Cerca nel sito per parola chiave

pubblicazioni - Presentazione

Life Cycle Assessment of hydrogen production from biogas digestate

pubblicazioni - Presentazione

Life Cycle Assessment of hydrogen production from biogas digestate

La metodologia Life Cycle Assessment è stata applicata ad un sistema di produzione di BioH2 mediante digestione anaerobica di una miscela di liquami zootecnici e pula di riso. Dai risultati si conclude che il sistema presenta un guadagno netto di energia e rappresenta una buona alternativa in termini di emissioni gas serra rispetto ad altri metodi di produzione.

The Life Cycle Assessment method was implemented to a BioH2 production system via anaerobic digestion using as feeding a mixture of swine digested sludge and rice bran. The system boundaries include biogas production, H2 purification and the avoided production of mineral fertilizers due to the displacement of high quality digestate coming from the process. Functional unit was 1m3 of BioH2. The results obtained show that a total of -47,46 MJ is required to produce 1 m3 of BioH2 in which -47,2 MJ is non-renewable fossil energy. There is a saving in the energy demand of 47,2 MJ/m3 BioH2 due to the credits for mineral fertilizers displaced by the digestate. Not considering these credits, 15,9 MJ of non-renewable fossil energy is required to produce 1 m3 of BioH2. Moreover the net energy ratio is equal to 7,5, implying that for each unit of energy consumed to produce BioH2, 7,5 units of energy were obtained.

Therefore this BioH2 production system has a considerable net energy gain, when credits coming from avoided production of fertilizer are included.Considering the credits for mineral fertilizers, the total GHG emissions of the system are estimated to be -2,91 kg CO2-eq per m3 of BioH2 produced. Not considering these credits, the total GHG emissions of the system are estimated to be 3,63 kg CO2-eq per m3 of BioH2 produced. The production of BioH2 by anaerobic digestion represents a good alternative in terms of greenhouse gas emissions when compared to other production methods.

Progetti

Commenti