• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.92-97
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• 2011

The effect of Group I alkali acetate promoters on vinyl acetate (VA) synthesis was evaluated. Catalyst product selectivity and ethylene conversion are compared to the unpromoted catalyst in the fixed-bed reactor with oxidation reaction of ethylene and acetic acid in gaseous phase over Pd-Au/$SiO_2$ catalyst. It was found that: a) the promoters were stabilized on the catalyst surface, b) common effect for the alkali promoted Pd-Au catalysts increaseed in product selectivity and ethylene conversion compared to unpromoted catalyst (these effects increase from top to the bottom of Group I). These promoting effect is due to the common-ion effect of acetate, present in the reaction, resulting in an increase in the activity of the catalyst. In addition a complementary theory for the effect of Au in the structure of the catalyst is proposed the imposition of distribution of palladium particles through decreasing the particle's diameter.

• Resources Recycling
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• v.27 no.4
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• pp.57-64
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• 2018

Water leaching of tungsten(W) and vanadium(V) was researched from their oxides through mechanochemical (MC) reaction with alkali compounds. Intensive grinding for the mixture of tungsten/vanadium oxide and alkali compounds (NaOH, $Na2CO_3$) was carried out with change of their mixing ratios and grinding duration. Water soluble compounds, $Na_2WO_4$ and $NaVO_3$, were synthesized through MC reaction and their solubilities increased in proportion to the mixing ratio of sodium compound and grinding times. Whereas vanadium leachability was less affected by the mixting ratio and grinding times. The leachabilities of 99.0% were accomplished by a short period of MC treatment, W (30 min.) and V (5 min.). This process enable us to extract W and V from their oxides via a water leaching, and can be applied to the selective recovery of W and V from $DeNO_x$ spent catalysts.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.164-168
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• 2003

Fatty acid methyl esters (FAMEs) show large potential applications as diesel substitutes, and they are known as biodiesel fuel. Biodiesel fuel as a renewable energy is an alternative that can reduce energy dependence on petroleum and air pollution. Several processes for the production of biodiesel fuel have been developed. Transesterification process under alkali-catalysis and short-chain alcohol gives high level yield of methyl esters in short reaction times. In this research, transesterification of rapeseed oil was investigated to produce the FAMEs. Experimental reaction conditions included molar ratio of oil to alcohol, concentration of catalyst, types of catalysts, reaction time, and reaction temperature. The conversion ratio of rapeseed oil enhanced with the alcohol-oil mixing ratio and with the reaction temperature.

• Journal of the Korean Applied Science and Technology
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• v.26 no.2
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• pp.179-185
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• 2009

The esterification of the reactants of Jatropha oil and methanol added by propyleneglycol was done using p-TSA catalyst. And then the emulsification of triglyceride and methanol was conduced by 1.0vol% GMS. The emulsified reactants were transesterified at $65^{\circ}C$ using TMAH and mixed catalyst (50wt%-TMAH+50wt%-NaOH) respectively. The esterification conversion at the 1:8 molar ratio of free fatty acid to methanol using 8.0wt% p-TSA was 94.7% within 80min. The overall conversion at the 1:8 molar ratio of mixed fat(50wt% Beef Tallow) to methanol and $65^{\circ}C$ using mixed catalyst was 95.4% The cloud point of Biodiesel decreased with the addition of petroleum diesel.

• Journal of the Korean Applied Science and Technology
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• v.25 no.3
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• pp.275-281
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• 2008

The esterification of free fatty acid in Jatropha oil added by propylene glycol using p-TSA catalyst was done, and then the transesterification of Jatropha oil added by 1.0vol% GMS as an emulsifier using TMAH, and mixed catalyst(60wt%-TMAH+ 40wt%-KOH) respectively was followed at $60^{\circ}C$. The esterification conversion at the 1:8 molar ratio of free fatty acid to methanol using 8.0wt% p-TSA was 94.7% within 60min. The overall conversion at the 1:8 molar ratio of Jatropha oil to methanol and $60^{\circ}C$ using mixed catalyst was 95.4%. The kinematic viscosity of Biodiesel using TMAH and mixed catalyst in 24h met the ASTM D-6751 above $30^{\circ}C$, and showed a little more than its criterion.

• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.298-305
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• 2001

Emulsified transesterification of soybean oil into biodiesel was investigated using potassium hydroxide and sodium methoxide catalysts with methyl glucoside oleic polyester as a methanol-in-oil emulsifier. The transesterification reaction conditions were optimized to obtain high yields of fatty acid methyl esters of the quality defined by biodiesel standards. The developed process resulted in $95{\sim}96%$ of overall yield from soybean oil by alkali-catalyzed methanolysis at $45^{\circ}C$ of reaction temperature with 6:1 of methanol-to-oil molar ratio and 1(v/v)% methyl glucoside oleic polyester in the presense of 0.8wt% KOH and 1.2wt% $NaOCH_{3}$.

• Journal of the Korean Chemical Society
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• v.28 no.6
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• pp.374-383
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• 1984

In order to elucidate the effect of alkali promoter on chemisorption of carbon monoxide on silica supported transition metal catalysts we have investigated the infrared spectra for carbon monoxide chemisorbed on silica supported nickel with and without potassium coating within the frequency range of 1800 ~ 2100cm$^{-1}$ at various nickel concentrations and CO pressures. For the system without potassium coating the IR band intensities are found to greatly depend on the nickel conwgfra concentration although the band positions are scarcely affected. The band positions are nearly coincident with those reported by other people, but we have clarified that the 2057cm$^{-1}$ band arises from Ni(CO)$_4$ molecules physisorbed on silicagel. Besides this, the effect of temperature on CO chemisorption has also been investigated. On coating with potassium we have found that all the bands observed for the system without potassium coating suffer red shifts by 2 ~ 10cm$^{-1}$ and the formation of Ni(CO)$_4$ is inhibited. Furthermore, we have recognized that on the nickel surface with potassium coating a disproportionation may occur to yield carbon dioxide molecules.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.4
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• pp.323-330
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• 2017

Ash remaining after coal combustion was used as a catalyst support for tar steam reforming with various proportions of $Al_2O_3$ added for higher reforming efficiency. At a constant Ni content of 12 wt%, a coal ash and $Al_2O_3$ were mixed at a ratio of 5:5, 7:3, 9:1. As a result, the catalytic activity for toluene steam reforming was improved by adding $Al_2O_3$ at $500-600^{\circ}C$. The catalysts with ratio 7:3 and 5:5 reached toluene conversion of 100% above $700^{\circ}C$. When comparing the catalysts in which the coal ash and $Al_2O_3$ mixed at a ratio of 5:5 and 7:3 with the Ni/Al catalyst, it was concluded that this coal ash catalyst has efficient catalytic performance.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.679-684
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• 1997

The major constituents in spent FCC catalysts are Si, Al, Fe, Ti, alkali metals and some others. The spent catalyst is also composed small amounts of rare metals such as Ce, Nd, Ni and V. The selective adsorption and concentration of Ce and Nd from the leaching solution of spent FCC catalysts with sulfuric acid($0.25mol/dm^3$) were carried out by the column method with a chelate resin having a functional group of aminophosphoric acid type. Ce and Nd were separated from eluate liquor containing Al, Nd and V by the precipitation process with oxalic acid. Vanadium is purified from chloride ion coexistance by solvent extraction, employing tri-n-octyl phosphine oxide as extractant with Al in the raffinate solution. Rare metals with the purity of 99 percent were obtained from the spent FCC catalyst.

• Journal of the Korean Applied Science and Technology
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• v.25 no.3
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• pp.299-312
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• 2008

The fat of Tra and Basa catfish (Mekong Delta, Viet Nam) was evaluated for the first time as the potential feedstock for biodiesel production, due to its abundance, availability and cheap cost. The unsaturated fatty acid contents of Tra and Basa fat were 57.97% and 64.17%, respectively. Biodiesel was prepared from Tra and Basa fat by methanolysis reaction using alkali catalysts like sodium hydroxide and potassium hydroxide. Effects of various process parameters on biodiesel production, such as molar ratio of methanol to fat, catalyst concentration, temperature and time were investigated. As those results, the transesterification can be performed under moderate conditions, and the biodiesel yields were shown more than 90%. KOH catalyst was the best catalyst for biodiesel production from both Basa and Tra fat. As the feedstock aspect, Basa fat was indicated more efficiency than that of Tra fat. The maximum yield could be achieved by the transesterification from Basa fat with 5:1 molar ratio of methanol to fat, 0.8% KOH catalyst, $50^{\circ}C$, and 50 min. For Tra fat, the optimal condition were at 6:1 molar ratio of methanol to fat, 0.8% KOH catalyst, $50^{\circ}C$, and 45 min. Nowadays, due to cheaper cost and abundance, Tra fat is a promised resource for cheap biodiesel production in Viet Nam.