Federico Dragoni

Suitability of giant reed (Arundo donax L.) for anaerobic digestion: Effect of harvest time and frequency on the biomethane yield potential

This study aimed to investigate the potential of giant reed for biomethane production by examining the influence of harvest time and frequency on the Biochemical Methane Potential (BMP), the kinetics of biomethane accumulation in batch reactors and the expected methane yield per hectare. The crop was cut at five different times, regrowths from early cuts were harvested in autumn and BMP of each cut was assessed. The highest BMP (392 NL kg VS(-1)) and the best kinetics of methane production were associated to juvenile traits of the crop. By coupling the early cuts with the corresponding regrowths (double harvest), the dry biomass (from 35 to 40 Mg ha(-1)) equaled that obtained by a single cut at end of the season (38 Mg ha(-1)), while the methane yield per hectare (11,585-12,981 Nm(3) ha(-1)) exceeded up to 35% the methane produced with a single harvest at crop maturity (9452 Nm(3) ha(-1)).

Energy conversion of biomass crops and agroindustrial residues by combined biohydrogen/biomethane system and anaerobic digestion.

Aim of this study was to evaluate the suitability of ensiled giant reed, ensiled maize, ensiled olive pomace, wheat bran for combined systems (CS: dark fermentation+anaerobic digestion (AD)) producing hydrogen-rich biogas (biohythane), tested in batch under basic operational conditions (mesophilic temperatures, no pH control). Substrates were also analyzed under a single stage AD batch test, in order to investigate the effects of DF on estimated energy recovery (ER) in combined systems. In CS, maize and wheat bran exhibited the highest hydrogen potential (13.8 and 18.9NLkgVS(-1)) and wheat bran the highest methane potential (243.5NLkgVS(-1)). In one-stage AD, giant reed, maize and wheat bran showed the highest methane production (239.5, 267.3 and 260.0NLkgVS(-1)). Butyrate/acetate ratio properly described the dark fermentation, correlating with hydrogen production (r=0.92). Wheat bran proved to be a promising residue for CS in terms of hydrogen/methane potential and ER.

Agroindustrial residues and energy crops for the production of hydrogen and poly-β-hydroxybutyrate via photofermentation.

The present study was aimed at assessing the biotransformation of dark fermented agroindustrial residues and energy crops for the production of hydrogen and poly-β-hydroxybutyrate (PHB), in lab-scale photofermentation. The investigation on novel substrates for photofermentation is needed in order to enlarge the range of sustainable feedstocks. Dark fermentation effluents of ensiled maize, ensiled giant reed, ensiled olive pomace, and wheat bran were inoculated with Rhodopseudomonas palustris CGA676, a mutant strain suitable for hydrogen production in ammonium-rich media. The highest hydrogen producing performances were observed in wheat bran and maize effluents (648.6 and 320.3mLL(-1), respectively), both characterized by high initial volatile fatty acids (VFAs) concentrations. Giant reed and olive pomace effluents led to poor hydrogen production due to low initial VFAs concentrations, as the original substrates are rich in fiber. The highest PHB content was accumulated in olive pomace effluent (11.53%TS), ascribable to magnesium deficiency.

Anaerobic digestion and Co-digestion of oleaginous Microalgae residues for biogas production

Anaerobic Digestion And Co-Digestion of Oleaginous Microalgae Residues for Biogas Production Federica Barontini*, Enrico Biagini, Federico Dragoni, Elisa Corneli, Giorgio Ragaglini, Enrico Bonari, Leonardo Tognotti, Cristiano Nicolella Università di Pisa Dipartimento di Ingegneria Civile e Industriale Largo Lucio Lazzarino, 56122 Pisa, Italy Centro di Ricerca Interuniversitario Biomasse da Energia (CRIBE) Via Vecchia di Marina, 6, 56122 Pisa, Italy Scuola Superiore Sant’Anna – Institute of Life Sciences Via Santa Cecilia, 3, 56127 Pisa, Italy federica.barontini@unipi.it