• Journal of the Korean Electrochemical Society
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• v.17 no.3
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• pp.179-186
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• 2014

Methanol electro oxidation on the surface of carbon paste modified by $NiCl_2/6H_2O$ was studied in 1M NaOH by potentiostatic and potentiodynamic methods. Ni/C catalyst by the concentration of 5% Ni showed about twice higher electro catalytic activity than Ni metal. The amount of monolayer's on the surface of electrode is almost one order higher for Ni/C than Ni electrode. The kinetic parameters and the diffusion coefficient of methanol were derived from chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) measurements.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.29-32
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• 2004

Reduction of methanol crossover in proton exchange membranes (PEMs) can be achieved by 1) the selection of materials, 2) the morphology control, and 3) the adequate crosslinking [1, 2]. The selection of polymer matrix of PEM for direct methanol fuel cells (DMFCs) is very important because the proton conductivity and methanol permeability are largely dependent upon the properties of polymers.(omitted)

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.227-238
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• 2016

This review article highlights different types of nano-sized catalysts for the selective alcohol oxidation to form aldehydes (or ketones) with supported or immobilized metal nanoparticles. Metal nanoparticle catalysts are obtained through dispersing metal nanoparticles over a solid support with a large surface area. The nanocatalysts have wide technological applications to industrial and academic fields such as organic synthesis, fuel cells, biodiesel production, oil cracking, energy conversion and storage, medicine, water treatment, solid rocket propellants, chemicals and dyes. One of main reactions for the nanocatalyst is an aerobic oxidation of alcohols to produce important intermediates for various applications. The oxidation of alcohols by supported nanocatalysts including gold, palladium, ruthenium, and vanadium is very economical, green and environmentally benign reaction leading to decrease byproducts and reduce the cost of reagents as opposed to stoichiometric reactions. In addition, the room temperature alcohol oxidation using nanocatalysts is introduced.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.550-556
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• 2022

The performance of enzymatic fuel cells that convert chemical energy contained in various organic molecules such as sugar, alcohol, organic acids, and amino acids into electrical energy is greatly affected by the cathode as well as the anode. This study aimed to develop a laccase-based cathode with high performance. An enzyme composite composed of an laccase, redox mediator, and carbon nanotubes was immobilized on the surface of electrode in multiple layers, and the effect of the number of layers and the presence or absence of carbon nanotubes on electrode performance was investigated. As the number of layers of the enzyme-mediator (Lac-(PVI-Os-dCl)) on the electrode surface increased, the amount of reduction current generated at the electrode increased. The enzyme-carbon nanotube-mediator composite electrode (Lac-SWCNTs-(PVI-Os-dCl)) generated a current 1.7 times greater than that of the Lac-(PVI-Os-dCl). It was found that the largest amount of current (10.1±0.1 µA) was generated in the electrode composed of two layers of Lac-(PVI-Os-dCl) and two layers of Lac-SWCNTs-(PVI-Os-dCl) in the evaluation of electrodes with different ratio of Lac-SWCNTs-(PVI-Os-dCl) and Lac-(PVI-Os-dCl). The maximum power density of the cell using the cathode composed of a single layer of Lac-(PVI-Os-dCl) and the cell using the optimized cathode were 0.46±0.05 and 1.23±0.04 µW/cm², respectively. In this study, it was demonstrated that the performance of cathode and the enzymatic fuel cell using the same can be improved by optimizing the layers of composites composed of laccase, redox mediator, and carbon nanotubes on the electrode surface.

• Advances in Energy Research
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• v.4 no.3
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• pp.189-202
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• 2016

This work emphasized optimum production of biodiesel using non-edible Prunus armeniaca (Bitter Apricot) oil via transesterification collected from the high altitude areas of Himachal Pradesh, India. In this study the author produced biodiesel through the process of transesterification by using an alkali catalyst with alcohol (methanol and ethanol), under the varying molar ratio (1:6, 1:9, 1:12), variable catalyst percentage (1% and 2%) and temperature ($70^{\circ}C$, $75^{\circ}C$, $80^{\circ}C$, $85^{\circ}C$). Furthermore, a few strong base catalysts were used that includes sodium hydroxide, potassium hydroxide, sodium metal and freshly prepared sodium methoxide. After screening the catalyst, response surface methodology (RSM) in connection with the central composite design (CCD) was used to statistically evaluate and optimize the biodiesel production operation using NaOH as catalyst. It was found that the production of biodiesel achieved an optimum level biodiesel yield with 97.30% FAME conversion under the following reaction conditions: 1) Methanol/oil molar ratio: 1:6, 2) Reaction time: 3h, 3) Catalyst amount: NaOH 2 wt. %, and 4) Reaction temperature: $85^{\circ}C$. The experimental results showed that the optimum production and conversion of biodiesel through the process of transesterification could be achieved under an optimal set of reaction conditions. The biodiesel obtained showed appropriate fuel properties as specified in ASTM, BIS and En- standards.

