The pyrolysis of brown coala nd the in-situ gasificatio n of “hot” char were carried outi n a newly-designed two-stage fixed-bed reactor.Firstly, the brown coal was pyroly zed in ul trapure argo n for 5 s under the temperature of 400 ℃, 600 ℃, and 800 ℃ at the pyrolysis stage.Then the reactor was shifted to the“gasification stage” immediately andt he “hot char” obtained at the pyrolysis stage was gasified in-situ for 2 ~30 min at 900 ℃ with a 15%H2 O balanced with argon to obtain a so-called in -situg asification char.TGA and Raman spectroscope were used to characterize the reactivity and microstructure of char, respectively.Results show that the yields of in-situ gasification char decrease significantly within the initial 10 min, and then decrease slowly with prolonging the holding time further (10 ~30 min).Plenty of O-containing functional gro ups are released int he first 2 min during gasification.The ratio of small aromatic ring systems to big arom atic ring systems decreases dramatically within 2 min, and then decreases slowly from 2 min to 30 min.Microstructure of char has an effe ct on its rea ctivity.With the char gasifica tion, the amorphou s carbon as well as small aroma tic ring systems with high activity decreases, leading to the char reactivity decreaseing consequently.%在自制两段新型固定床反应器上进行了褐煤热解及“热”半焦的原位气化反应的研究。在高纯氩气、400／600／800℃的条件下，对褐煤热解5 s 后，立刻将反应器移到气化段，同时切换气氛为15％水蒸气对“热”半焦进行原位气化反应（900℃、2～30 min），制得原位气化半焦。利用 TGA 和 Raman 光谱仪，对原位气化半焦进行反应性和微观结构表征。结果表明，原位气化半焦产率及反应性在气化10 min 内降低幅度相对较大，10～30 min 降低相对缓慢。大部分的含氧官能团在气化2 min 内被释放，气化2 min 后含氧官能团变得非常少。半焦中小的芳环与大环体系之比在气化2 min 内急剧降低，2～30 min 降低较为缓慢。半焦的微观结构对其反应性有一定的影响，随着气化反应的不断进行，半焦中无定形结构、小的缩合芳环等活性基团逐渐减少，反应性相应降低。
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