Study Of Preparation Of Metallurgical Reducing Gas Lignite

This paper combined conversion technologies of coal and metallurgical.It used gasification of coal to replace expensive natural gas and coke gas as the reducing gas source for metallurgy. Yunnan where resources of lignite are relatively richer than gas and oil that it used low carbon content of lignite as primary energy is used directly in metal smelting process that it is meaningful. This pape is chosed "research on making metallurgical reducing gas from lignite" as the topic of this article.Experiments of thermal analysis、pyrolysis and gasification on lignite have been done for providing related basic data of preparation of metallurgical reducing gas and Process plan.The research has been made on kinetics and pyrolysis characteristic of zhaotong lignite province in non-isothermal pyrolysis process by TG analysis.The result indicates that the non-isothermal pyrolysis process of this kind of zhaotong lignite can be divided into 3 sections as follows:130℃～300℃、300℃～750℃、750℃～1100℃. The order of every reaction section is 1 approximately and the activation energy of every section presents increasing by degrees. The activation energy for the sections can be listed as 12.677KJ/mol、42.253KJ/mol、57.777KJ/mol. maximum weightlessness temperature Tmax is 436℃, the rate of maximum weightlessness (dw/dT)max is 0.55%.min-1.In this paper the pyrolysis test of zhaotong lignite was carried out. The effect law of increasing temperature rate and pyrolysis temperature on gas composition, gas heating value and yield of gas was obtained. Results showed:CO2 content of gas reduce with increasing pyrolysis temperature obviously. CO and H2 content of gas, gas heating value and yield of gas increase with increasing pyrolysis temperature.CH4 content of gas increase first and then reduce with increasing pyrolysis temperature; At the same temperature, CO2and CH4 content of gas reduce with rise of increasing temperature rate. CO content of gas increases with rise of increasing temperature rate. Gas heating value and yield of gas increase with rise of increasing temperature rate. Rise of range is large first and then small. The effect of increasing temperature rate on H2 content of gas is negligible. In the test the process conditions of the maximum heating value:The pyrolysis temperature is 650℃. The increasing temperature rate is 15℃/min. the maximum heating value is 9.27MJ/m3.In the test gasification of lignite semi-coke was investigated by using pure oxygen and steam. Results showed that CO and H2 content of gas, calorific value and yield of syngas increase with increasing gasification temperature.CO2 and CH4 content of gas reduce with increasing gasification temperature; At the same gasification temperature, with rise of pure oxygen flow, CO and H2 content of gas increase first and then reduce.CO2 content of gas increases and CH4 content of gas reduces. The calorific value and yield of syngas have a maximum value.