Esterification of Free Fatty Acid in Used Cooking Oil Using Gelular Exchange Resin as Catalysts

The esterification of free fatty acids (FFA) in used cooking oil was investigated using gelular ion exchange resins, SK104H and SK1BH catalysts. Characterization methods such as Fourier transform-infra red (FT-IR) spectroscopy, particle size distribution (PSD), scanning electron microscopy (SEM), elemental analysis (CHNS) and acid capacity analysis were conducted to determine the physicochemical properties of the catalysts. These catalysts were then subjected to a screening study to select the best performance catalyst, which further subjected to esterification reaction using one-variable-at-a-time (OVAAT) method. Using OVAAT method, the effect of mass transfer resistance, catalyst loading, reaction temperature and methanol to oil mass ratio were studied to optimize esterification reaction conditions. The conversion of FFA in the used cooking oil was successfully achieved 88% under optimal conditions of 18:1 methanol to oil mass ratio, reaction temperature of 60oC, catalyst loading of 3.0 wt. % and 300 rpm of stirring speed. Excellence catalytic performance may attributed to the smallest average particle size, high sulfur content and high acid capacity value of SK104H, resulting high conversion of FFA

Carbon dioxide (CO2) dry reforming of glycerol for hydrogen production using Ni/La2O3 and Co/La2O3

Converting glycerol, obtained from biodiesel industry via dry reforming is considered as a promising route to improve the economic viability of biodiesel industry. The objective of this research work is to synthesize, characterize and conduct the catalytic activity test of CO2 glycerol dry reforming using Nickel (Ni) and Cobalt (Co) supported Lanthanum oxide (La2O3) as catalyst. In this research, Ni/La2O3 and Co/La2O3 were tested in a fixed bed reactor at 700 oC, 1 atm and CO2: glycerol of 1:1. The catalysts were prepared by using wet impregnation method and characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Bruanauer-Emmett-Teller (BET) and Fourier-Transform infrared spectroscopy (FTIR). From the characterization analysis, the results revealed that Ni based supported by La2O3 have smaller metal crystallite size as compared to Co supported La2O3 due to highly-dispersed of La2O3 in the Ni catalyst. The surface morphology of 10 wt% Ni/La2O3 catalyst also shows some crystallite particles with small diameter covered the lanthanum oxides support consistent with XRD result. BET surface area measurement gives higher surface area, 28.29 m2/ g for 10 wt% Ni/La2O3 as compared to 10 wt% Co/La2O3 which gives 13.032 m2/ g. Reaction studies demonstrated that 10 wt% Ni/La2O3 gives the highest performance of hydrogen production and glycerol conversion as compared to calcined La2O3, 5 wt% Ni/La2O3, 15 wt% Ni/La2O3, and 10 wt% Co/La2O3 with the yield and conversion of 11.8 % and 18.6 % respectively. Excellence catalytic performance of 10 wt% Ni/La2O3 may attribute to high activity of 10 wt% Ni/La2O3 towards hydrogen rich gas and great stability. Besides, smaller metal crystallite si

Study on the kinetics of cation exchange resins as catalysts in free fatty acid (FFA) esterification of simulated used cooking oil

Used cooking oil (UCO) is one of the potential substitutes for conventional biodiesel feedstock due to its low cost. In spite of its advantage, UCO has high free fatty acid (FFA) level which contributes to saponification reaction when it was directly utilised in base catalysed transesterification reaction. Ion exchange resins have been widely used in FFA esterification reaction to reduce the FFA content as this type of catalyst exhibits good catalyst performance in a short period of time. Nevertheless, conventional ion exchange resin has low acidic sites, moderate specific surface area and pore volume, poor durability and thermal stability. Therefore, in this study styrene-divinylbenzene (DVB) resins; RCP160M, RCP145H, PK228LH, PK216LH, PK208LH, SK104H and SK1BH with different textural and morphological properties were used as catalysts for the esterification of FFA in simulated used cooking oil (SUCO). These resins were characterised using Fourier transform-infrared spectroscopy (FT-IR), nitrogen physisorption, scanning electron microscopy (SEM), elemental analyser (CHNS), titration and particle size distribution (PSD) analyser to determine their physicochemical properties. These catalysts were screened to determine the best performance catalyst under reaction conditions of 300 rpm stirring speed, 5 wt. % catalyst loading, 60 ˚C and 12:1 methanol to oil mass ratio. The best performance catalyst was used in the subsequent studies focusing on the effect of mass transfer resistance, the effect of catalyst loading, reaction temperature, and methanol to oil mass ratio to investigate the best conditions in a batch mode system. The study proceeded with the kinetics of FFA esterification by developing three kinetic models; Pseudo homogeneous (P-H), Langmuir-Hinshelwood-Hougen-Watson (LHHW) and Eley-Rideal (Case I and Case II) to determine rate constant and activation energy of the reaction using POLYMATH 6.10 program. The results revealed that RCP160M was found to give the best catalytic performance as it outperformed the other catalysts and achieved maximum FFA conversions. This may attributed to the high specific surface area and total pore volume of RCP160M. 95 % of FFA conversion was achieved at the best reaction conditions with a stirring speed of 300 rpm, catalyst loading of 4 wt. %, a reaction temperature of 60 ˚C, and methanol to oil mass ratio of 18:1. During the reusability study, the catalytic activity of RCP160M decreased about 5-15 % for each cycle. The decrease of FFA conversion was due to pore blockage by oil during the reaction and simultaneously blocked the reactants from accessing the active sites. Besides, the loss of active sites during washing process might possibly occur between the reuse cycles. The kinetic results revealed that the experimental data were best-fitted to the E-R model (Case II) with the activation energy of 37.2 kJ/mol. This study showed that the reaction was limited by surface reaction where the adsorption of non-polar FFA molecules was more favourable than the adsorption of polar methanol molecules. In future, it was recommended that further work is necessary to improve the regeneration procedure of RCP160M as this catalyst can be potentially used as a catalyst for biodiesel production

