基于Py-GC联用的煤快速热解实验研究

采用居里点裂解仪-气相色谱仪(Py-GC)联用的方法研究了4种煤的快速热解特性,分析了挥发分主要气相产物及其析出规律.结果表明,大于等于50%的挥发分在热解初期(t ≤ 2 s)释放,采用箔片装载方式的居里点裂解仪完全热解1 mg煤样需要10 s;挥发分主要气相产物中,各气体组分的生成量(mmol/g_coal)顺序为H₂ > CH₄ > CO > CO₂ > C2(C₂H₆、C₂H₄)> C3(C₃H₈、C₃H₆);挥发分释放量随热解温度的升高而增加,相同热解条件下,次烟煤挥发分的释放率高于贫煤和无烟煤;H₂和CH₄的生成量依赖于热解温度,热解温度越高,H₂和CH₄的生成量越多;CO和CO₂的生成量不仅与热解温度相关,而且与煤中的氧含量紧密相关,氧含量越高的煤热解生成的CO和CO₂越多;C2和C3气体的生成量相对于其他气体很少,体积占挥发分气相产物的5%.

Experimental study on flash pyrolysis of pulverized coals in Py-GC

Flash pyrolysis characteristics of four Chinese coals were studied in a Curie-pointed reactor and gas chromatography (Py-GC) combined system. The yield of volatile matter (VM) and evolution of gaseous VM components were measured. It is found that ≥ 50% of VM is released at the early stage (t ≤ 2 s) of flash pyrolysis. It needs ~10 s to totally devolatilize 1 mg coal in the Curie-point reactor with the sample wrapped in a ferromagnetic foil. The yields of gaseous VM component are in the order of H₂ > CH₄ > CO > CO₂ > C2(C₂H₆, C₂H₄) > C3 (C₃H₈, C₃H₆). The yield of VM increases as the pyrolysis temperature increases. Under the same pyrolysis condition, high VM content coals released more VM than the low VM content ones. Yields of H₂ and CH₄ increase greatly with the pyrolysis temperature. Yields of CO and CO₂ depend on both the content of oxygen in the coal and pyrolysis temperature. Amounts of C2 and C3 gases are relatively much less than the others, accounting for less than 5% in volume in the gaseous VM.