Production of ethanol 3G from Kappaphycus alvarezii: Evaluation of different process strategies

• Published in: Bioresource technology Vol. 134; pp. 257 - 263
• Main Authors: Hargreaves, Paulo Iiboshi, Barcelos, Carolina Araújo, da Costa, Antonio Carlos Augusto, Pereira, Nei
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-04-2013; Elsevier
• Subjects: Biofuel; Biofuel production; Biological and medical sciences; Biomass; Biotechnology; Biotechnology - methods; Carbohydrate Metabolism - drug effects; Carrageenan - metabolism; Cellulose - metabolism; Charcoal - pharmacology; Energy; Enzymatic hydrolysis; Ethanol - metabolism; Fermentation; Fermentation - drug effects; Fundamental and applied biological sciences. Psychology; Furaldehyde - analogs & derivatives; Furaldehyde - isolation & purification; Galactose - metabolism; Glucose - metabolism; Hydrolysis - drug effects; Industrial applications and implications. Economical aspects; Kappaphycus alvarezii; Macroalgae; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; Rhodophyta - drug effects; Rhodophyta - metabolism; Saccharomyces cerevisiae - drug effects; Saccharomyces cerevisiae - metabolism; Sulfuric Acids - pharmacology; Biofuel; Fermentation; Enzymatic hydrolysis; Macroalgae; Rhodophyta; Hydrolysis; Ethanol; Algae; Enzymatic digestion; Alga; Florideophyceae
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.02.002

► Evaluation of different process strategies for producing ethanol from red algae. ► Activated charcoal powder was efficient in removing HMF in the hydrolysate. ► Increasing inoculum size to reduce the inhibition of galactose uptake.
This study evaluated the potential of Kappaphycus alvarezii as feedstock for ethanol production, i.e. ethanol 3G. First, aquatic biomass was subjected to a diluted acid pretreatment. This acid pretreatment generated two streams – a galactose-containing liquid fraction and a cellulose-containing solid fraction, which were investigated to determine their fermentability with the following strategies: a single-stream process (simultaneous saccharification and co-fermentation (SSCF) of both fractions altogether), which achieved 64.3gL−1 of ethanol, and a two-stream process (fractions were fermented separately), which resulted in 38gL−1 of ethanol from the liquid fraction and 53.0gL−1 from the simultaneous saccharification and fermentation (SSF) of the solid fraction. Based on the average fermentable carbohydrate concentration, it was possible to obtain 105L of ethanol per ton of dry seaweed. These preliminaries results indicate that the use of the macro-algae K. alvarezii has a good potential feedstock for bioethanol production.