Respirometric index as a tool for biogas generation production from poultry manure

Over the past three following decades poultry production has been strongly growing (in EU around 5% per year). This increase determined a higher volume of livestock and poultry farming waste which represents a potential renewable fuel. The poultry waste composition, the technical solution for energy recovery and the corresponding yields strongly depend on the biomass origin (animal species) and on the mode of farming (diet, housing, ambient growth, stage of production, etc.). A very important parameter is moisture. In fact, if its value is higher than 30% (minimum value for which the biological activity is not inhibited), it is possible to send the poultry manure to a biological process, such as the anaerobic digestion (AD). The purpose of this paper is to propose a rapid method for assessing the potential of biogas in anaerobic digestion of poultry manure, with the goal of helping the choices of operators of AD. The tests normally applied for the measurement of the anaerobic biogasification potential (ABP) are not viable as a routine analysis: this kind of test is expensive and time consuming (from 21 days to determine the partial production of biogas up to 100 days for the total production of biogas). In this work a method based on the dynamic respiration index (DRI) was proposed. The application allows a rapid determination of the value of the ABP (1-5 days). In addition, two dynamic respirometric approaches were considered.