Acid and enzymatic hydrolysis of the residue from Castor Bean (Ricinus communis L.) oil extraction for ethanol production: detoxification and biodiesel process integration

• Published in: Journal of the Brazilian Chemical Society 2008, Vol.19 (3), p.418-425
• Main Authors: Melo, Walber C., Santos, Alexandre S. dos, Santa Anna, Lídia Maria M., Pereira Jr, Nei
• Format: Article
• Language: English
• Subjects: CHEMISTRY, MULTIDISCIPLINARY
• ISSN: 0103-5053; 1678-4790
• DOI: 10.1590/S0103-50532008000300008

The starch hydrolysis process of Castor Bean Cake by (CBC) acid or enzymatic combination of alpha-amylase, glucoamylase and pullulanase was evaluated and followed by fermentation. The chemical hydrolysis resulted in 27.3 g L-1 of sugars with 33.4% of hydrolysis efficiency. The generated hydrolyzate was fermented yielding 11 g L-1 of ethanol (Y P/S=0.48 g g-1). The best enzymatic hydrolysis condition was as follows (per gram of CBC): 200 µL of a-amylase, at 90 ºC; 200 µL of glucoamylase and 100 µL of pullulanase, both at 60 °C, which yielded 75 g L-1 of total reducing sugars corresponding to 91.4 % of hydrolysis efficiency. These sugars were subsequently converted to 34.5 g L-1 of ethanol. The acid hydrolysis process was also capable to allow the detoxification of the Castor Bean Cake.