| Summary: | 碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程所 === 98 === The world generates 1.1 million metric tons of solid waste from the production of 8 million metric tons of soybean sauce. Soy sauce residue contains 25-35% of non-edible oils that can be extracted and reused, but only a small fraction of soy sauce residue is used as animal feeds or supplement materials for composting.
This work was to study if residuals oils extracted from the residue generated in the soy sauce manufacturing facilities could be successfully converted into useable biodiesel via a two-step esterification process.
Experimental results showed that residues from five different facilities contained 12.2~35.7% of fats. The fatty acids in the residual oils were polyunsaturated fatty acids containing linoleic acid (52~60%), oleic acid (13~24%), palmitic acid (10~16%) and α-Linolenic Acid, (6~8%), which were similar to those of vegetable oils. Three-to-four times of pre-esterification were required to convert free fatty acids into methyl esters due to high acid values (44.68~90.15 mg KOH/g). The methyl esters conversion via a transesterification process were between 71 and 81%. The biodiesels synthesized met the specifications of USA, European Union) and ROC.
Residual oils extracted the residue from D facility were used to study the effects of the temperature, catalyst concentration and the methol/oil ratio on the yield of the transesterification process. The experimental design method was used for the selection of the experimental conditions and the multivariate regression analysis was used to fit the data to an empirical quadratic equation. The optimal yield was found to be 78.41% when the temperature, catalytic concentration and methanol/oil ratio were 56.1℃, 0.33wt% and 3.95, respectively.
This study demonstrated that the reside from the soy sauce manufacturing facility could be successfully converted into useful biodiesel.
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