internodes of sugarcane was extracted and purified in specialized mill factories and is
used as raw material in food industries or fermented to produce ethanol. Ethanol is
produced on large scale by the Brazilian sugarcane industry and yet the world
demand for sugar is the primary driver of sugarcane agriculture [7].
Sugarcane tops or trash (SCT) is regarded as an agricultural residue that represents the top fragment of the sugarcane plant along with its leaves [8], and the
one-third portion of sugarcane plant holds SCT (dry mass basis) [9]. Currently, these
unutilized residues were dumped and burnt on the fields after sugarcane cultivation.
To some extent, the green SCT obtained immediately after the cultivation was used
as animal fodder [4, 10]. This cellulose-rich SCT can be employed to extract the
bioethanol by taking advantage of its rich cellulosic matter and the huge availability.
Extraction of bioethanol from cellulosic SCT will neither affect food supply nor
interfere negatively with sugar-based food or juice extracted from stalks of sugarcane plant.
2 Steps Involved in Bioethanol Production
The process of converting lignocellulosic biomass into bioethanol mainly consists of
four unit operations such as pretreatment, hydrolysis or saccharification, fermentation, and product recovery [3, 11, 12]. The overall schematic representation of
bioethanol production from lignocellulosic biomass is presented in Fig. 1. Prior to
pretreatment step, the raw lignocellulosic biomass was subjected to size reduction as
shown in Fig. 2. Pretreatment is essential to alter the biomass size and structure and
its sub-microscopic chemical composition so that hydrolysis of the carbohydraterich solid fraction to monomeric sugars can be achieved more rapidly with greater
yields. Hydrolysis involves the processing step that converts the carbohydrate polymers into monomeric sugars. Six carbon sugars (hexoses) are readily fermented to
ethanol by various naturally occurring organisms. However, the five carbon sugars
Fig. 1 Steps involved in bioethanol production
Lignocellulosic Sugarcane Tops for Bioethanol Production: An Overview
91
used as raw material in food industries or fermented to produce ethanol. Ethanol is
produced on large scale by the Brazilian sugarcane industry and yet the world
demand for sugar is the primary driver of sugarcane agriculture [7].
Sugarcane tops or trash (SCT) is regarded as an agricultural residue that represents the top fragment of the sugarcane plant along with its leaves [8], and the
one-third portion of sugarcane plant holds SCT (dry mass basis) [9]. Currently, these
unutilized residues were dumped and burnt on the fields after sugarcane cultivation.
To some extent, the green SCT obtained immediately after the cultivation was used
as animal fodder [4, 10]. This cellulose-rich SCT can be employed to extract the
bioethanol by taking advantage of its rich cellulosic matter and the huge availability.
Extraction of bioethanol from cellulosic SCT will neither affect food supply nor
interfere negatively with sugar-based food or juice extracted from stalks of sugarcane plant.
2 Steps Involved in Bioethanol Production
The process of converting lignocellulosic biomass into bioethanol mainly consists of
four unit operations such as pretreatment, hydrolysis or saccharification, fermentation, and product recovery [3, 11, 12]. The overall schematic representation of
bioethanol production from lignocellulosic biomass is presented in Fig. 1. Prior to
pretreatment step, the raw lignocellulosic biomass was subjected to size reduction as
shown in Fig. 2. Pretreatment is essential to alter the biomass size and structure and
its sub-microscopic chemical composition so that hydrolysis of the carbohydraterich solid fraction to monomeric sugars can be achieved more rapidly with greater
yields. Hydrolysis involves the processing step that converts the carbohydrate polymers into monomeric sugars. Six carbon sugars (hexoses) are readily fermented to
ethanol by various naturally occurring organisms. However, the five carbon sugars
Fig. 1 Steps involved in bioethanol production
Lignocellulosic Sugarcane Tops for Bioethanol Production: An Overview
91