铁镍复合助剂对煤热解过程中氮迁移规律的影响

为了减少煤炭燃烧过程中NO_x的排放，在管式炉中进行了煤与金属助剂（FeCl₃、NiCl₂）的热解实验，研究了助剂负载量、热解温度、助剂添加方式对氮迁移及N₂产率的影响并且对复合助剂作用机理进行了探讨。结果表明：随着助剂负载量的增加，氮脱除率及N₂产率呈现先增加后趋于稳定的趋势，且负载量以0.8%Fe复合1.0%Ni为最佳。在700~1000℃的热解温度范围内氮脱除率及N₂产率随热解温度的增加而增加。对煤进行溶胀处理添加复合助剂后，氮脱除率及N₂产率要优于未经处理的煤样。铁基助剂与镍基助剂在催化煤热解氮迁移过程中形成互补，铁基助剂的添加增加了镍基助剂的活性，弥补了单助剂的劣势，且复合助剂相比于单助剂有更强的氮脱除效果并且N₂产率达到最高39%。铁镍复合助剂对煤中N-5转化为N₂的催化效果更加明显，因为复合助剂对吡咯的内氢转移和开环有更强的催化作用。本研究能够为煤炭洁净化利用提供理论和实验依据。

Nitrogen migration regarding the addition of iron-Ni composite additives during coal pyrolysis

In order to reduce NO_x emissions in the coal combustion process, the pyrolysis experiments of coal and metal additives (FeCl₃, NiCl₂) were carried out in a tube furnace. The effects of additive loading, pyrolysis temperature, and adding method of additives on nitrogen migration and N₂ yield were investigated, and the mechanism of compound additives was discussed. The results indicate that as the loading of the additive increases, the nitrogen removal rate and N₂ yield tend to stabilize after increasing, and the loading is preferably 0.8% Fe and 1.0% Ni. In the pyrolysis temperature of 700—1000℃, the nitrogen removal rate and N₂ yield increase with the increase of pyrolysis temperature. By swelling treatment of coal and the addition of composite additives, the nitrogen removal rate and N₂ yield are higher than untreated coal samples. In the process of nitrogen migration during the coal pyrolysis, iron-based additives and nickel-based additives complement each other. The addition of iron-based additives increases the activity of nickel-based additives to make up for the disadvantages of single additives. Compared with the single additive, the compound additive has a stronger nitrogen removal effect and the N₂ yield reaches a maximum of 39%. The Fe-Ni composite additive has a better catalytic effect on the conversion of N-5 to N₂ in raw coal, as the composite additive has a stronger catalytic effect on the internal hydrogen transfer and ring opening of pyrrole. This research can provide theoretical and experimental basis for the clean utilization of coal.