Boonyawan Yoosuk

Waste shells of mollusk and egg as biodiesel production catalysts.

The solid oxide catalysts derived from waste shells of egg, golden apple snail, and meretrix venus were employed to produce biodiesel from transesterification of palm olein oil. The shell materials were calcined in air at 800 degrees C with optimum time of 2-4h to transform calcium species in the shells into active CaO catalysts. All catalysts showed the high biodiesel production activity over 90% fatty acid methyl ester (FAME) in 2h, whilst the eggshell-derived catalyst showed comparable activity to the one derived from commercial CaCO(3). The catalytic activity was in accordance with the surface area of and the Ca content in the catalysts.

Improving transesterification acitvity of CaO with hydration technique

An efficient technique for increasing the transesterification activity of CaO obtained from calcination of CaCO(3) was proposed in order to make them highly suitable for use as heterogeneous catalysts for biodiesel production. CaO was refluxed in water followed by the synthesis of the oxide from hydroxide species. The characterization results indicate that this procedure substantially increases both the specific surface area and the amount of basic site. Hydration and subsequent calcination also generates a new calcium oxide with less crystalline. Transesterification of palm olein was used to determine the activity of catalysts to show that the decomposed-hydrated CaO exhibits higher catalytic activity than CaO generated from calcination of CaCO(3). The methyl ester content was enhanced 18.4 wt.%.

Economical and green biodiesel production process using river snail shells-derived heterogeneous catalyst and co-solvent method.

River snail shells-derived CaO was used as a heterogeneous catalyst to synthesize biodiesel via transesterification of palm oil with methanol. The shell materials were calcined in air at 600-1000°C for 3h. Physicochemical properties of the resulting catalysts were characterized by TGA-DTG, XRD, SEM, BET, XRF, FT-IR and TPD. CaO catalyzed transesterification mechanism of palm oil into biodiesel was verified. The effects of adding a co-solvent on kinetic of the reaction and %FAME yield were investigated. %FAME yield of 98.5%±1.5 was achieved under the optimal conditions of catalyst/oil ratio of 5wt.%; methanol/oil molar ratio of 12:1; reaction temperature of 65°C; 10%v/v of THF in methanol and reaction time of 90min. The results ascertained that river snail shells is a novel raw material for preparation of CaO catalyst and the co-solvent method successfully decreases the reaction time and biodiesel production cost.

Sr–Mg Mixed Oxides as Biodiesel Production Catalysts

The Sr–Mg basic catalysts were developed for biodiesel production through transesterification of palm oil with methanol. The evidence for synergistic effects between active Sr and Mg species was clearly demonstrated by transesterification tests over a series of Sr–Mg catalysts with varied Sr‐to‐Mg molar ratios. The catalyst properties were characterised by means of temperature‐programmed desorption of CO2 (CO2‐TPD), N2 sorption, XRD, SEM and TEM experiments. The super strong basic site was formed in Sr–Mg catalysts through a partial solid state reaction induced by thermal treatment at 600 °C. The new basic site, together with the original basic site from SrO (average basic site density=757 μmol m−2), effectively catalysed a transesterification reaction at mild conditions. Biodiesel containing 96 % methyl esters was obtained at reaction conditions of 75 min, 60 °C, 0.1 MPa, 3 wt. % catalyst loading and a methanol‐to‐oil ratio of 6:1, and the catalyst exhibited good reusability. Improved surface areas and porosities were also achieved compared to the unsupported SrO. Density functional theory (DFT) calculations of methylpropanoate adsorption on SrO, MgO and Sr/MgO showed that the adsorption energies of all adsorbate–surface complexes corresponded well with the experimental catalytic activity, which increased in the order MgO

Investigation of operating parameters of water extraction processes for improving bio-oil quality

Water extraction of slow-pyrolysis bio-oil, in order to improve its quality, was investigated in terms of different schemes and operating parameters. The water extraction separated the bio-oil into two phases: an aqueous phase and an organic water-insoluble fraction (or “pyrolytic lignin”). Properties of the pyrolytic lignin extracted with different extraction schemes and conditions were characterized and compared. The results showed that the water temperature and stirring time did not significantly affect the pyrolytic lignin’s properties. The water : bio-oil ratio, however, could remarkably reduce the pyrolytic lignin’s acidity. Given the findings, an effective time- and resource-saving extraction scheme with appropriate operating conditions could be devised. The resulted pyrolytic lignin, which was essentially the “upgraded” bio-oil, had notably lower acidity, higher heating value, and more stability than the starting bio-oil, due to the removal of alcohols, ketones, carboxylic acids, sugars, ethers, as well as reactive compounds by the water extraction.

