XRD和Raman法评估热解气氛中H2和CO对半焦化学结构的影响  

Effect of H2 and CO as pyrolysis atmosphere on chemical structure of char by XRD and Raman methods

作　　者：张小蕊 邹冲[1] 赵俊学[1] 马成[1] 胡冰[1] 刘诗薇[1] 何江永 ZHANG Xiao-rui;ZOU Chong;ZHAO Jun-xue;MA Cheng;HU Bing;LIU Shi-wei;HE Jiang-yong(School of Metallurgical Engineering,Xi′an University of Architecture and Technology,Xi′an 710055,China)

机构地区：[1]西安建筑科技大学冶金工程学院

出　　处：《燃料化学学报》2019年第11期1288-1297,I0001,共11页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(51374166,51704224);陕西省重点研发计划项目(2017TSCXL-GY-04-01,2015Ktzdsf01-04);陕西省高校科协青年人才托举计划(20190603);陕西省教育厅服务地方专项计划项目(17JF012)资助~~

摘　　要：采用XRD和Raman光谱分析方法研究了神木煤在热解主要温度区间(450-750℃)及在三种热解气氛(N2、含H2及含CO)下的化学结构演变规律,并比较了两种方法所获结构参数的相关性。结果表明,原煤在N2气氛下热解制备的半焦,其炭微晶尺寸在横向上不断增长,纵向上层面间距逐渐增大,堆垛高度在650℃左右剧烈转变;Raman参数AD1/AG增加,而AG/Aall降低,表明半焦有序性结构比例降低。热解气氛中的H2促进了炭微晶结构的纵向发展,提高了小分子基团的转化程度,使得半焦有序化程度升高。热解气氛中的CO对炭微晶结构参数影响小于H2气氛,但在700℃以下,CO因析炭作用产生的致密炭颗粒包裹于半焦表面,导致半焦炭有序化程度提高。半焦的Lc与AG/Aall及d002与AD1/AG之间存在一定相关性;La与AD1/AG呈较好的正相关性。XRD and Raman spectroscopy were used to study chemical structure evolution of Shenmu coal in the main pyrolysis temperature range(450-750℃)and three pyrolysis atmospheres(N2,H2-containing and CO-containing).Correlation of structural parameters obtained by the two methods was compared.The results show that the char prepared by pyrolysis of raw coal in N2 has a continuous increase in the size of carbon crystallites in the transverse direction,AGradual increase of spacing in the longitudinal direction,and a sharp change of stacking height around 650℃.Raman parameter AD 1/AG increases,while AG/A all decreases,indicating ADecrease in proportion of the ordered char structure.The H2-containing atmosphere promotes the longitudinal development of the carbon crystallite structure,increases the conversion of small molecule groups and the ordered degree of char.The influence of CO-containing atmosphere on the carbon crystallite structure parameters is less than that of the H2 atmosphere.But below 700℃,the dense carbon particles produced by CO-containing atmosphere due to carbon deposition are entrapped on the char surface,resulting in an increase in the ordered degree of char carbon.There is a certain correlation between Lc and AG/A all,and d 002 and AD 1/AG of char;L a has AGood positive correlation with AD 1/AG.

关 键 词：低阶煤 半焦 热解气氛 XRD 化学结构 RAMAN光谱 

分 类 号：TQ530.2[化学工程—煤化学工程]