Comparison of red, brown and green seaweeds on enzymatic saccharification process

The production of bioethanol from seaweeds using acid hydrolysis and the enzymatic saccharification was studied. Red seaweed (Gelidium amansii), brown seaweed (Laminaria japonica), and green seaweed (Codium fragile) were selected, and the characteristics of their conversion to bioethanol were analyzed. The optimum conditions of the dilute acid hydrolysis preprocessing for bioethanol production from the seaweed were a reaction temperature of 150 °C, sulfuric acid content of 5.0 wt.%, and reaction time of 60 min. The seaweeds listed in order of bioethanol conversion performance are red seaweed > brown seaweed > green seaweed. The optimum dosage of enzyme was 2.0 mL per 10 g of seaweed. The optimal fermentation conditions for bioethanol production using seaweed included a commercial yeast dosage of 30 wt.% and a fermentation time of 3 days.