertices. Four models of first and second order were used for the kinetic
performance of the anaerobic digestion process description.
Results and Discussion:
The models explained between 98.54 until 99.90% the variability of obtained experimentally methane yield. The best methane yield (351.19 L/kg volatile solids) was obtained for the mixture with maximum percentage of rice dried residue.
Conclusions:
This study shows the potentialities of biogas production from residues generated in a grains agro-industrial enterprise. However, technology selection must be based in reactors with agitation, which must be evaluated in semicontinuous regime.