Title : Green energy: Bioethanol production from non-edible macroalgae of Cagayan Province, Northern Philippines
Abstract:
The study determines the bioethanol production from selected non-edible macroalgae using different microbial fermenters. The bioethanol production included two processes; first involving acid pretreatment was carried out in this study to further degrade the complicated sugar present in macroalgae for seven (7) days. Second, anaerobic fermentation using four microbial fermenters. The result of the study showed that there were fifteen (15) species of macroalgae collected and identified. Among the fifteen non-edible macroalgae, the top ten with the highest percentage dry weight includes the three species of Halimedeae with Percentage Dry Weight (PDW) of 33 per cent, 27 percent and 24 percent for H. macrolaba, H. opuntia and H. tuna respectively. In terms of sugar content using Brix refractometer, the top five non-edible macroalgae species after pre-acid treatment were as follows: Liagora sp., Galaxaura oblongata, Sargassum crasssifolium with 3°Br; and Turbinaria oranata together with Padina japonica with 2°Br. The used of 30g/0.1kg dry weight sample among the five selected non-edible macroalgae utilized in the fermentation process yielded sufficient ethanol of 2.99 percent to 4.17 percent. Statistically, regardless of the non-edible macroalgae and microbial fermenter used in the study, there was no significant difference in their ethanol production. However, Liagora sp. showed the highest percentage ethanol production and the yeast microorganism Candida tropicalis was the best fermenter. Bioethanol from non-edible macroalgae such as the species of Liagora sp, G. Oblongata, S. crassifolium, T. oranata and P. japonica which were available. The result give a promising source of green energy for future development.
Key words: Bioethanol, Macroalgae, Fermenter, Percentage dry weight, Acid pretreatment
