Judul: Penentuan Suhu Reaksi dan Rasio Volume Gliserol dan Palm Fatty Acid Distillate untuk Sintesis Mono-Diasilgliserol
Abstrak: Mono-diacylglycerol (M-DAG) is one of emulsifiers which can be obtained by esterification of glycerol and free fatty acids. Glycerol are used is glycerol byproduct of biodiesel production, while the free fatty acids that are used is Palm Fatty Acid Distillate (PFAD). The main objective of this research is to determine the volume ratio of glycerol and PFAD, also the best temperature for the synthesis of M-DAG. The research began with the purification of crude glycerol that produced glycerol which had 73-81% glycerol content, 1.14% ash content, and pH 5. Glycerol and PFAD were reacted using 2% of methyl ester sulfonic acid catalyst for 60 minutes then the result’s characteristic was analyzed. The best temperature and volume ratio is at 160 °C with ratio between 1:3 and 1:4. This condition resulting M-DAG with yield 32.60% and 27.20%, amount of M-DAG was 61.99% (24.68% MAG, 37.31% DAG) and 49.92% (20.27% MAG, 29.66% DAG), 70.97% and 71.19% emulsion stability, 55 °C and 56 °C melting point, pH 3, 40.01% dan 39.01% acid value, and also dry and whitey-brown physical characteristic
Keyword: M-DAG, mono-diacylglycerol, emulsifier, PFAD, glycerol

Judul: Penentuan Waktu Reaksi dan Konsentrasi Katalis untuk Sintesis Mono-Diasilgliserol
Abstrak: Mono-diacylglycerol is an emulsifier that containing monoglycerides and diglycerides, which is made by reacting glycerol and fatty acids with the help of a chemical catalyst. This research was aimed to produce mono-diacylglycerol from glycerol, by-product of biodiesel production and palm fatty acid distillate, by-product of frying oil production, and to know the best reaction time and concentration of catalyst to produce mono-diacylglycerol through esterification process. The steps consisted of glycerol purification, characterization of purified glycerol and palm fatty acid distillate. This was followed by determinating the reaction time (60, 75, and 90 minute) and concentration of catalysts (1.5%, 2%, and 2.5%) for production of mono-diacylglyserol, and characterization of mono-diacylglycerol which has been producted. In this research was used a methyl ester sulphonic acid as the catalyst. The best products was mono-diacylglycerol with catalyst concentration of 1.5% and reaction time 75 minutes. This condition producted M-DAG with yield 30.20%, the percentage fraction of monoacylglycerol 16.21%, diacylglycerol 31.00%, melting point of 57 oC, pH 4, emulsion stability 85.94%, acid value 23.18 mg KOH/g sample, texture rather dense, quite dry, and whitey-brown color.
Keyword: esterification, mono-diacylglycerol, emulsifiers, fatty acids, glycerol

Judul: Centrality test for Non-Normal And Skewed Population
Abstrak: The t modified 2 test is more robust than t test for skewed popnlation. This test tolerate the population skewness from -1.2 to 1.2 sample size is reather than 25. The sign test robust to the populated skewed population, but the value of the estimated always close to the size of the tcst. Wilcoxon test is not robust to the population skewness. This test is more suittalble for Symmetric population
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