Basic Research Of Combustion Of Rdf Prepared By Municipal Solid Waste Under Oxygen-Enriched Atmosphere

With rapid development society and economy, the disposal of the huge amount of municipal solid waste (MSW) increasing rapidly with the developing urbanization process have been attention, while a large number of rural agricultural and forest waste has not been used effectively, resulting in waste of resources. Refuse-derived fuel (RDF) made from high calorific waste and biomass is considered a preferential solution to maximize the recovery of energy due to its high density, high heating value, high efficient combustion, and low secondary pollution compared to rural waste. In this thesis, RDF’s preparation method, characteristic of briquetting and incineration under oxygen-enriched atmosphere are studied in details, and the simulation of RDF combustion processes under oxygen-enriched atmosphere based on aspen plus is carried on.The results of RDF characteristic of briquetting show that the ratio of PE component is less than50%, saw dust is the biomass supplement and rate of water content is from10%to14%, the characteristic of briquetting is better.Then, the characteristics of polluting emission of RDF oxygen-enriched combustion are studied in the tube furnace, the results show that the generation of NO is almost at the earlier stage of combustion; when the temperature is more than700℃or the oxygen concentration is more than60%, the peak value of NO instantaneous concentration increases sharply; the temperature is more than700℃, peak value of SO2instantaneous concentration increases sharply; with the gradual increase of the oxygen concentration, the detention period of SO2release is shorten.The combustion process of RDF under oxygen-enriched atmosphere is investigated by means of thermogravity-differential temperature analyser (TG-DTA). The combustion process of RDF consists of three phases:drying, releasing and burning of volatiles and burning of fixed carbon. With increasing heating rate, the combustion moves to higher temperature area. With the gradual increase of the oxygen concentration, the rate of combustion increased. The combustion process of RDF could be regarded as superposition of a number of first order reactions.At last, the combustion model of RDF under oxygen-enriched atmosphere is established based on the software of Aspen Plus.The combustion product of RDF is simulated by this model. The affect of combustion temperature and coefficient of excess oxygen(δ) on combustion product of RDF, there is also a comparison of combustion product of RDF between oxygen-enriched atmosphere and air atmosphere.The results show that the amount of NOx increases rapidly with an increasing of temperature and δ, it makes no difference of amount of SO2and SO3when the temperature changed; the amount of SO2increased with an increase of δ when δ is less than1, when δ is more than1,there is lesser effect on SO2amount with an increase of δ, but the amount of SO3increased slightly.