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This research studied the suitable technique for the production of methyl ester from waste palm oil in the water pond of a palm oil mill. The composition of the waste palm oil was 73.82% fatty acid, 5.07% triglyceride, 3.39% diglyceride and 17.76% unknown compounds. The unknown compounds were separated via simple distillation carried out at a temperature range of 300-350oC.First, the experiments were carried out in screw capped bottles using filtrated as-received waste oil as the reactant. The esterification and transesterification process were conducted using sulfuric acid catalyst in a methanol solution. The key parameters studied were mole ratio of waste oil to methanol (1:1 to 1:72), amount of catalyst from 0.1-20 v/w% of the reactant, temperature range of 60-98oC and reaction time range of 15-180 minutes. Thin Layer Chromatography (TLC) analysis showed 85-90% purity of methyl ester with 4-5% of mono-, di-, and triglycerides and fatty acids and about 5-10% of the unknown compounds for the best condition. The resulting yield of biodiesel was 84-88%. Eradication of contaminants by distillation gave about a 75% distillate yield. Distilled waste palm oil was esterified and transesterified using the previous optimum condition of as-received waste oil, but the reaction time and temperature were varied. The optimal result was obtained by using distilled waste palm oil to methanol molar ratio of 1:8, sulfuric acid of 1 v/w% of reactant, reaction temperature of 70oC and reaction time of 1 hour. TLC analysis indicated a biodiesel composition of methyl ester, free fatty acid, diglyceride and monoglyceride of 96.39%, 3.20%, 0.24% and 0.17%, respectively. The yield of biodiesel was 96-98% having physical fuel properties according to Thailand standard for methyl esterFinally, the distilled waste palm oil was esterified using a 3 liters continuous stirred-tank reactor (CSTR). Using the suitable condition for the batch process and an hour retention time, the resulting biodiesel contained methyl ester, free fatty acid, diglyceride and monoglyceride at compositions of 94.34%, 3.22%, 1.60% and 0.84%, respectively, which were very close to the qualities from the batch process.

Fatty alcohol is an important raw material for the production of surfactants, and is currently in demand by markets and has a high potential for growth. Moreover, fatty alcohol can be made from methylester that is produced from fats and natural oil. The production of fatty alcohol involved hydrogenation using the suspension method process and methyl ester in palm oil as the raw material. Copper chromite was used as the catalyst for the hydrogenationreaction and the experiment was proceeded in a close system pressure reaction vessel. The reaction was conducted at approximately 150-250oC, 1100-1700 psig, 2-8% catalyst W/V of methyl ester and reaction timefrom 5-20 hr. After the reaction, the products were analysed to check for percent conversion using gas chromatography (GC). The hydrogenation reaction began at 200oC. The best hydrogenation reaction for theproduction of fatty alcohol occurred at 250oC, 1700 psig, 6% catalyst and reaction time of 20 hr, which gave a purity greater than 97%.

Volatile organic compounds (VOCs) have been found in wastewater of many chemical industries. Evaporation of VOCs from open water basin in waste treatment facilities causes air-pollution and has been regulated in many countries. Reduction or prevention of VOCs evaporation from open water basin is then necessary. The aim of this research was to investigate the influence of surface film generated by an insoluble surfactant on the mass transfer coefficient of VOCs evaporating from water. Hexadecanol and octadecanol were used as surfactant in this investigation with the amount in the range of 0 to 35 μg/cm2 and 0 to 25 μg/cm2, respectively. The VOCs used in this study were methanol, acetone, methyl ethyl ketone and toluene. The experimental results showed that the surfactant film can reduce the gas film and liquid coefficients by 56 and 80 %, respectively. The suitable amounts of the surfactant were 25 μg/cm2 for hexadecanol and 15 μg/cm2 for octadecanol. From this investigation we can conclude that covering the water surface with a film of hexadecanol or octadecanol could significantly reduce the VOCs evaporation rate.Finally, the empirical equations correlating gas film and liquid film coefficient to amount of surfactants were developed and verified against the experimental data. The predicted values of the overall mass transfer coefficients, obtained by using these empirical equations, were in good agreement with the measured values. Thus the empirical equations of mass transfer coefficients developed in this work can be used to predict the evaporation rates of VOCs from water surface covered by hexadecanol or octadecanol film.