• Journal of Korea Soil Environment Society
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• v.1 no.1
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• pp.67-79
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• 1996

Clay soils typically have low hydraulic conductivities in the presence of high polarity pore fluid, such as water. Low polarity fluids, such as hydrocarbon fuels and halogenated organic solvents, typically cannot migrate into clay pores because they cannot displace the pore water. Oxygenated additives in gasoline, such as alcohols and methyl-tert-butyl ether, are increasingly used to control air pollution emissions. These relatively polar and highly water-soluble compounds may facilitate displacement of pore water and enhance migration of fuels and solvents through clay-rich soil strata. In the reported research, the migration of gasoline-alcohol fuel mixtures (gasohol) through consolidated clay was examined. Prepared kaolinite clay samples were consolidated from slurry, and various combinations of gasoline, alcohol, and water were applied to the clays under 152 Pa gauge pressure. Movement of the fluids into the clay samples was monitored by measur ing displaced pore fluid and by magnetic resonance imaging of the samples. The structures of selected samples were examined using environmental scanning electron microscopy. Results of the research suggest that alcohol added to hydrocarbon fuels can enhance migration through some clays significantly. Gasoline did not migrate appreciably into water saturated clay, even after 14 days under pressure. The gasohol mixture migrated readily into the clay in only 20 minutes. Increased hydraulic conductivity of the clay in the presence of gasohol is hypothesized to be due to the collapse of the clays pore structure when ethanol is present, creating larger pores. Increasing pore diameter decreases the capillary pressure needed for the gasohol to replace water and allows gasohol to migrate through the clay.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.1
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• pp.102-108
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• 2006

On the refutation demanded for a control of various toxic substances. PCBs(poly chlorinated biphenyl) has a fatal poisonous matter in the ecosystem and the environmental pollution as it Is a kind of stable chemical substance. Especially, the gross Product of PCBs is estimated at about one million tonnage all over the world. However it is kept on storing in untreated state, then has a deterioration by the Prolonged storage and a risk of overflowing. Therefore, this research examined the fundamental characteristics of combustion and emission for the target of using the IPA (iso-propyl alcohol) solution as a part of PCBs control. IPA was filled to three kinds of Vessel, i.e. Vessel I, II, and III, and then was investigated as follows combustion shape, flame temperature. mass burning velocity, and PM(Particulate matter). A radial thermometer and a C-A thermocouple measured the flame temperature, and the optical extinction method by using He-Ne laser and the filter weight method used in the PM measurement. As a result, with an increasing of L/S ratio, the flame length become shorter and the burning velocity is more rapid, but the particulate matters is higher. It is supposed that the air flow rate is high on Vessel. and then the combustion is Promoted in the surface area of the upstream zone. The future works plan to investigate the characteristics with an using of the mixing of IPA and PCBs

• Journal of Electrochemical Science and Technology
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• v.11 no.3
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• pp.220-237
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• 2020

Modern electrochemical energy devices involve generation and reduction of fuel gases through electrochemical reactions of water splitting, alcohol oxidation, oxygen reduction, etc. Initially, these processes were executed in the presence of noble metal-based catalyst that showed low overpotential and high current density. However, its high cost, unavailability, corrosion and related toxicity limited its application. The search for alternative with high stability, durability, and efficiency led scientists towards carbon nanoparticles supported catalysts which has high surface area, good electrical conductivity, tunable morphology, low cost, ease of synthesis and stability. Carbon nanoparticles are classified into two groups based on morphology, one and zero dimensional particles. Carbon nanoparticles at zero dimension, denoted as carbon dots, are less used carbon support compared to other forms. However, recently carbon dots with improved electronic properties have become popular as catalyst as well as catalyst support. This review focused on the recent advances in electrocatalytic activities of carbon dots. The mechanisms of common electrocatalytic reactions and the role of the catalysts are also discussed. The review also proposed future developments and other research directions to overcome current limitations.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.2
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• pp.129-138
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• 2008

Demand for alternatives to petroleum is increasing the production of biofuels from food crops such as corn, soybeans, sorghum and sugarcane, etc. At least for the next 5 years, ethanol demand will be increased greatly in the United States and in the world. Presently, most ethanol produced in the United States is corn (Zea mays) ethanol. As a result, especially in the Americas and Southeast Asia, agricultural land is diverted to biofuel production. Even though biofuel industry has many advantage including national security, economical, energetical and sustainable impacts, it is driving grain prices up and creating considerable concern about the potential negative impacts on a wide range of food products that depend on gain : chicken, pork, beef, and dairy products such as milk, cheese, yoghurt, cream and ice cream. Feedstock crops are crops such as switchgrass(Panicum virgatum, L.), corn stover and grasses that can be used in industrial processes such as fermentation into alcohol fuels. Feedstock is no compete with food. Furthermore it is friendly environmental bioenergy crops. In Korea, with increasing demand for fossil fuels the exploration of alternative sources of liquid fuel is inevitable. I suggest Korea need to research and to develop actively on feedstock for biofuel production through this review.

• Membrane Journal
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• v.32 no.6
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• pp.383-389
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• 2022

Membrane separation process is an important technique utilized for various applications. This separation process proceeds due to a driving force such as concentration gradient, pressure or electrical potential gradient etc. Pervaporation is one of the separation process based on solution-diffusion mechanism. The pressure of the permeate side is reduced by creating vacuum and separation is driven due to pressure difference. Purity of the fuel or chemical like ethanol or isopropyl alcohol are improved by dehydration process through porous zeolite membrane. These membranes have high thermal, chemical, mechanical stability. This review is classified mainly into two different sections: Ethanol and bio-oil dehydration by zeolite membrane.