The Transformation Of Inorganic Sodium And It’s Effect On The Products During The Pyrolysis Of Zhundong Coal

Zhun Dong coal field in Xinjiang region is the biggest bulk coal field in our country, it’s coal reserves accounted for 7% of the total number of whole country. Because Zhun Dong coal has a higher alkali metal sodium content than other type power coal.On the one hand, in the process of combustion and heat transfer to make tail heating surface fouling and slagging and corrosion;On the other hand, sodium also a high efficient catalyst,it can activate the oxygen containing functional groups in the coal, such as carboxyl and hydroxyl, and C-C bond,catalytic char gasification, reduce the ignite.Geometrical shape of sodium in coal in the process of coal pyrolysis and gasification’s catalytic activation effect is different, and the various forms of sodium can be transformed in the process of coal heat utilization.Therefore, the research of sodium forms for efficient utilization in the process of pyrolysis of Zhun Dong coal is very important.Water-soluble sodium is the predominant chemical form in Zhundong coals,and account for more than 80% of total soluble sodium.Taking water-soluble inorganic sodium in Zhun Dong coal as the research object, loading with different chemical forms of water soluble sodium directionally after pickling, studying its morphological transformation in the pyrolysis process.And in a horizontal furnace rapid pyrolysis experiment system, analyzing transformation regularity of occurrence of water-soluble inorganic sodium in in the process of coal pyrolysis. On this basis, making the research about water soluble sodium’s influence on the pyrolysis products of volatiles’ generated characteristics, through the corresponding relationship with the functional groups in coal and pyrolysis products, getting the water-soluble inorganic sodium’s influence on functional group cracking. Water soluble sodium for pyrolysis carbocoal reactivity is also studied to get the influence trend of different chemical forms of water soluble sodium on coke reactivity,and analyzing the impact mechanism.Research has shown that during pyrolysis reciprocal transformation between different forms of sodium in coal, and different chemical forms of sodium in the pyrolysis process of transformation is different.Under high temperature, there are still a lot of water soluble in sodium in the Na2SO4-loaded coal coke made,and water soluble almost all transformed into gas evaporated into gas phase in the Na Cl-load of the coal coke. Bear the load of Na HCO3 coal due to the process of ion exchange happened, morphological transformation in the process of pyrolysis have significant difference with the other two kinds of inorganic sodium, durin g the period of temperature 300℃ to 600℃ water soluble sodium and ammonium acetate soluble sodium has a significant mutual transformation phenomenon.Analyzing the volatile produced from coal,loaded with different chemical forms of water soluble sodium, pyrolysis, found that the pickling process has no significant effect on coal pyrolysis total volatile yield,except the reduce of tar productive rate obviously.The effect of sodium mainly reflects on the influence of the components of pyrolysis products.That water soluble inorganic sodium has a greater effect on coal pyrolysis products.Using multicomponent gas analyzer to analyze the pyrolysis products of CO and CH4 were tested and analyzing the different chemical forms of water soluble sodium’s different trends about the generation characteristics and the water soluble sodium’s effect on the functional groups of coal pyrolysis process.That different chemical forms of water soluble sodium impact on different functional groups in different temperature range in the process of pyrolysis.Making the pyrolysis experiment about bearing the load of different chemical forms of water-soluble sodium coal at 500℃, 700℃ and 900℃. By TGA, the reactivity of coke samples produced at at different temperature of different chemical forms of water soluble sodium loaded coal, was tested,th e results showed that the inorganic sodium significantly improve the coke reactivity, and the activity of different chemical forms of water soluble sodium is at different levels.Under 500℃, 700℃ in the sample preparation, Na HCO3 is presented the strongest catalysis, and 900℃,the Na2SO4-loaded coal preparation of coke samples showed the highest reactivity.