Abstract:

The influence of multiple process factors affecting the oil shale particles size distribution and the degree of fragmentation/pulverization was studied in fixed-bed during thermal effect.The results show that with the temperature increasing from 120℃ to 900℃,the fraction of retention particles (25-13 mm) is decreased from 96.54% to 82.69%.The fragmentation particles group (13-1 mm) are increased from 2.01% to 10.63%(13-6 mm grain size increased the highest rate);The pulverization particles group (less than 1 mm) are increased from 1.45% to 6.68%(the fractions of particles less than 0.075mm are significantly changed).The degree of fragmentation and pulverization are increased with particles size and holding time as well.Impact of multi-factor on fragmentation is revealed using gray relational analysis method as follows:temperature > size > time,and the impact on pulverization is:temperature > time > size.Through the analysis of TGA,XRF,XRD,SEM-EDS,the internal incentives affecting fragmentation/pulverization are revealed:vapor-volatile arising,calcite decomposition behavior,indirect reinforcement with time,and internal air resistance/particle material resistance.The descriptive model of oil shale fragmentation-pulverization in fixed-bed during thermal effect is built based on these factors.

Key words: oil shale, fixed-bed, pyrolysis, particle size distribution, fragmentation, pulverization, gray relational analysis

摘要：

在固定床中定量研究了热作用过程多种工艺因素对油页岩颗粒的粒度分布及碎裂/粉化程度的影响。结果表明：温度由120℃升至900℃，固相产物中25~13 mm保持粒级比率由96.54%降至82.69%；13~1 mm碎裂粒群比率由2.01%增至10.63%（13~6 mm粒级增幅最高）；<1 mm粉化粒群比率由1.45%增至6.68%（<0.075 mm粒级变化最显著）。颗粒尺度的增加及保温时间的延长亦使得油页岩的碎裂及粉化程度加剧。多因素灰色关联分析结果显示：对油页岩碎裂程度的影响为：温度>粒度>时间；对粉化程度的影响为：温度>时间>粒度。通过对油页岩的多种测试表征（TGA、XRF、XRD、SEM-EDS），揭示了上述因素影响油页岩热碎的内在诱因（水汽行为、挥发分析出行为、方解石分解行为、时间间接强化、颗粒内部气阻/材料抗力的影响），并基于此构建了油页岩热作用过程碎裂-粉化历程描述模型。

关键词: 油页岩, 固定床, 热解, 粒度分布, 碎裂, 粉化, 灰色关联