Experimental study on sodium release characteristics during thermal conversion of high-alkali coal
In order to study release characteristics of sodium during thermal conversion of high-alkali coals,the release characteristics of sodium in high-sodium coal and low-sodium coal were compared and analyzed through combustion experiments and pyrolysis experiments of raw coal and water-washed coal,so as to explore the release law changes of different forms of sodium in coal samples during combustion and the influence of atmosphere changes on sodium release.The results show that,during the combustion experiment,the release of sodium from high-alkali coal increases slowly at 300~500 ℃ and rapidly at 500~1 100 ℃,and the release of sodium from low-alkali coal increases rapidly at 300~500 ℃ and slowly at 500~1 100 ℃.It can be seen that,coal quality is one of the main reasons affecting sodium release,and sodium release will be greatly affected by the difference in coal composition.The release law of sodium during combustion and pyrolysis is basically the same,the sodium release rate changes slowly during the pyrolysis process,and is about 7.0%lower than that of the combustion process.The release characteristics of organic sodium and water-soluble sodium are different due to different release routes.