Optimization of microwave-assisted alkaline pre-treatment method for the cellulolytic fermentation of abaca stripping waste into glucose

Department of Chemical Engineering, Bicol University, Legazpi City, Albay, 4500, Philippines

Corresponding author: jrbarajas12@gmail.com

Abstract

Abaca fiber remains a vital export product that contributes primarily to the continuous economic growth of the Philippines. However, the voluminous amount of byproducts generated has consistently caused setbacks which often result to major losses to the growing abaca industry in the country. In an attempt to provide a practical solution to the emerging problem, we investigate the utilization of abaca stripping waste (ASW) as a precursor material to produce bioethanol. We test the extent of conversion of the hemicellulose-rich by product to glucose. A box-behnken experimental design was used to obtain the optimal conditions in the conversion process. Alkaline concentration (%), microwave power (W), and microwave time (min) were found to have significant influence on the glucose yield. Actual values of these independent variables were chosen on the basis of preliminary experimental results. Optimum conditions using ridge analysis were found to be: alkaline concentration 2.55%, microwave power 124.0 W, and microwave time at 1.0 min. Conversion to glucose was also performed at optimum conditions. In conclusion, a high glucose yield obtained which is suitable for bioethanol fermentation presents evidence encouraging the utilization of abaca stripping waste to produce high value products.