Solar assisted biogas plant production and utilization

Abstract

Today, people are seeking various new energy sources in order tosolve the energy crisis. The main factors which encouraged us to study onthis object can be stated as follows, biogas which is one of the alternativeenergy sources has a high calorific v~lue. Furthermore, the wastes whichis necessary to produce biogasis easily available. Meanwhile, the enviromentalpollution is another limiting ~ondition for an alternative energysource. Biogas also helps to keep the nature clean.Biogas is the result of a natural process where organic matter isfermented under anaerobi c conditi ons. That organi c matter i nvol ves manurefrom cattle, piggeries and poultry with some organic wastes that includescellulose. The biogas, approximately, is the mixture of Methane with 60per cent and carbondioxide with 40 per cent in volume.It is known that,manure from cattle which is very useful as afertilizer in the fields is used as fuel for cooking and heating purposesin the villages in our Country. The main proble,m s are the supplying fuelwhich is cheap and healthy for peasant people and the preventing the useof manure as fuel. Actually, the use of manure from cattle as fuel causeseconomical. damage. Biogas which is presented as a cheap and healthy gasfuel has more advantages as follows; since the amount of phospor and nitrogenin organic wastes does not change, and these wastes do not includethe pathogenes after anaerobic fermentation, they can be used as a qualifiedfertilizerin the fields. Additionally, air pollution can be reducedbecause the need to oxygen of the organic wastes decreases after anaerobicfermentation.During biogas production, the temperature of the inside of thedigester should be between 20-25·C.In this study, a fiberglas digester with 10 m3 in volume and a metalgas holder are used. Four solar collectors and an internal heat exchangerare the other components of the plant. The pressure and the temperatureof the digester are measured, and pH of the wastes is controlled. Actually,the analysis of manure is made and the C/N ratio is determined.Biogas which is obtained in the farm is got ready to utilize forhot water needs. Furthermore, the pay~back period of the cost of this plantis searched. The feasibility analysis of the solar assisted biogas plantsin Turkey is also made.