Studies on the performance of tubular flow reactor for esterification of free fatty acid from used cooking oil using highly porous cation exchange resin as catalyst

Semi-batch esterification of free fatty acid (FFA) from used cooking oil with methanol was carried out using RCP160M cation exchange resin in a tubular flow reactor (TFR). The results revealed that the conversion of FFA increased with the increase of catalyst bed height, methanol to oil mass ratio and decreases with increase of feedstock flow rates. However, the FFA conversion was decreased upon further increases of methanol to oil mass ratio from 6:1 to 12:1. This might possibly happen due to several factors such as mass transfer limitation between reactants and catalyst and inhomogeneity of the reactants during the reaction

Reforming of Glycerol for Hydrogen Production over Ni Based Catalysts: Effect of Support Type

This current work focuses on hydrogen production that is a component in syngas by glycerol dry reforming over 15% nickel (Ni) loading supported on different oxides, namely CaO, ZrO2, and La2O3. The screening process was conducted in a fixed-bed reactor at 700°C under atmospheric pressure. It was found that 15% Ni/CaO showed the best performance in screening studies. The effect of temperature and the carbon to glycerol ratio (CGR) was then analyzed for this catalyst. From the analysis, it was seen that 15% Ni/CaO has its optimum condition at 800°C and CGR = 1, where it gives the highest glycerol conversion (XG = 37.66%) and hydrogen yield (YH = 32.45%)

Studies on free fatty acid esterification of used cooking oil: investigation on the performance of sulphonated cation exchange resins

Used cooking oil (UCO) is one of the potential substitutes for conventional biodiesel feedstock. In this study, different types of macroporous cation exchange resins, namely RCP160M, RCP145H, PK228LH, PK216LH, PK208LH, SK104H and SK1BH, were used as catalysts in the UCO esterification process. These resins were characterised using Fourier transform infrared spectroscopy (FT-IR), nitrogen physisorption, scanning electron microscopy (SEM), an elemental analyser (CHNS), titration and a particle size distribution (PSD) analyser to determine their physicochemical properties. These catalysts were screened and RCP160M resin was found to give the best catalytic performance. RCP160M was used in subsequent studies focusing on the effect of different esterification variables. A conversion rate of 95% of free fatty acid (FFA) was achieved at the optimum condition with catalyst loading of 4 wt. %, reaction temperature of 60°C, and methanol-to-oil mass ratio of 18:1. RCP160M shows great potential as a catalyst in the biodiesel pre-treatment process as it outperformed the other catalysts and yielded maximum FFA conversion. This may be attributed to its higher specific surface area and total pore volume. The kinetic results revealed that the experimental data was best fitted to the Eley-Rideal model (Case II) with the activation energy of 37.2 kJ mol−1

Esterification reaction of free fatty acid in used cooking oil using sulfonated hypercrosslinked exchange resin as catalyst

The production of valuable fatty acid alkyl ester (FAAE) commercially known as biodiesel from used cooking oil (UCO) as feedstock has recently gained global interest. To carry out this production process, an esterification reaction is necessary to minimize the amount of free fatty acid (FFA) in the UCO. The purpose of this research work is to evaluate the performance of the newly snythesized sulfonated hypercrosslinked exchange resin (SHER) for the esterification reaction. The catalyst was first synthesized and characterized using various physicochemical analyses (i.e. Fourier transform infra-red (FTIR), surface morphology, N2 physisorption analysis and thermogravimetric analysis (TGA)) and further subjected to the esterification reaction to determine the reaction kinetics. The esterification reaction was conducted at various catalyst loading (1−8 wt%), reaction temperatures (40−60 ◦C), and methanol to oil molar ratios (6:1−24:1). From the characterization study, SHER was found to have high decomposition temperature (up to 398 ◦C) and specific surface area (836 m2 g−1). Additionally, SHER had the capability to accommodate high number of active sites which could benefit the esterification reaction. The highest FFA conversion of 97% was achieved at 5 wt% catalyst loading, 60 ◦C of reaction temperature and 12:1 methanol to oil mole ratio in 2 h reaction time. Analyses of the spent catalyst revealed the presence of impurities residue on the SHER’s surface following the esterification reaction, and the catalyst pore remained evident even after several reusability cycles. Finally, the Eley-Rideal, pseudo-homogeneous and Langmuir-Hinshelwood-Hougen-Watson kinetic models were proposed. Due to its high activation energy; i.e. 48.4 kJ mol−1, the reaction was found to be limited by surface reaction and governed by the chemical step