Journal of Energy Bioscience 2024, Vol.15, No.2, 60-71 http://bioscipublisher.com/index.php/jeb 61 sugarcane as a biofuel feedstock, highlighting its role in reducing GHG emissions and promoting renewable energy. Furthermore, the study will discuss the potential for integrating sugarcane ethanol production with other agricultural and industrial processes to enhance its commercial viability and environmental benefits. By consolidating existing knowledge and identifying research priorities, this study seeks to provide a comprehensive understanding of the application of sugarcane in ethanol fuel production and its future prospects. 2 Theoretical Basis of Ethanol Production from Sugarcane 2.1 Chemical composition of sugarcane relevant to ethanol production Sugarcane (Saccharum spp.) is a tropical perennial grass belonging to the family Poaceae, widely used for sugar production. The primary components of sugarcane relevant to ethanol production include sucrose, glucose, and fructose, which are fermentable sugars. Additionally, sugarcane bagasse, the fibrous residue remaining after juice extraction, contains lignocellulosic materials that can be utilized for second-generation ethanol production (Dias et al., 2013). The high sugar content in sugarcane makes it an efficient feedstock for ethanol production, contributing significantly to the global biofuel supply (Talukdar et al., 2017). 2.2 Biochemical pathways for ethanol production from sugarcane The biochemical pathways for ethanol production from sugarcane primarily involve the fermentation of sugars. The process begins with the extraction of juice from sugarcane, which contains high concentrations of sucrose. This sucrose is then hydrolyzed into glucose and fructose, which are subsequently fermented by yeast (typically Saccharomyces cerevisiae) to produce ethanol and carbon dioxide. The overall reaction can be summarized as: [C6H12O6→2C2H5(OH)2+2CO2]. In addition to first-generation ethanol production from sugarcane juice, second-generation ethanol can be produced from lignocellulosic biomass (bagasse and cane trash) through processes involving pretreatment, enzymatic hydrolysis, and fermentation (Dias et al., 2013; Khatiwada et al., 2016). 2.3 Conversion technologies: fermentation and distillation processes The conversion of sugarcane to ethanol involves several key technologies, including fermentation and distillation. During fermentation, the extracted sugarcane juice is mixed with yeast in large fermentation tanks, where the sugars are converted to ethanol and carbon dioxide. The fermentation process typically takes 24 to 48 hours, after which the ethanol concentration in the mixture reaches around 10%-15% (Goldemberg and Guardabassi, 2010; Dias et al., 2015). Following fermentation, the ethanol is separated from the fermentation broth through distillation. The distillation process involves heating the mixture to vaporize the ethanol, which is then condensed and collected as a concentrated ethanol solution. This solution is further dehydrated to produce anhydrous ethanol, which is suitable for use as fuel (Goldemberg and Guardabassi, 2010). Advances in distillation technology, such as the use of molecular sieves and azeotropic distillation, have improved the efficiency and yield of ethanol production (Dias et al., 2015). 2.4 Advances in biotechnology enhancing ethanol yield Recent advances in biotechnology have significantly enhanced the yield and efficiency of ethanol production from sugarcane. Genetic engineering of sugarcane varieties has led to the development of high-yielding and disease-resistant strains, which can produce more fermentable sugars per hectare (Goldemberg and Guardabassi, 2010). Additionally, the identification and utilization of key enzymes involved in the hydrolysis of lignocellulosic biomass have improved the efficiency of second-generation ethanol production (Talukdar et al., 2017). Biotechnological innovations, such as the development of genetically modified yeast strains with higher ethanol tolerance and productivity, have also contributed to increased ethanol yields. These yeast strains can ferment sugars more efficiently and withstand the inhibitory effects of high ethanol concentrations, leading to higher overall ethanol production (Dias et al., 2013; Talukdar et al., 2017). Furthermore, process optimization techniques, including thermal integration and the use of more efficient equipment, have reduced energy consumption and increased the sustainability of ethanol production from sugarcane (Ensinas et al., 2009).
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