STATISTICAL SCREENING AND SELECTION OF SWEET SORGHUM VARIETIES FOR BIOETHANOL PRODUCTION

Abstract

This study aims at the screening of four cultivars of sorghums as a feedstock for bioethanol production. The straw of these varieties were subjected to pretreatment (dilute sulfuric acid) followed by enzyme hydrolysis to evaluate their potential to produce sugars. Four factor full factorial experimental design (2×2×2×4=32) was used to investigate the effects of experimental factors; sorghum varieties (84-Y-01, 85-G-86, Mr. Buster and RARI S-3), acid concentration (1 and 2%), temperature (121 and 140˚C) and pretreatment time (30 and 60 min). The tested sorghum varieties follow the order 85-G-86 (47 g/100g) > Mr. Buster (44.6 g/100g) > 84-Y-01 (42 g/100g) > RARI S-3 (36 g/100g) for their sugar yield. The factors followed given order of significance; variety > temperature > acid concentration > pretreatment time. Sorghum variety (85- G-86) was selected as an appropriate feedstock for bioethanol production due to its higher sugar yield and lower concentration of by-products and furans.