煤、油页岩和石油焦混烧特性及其动力学

为了充分利用劣质燃料油页岩和难以利用的高硫石油焦,以煤、劣质燃料油页岩及高硫燃料石油焦的混合燃料为研究对象,采用热重-差热的试验方法和差减微分法,对其混烧特性曲线和混烧特性机理进行分析,计算出试样各种燃烧特性参数及燃烧动力学参数。结果表明:煤、油页岩、石油焦的质量比为1∶6∶3的混烧试样S7的DTG曲线先后出现挥发分的析出着火燃烧峰和剩余固定碳的着火燃烧峰;煤、油页岩、石油焦的质量比为6∶3∶1的混烧试样S4的可燃特性指数及着火特性指数均大于油页岩及石油焦的值,而且混合试样的燃尽指数均大于煤及石油焦的值,同时,混合样品的综合燃烧特性指数均大于油页岩的值;试样S4的活化能最小,该混合试样的燃烧反应最容易进行。只要煤、油页岩及石油焦混合比例适当,其混合燃烧特性将优于油页岩及石油焦单独的燃烧特性。

Co-combustion characteristics and kinetics of coal,oil shale and petroleum coke

In order to efficiently utilize the low-grade fuel oil shale and high-sulfur petroleum coke,the coals were mixed with low-grade fuel oil shale and high-sulfur petroleum coke in different proportions.The co-combustion characteristics and mechanism were analyzed by TG-DTG-DSC and Freeman-Carroll method.The combustion characteristics parameter and kinetics parameters were investigated.Results show that the DTG curves of S7 with mass mixing ratio of coal,oil shale and petroleum coke being 1:6:3 present peaks from combustion of released volatile and residual fixed carbon.The sample S4 with mass mixing ratio of coal,oil shale and petroleum coke being 6:3:1 demonstrates greater combustible properties and ignition characteristics index than the values of oil shale and petroleum coke.Burnout indexes of various mixed samples are greater than that of coal and petroleum coke,and synthetic combustion characteristics index of each mixed sample is larger than the synthetic combustion characteristics index of the oil shale.While the activation energy of S4 is minimum,thus the combustion reaction of it is most easily to occur.In summary,mixed combustion characteristics are better than the independent combustion characteristics of oil shale or petroleum coke,which is feasible to solve the difficult of combustion of oil shale and petroleum coke separately.