添加CaO对煤热解行为影响的实验研究
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摘要
为研究高钙碳摩尔比对煤热解过程的影响特性,基于热重红外联用系统与固定床实验系统对宁夏烟煤开展了添加CaO吸收剂的煤热解实验。实验采用钙碳摩尔比分别为0,0.25,0.5与1,结果表明:CaO可显著改变煤失重及气态产物析出历程,添加CaO的热解DTG曲线在400℃与650℃存在失重峰,分别对应CaO水合产物Ca(OH)_2与碳酸化产物CaCO_3分解。此外CaO加入亦降低固态热解产物收率,同时促进热解过程CO,CH_4,H_2产出,并显著改变CO_2析出历程,当钙碳摩尔比由0增至1时,H_2产出增加5.21%,CO产出增加44.13%,CO_2降低17.80%,促进与抑制效果均与钙碳摩尔比成正比。
In oder to investigate the influnces of CaO on the behavior of coal pyrolysis,experiments on the coal/CaO co-pyrolysis were conducted by TG-FTIR system and fixed bed reactor with Ca/C mole ratio of 0,0.25,0.5 and1.0.The results indicate that coal pyrolysis process is affected remarkably by the additive CaO.By comparing with pure coal pyrolysis,there are two additional weight loss peaks in the DTG profiles of pyrolysis with CaO addition,which correspond to the decomposion of Ca(OH)_2and CaCO_3respectively.The yield of solid product and CO_2is inhibited.Meanwhile the yields of CO,H_2,CH_4is enhanced by CaO.The release process of CO_2duiring pyrolysis is also changed remarkably.With the Ca/C mole ratio increases from 0 to 1,the yields of H_2and CO are improved by 5.21%and 44.13%respectively,and the CO_2release is lowered by 17.8%.The promoiton and inhibition effects are both positively related to the Ca/C mole ratio.
In oder to investigate the influnces of CaO on the behavior of coal pyrolysis,experiments on the coal/CaO co-pyrolysis were conducted by TG-FTIR system and fixed bed reactor with Ca/C mole ratio of 0,0.25,0.5 and1.0.The results indicate that coal pyrolysis process is affected remarkably by the additive CaO.By comparing with pure coal pyrolysis,there are two additional weight loss peaks in the DTG profiles of pyrolysis with CaO addition,which correspond to the decomposion of Ca(OH)_2and CaCO_3respectively.The yield of solid product and CO_2is inhibited.Meanwhile the yields of CO,H_2,CH_4is enhanced by CaO.The release process of CO_2duiring pyrolysis is also changed remarkably.With the Ca/C mole ratio increases from 0 to 1,the yields of H_2and CO are improved by 5.21%and 44.13%respectively,and the CO_2release is lowered by 17.8%.The promoiton and inhibition effects are both positively related to the Ca/C mole ratio.
引文
[1]WANG Qinhui,RONG Nai,FAN Hongtao,et al.Enhanced hydrogen-rich gas production from steam gasification of coal in a pressurized fluidized bed with Ca O as a CO2sorbent[J].International Journal of Hydrogen Energy,2014,39(11):5781-5792.
[2]FRANKLIN H D,PETERS W A,HOWARD J B.Mineral matter effects on the rapid pyrolysis and hydropyrolysis of a bituminous coal.1.Effects on yields of char,tar and light gaseous volatiles[J].Fuel,1982,61(2):155-160.
[3]LAI C K S,CHEN P,LONGWELL J P,et al.Thermal reactions of m-cresol over calcium-oxide between 350 and600℃[J].Fuel,1987,66(4):525-531.
[4]KHAN M R,SESHADRI K.Compositional changes in the mild gasification liquids produced in the presence of calcium compounds[J].Fuel Processing Technology,1991,27(1):83-94.
[5]JIA Yongbin,HUANG Jiejie,WANG Yang.Effects of calcium oxide on the cracking of coal tar in the freeboard of a fluidized bed[J].Energy&Fuels,2004,18(6):1625-1632.
[6]ZHU Tingyu,ZHANG Shouyu,HUANG Jiejie,et al.Effect of calcium oxide on pyrolysis of coal in a fluidized bed[J].Fuel Processing Technology,2000,64(1/2/3):271-284.
[7]MATERIC V,SMEDLEY S I.High temperature carbonation of Ca(OH)2[J].Industrial&Engineering Chemistry Research,2011,50(10):5927-5932.
[8]NELSON P F,SMITH I W,TYLER R J,et al.Pyrolysis of coal at high-temperatures[J].Energy&Fuels,1988,2(4):391-400.
[9]HAN Long,WANG Qinhui,MA Qiang,et al.Influence of Ca O additives on wheat-straw pyrolysis as determined by TG-FTIR analysis[J].Journal of Analytical and Applied Pyrolysis,2010,88(2):199-206.
[10]肖军,沈来宏,郑敏,等.基于TG-FTIR的生物质催化热解试验研究[J].燃料化学学报,2007,35(3):280-284.
[11]谢克昌.煤的结构与反应性[M].北京:科学出版社,2002.
[12]ELLIG D L,LAI C K,MEAD D W,et al.Pyrolysis of volatile aromatic hydrocarbons and n-heptane over calcium oxide and quartz[J].Industrial&Engineering Chemistry Process Design and Development,1985,24(4):1080-1087.
[2]FRANKLIN H D,PETERS W A,HOWARD J B.Mineral matter effects on the rapid pyrolysis and hydropyrolysis of a bituminous coal.1.Effects on yields of char,tar and light gaseous volatiles[J].Fuel,1982,61(2):155-160.
[3]LAI C K S,CHEN P,LONGWELL J P,et al.Thermal reactions of m-cresol over calcium-oxide between 350 and600℃[J].Fuel,1987,66(4):525-531.
[4]KHAN M R,SESHADRI K.Compositional changes in the mild gasification liquids produced in the presence of calcium compounds[J].Fuel Processing Technology,1991,27(1):83-94.
[5]JIA Yongbin,HUANG Jiejie,WANG Yang.Effects of calcium oxide on the cracking of coal tar in the freeboard of a fluidized bed[J].Energy&Fuels,2004,18(6):1625-1632.
[6]ZHU Tingyu,ZHANG Shouyu,HUANG Jiejie,et al.Effect of calcium oxide on pyrolysis of coal in a fluidized bed[J].Fuel Processing Technology,2000,64(1/2/3):271-284.
[7]MATERIC V,SMEDLEY S I.High temperature carbonation of Ca(OH)2[J].Industrial&Engineering Chemistry Research,2011,50(10):5927-5932.
[8]NELSON P F,SMITH I W,TYLER R J,et al.Pyrolysis of coal at high-temperatures[J].Energy&Fuels,1988,2(4):391-400.
[9]HAN Long,WANG Qinhui,MA Qiang,et al.Influence of Ca O additives on wheat-straw pyrolysis as determined by TG-FTIR analysis[J].Journal of Analytical and Applied Pyrolysis,2010,88(2):199-206.
[10]肖军,沈来宏,郑敏,等.基于TG-FTIR的生物质催化热解试验研究[J].燃料化学学报,2007,35(3):280-284.
[11]谢克昌.煤的结构与反应性[M].北京:科学出版社,2002.
[12]ELLIG D L,LAI C K,MEAD D W,et al.Pyrolysis of volatile aromatic hydrocarbons and n-heptane over calcium oxide and quartz[J].Industrial&Engineering Chemistry Process Design and Development,1985,24(4):1080-1087.
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