Production of Bioethanol from Corn Cobs

Bioetanol je proizveden procesom istodobne saharifikacije i fermentacije (eng. Simultaneous saccharification and fermentation, SSF) s kvascem Saccharomyces cerevisiae na enzimskom hidrolizatu predobrađenih kukuruznih oklasaka. Istraživan je učinak trajanja predhidrolize kukuruznih oklasaka na učinkovitost procesa proizvodnje bioetanola te je uspoređen s konvencionalnim procesom SSF. Dvije smjese komercijalno dostupnih enzima rabljene su za hidrolizu sirovine; prva je sadržavala Celluclast 1.5L (Sigma) i β-glukozidazu (Carl Roth), a druga smjesa Celluclast 1.5L (Sigma) i Viscozyme L (Sigma). Dva dana predhidrolize imala su pozitivan učinak na prinos bioetanola, dok je dulje trajanje predhidrolize smanjilo prinos bioetanola. Najveća koncentracija etanola od 41,24 g dm–3 postignuta je u procesu SSF uz dva dana predhidrolize koja je iznosila 63,15 % teoretskog iskorištenja izračunatog na neobrađeni kukuruzni oklasak. Najveća ukupna produktivnost procesa od 0,36 g dm–3 h–1 postignuta je konvencionalnim SSF-om uz enzimsku smjesu koja je sadržavala Celluclast 1.5L (Sigma) i Viscozyme L (Sigma). Koncentracija etanola iznosila je 36,6 g dm–3, što je 56,02 % teoretskog prinosa etanola na neobrađeni kukuruzni oklasak. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.Bioethanol was produced from cellulase-hydrolysed pretreated corn cobs by simultaneous saccharification and fermentation (SSF) with yeast Saccharomyces cerevisiae. The effect of the duration of the corn cob prehydrolysis step on ethanol yield by SSF process was studied and compared to the conventional SSF process. Two mixtures of commercially available enzyme preparations were used for biomass hydrolysis; the first contained Celluclast 1.5L (Sigma) and ß-glucosidase (Carl Roth), and the second mixture contained Celluclast 1.5L (Sigma) and Viscozyme L (Sigma). Two days of prehydrolysis had a positive effect on ethanol yield, while the yield decreased with longer prehydrolysis. The highest ethanol concentration of 41.24 g dm–3 was obtained by SSF process with two days of prehydrolysis, which corresponded to 63.15 % of the theoretical yield based on untreated corn cobs. However, the highest total productivity of 0.36 g dm–3 h–1 was observed in conventional SSF process using enzyme mixture containing Celluclast 1.5L (Sigma) and Viscozyme L (Sigma). Concentration of ethanol was 36.6 g dm–3 which corresponded to 56.02 % of the theoretical yield based on untreated corn cobs. This work is licensed under a Creative Commons Attribution 4.0 International License