Optimization Method for Bioethanol Production from Giant Cassava (<i>Manihot esculenta</i> var. Gajah) Originated from East Kalimantan

Abstract

Here is the first report of bioethanol production from giant cassava, a variety of cassava originated from East Kalimantan. Hydrolysis on freshly grated cassava with two different acids was studied separately. The experiment was conducted as a single factor experiment in Completely Randomized Design (CRD) with five treatments (0.0–1.0 M of acid solution), each replicated three times. Reducing sugars, unhydrolyzed substance (fibers), and hydrolysate clarity was determined. The experiment was continued by studying fermentation condition using factorial experiment (2 x 4) in CRD. The first factor was starter concentration (Saccharomyces cerevisiae, 5 and 10%) and the second factor was fermentation time (2–11 days). Biomass and alcohol content in fermentate were determined. The data were analyzed by ANOVA, excluding alcohol content that analyzed by the non-parametric statistic. Optimization using regression analysis showed that hydrolysis by HCl was more effective than H2SO4. Hydrolysis solution of 0.58 M HCl gave an optimum reducing sugar in hydrolysate (5.6%), which equivalent to a yield of 28.18%. Starter concentration affected significantly on biomass and alcohol content (p &lt; 0.001) of fermentate, while fermentation time affected significantly only on alcohol content (p &lt; 0.001). Optimum condition of cassava hydrolysate fermentation (100 mL) was using 5% yeast for 8 days, which gave a yield of 14.17% bioethanol.

Conversion of Lignocellulose for Bioethanol Production, Applied in Bio-Polyethylene Terephthalate

“…The monosaccharides are utilized as a feedstock for the fermentation process for making bioethanol. The most common acids used for hydrolysis are sulfuric acid, phosphoric acid, and hydrochloric acid [ 97 , 98 , 99 ]. The advantage of acid hydrolysis for producing sugar in the bioethanol process is that the acid can easily access the cell wall.…”

The Characteristics of Cassava Var. Gajah (Manihot esculenta C) Derivative Products as a Thickening Agent in the Manufacturing of Tamarind (Tamrindicus indica) Paste

“…Cassava var. Gajah (Manihot esculenta C) is a superior plant typical of East Kalimantan which its use continues to be developed [1]. This plant can produce cassava tubers up to 50 kg per tree, ten times more than other types of cassava.…”