Bioconversion of potatoes to bioethanol

Abstract

With the depletion of the world´s petroleum supply, there has been an increasing worldwide interest in alternative, non-petroleum based sources of energy. Ethanol derived from biomass has the potential to be renewable transportation fuel that can replace gasoline. Moreover bioethanol can play an important role in reducing green-house gas emission. Ethanol use will increase because of its biodegradable, renewable and performance qualities. It is a high performance fuel in internal combustion engines and burns relatively cleanly, especially as the amount of gasoline with which it is blended decreases. The largest potential feedstock for ethanol includes materials such as agricultural residues, forest residues, wood, grass, waste paper and municipal wastes. In the present work, potatoes were used as example of starch-based biomass. Different variables were studied for their effect on the percent of bioethanol produced as a result to saccharification and fermentation of the raw material, which included: quantity of enzyme (α-amylase and/or Aspergillus Niger (AN), addition of yeast (Saccharomyces cerevisiae (SC)), temperature during fermentation, separate saccharification and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). The maximum percent of alcohol was 56% (b.w.) at 40°C when 3g of α-amylase and 8g of yeast were added using SSF strategy. A comparison between obtained results and published data and strategies were presented.