Towards stabilization of bio-oil by addition of antioxidants and solvents, and emulsification with conventional hydrocarbon fuels

Bio-oil is liquid fuel produced by fast pyrolysis, typically, of biomass. Bio-oil comprises a mixture of highly oxygenated compounds, carboxylic acids and trace water. Upgraded bio-oil can be used as a substitute for conventional fuels. However, bio-oil is inherently unstable. The various compounds in bio-oil can react through many chemical reactions, such as polymerizations, during the storage of bio-oil, resulting in adverse changes in the bio-oils properties, especially increasing viscosity over time. In the present study, three sets of methods to improve the bio-oils stability were investigated: addition of antioxidants, addition of solvents, and emulsification with conventional hydrocarbon fuels. In the first set of methods, three kinds of antioxidants (propyl gallate, tert-butyl hydroquinone, and butylatedhydroxyanisole) were added in 1000-ppm concentration to bio-oil. In the second set, 10wt% of solvents, including acetone, biodiesel, ethanol, ethyl acetate, and methanol, were added to the bio-oil. Finally, the third set involved emulsification of bio-oil with different conventional hydrocarbon fuels, including diesel, gasoline, and biodiesel, using octanol as a surfactant. All test samples were subjected to accelerated aging, involving exposure to high temperature of 80°C for 5 days. The viscosity of the samples, chosen as the main indicator of the aging, was measured daily. The results showed that under the accelerated testing conditions, pure bio-oil aged significantly, with 44.65% increase in viscosity. The bio-oil with antioxidants, on the other hand, aged more slowly, with 17-20% viscosity increase. The addition of solvents also slowed down the aging drastically, especially in the case of biodiesel, with only 4.91% viscosity increase. Emulsification with conventional hydrocarbon fuels also showed promising results, with similar trends to those of antioxidant and solvent addition. All results showed that the three sets of stabilizing methods can improve the bio-oils stability significantly, with slightly varying degree of effectiveness. Selection of an optimal method in practice depends on the particular constraints and circumstances of each operation.

Hydration—Dehydration Technique: From Low Cost Materials to Highly Active Catalysts for Bio-Diesel Production

An efficient technique for increasing the trans esterification activity of low cost natural rocks (calcite and dolomite) was proposed in order to make them highly suitable for use as heterogeneous catalysts for biodiesel. This technique involves water treatment of the oxide phase under mild conditions followed by thermal decomposition at an elevated temperature. The transformation of oxide to hydroxide phase and the reverse occurred simultaneously during the hydration–dehydration step with changes in the chemical and textural properties of the sample. The effectiveness of the hydration interaction appears to be due to a change in pore-size distribution, which is created by particle expansion in the formation of the hydroxide structure and the formation of more porosity and surface area during the dehydration and re-crystallization of oxide structure. Trans esterification of palm olein was used to determine the activity of catalysts to show that this technique make catalyst has higher activity than the typical calcinations method. This study provides an understanding regarding how this hydration–dehydration process influences the properties and activity of dolomite.

Stabilization of Empty Fruit Bunch (EFB) derived Bio-oil using Antioxidants

Abstract Bio-oil is a promising alternative source of energy which can be produced from empty fruit bunch (EFB). Bio-oil comprises a mixture of highly oxygenated compounds, carboxylic acids and trace water. Bio-oil can be used as a substitute for conventional fuels after it is upgraded. However, the oil can react through many chemical reactions such as polymerization and lead to an increase in viscosity of bio-oil during storage. Thus, this paper explores the stabilization of empty fruit bunch derived bio-oil. The objective of this project is to select the optimum condition, to study the accelerated aging of bio-oil and the effect of addictive in stabilizing the bio-oil. The bio-oil is produced from the catalytic pyrolysis of EFB. The optimum reaction condition applied is 5 wt% of H-Y catalyst at reaction temperature of 500 °C and nitrogen flow rate of 100 ml/min. At this optimum condition, it is able to obtain the maximum bio-oil yield. The method used in this research to improve the stability of the bio-oil is through addition of antioxidants. Four different types of antioxidants which are propyl gallate (PG), tert-Butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA) and calcium chloride salts (CaCl 2 ) are added to the bio-oil separately in the amount of 1,000 ppm. All the test samples are subjected to accelerated aging involving exposure to high temperature of 80 o C for 7 d. The properties of samples which are chosen as the indicator of aging are viscosity, water content and acidity. The effectiveness of antioxidants increase in the following order: CaCl 2 , BHA, TBHQ and PG. The antioxidants used are able to improve the stability of bio-oil in terms of viscosity and water content during aging. All the antioxidants helped to reduce the acidity of bio-oil except for CaCl 2 . The results from Gas Chromatography-Mass Spectrometry (GC-MS) analysis showed that the chain reaction of polymerization stopped by phenolics and decrease in carbonyls and ethers can lead to decreased in water content during aging. In addition, molecule decomposing reactions also reduced and resulted in lower acidity.

Influences of Water on the Hydration of Calcined Natural Calcite: Properties and Transesterification Activity Improvement

This paper presents the technique that can considerably improve basicity and transesterification activity of calcined natural calcite. Calcined calcite was refluxed in water followed by the calcinations at 600 oC. The characterization results indicate that this procedure substantially increases both the specific surface area and the amount of basic site. Hydration and subsequent calcination also generates a new calcium oxide with less crystalline. ME content was enhanced to 93.9 wt% in 1 hr from 75.5 wt% of calcined calcite. The results imply that the active sites produced by the calination of hydrated sample at 600 oC have higher basicity than those generated from calcinations of fresh calcite at 800 oC. The present study provides new insights for improving catalyst activity by tailoring the preparation conditions.