Papers by Keyword: Free Fatty Acid

Abstract: Rice husk ash (RHA), a waste product of the rice mill, is rich in silica. This study aimed to investigate the use of RHA as a potential adsorbent for the removal of free fatty acid (FFA) from the waste frying oil (WFO). Acid pre-treatment of RH prior to combustion using hydrochloric acid (HCl) was proposed to improve its adsorption performance. The synthesized acid-pretreated RHAs were characterized using Fourier Transformed Infrared (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). It was found that the aRHAs achieved higher silica purity with low levels of organic impurities as compared to untreated RHA. Additionally, aRHAs possessed porous morphology, especially when treated with higher HCl concentration, as revealed by SEM analysis. EDS analysis confirmed the high silica purity with negligible amount of metal impurities for all the RHAs. For adsorption kinetic models and adsorption isotherms, results showed that the intraparticle diffusion model and the Langmuir isotherm gave the best description to the experimental data with the lowest Chi-square values, reported at 0.02 and 5.46, respectively.

Abstract: In this study, Amberlyst-15 as heterogeneous catalyst was used for the reduction of free fatty acid (FFA) from the palm oil mill effluent (POME) for biodiesel production with acid-catalyzed esterification process. The objective of this study was to decrease a high FFA in POME to less than 2 wt.% FFA, for used as a raw material to produce biodiesel in the second-step transesterification process. Amberlyst-15 as an eco-friendly catalyst with non-toxic wastes after reactions, when compared to homogeneous catalysts such as sulfuric acid. Therefore, an esterification reaction with a heterogeneous acid catalyst was carried out to examine the FFA conversions. The conditions of two parameters of Amberlyst-15 catalyst (10–40 wt.%), and 1–8 h reaction time were varied, whereas the methanol to oil molar ratio and the speed of the stirrer were fixed at 5:1 and 300 rpm, respectively. As a result, the FFA sharply decreased from 89.16 wt.% to 1.75 wt.% under the conditions of 40 wt.% of Amberlyst-15, 5 h reaction time, 5:1 molar ratio methanol to oil, speed of the 300 rpm stirrer. The Amberlyst-15 had the potential to reduce high FFA in POME using the esterification reaction.

Abstract: Global increase in fuel prices and the associated problem of harmful emissions from combustion of fossil fuels has necessitated the need for more energy sources to sustain energy security and mitigate the negative environmental implications from the continuous use of petroleum diesel. This research is primarily focused on the production of biodiesel from Melia azedarach oil, which has not been much explored as a feedstock for diesel substitute. In consideration of the nutritional demands for edible oil seeds, the use of edible vegetable stock to produce biodiesel raises major ethical concerns with non-edible oil seeds presenting more feasible solution to energy crises. Oil was extracted from Melia azedarach seeds by exploring both mechanical and chemical methods. Biodiesel was produced from the extracted oil via alkali alcoholysis. An innovative Ultraviolet-Visible Spectroscopy (UV-VIS) was adopted as a process tracking mechanism for biodiesel production. An oil yield of 4.32% of crude oil was extracted using n-hexane under an extraction time of 24h and temperature of 55°C. Esterification parameters of 45:1 Molar concentration of alcohol to oil, reaction temperature of 53°C, a reaction time of 50 mins and concentrated sulphuric acid weight fraction of 5% gave a free fatty acid conversion of 89.37%. Based on the results obtained, the seed oil has been established as a promising feedstock with promising efficiency for biodiesel production. However, large scale extraction of oil from the seed for industrial production of biodiesel must be further investigated.

Abstract: The objective of this research was to study the optimum condition of esterified oil production from low free fatty acid of mixed crude palm oil (LMCPO) by using a response surface methodology (RSM) with esterification reaction in a batch mode. LMCPO obtained from a vacuum refining process of mixed crude palm oil (MCPO) to extract the partial FFA in oil which was used as a raw materials in a food production. Therefore, remaining FFA of 6.170 wt.% in LMCPO should be reduced to less than 1 wt.% by using esterification when required these oils to use as feedstock for producing biodiesel. After esterification process, FFA in esterified oil was studied to optimize the four independent variables of methanol (5-25 vol.%), sulfuric acid (0.5-4.5 vol.%), reaction time (5-65 min) and speed of stirrer (100-500 rpm). The results showed that the optimal condition of 25 vol.% methanol, 2 vol.% sulfuric acid, 500 rpm speed of stirrer, and 30 min reaction time at 60°C reaction temperature can decreased the FFA level to less than 0.212 wt.%. However, it was found out that the high consumptions of methanol and sulfuric acid required for reducing FFA to lowest value. Thus, the selected condition of 17.4% methanol, 1.6% sulfuric acid, 300 rpm speed of stirrer, and 35 min reaction time was chosen to save the chemical contents because this condition achieved to reduce FFA to acceptable level of 1 wt.%. For the actual experiment, FFA can be decreased to 0.212 wt.%, and 1.028 wt.% respectively. The yields of 96.67 wt.% for crude esterified oil and 94.22 wt.% for pure esterified oil were achieved based on LMCPO under the selected condition.

