CAJ | 학술논문

为了揭示水蒸气对半焦反应性和微观结构的影响,在自制两段新型反应器上依次进行了褐煤干燥、热解及“热”焦的水蒸气原位气化研究。利用TGA、BET和Raman光谱仪,对原位气化半焦进行反应性和微观结构解析。结果表明,在反应温度为600℃时,水蒸气对半焦转化率、反应性及微观结构影响很小。温度达到700~900℃,在半焦与水蒸气接触的前2 min,虽然半焦转化率变化不大,但其反应性、小环(3~5个芳环)与大环(≥6个环)体系之比及含氧官能团却急剧降低；大于2 min,半焦转化率逐渐增大,反应性、小环与大环之比及含氧官能团缓慢降低；而半焦孔结构在2 min 前后却具有基本一致的变化趋势。半焦与水蒸气接触的前2 min,小环与大环之比和含氧官能团急剧降低是导致反应性显著降低的重要因素,大于2 min,芳环体系的变化是导致反应性进一步降低的原因。
위료게시수증기대반초반응성화미관결구적영향,재자제량단신형반응기상의차진행료갈매간조、열해급“열”초적수증기원위기화연구。이용TGA、BET화Raman광보의,대원위기화반초진행반응성화미관결구해석。결과표명,재반응온도위600℃시,수증기대반초전화솔、반응성급미관결구영향흔소。온도체도700~900℃,재반초여수증기접촉적전2 min,수연반초전화솔변화불대,단기반응성、소배(3~5개방배)여대배(≥6개배)체계지비급함양관능단각급극강저；대우2 min,반초전화솔축점증대,반응성、소배여대배지비급함양관능단완만강저；이반초공결구재2 min 전후각구유기본일치적변화추세。반초여수증기접촉적전2 min,소배여대배지비화함양관능단급극강저시도치반응성현저강저적중요인소,대우2 min,방배체계적변화시도치반응성진일보강저적원인。
To examine the effects of steam on the char reactivity and its microstructure, experiments of drying and pyrolysis of brown coal as well as the in-situ gasification of"hot" char were carried out in a newly-designed two-stage reactor. The reactivity and microstructure of in-situ gasification char were characterized by TGA, BET and Raman spectroscopy respectively. The results show that at low temperature of 600 ℃, the steam has little effect on the conversion, reactivity and microstructure of char. When it reaches 700~900℃, there are different change trends before and after 2 min of reaction between char and steam. In the first 2 min, the reactivity, the ratio of small aromatic ring systems ( 3 ~5 rings ) to the large fused rings (≥6 rings ) and O-containing functional groups decrease dramatically although the char conversion varies little; after 2 min, however, char conversion increases gradually, char reactivity, the ratio of small to big aromatic ring systems and O-containing functional groups decrease slowly. In addition, the pore structure of char follows almost the same variation before and after 2 min. During the first 2 min, a sharp decrease of the ratio of small to big aromatic ring systems and O-containing functional groups are the important factors leading to the decrease of char reactivity;while after 2 min, the change of aromatic ring systems results in the further decrease of char reactivity.