Experimental Study On Pyrolysis Characteristics And Combustion Characteristics Of Inner Mongolia Lignite Char

With the economic development and social progress, the problem of irrational energy consumption structure is increasingly prominent in the way of sustainable development. In the face of increasing energy and the environment pressure, China’s energy structure reform is imperative.Coal is the long-term primary energy in our country. The uses of coal resources in the past always use high-quality coal to take precedence over low rank coal. With the rapid development of the national economy and increasing demand for coal, the high-quality coal supply is becoming tighter. Our country has a large number of low rank coal is difficult to use. So it is more and more give emphasis to the use of low rank coal. Achieve clean and efficient utilization of low rank coal are important to ease the energy supply and the reform of China’s energy structure.First, the industry analysis and elemental analysis of Shengli coal field, Huolinhe coal mine and Baiyinhua coal mine were studied and compared. The results showed that the moisture content of three lignites are less than 20%. Shengli lignite has the minimum moisture content. Volatile content of three lignite are around 35%. Three lignite have a high oxygen content, so the combination of C and H is relatively high. Therefore Inner Mongolia lignite has a larger upgrading space.The second, thermogravimetric analyzer is used to investigate the pyrolysis characteristics of three lignite on the condition of different granularity and different heating rate. The results show that: Pyrolysis of lignite can be divided into three stages, including dehydration, volatile organic compounds analyzed and decomposed, into coke. Typically smaller the particle size and the lower the heating rate, pyrolysis more completly. The volatile temperature and maximum weight loss rate corresponds to the lower temperature.The third, using TG-FTIR methods research lignite pyrolysis products, escaping gas and pyrolysis oil component, summarize the pyrolysis rule. The results show that: Products of lignite pyrolysis are complex. Different Lignite has basically same pyrolysis products. The Main non-condensable gases of lignite pyrolysis are SO2, NH3, CO2, CH4, CO. The main ingredient of pyrolysis oil are olefins, aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, monocyclic aromatic hydrocarbons, alcohols, phenolic compounds, ketones, esters, carboxylic acids, acid amides, oxygen-containing compounds, nitrogen and phosphorus compounds, sulfur compounds, nitrite ester compounds, halogen compounds and so on.Then three lignite were made into char at different final temperature. After the comparison and research of the industry analysis and elemental analysis, thermogravimetric method was used to study pyrolysis temperature on its combustion characteristic.. And then the semi-coke combustion combustion kinetics was analysed. The results show that: Lignite char combustion characteristics of discrimination index calculation, obtained with the final pyrolysis temperature increases, the stability of semi-coke increased. Coast-Redfern integral method utilizing the three and a half lignite coke combustion kinetics analysis, when the reaction order of 1.5, kinetic fitting correlation coefficient R value of 0.99, it is accurately fit. With the final pyrolysis temperature increases, char combustion needs more and more energy, which is same conclusion on the research of industry analysis, elemental analysis and combustion characteristics index.After the pyrolysis, lignite is convert into high-quality fuel, which has low moisture content and high calorific value. It shows the trend from the low rank coal to high-quality coal.