Anaerobic digestion of manure mixed with maize and biogas production

In a moment where the world is asking for more energy the choice to use the biomass as a resource could mean to solve different and important problems. In this case the waste will become useful material that can be used both on a rural scale or as an industrial implementation. This paper presents results from laboratory studies to measure the methane yield and rate of digestion of cow manure and maize silage mix. Using sample of manure from the Fontanacervo farm placed in Villastellone (To) and maize silage from the Vanzetti farm places in Candiolo (To) Italy, we determined the above parameters. The digestion was conducted in an own made experimental 120-l reactor using batch operation, the digester was built to process sullage from farm and cheese factory. It can send remotely the acquired data of pressure, temperature, pH and biogas volume production using a GSM modem connection. The temperature of the process was established around 35°C for the entire period of the test. The experiment consists in a single batch load phase, with a global duration of 40 days. The co-digestion method is usually used inside Italian anaerobic digesters, but the real efficiency of the used mix is often not well known. The effort of this paper is to conduct a deep analysis of a specific biomass mix that is very often used as digester feed. The obtained values confirm that a mix rate of this type can be hardly optimized to reach a better methane yield.