Four waste materials, paper, wood, textile and kitchen garbage, in municipal solid waste were gasified separately with oxygen in a fixed bed reactor. The yields of products char, tar and gas, the composition of gas components H2, CO, CO2 and CH4, and the lower heating value(LHV) were examined at temperatures between 700 and 900 °C and equivalence ratio(ER) between 0.14 and 0.32. Characteristics of gas evolution during gasification were investigated. Results show that a higher temperature improves the formation of H2 and CO while lowers the yield of CO2 and CH4. The LHV of syngas increases with temperature and varies in the range of 6–10 MJ·m-3, reaching the maximum at 800 °C or above. As ER increases, both combustible gas component and LHV of syngas decrease while the yield of CO2 rises linearly. The appropriate ER for obtaining high quality gas is in the range of 0.18–0.23.Temperature and ER have significant effects on the product distribution. Higher temperature and ER are favorable for higher gas yield and lower yield of char and tar in the gasification of textile and kitchen garbage. At 800 °C, the gas evolution may be divided into two regions. In the first region, the flow rate of gas increases and then decreases rapidly, while in the second region the flow rate decreases monotonically to lower level.
Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laboratory-scale reactor. Effects of several key operational parameters on NO removal efficiency are studied, including TiO2 content, H2O2 initial concentration, UV lamp power, NO initial content, oxygen volume fraction and TiO2/H2O2 solution volume. The results illustrate that the NO removal efficiency increases with the increasing of H2O2 initial concentration or UV lamp power. Meanwhile, a lower NO initial content or a higher TiO2/H2O2 solution volume will result in higher NO removal efficiency. In addition, oxygen volume fraction has a little effect.The highest NO removal efficiency is achieved at the TiO2 content of 0.75 g/L, H2O2 initial concentration of 2.5 mol/L, UV lamp power of 36 W, NO initial content of 206×10-6 and TiO2/H2O2 solution volume of 600 m L. It is beneficial for the development and application of NO removal from coal-fired flue gas with UV/TiO2/H2O2 process.
