Wonihl Cho

Oxidative coupling of methane with microwave and RF plasma catalytic reaction over transitional metals loaded on ZSM-5

Abstract In the microwave and radio frequency (RF) plasma catalytic reaction at room temperature, the oxidative coupling of methane (OCM) over transitional metals loaded on ZSM-5 has been carried out. The transitional metals, Fe, Ni, Co and Cu (1B family element), loaded on ZSM-5 have been tested for the OCM using the plasma catalytic reaction. In this work, the conversion of methane to C2 products has been improved without the carbon deposition when the oxygen as a co-reactant gas was supplied. The order of the catalysts of higher conversion to C2 products in the microwave plasma reaction with plasma power of 120xa0W is Co–ZSM-5>Fe–ZSM-5≒Cu–ZSM-5>Ni–ZSM-5. Selectivity to ethylene is as high as 29.8%, to ethane 10% and to acetylene 49.9% and conversion of methane was as high as about 54.9% with pressure of 5–10xa0Torr, total flow rate of 125xa0ml/min and a methane/oxygen ratio of 4:1 over Co–ZSM-5. It is suggested that the catalyst may provide an active site for combination of radicals. It was found that yield of C2 products has been enhanced in the microwave plasma catalytic reaction, as microwave plasma system of high frequency has better energy efficiency than RF plasma system of low frequency.

The conversion of natural gas to higher hydrocarbons using a microwave plasma and catalysts

Methane, the major constituent of natural gas, had been converted to higher hydrocarbons by a microwave plasma. The yield of C2+ products increased from 29.2% to 42.2% with increasing the plasma power and decreasing the flow rate of methane. When the catalysts were used in the plasma reactor, the selectivities of ethylene and acetylene increased while the yield of C2+ remained constant. Among the various catalysts used, the Fe catalyst showed the highest ethylene selectivity of 30%. When we introduced the actual natural gas, more C2+ products were obtained (46%). This is due to the ethane and propane in the natural gas. When an electric field inductance for evolving the high plasma was applied, a high yield in C2+ products of 63.7% was obtained for the Pd-Ni bimetal catalyst.

A DIRECT CATALYTIC CONVERSION OF NATURAL GAS TO C2+ HYDROCARBONS BY MICROWAVE PLASMA

Methane, the major constituent of natural gas, was converted to higher hydrocarbons by a microwave plasma. The yield of C2+ products increased from 29.2 % to 42.2% with increasing plasma power and decreasing flow rate of methane. When catalysts were used in the plasma reactor, the selectivities of ethylene and acetylene increased, while the yield of C2+ remained constant. Among various catalysts used, Fe catalyst showed the highest ethylene selectivity of 30 %. And when the actual natural gas was introduced, more C2+ products were obtained (46%). This is due to the ethane and propane in the natural gas. Applying electric field inductance for evolving the high plasma, we obtained high C2+ products of 63.7 % when Pd-Ni bimetal catalyst was used.

Plasma catalytic reaction of natural gas to C2 product over Pd-NiO/Al2O3 and Pt-Sn/Al2O3 catalysts

The decomposition of natural gas over Pd-NiO/Al2O3 and Pt-Sn/Al2O3 is carried out in a microwave catalytic reaction at room temperature. The decomposition of methane is caused by collision by excitation of unstable electronic state. Measuring the flow rate and plasma power can provide kinetic data and indicate the mechanism. The conversion of C2 products increases from 47 to 63.7% in the microwave plasma catalytic reaction with electric field. Comparing the activities of catalysts, Pd-NiO/Al2O3 bimetallic catalyst is more active than Pt-Sn/Al2O3 catalyst because of modification of the surface of catalysts by carbon formation. The kinetic modeling of plasma of methane conversion seems related to the power of the electric discharge. It was also revealed that proper coking or polymeric carbon formation improves the catalytic activity; therefore, the conversion of methane may increase over Pd-Ni/Al2O3 catalyst in the plasma system.

An Electrochemical Study on the Carbon Black Conductor Prepared by Plasma Pyrolysis of Methane

Plasma carbon black(PB) which prepared by plasma pyrolysis of methane was treated at 800, 1300 and under torr. Four different samples including raw PB were added to , cathode active material of lithium secondary battery, to investigate effects of properties of plasma black as conductors on electrochemical characteristics. Based on our experimental results, PB conductors with low amount of surface functional groups and high electrical conductivity enhanced the cyclability and the initial discharge capacity. However, deterioration of rate capability and cyclability were observed (or the plasma black treated at For the plasma black conductor prepared from plasma pyrolysis, the effects of properties of carbon black on electrochemical characteristics were combined results of changes in electrical conductivity and structural properties such as agglomeration of plasma black. The conductivity of plasma black increased with treatment temperature, while dispersion of plasma black decreased. As a result, the high cyclability of cell was observed at of heat treatment temperature.

Automatic Heat-Shrink Sleeve Applicator Using the Low-Temperature Catalytic Combustor

Catalytic combustion for applying heat shrink sleeves (HSS) to a pipeline in KOGAS was investigated. We used a low temperature catalytic combustor in order to place HSS in the conduit. The surface temperature of the catalytic combustor maintained the conditions at which HSS can become well-adhesive at the conduit. Therefore, the automatic HSS construction provided the chance to establish gas pipeline safety by an automatic catalytic combustor device.