The ESTERIFICATION of free fatty acids (FFA) with methanol is studied using Sulfonated Porous Carbon (SPC) as catalyst. In compare to the amorphous sugar catalyst and protonated Nafion, the proposed catalyst shows stability and high efficient performance in biodiesel production. The highest initial rate of oleic acid conversion is obtained at catalyst loading of 1 mmol H+ and mole ratio of MeOH/Oleic acid of 10. The prepared Sulfonated Porous Carbon reused at least three times without loss of activity.

Vegetable oils and fats in comparison with diesel fuel have high viscosity, by trans-ESTERIFICATION method the viscosity of oil can be decreased. Trans-ESTERIFICATION of triglyceride with alcohol is one of the methods for production of biodiesel. In this study sunflower oil, methanol and ethanol, with molar ratio of (1: 3, 1: 4, 1: 6, 1: 8) and temperature (40, 50, 60oC) were dependent parameters employing potassium hydroxide as a catalyst at the concentration of 1%. The reaction was carried out for 90 min at 600 rpm. The product viscosity was measured at 40ºC.Gas chromatogram showed that the highest yield of methyl and ethyl ester of sun flower oil at 1: 8 molar ratio of oil to alcohol at 60oC could be obtained. The conversion rates were 96% and 85% for methyl ester and ethyl ester respectively. It was found that temperature and the ratio of oil to alcohol are two important factors in biodiesel production and thus increasing biodiesel yields. The result suggested that molar ratio of methanol to oil (1: 8) at 60oC for biodiesel production is optimal.

In this study, magnetite nanoparticles were obtained from Fe(II) and Fe(III) salts in an alkaline medium. The nanoparticles were then protected from oxidation by a silica shell formed by the sol-gel method using tetraethoxy orthosilicate (TEOS) in an EtOH/H2O mixture. The synthesized Fe3O4@SiO2-SO3H magnetic nanocatalyst was characterized with Fourier transform infrared (FT-IR) spectroscopy, wide angle X-ray diffraction (WXRD), thermal gravimetric analysis (TGA), energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), Hammett acidity function and pH analysis as well as Brunauer-Emmett-Teller surface area measurement (SBET). Finally, the ESTERIFICATION reaction of phthalic anhydride, mono-and dicarboxylic acids with various alcohols was chosen to show the catalytic activity of the magnetic nanocatalyst. The reaction conditions were optimized and catalyst recovery was also demonstrated. The nanocatalyst was magnetically separated and reused several times without significant loss of activity.

Since the conventional ESTERIFICATION method requires long processing time and gives low yield, the intensification of this process is still an interesting subject to be investigated. To reduce the oil extraction cost from seeds which accounts for almost 70% of total processing cost, in situ ESTERIFICATION has been recently introduced. The objective of this study was to produce biodiesel from rubber seeds oil through in situ ESTERIFICATION, assisted by ultrasound irradiation at 42 kHz for 30 min. The experiment was carried out in two stages of catalyst additions: H2SO4 (varied from 0. 1-1% v/v) and NaOH (0. 1%) and the ESTERIFICATION was conducted at 60 oC for 30 min under ultrasound frequency of 42 kHz. The results showed that the optimum yield of fatty acid methyl ester (FAME) was 35% which correspond to yield of biodiesel of 92. 5% under conditions of rubber seed ratio to methanol 1: 1. 75 (w/v), catalyst H2SO4 loading of 1% and catalyst KOH loading of 0. 1%.

In this study, a vapor permeation-integrated heterogeneous catalytic ESTERIFICATION reaction was investigated to improve the ester conversion of propionic acid and isopropanol. The reaction was carried out using Amberlyst 15 (Rohm & Haas) as a catalyst with different weight fractions of 3%, 4%, 10%, and 12% wt. relative to propionic acid. A hydrophilic PERVAP®, 2201 membrane (Sulzer) was used to remove water vapor from the glass reactor. Different molar ratios (1: 1, 1. 5: 1, and 3: 1) of alcohol to acid were used in the feed mixture. Applying the coupled membrane system, using 12wt. % of catalyst, increased the acid conversion from 39% (when no membrane was employed) to nearly 90% for three hours after the beginning of the process.

In this work, kinetics and thermodynamics of ESTERIFICATION reaction were studied. This research investigated the ESTERIFICATIONreaction between methanol and acidified oil catalyzed by sulfonated cation exchange resin and proposed a new rate equation forconsideration of kinetics of this reaction according to the Langmuir-Hinshelwood mechanism. Thermodynamics and kineticsparameters were calculated according to this equation. The results of this study showed that this new equation was a reasonableequation for kinetics study of the ESTERIFICATION reaction. Also, kinetics parameters were calculated for this reaction. Activationenergy and Arrhenius pre-exponential factor were equal to 75. 2477 􀝇 􀝆 /􀝉 􀝋 􀝈 and 8. 9994 􀵈 10􀬵 􀬷 􀜮 􀝅 􀝐 /􀝉 􀝋 􀝈 . 􀝄 respectively.