Methyl ester was produced from many sources of oil palm products, namely used frying oil, RBD palm oil, degummed and deacidified palm oil, palm stearin and superhard palm stearin. Production process was a conventional transesterification batch process using methanol as reactant and sodium hydroxide as catalyst. Production procedure consisted of oil preparation, solvent preparation, reaction step, glycerol separation, washing step and finishing step. Thin layer chromatograph was used to determine the composition of product and nearly 100% methyl ester was obtained at a suitable condition. Molar ratio of oil: methanol was about 1:6, which equal to 20% by weight of methanol. Sodium hydroxide was 0.5-1 %wt. of oil. The production temperature was 60-80ºC, mixing time was only 15-30 minutes and reaction time was 3-4 hours. Many fuel properties of methyl ester were very close to high-speed diesel such as viscosity, density, heating value and boiling point range. Pour point of methyl ester was higher than diesel owing to the high composition of saturated methyl ester that has a high melting point.

Stearin adulteration in refined palm oil crystallization was investigated for industrial separation of stearin and olein. The important standard properties of olein are the iodine value which must be higher than 55-57, and the cloud point which must be lower than 9ºC. The crystallization temperature is the most important parameter of the process to obtain the standard olein properties and should not exceed 20ºC. Longer crystallization time is possibly the cause of lower yields but higher quality. The stearin adulteration at the ratio of 1:9 leads to higher yields, but the quality of stearin adulteration shows unimportant effects. The uniformity of heat and mass transfer in the crystallization process are important factors in obtaining higher yields and quality of olein.

This paper presents the frequency and temperature-dependence complex permittivity (ε = ε' + jε") of three layers (the mesocarp, shell and kernel) in palm fruit var. Tenera. The complex permittivity was measured and reported at frequencies between 0.5-6 GHz from 10-70?C. Dominated by the frequency characteristic of free water in these three layers, the ε' and ε" decreased significantly with the increase in temperature at the measured frequencies. The temperature characteristic of ε at 2.45 GHz was investigated. It was found that ε', ε" and the loss tangent for the mesocarp layer were higher than those of the kernel and shell layer. This was especially so for the loss tangent case; this means that the mesocarp layer can absorb microwave energy and convert it to heat more readily than the other two layers. The penetration depth,Dp, for each layer at 2.45 GHz between 10-70°C was computed and confirms volumetric heating does occur in all three layers. Temperature-dependence models for εof all three layers at 2.45 GHz were formulated by applying regression analysis to the measured ε with a 95% confidence interval. The three models were applied to form a multilayer concentric model for palm fruit and can be applied for microwave heating. The temperature distribution profiles in the palm fruit predicted from the model and the experimental results showed good agreement. [ABSTRACT FROM AUTHOR]

Glycerol, a by-product from transesterification, is well-known as one of the factors inhibiting the reaction. Previous works have mostly shown that the reaction rate slows to a near-steady state and eventually reaches chemical equilibrium. This work aimed to study the inhibiting behavior of glycerol on the transesterification of palm oil. Observation under an LCD digital microscopy showed that glycerol-coated droplets of catalyst-methanol dispersed in the triglyceride phase. This work proposes that glycerol inhibits transesterification by the following mechanism: Droplets of catalyst-methanol disperse into the triglyceride phase; the reaction takes place at an interphase called the reactive zone; methyl ester, the desired product, has low polarity and moves to the triglyceride phase, whereas glycerol, the non-desired product, is more highly polar and accumulates on the droplet surface of catalyst-methanol droplets, inhibiting triglyceride mass transfer and diluting the concentration of the catalyst-methanol. The triglyceride mass transfer coefficient and reaction rate constant were both investigated and expressed as the exponential function.