Speaker
Description
The anaerobic digestion of macroalgae is known for being a possible process to obtain biogas. However, due to the high organization of the macroalgae molecular structure, a pre-treatment is usually needed to improve the biogas production. In this context, gamma irradiation can be used as an alternative pre-treatment aiming to improve the digestibility of polysaccharides and other carbohydrates available in biomass and thus improve the biochemical conversion of biomass to biofuel.
To evaluate the efficiency of gamma irradiation pre-treatment, two algae, Saccharina latissima (SL) and Gracilaria gracilis (G) were selected. After preliminary studies, a dose of 20 kGy was applied to the dried algae using a dose rate of 0.7 kGy.h-1. Biogas was then produced through anaerobic digestion using as substrate synthetic food waste, and macroalgae as co-promoter of the digestion. Anaerobic digestate from wastewater sludge was used as inoculum.
Several analyses were carried out for the characterization of algae. Cumulative biogas production as well as the composition of the biogas was also studied as function of the different variables (algae SL/G), ratio substrate/algae, irradiated/non-irradiated algae).
Results indicate that irradiated macroalgae lead to higher biogas production yields in both studied algae.
