Abstract

Agricultural and forestry wastes are the popular renewable resources due to its price and efficiency. In recent decades, there are a lot of successful researches about bioethanol from lignocellulose to decrease the fossil fuels consumption. To produce bioethanol from lignocellulose materials, the prerequisite step is pretreatment step to remove lignin, to break the tight structure of lignin-cellulose-hemicellulose complex, to facilitate the contact between hydrolysis agent and cellulose. Alkaline pretreatment has been known as the most popular method. In this study, NaOH solution after the first pretreatment will be used again, adding a minimum amount of NaOH. The addition is calculated so that the total amount is reduced while maintaining the pretreatment efficiency. Analysis results showed that an aqueous solution of 2.0 wt.% NaOH can be used to pretreat the biomass for the first time in 24h, the first pretreatment allow the cellulose enrichment of raw materials from 41.2 % to 53%, in the second reused pretreatment, the addition give the same efficiency. The total amount of alkaline solution decreases 30.3% and the pure water decrease 41.2%, compared to the traditional method. The proposed method achieves the main goal: reduce significantly chemical costs, have a positive and practical meaning in contributing to solve the economic - technical problem of the second generation bioethanol’s production technology.