Abstract: The aim of this research was to develop a two-step technique to prepare biodiesel from waste palm oil (WPO) with high free fatty acid content. The developed process consists of esterification and transesterification steps. Response surface methodology (RSM) was applied for investigating the experimental design for esterification step. Design of experiment was performed by application of 5-levels-3-factors central composite design in order to study the optimum condition for decreasing FFA in WPO. The WPO with low FFA was further experimented in transesterification step to obtain fatty acid methyl ester (FAME). The investigated results showed that the WPO containing 48.62%wt of high FFA. The optimum condition of esterification step was 28 moles of methanol to FFA in WPO molar ratio, 5.5% sulfuric acid concentration in 90 min of reaction time and 60 °C of reaction temperature. After transesterification step, WPO biodiesel gave methyl ester content at 84.05% according to EN 14103 method. The properties of WPO methyl ester meet the standards of Thailand community biodiesel that can be used as fuel in agricultural machine.

Abstract: In Thailand, the ethanol production was produced from factory fermentation of many food crops such as sugar cane, molasses, and cassava. Thus, this alcohol is not required to be imported from abroad. Moreover, the advantages of ethanol over methanol are less toxic, and the fatty acid ethyl ester (FAEE) has higher heat content, cetane number and lower cloud point, pour point than the fatty acid methyl esters (FAME). In this study, the 95% commercial ethanol (as a low-grade ethanol) was used to reduce the acid value in the mixed crude palm oil (MCPO). The Response surface methodology (RSM), a 5-level 2-factor central composite design (CCD), was employed to optimize the ethanol, and sulfuric acid. The results showed that the 95% ethanol can reduced the acid value from 34.5 mgKOH/g to less than 2 mgKOH/g. Therefore, the esterified oil can be used to produce biodiesel by base-catalyzed transesterification when the optimal condition: 81.3 vol.% ethanol, 10 vol.% sulfuric acid, and 75°C reaction temperature are used. Moreover, the acid value in MCPO was sharply reduced to less than 7.477 mgKOH/g at 5 min, and to less than 1.621 mgKOH/g after 30 min of reaction time when the model of optimal condition was verified.

Abstract: Free fatty acid (FFA) in mixed crude palm oil (MCPO) must be reduced to less than 1 wt.% or 2 mgKOH.g^-1 of acid value by the acid-catalyzed esterification process when the base-catalyzed transesterification was used to produce the biodiesel for the two-stage process. This study was to investigate the effects of acid catalyst types: sulfuric acid (H₂SO₄), phosphoric acid (H₃PO₄), and hydrochloric acid (HCL) at 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 vol.% of acid catalyst concentration on the reduction of acid value in MCPO by the continuous static mixer. Results indicated that H₂SO₄ has the most significant variable affecting the acid value in MCPO. The acid catalyst concentration of 1.0 and 1.5 vol.% H₂SO₄ can reduce the acid value to less than 2 mgKOH.g^-1 with 15 vol.% of methanol and 5-meter in the length of static mixer, while both H₃PO₄ and HCL could not reduce the acid value was reduced to less than 2 mgKOH.g^-1. Moreover, the results clearly indicated that HCL has the lowest significance effect on the acid value reduction in MCPO by the esterification reaction.

Abstract: In this work, effect of big paddy hermetic tent (BPHT) modified atmosphere packaging (MAP) of 0.5mm PE and traditional MAP using 0.05mmPE on free fatty acid property were investigated. The results showed that BPHT, which were charged 5% O₂ and 5% CO₂, was the optimal storage condition to preserve rice grain fresh. Little O₂ decreasing and CO2 increasing were generated in traditional MAP other than fruits and vegetables, because grain respiration rate were low relatively. After five moths storage of rice grain, BPHT storage inhibited the free fatty acid content increasing and lox enzyme activity. BPHT storage with atmosphere charging at storage beginning was the distinctly energy conservation storage method for grains.