Oil Extraction of Mechanically Compressed Residues of Jatropha Seeds
Date Issued
2012
Date
2012
Author(s)
Chiang, Tien-Gang
Abstract
Biodiesel has been viewed as a very feasible“renewable energy”and one of the ways to achieve the goal of “using renewable energies as energy sources”.
Among the available raw oil sources of biodiesel, Jatropha curcas L. seed (JCL seed) is an attractive biodiesel feedstock, because it is inedible to avoid food deficiency and easy to plant, and contains high oil content. Moreover, the price of JCL seeds is lower than those of edible oils, partly overcoming the problem of high cost of raw source oils. For further reducing the cost, properly using the residues from the biodiesel production process seems to be a good option. Thus, this study attempted to introduce an efficient way of utilizing the “mechanically expelled residues of JCL seeds” -a by-product of oil-expelling process. Solvent extraction was employed to further extract the residue oil from the mechanically expelled residues of JCL seeds.
The by-product utilizing process started from the mechanically expelling of JCL seeds, followed by grinding, sieving and extraction of the residues. Solvents for oil extraction were selected by the consideration of incorporation with the transeasterificaion of oil with alcohol to produce biodiesel. Four alcohols, namely methanol, ethanol, 1-propanol and isopropanol were employed. The oil-containing alcohol can then be adjusted to proper molar ratio of alcohol to oil for the subsequent use in biodiesel production. The oil extraction abilities of alcohols were assessed and compared with that of n-hexane, which has been recognized as one of the best non-toxic solvent for extracting the oil.
Shaking extraction of oil was performed to establish the equilibrium relationship between the oil concentrations in solvent and residue phases. For enhancing the oil extraction ability and rate, a high gravity rotating packed bed (RPB) was adopted. The results indicate that Freundlich isotherm can be applied to describe the equilibriums for the four alcohols examined. The oil extraction abilities are in the following order: hexane > isopropanol ≒ 1-propanol > ethanol > methanol. As for the RPB oil extraction system, the results reveal that it not only increases the extraction ability of solvents but also significantly reduces the time to reach equilibrium, from 2-day to 60 min. Comparing the kinetics of oil extraction using isopropanol in RPB and shaker systems further support that the RPB system gives higher desorption rate than the shaker system. Therefore, the results indicate that RPB extracts more oil in JCL expelled residues and faster than the traditional shaker.
Subjects
extraction
solvent
high gravity rotating packed bed
adsorption
jatropha residues
SDGs
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-101-R99541118-1.pdf
Size
23.54 KB
Format
Adobe PDF
Checksum
(MD5):ba97ae50907f1beae372928b0c81e9e2