Production of Carboxylic acids from Acidogenic Fermentation of Algefiber? (Sea Weed Sludge) using a Mixed Culture of Marine Microorganisms

摘要

Seaweed (Macro algae) has an increasing interest as a biomass source for biofuel production. In this study, carboxylic acids were produced from seaweed derived biomass using the MixAlco? process. Algefiber?, derived from red seaweed (Eucheuma spinosum) from seaweed processing (FMC Biopolymer), was used as the biomass source. This alkaline pretreated waste biomass was anaerobically digested using a mixed culture of marine-derived microorganisms. The fermentation was carried out at 350C (mesophilic) and 550C (thermophilic) in bench scale batch fermenters. The acidogenic digestion and suppression of methanogenesis were achieved by adding small doses of iodoform. Calcium carbonate and ammonium bicarbonate were used as buffers to maintain the pH of the fermentation. The produced carboxylic acids ranged from 2 to 7 carbons. The total carboxylic acid production was found to be higher at lower temperature. Acetic acid was the prominent acid at both temperatures but the proportion of acetic acid in the mixture was greater at thermophilic temperature. Produced carboxylic acids, neutralized with above buffers to form carboxylate salts, can be chemically upgraded to higher alcohols liquid biofuel.