Effect of alternative sources of input substrates on biogas production and its quality from anaerobic digestion by using wet fermentation

The aim of the study was to confirm the suitability of alternative input substrates for production of biogas in order to decrese the need of utilization of high quality maize silage. All of the experiments were conducted by employement of wet fermentation process in mesophilic conditions (temperature in fermentor 40±1°C) in experimental fermentor with volume 5 m3. The experiments were realised in operating conditions of biogas station designed for utilization of agricultural biowaste. The experiments were divided into two alternatives (I and II cycle) and one controle input substates. In the first alternative (I cycle) wasdaily dosage formed by 33kg of Amaranthand 250L of controle manure mixture. In this cycle, more than 3–times greater specific production of biogas was observed with average methan content 63.9% in comparison with controle manure mixture (80:20%, liquidmanure and manure). In the second alternative (II cycle) was daily dosage formed by 19.5kg of sugar beer cuts, 3.3kg of maize silage, 1.9kg of oil-seed rape moldings, 2.5kg of glycerine and 250L of controle manure mixture. In this cycle, more than 5.9–times greater specific production of biogas was observed. The decrease in averare methan content 55.1% however also decrease in average content of hydrogen sulphide (128ppm) was observed as well. An unquestionable advantage for both tested alternative mixed substrates was increase in biogas production and its quality in comparison with control substrate based on manure. At the basis of these findings can be concluded that both tested alternative input substrate mixtures are suitable as co–fermentation substances with great potential to increase the biogas production and its quality in case of wet fermentation processes.