Effect of Acids and Alkaline Pretreatment of Used Tea Waste Powder under Microwave-Assisted Pretreatment

There are numerous methods to enhance the quality of cellulose for efficient and sustainable fuel production, the acid and alkaline pretreatment methods have become increasingly popular due to their accessibility and affordability. These methods are typically used to eliminate lignin, disrupt the cellulose crystalline structure, and reduce its rigidity. This study focuses on the use of pretreatment with four different types of acids (Hydrochloric Acid, Phosphoric Acid, Acetic Acid, and Sulfuric Acid) and four types of alkaline (Calcium Hydroxide, Sodium hydroxide, Potassium Hydroxide, and Ammonium Hydroxide) were used to soak the used tea waste powder as a raw material under microwave-assisted pretreatment. The effectiveness of acid and alkaline pretreatment methods under microwave heating on used tea waste powder was evaluated through infrared analysis. The experiments were conducted at varying microwave temperatures (100–200 °C), reaction times (2–7 min), and with a 2 g doses of used tea waste powder in 100 mL of diluted acid, and 5% of alkaline solution. The weight loss of liquid and solid samples after acid and alkaline pretreatment under the aid of microwave pretreatment were calculated. FTIR analysis results showed a significant improvement in the characteristics of the treated samples compared to the untreated used tea waste powder.