Study on producing bioethanol from castor shell / Perajurit Putra Iskandar

Project paper (Bachelor of Chemical Engineering (Gas Technology)) -- Universiti Malaysia Pahang – 2012

Bibliography : p. 34-36

As know the biggest by product of processing castor seed is castor shell. The composition of castor shell from the whole seed is 35% and the shell itself is made from mainly cellulose. In this study, the cellulose in the castor shell is utilized to produce ethanol. Cellulose resource has got much attention as a promising replacement of fossil fuel. The hydrolysis of cellulose is the key step to chemical product and liquid transportation fuel. So far, various methods using acid catalyst and or enzyme have been proposed for the hydrolysis of cellulose to recover glucose for producing ethanol. The cellulose content in the castor shell must make available for hydrolysis by treatment with mixture of nitric acid and sulfuric acid. Before proceed to hydrolysis process the extracted cellulose must be characterized first with FTIR(Fourier transform infrared spectroscopy) to made confirmation of the presence of cellulose in the castor shell . In this study the hydrolysis of cellulose is done at 120oC at 0.1Mpa for 12h and at this optimum level sugar is produce. The further process is fermentation of the sugar using baker yeast (Saccharomyces cerevisiae) to produce bioethanol. Based on the result of FTIR analysis on the characterization of the extracted cellulose from the castor shell there is positive sign of the presence of cellulose content inside the castor shell. Through the DNS(Dinitrosalicylic Acid) ,the sugar content inside the hydrolyze cellulose is analyze by using glucose with different concentration as the standard (0.015 g/ml ,0.040 g/ml and 0.080 g/ml) with UV-VIS as the data analyzer for determining the concentration of sugar inside the hydrolyzed sugar. From this UV-VIS analysis the amount of sugar absence in the sample is 32 mg/l from 3.33g of treated cellulose from the castor shell. Generally, an increase in the acid concentration decreased the sugar yield due to possible sugar degradation, with xylose most affected by an increase in acid concentration. ), Analyzing the relationship between sugar degradation and acid concentration, suggests that pentoses (arabinose and xylose) are prone to degradation with increased acid concentration, which may indicate that the acid also acts as a catalyst for sugar decomposition. These data also indicate that acid concentration affects the reaction and product yield, with more rapid glucose formation found with increased acid concentration.