氢气压力对煤加氢反应影响的热重-气相色谱实验研究  

Thermogravimetric-gas chromatographic study on effects of hydrogen pressure on coal hydrogenation

作　　者：管清亮[1] 毕大鹏[1] 玄伟伟[1] 张建胜[1] 

机构地区：[1]清华大学热能工程系热科学与动力工程教育部重点实验室,北京100084

出　　处：《燃料化学学报》2015年第8期914-922,共9页Journal of Fuel Chemistry and Technology

基　　金：国家高技术研究发展计划(863计划;2011AA05A201)

摘　　要：采用加压热重分析仪和气相色谱仪联用的方法研究了府谷烟煤和海拉尔褐煤加氢反应过程中的失重规律和主要气体产物析出规律,升温速率15℃/min,压力0.1～5.0 MPa,反应终温1 000℃。实验结果表明,煤粉加氢反应主要分为初始干燥脱气、热分解及挥发分加氢,半焦加氢气化和焦炭加氢气化四个阶段。氢气压力的提高促进了挥发分自由基的加氢反应,抑制了含氧官能团脱除形成碳氧化物。在热分解及挥发分加氢阶段,府谷烟煤失重速率随氢气压力的升高而减小,氢气压力对海拉尔褐煤失重速率的影响不大。在半焦加氢气化阶段,CH4生成速率随氢气压力的升高而增大,当氢气压力较高时（3～5 M Pa）,海拉尔褐煤CH4生成速率随氢气压力的升高不再增大。海拉尔褐煤Odaf较高,其半焦中含氧官能团提供的活性位较多。府谷烟煤H/C原子比较高,能提供更多的内部氢。府谷烟煤和海拉尔褐煤焦炭加氢反应动力学参数分别为k0=2.38×10^7（min^-1·MPa^-1）,E=231 k J/mol,n=1和k0=2.64×10^3（min^-1·MPa^-0.736）,E=127 kJ/mol,n=0.736。Thermogravimetric characteristics and evolution of main gaseous products during hydrogenation of two coals were studied in a thermogravimetry-gas chromatography combined system at 15 ℃ / min,0. 1 ～ 5 MPa and a final temperature of 1 000 ℃. The results showthat the hydrogenation process occurs in four stages： drying and degassing,hydropyrolysis,rapid hydrogasification,and slowhydrogasification. With increasing hydrogen pressure,hydrogenation of volatile radicals is promoted and decomposition of oxygen-containing functional groups forming carbon oxides is inhibited. During hydropyrolysis stage,the weight loss rate increases with hydrogen pressure for FG coal,while the hydrogen pressure has little influence on that for HLE coal. During the rapid hydrogasification stage,the evolution rate of CH4 increases with hydrogen pressure; for HLE coal the evolution rate of CH4doesn＇t increase with hydrogen pressure any more at high pressures（ 3 ～ 5 MPa）. The HLE coal with higher oxygen content contains more active sites provided by the oxygen-containing groups in the semichar. The FG coal with higher H / C atomic ratio is able to provide more hydrogen by itself during hydrogenation reactions. The kinetic data of the slowhydrogasification stage is k0= 2. 38 × 10^7（ min^-1·MPa^-1）,E =231 k J / mol,n = 1 for the FG coal and k0= 2. 64 × 10^3（ min^-1·MPa^-0. 736）,E = 127 k J/mol,n = 0. 736 for the HLE coal.

关 键 词：加氢热解 加氢气化 压力 热重分析 

分 类 号：TQ530[化学工程—煤化学工程]