This work is a comprehensive study focusing on various methods for processing wheat straw to enhance its suitability for bioethanol production. It delves into mechanical, physical, chemical, and biological pretreatments, each aimed at improving the enzymatic hydrolysis and fermentation processes necessary for bioethanol production. Mechanical and physical pretreatments involve reducing the size of wheat straw to improve enzymatic hydrolysis. Physical methods include heating and irradiation, which alter the structural properties of wheat straw. Chemical pretreatments involve using acids, alkalis, and organic solvents to remove lignin and hemicellulose, making cellulose more accessible for hydrolysis. Biological pretreatments utilize microorganisms and fungi to degrade lignin and other complex compounds, enhancing the breakdown of cellulose. The study presents data on the effectiveness of these treatments in terms of lignin removal, sugar yield, and overall bioethanol production efficiency. The research is aligned with the global move towards renewable energy sources and emphasizes the importance of utilizing agricultural waste, like wheat straw, for sustainable energy production.
To reduce environmental pollution, a renewable source of energy that we may utilize is bioethanol obtained from wheat straw. Wheat straw was ground to 40–50 mm in size and heat-treated with high-pressure steam to release lignocelluloses, making them accessible to enzymes during saccharification. Through mechanical pretreatment, a substrate was obtained, which contains toxic components in concentrations that do not diminish the performance of the enzymes in the enzymatic hydrolysis phase. Through the thermal pretreatment of wheat straw, its acidity was improved, influencing the amounts of glucose, xylose, and other components emitted. Following enzymatic hydrolysis, very small concentrations of sugars were released. In order to increase the efficiency of the transformation of sugars into ethanol during the fermentation process, a strain of yeast, Trichoderma reesei multiplied in the laboratory, was added, under the conditions of temperature—28 degrees and stirring—800 rpm. Trichoderma reesei penetrated the wheat straw substrate, facilitating the subsequent hydrolysis process. The improved biodegradation of the pretreated straws was highlighted by the electron microscopy analysis.