플라즈마 방전 이산화탄소 저감 특성

Abstract

Carbon dioxide emission is increasing with the industrial development and the increase in the fossil fuel consumption, and accounts for about 80% of the greenhouse gas. Therefore, carbon dioxide is one of the gases that must inevitably reduced. To efficiently decompose CO2, a high-temperature plasma torch and a gliding arc plasmatron were designed and fabricated in this study. Tests were performed by parameter with gas additives such as CO2, TiCl4, CH4 and steam to determine the characteristic of CO2 decomposition due to plasma. The CO2 conversion rate, energy decomposition rate, generated gas concentration, H2 and CO selectivity, characteristics of the generated carbon-black and TiO2 were examined. In the tests by parameter with the two reactors, the maximum CO2 conversion rate was used as the values for comparison. In the test with the high-temperature plasma torch, the CO2 conversion rate was 28.9% when CO2 alone was supplied, 44.6% with the TiCl4 additive, and 100% with the CH4 additive. This indicated that the CH4 additive resulted in the best performance of CO2 decomposition. In addition, XRD and SEM measurements were performed to compare the generated carbon-black and TiO2 with the commercial carbon-black and TiO2 in the market. The results showed that the characteristics of the carbon-black generated after the test with the CH4 additive were similar to those of the commercial carbon-black. The TiCl4 generated from the TiO2 additive test had both an anatase and rutile phases unlike the commercial TiO2, and the portion of the anatase phase increased with the increase in the CO2 flow rate and the decrease in the temperature. In the test with the gliding arc plasmatron, the maximum CO2 conversion rate was 12.3% when CO2 alone were supplied, 7.8% with the steam additive, and 43% with both CH4 and steam additives, which was the highest CO2 decomposition rate. The addition of both CH4 and steam generated 38% H2 and 17% CO. Because O2, which is involved in the oxidation of the generated CO, was first consumed for the injected CH4, the reduction to CO2 was suppressed. In this study, a high-temperature torch and a gliding arc plasmatron were used to decompose the greenhouse gas CO2. The high-temperature plasma torch generated the synthetic gas that contained H2 when CH4 was injected as an additive, and it was suitable for CO2 decomposition. It seems that the generated carbon-black can be used in the semiconductor and next generation battery sectors. The gliding arc plasmatron will reduce part of CO2 in the fossil fuel combustion device when it is used for CO2 recycling cycle when both CH4 and steam are injected without economic balance problem.