Energetically feasible biohydrogen production from sea eelgrass via homogenization through a surfactant, sodium tripolyphosphate

The present work aimed to increase the liquefaction and biohydrogen recovery of sea eelgrass by combining the surfactant, sodium tripolyphosphate (STPP) with dispersion homogenization. Firstly, the dispersion homogenization (DH) of sea eelgrass was performed by varying the dispersion revolution speed (rpm) from 4000 to 16,000 and treatment time from 0 to 60 min. The conditions for STPP induced dispersion homogenization (SDH) pretreatment (10,000 rpm and 0.05 g/g TS of STPP dosage) was optimized based on the liquefaction (solubilization) of sea eelgrass biomass. A higher liquefaction of 25.6% was achieved through SDH pretreatment. Bioacidification result shows that the percentage increment of volatile fatty acids (VFA) in SDH was found to be 54% higher when compared to DH. SDH pretreated sea eelgrass, when subjected to biohydrogen production yielded a peak production of 23.2 mL H₂/g VS than DH (16 mL H₂/g VS) and control-untreated raw biomass (3.2 mL H₂/g VS). The preliminary energy analysis revealed that SDH was considered to be an energy efficient pretreatment process with energy ratio of 1.9 when compared to DH (0.75).