A Feasibility Study about Cellulosic Ethanol Industrialization

Abstract

The second-generation of biomass ethanol, also known as cellulosic ethanol, is a major topic of discussion. The immaturity of pretreatment technology is one of the main factors restricting the scale-up of the second-generation bio-ethanol technology. Appropriate pretreatment methods can improve the accessibility of cellulose, reducing the cost of separating cellulose, hemicellulose and lignin, while increasing the yield of cellulosic ethanol. Pretreatment methods are mainly divided into four categories, namely chemical pretreatment, physical and chemical pretreatment, physical pretreatment as well as biological pretreatment methods. By analyzing the principles, effects, advantages and disadvantages of the popular pretreatment methods, whether they were suitable for industrialization were assessed. According to the results, chemical treatment methods are most frequently used but restricted to the high cost, difficulty in recovery, the impact of organic solvents and the safety problems. Physicochemical pretreatment methods are popular but has the problem of high energy cost. Besides, biological methods are not suitable for industrialization due to the high time-consuming and low degradation efficiency. Physical pretreatment is currently only a supplement of chemical pretreatment and physicochemical pretreatment, while due to its advantages such as the efficiency of pretreatment, reduction of the dosage of chemicals and low cost, it is worth being studied in the future.