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对褐煤、松木屑、稻壳、秸秆及其掺混试样在CO_2气氛下进行共气化热重实验,采用扫描电镜与傅里叶红外光谱仪对不同温度下(320~850℃)所得半焦的物化结构进行研究分析。研究发现:松木屑与褐煤按质量比1∶1掺混时,其开始气化温度和气化终止温度有所降低,说明混合燃料的气化特性较好;松木屑半焦中存在K、Ca等碱金属含量较高的球形颗粒物;随着气化温度的升高依次发生变形—褶皱—塌陷的变化过程,而碱金属的挥发主要集中在焦炭气化阶段;与褐煤相比,松木屑中羟基、脂肪族烷烃键等含量较高,气化时较低温度时即会断裂,从而为气化反应提供充足的还原性气氛。共气化过程中,小分子侧链—NH—键、烷基—CH_2—、—CH_3键、芳香性烷键结构上的—CH_2—、—CH_3键、C==C键、醚键等含氧官能团的谱峰消失温度较褐煤单独气化时提前,表明共气化过程中生物质的加入加速了—NH—、—CH_2—、—CH_3、C==C及醚键等的断裂,进一步从微观角度证实生物质与煤共气化的协同作用。
The thermal gravimetric experiments of co-gasification of lignite, pine chips, rice husks, straw and their blended samples under CO 2 atmosphere were carried out. The SEM images and FTIR spectra of semi-coke from different temperatures (320-850 ℃) The materialized structure of research and analysis. The results show that when the mixture of pine chips and lignite is mass ratio 1: 1, the initial gasification temperature and gasification termination temperature decrease, indicating that the gasification characteristics of the mixed fuel are better. There are K, Ca, etc. The spherical particles with high content of alkali metal, the deformation-fold-collapse process followed by the increase of gasification temperature, while the volatilization of alkali metals mainly concentrated in the coke gasification stage. Compared with lignite, , Aliphatic alkane bonds and other content is higher, the gasification will be ruptured at lower temperatures, so as to provide sufficient gasification reaction reducing atmosphere. During the co-gasification process, small-molecule side-chain -NH-, alkyl -CH 2 -, -CH 3 bonds, -CH_2 -, -CH_3 bonds, C == C bonds, The disappearance temperature of oxygen functional groups peaked earlier than that of lignite alone, indicating that the addition of biomass accelerated the fracture of -NH -, - CH 2 -, - CH 3, C == C and ether bonds, and further Synergism of co-gasification between biomass and coal was confirmed from the microscopic point of view.