Bioconversion of Potatoes to Bioethanol

Rokaya I M Mahran,Mohamed E O Yehia,Mahmoud M Elewa,Mona M Naim,Mervette El-Batouti

doi:10.37358/rc.20.10.8356

Abstract

With the depletion of the world�Ls 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 (��-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 ��-amylase and 8g of yeast were added using SSF strategy. A comparison between obtained results and published data and strategies were presented.

Highlights

In recent years increasing interest in the production of biofuels especially bioethanol as an alternative to fossil fuels has gained considerable attention in various countries Brazil and the U.S.A. [1]
The maximum percent alcohol concentration achieved in this case was 49.6. This result has been obtained by Khan et al [13] for the production of bioethanol through enzymatic hydrolysis, the data of their study of potato revealed that significant % bioethanol was produced at high temperature
The results show that the percent of bioethanol was 49.84% for 1g α-amylase, while the percent of bioethanol reached 35% when another gram of α-amylase was added to the same solution

Summary

Introduction

In recent years increasing interest in the production of biofuels especially bioethanol as an alternative to fossil fuels has gained considerable attention in various countries Brazil and the U.S.A. [1]. Depletion of petroleum-based fuels worldwide, with the concomitant rise in its prices has led to the search for substitutes other than petroleum for production of energy In this context, bioethanol is currently produced from a variety of starch-based crops such as potatoes, rice, corn, wheat, and cassava [2] lignocellulosic biomass which includes agricultural residues (e.g., corn stover and crop straw), herbaceous crops (e.g., switchgrass), forestry residues and municipal solid wastes (e.g., waste paper) [3]. The hydrolysate contains varying amounts of monosaccharides, both pentose and hexose, and a broad range of substances either derived from raw material or resulting as reaction products from sugar and lignin degradation. Many of these substances may have an inhibitory effect on the microorganisms in subsequent fermentation steps. Among the xylose fermenting yeasts Pichia stipitis has shown promise for industrial applications because it ferments xylose rapidly with a high ethanol yield [5]

Methods

Results

Conclusion