矿物质对煤焦表面性质和煤焦-CO_2气化反应的影响  

EFFECT OF MINERAL MATTER ON MICROSTRUCTURAL PROPERTIES AND CO_2-GASIFICATION OF HIGH-ASH COAL CHARS

作　　者：谢克昌[1] 赵明举[1] 凌大琦[1] 

机构地区：[1]太原工业大学

出　　处：《燃料化学学报》1990年第4期316-323,共8页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金;山西省自然科学基金

摘　　要：制备了高灰分含量的年轻烟煤——义马煤和西曲焦煤洗中煤(西曲煤)脱灰前后的焦样。用常温CO_2吸附法测定了它们的初始和不同热解转化率下的比表面积。实验发现,矿物质对煤在成焦过程中的孔扩展和表面生成有促进作用,原煤焦和脱灰煤焦比表面积随转化率的变化规律不同。这些焦样在加压下的CO_2气化动力学研究表明,矿物质具有一定的催化作用。灰分单独添加的实验结果表明,所有灰组成对脱灰西曲煤在热解中的孔扩展都有促进作用,其中CaCO_3和α-Fe_2O_3还对煤焦气化有催化作用,而SiO_2、Al_2O_3等矿物组分会与K_2CO_3反应生成不具催化作用的非水溶六方钾霞石等化合物。Two kinds of Chinese high-ash coal, Yima gas coal and middling from washed Xiqu coking coal, were used as the parent coals. Demineralized coal samples and mixtures of the demineralized Xiqu middling with individual coal-like minerals of CaCO_3, Fe_2O_3, SiO_2 and Al_2O_3, as well as the coal ash were prepared. The samples and mixtures were devolatilized under N_2 and/or CO_2 atmosphere. Microstructural properties, including specific surface area of the chars were determined at 298K by gravimetric adsorption method using CO_2 as the adsorbate. Morphologies of the chars were examied by TEM. Gasification experiments convering a range of temperatures(1173 to 1423K) and under pressures of 0.1 and 1.0 MPa were conducted at high heating rate for the chars, including the parent coat chars and the demineralized Xiqu chars mixedits ash component and additives such as K_2CO_3, using a unique high tempeerature/pressure thermal gravimetric analyzer. Reactivity, conversion, activation energy and other kinetic data were determined for the chars and results showed that 1) mineral matters could promote the development of micropores and thus increase specific surface area of the chars; 2) CaCO_3(?) Fe_2O_3 and the parent coal ash could also catalyze the CO_2-gasification reaction of Xiqu chars to a certain extent; 3) K_2CO_3 might react with SiO_2 and A1_2O_3 in the coal and produce the non-aquo-soluble compounds such as kalisilite which has no catalytic effect.

关 键 词：矿物质 气化 煤 热解 高灰煤 加压 

分 类 号：TQ520.1[化学工程—煤化学工程]