Study On Active Components For Reductive Desulfuration Catalyst Influenced By Pulse Plasma

At present, two aspects about researches between plasma and catalyst were discussed. For one thing, how were higher performance catalysts prepared by plasma technologies? For another, plasma can enhance catalytic activation, and which elements can influence activation? However, little are researched as below: how does plasma enhance catalytic activation, how does plasma influence catalytic components and their contents, and how do catalytic components, their contents and activation change under temperature and plasma, and what are different aspects? Above questions will be discussed in this thesis. At first, we developed a higher frequency and higher voltage millimicro grade switching power supply. It comprised two bridge-type inverter circuits by using IGBT semiconductors. It can keep output voltage steady and change output voltage frequency by PIC16C74 & PIC16C73 single chip microcontroller generating PWM signals. By using RC absorbing circuit , not only surging was resolved, but current and voltage surging were attenuated. A needle—gauze reactor was used in this thesis. The reaction was carried out by rare earth catalyst La2O3 reducing SO2 by CO. Firstly, La2O3 was pretreated by hydrolyzation, Secondly, catalyst was subjected to temperature and temperature—plasma for 2 hours, respectively. After that, catalyst was measured by XRD in order to determining their phase components and calculating phase contents. The results were as below: Temperature determined catalyst activation and phase components, and plasma only influenced phase contents. Temperature and plasma must both match mutually. If so, plasma can enhance catalyst activation in the most suitable temperature. There were different influence and effect for the same catalytic phase in a different temperature while voltage increasing. For activation phase La2O2S, plasma exhibited a better effect than temperature, and La2O2S content dropped initially and increased latterly while voltage increasing in 450℃; however, its content decreased in plasma than in temperature, but it rose up as voltage increasing in 500℃. Flowing volume resulted in a different result for the same phase in a different temperature, even if there was also a difference in the same temperature under temperature and plasma-temperature. For activation phase La2O2S, it firstly increased and later decreased slowly in temperature, and that it also firstly increased and later decreased in plasma-temperature while flowing volume increasing in 450℃. However, it firstly decreased and later increased slowly in temperature, and that it increased slightly at first and decreased slowly secondly in plasma-temperature while flowing volume increasing in 500℃. There was the most suitable flowing volume. In this flowing volume La2O2S content was higher ,and plasma and temperature showed the best effect.