Abstract:

The pore change and the volatile matter release of Shenmu coal and Huadian oil shale during thermal pretreatment at 150-400℃ were investigated.The effect of the pretreatment on the successive slow pyrolysis of the coal and oil shale was studied.The results showed that,after the thermal pretreatment,the pore structure of oil shale significantly increased and the specific surface area increased by more than 4 times and pore volume increased by more than 5 times.In contrast,the pore structure of Shenmu coal significantly reduced,in particular,for the pore larger than 1 nm,its pore volume reduced by nearly 60% and the surface area reduced by nearly 80%.However,the pore below 1 nm is relatively stable,and the pore volume and specific surface area reduced by only about 10%.When the thermal pretreatment temperature is below 400℃,in addition to the removal of adsorbed water,other volatile components,mainly CO₂,and a small amount of CO,also were released,but the total mass loss caused by volatile release is not more than 5%.The slow pyrolysis experiments with a fixed bed reactor showed that,after the thermal pretreatment,the oil yield of oil shale increased by 22.7%,the yield of water and gas products reduced,and the content of H₂ in the gas decreased while CH₄ increased.The thermal pretreatment had no obvious influence on the oil yield of coal pyrolysis,while increased the yield of the gas product and CH₄ content in the gas and decreased H₂ content.

Key words: oil shale, coal, thermal pretreatment, pyrolysis

摘要：

对比研究了神木煤和桦甸油页岩在150~400℃热预处理时的孔隙变化和挥发分析出规律以及热预处理对后续慢速升温热解反应产物的影响。结果表明，热预处理显著增加了油页岩的孔隙结构，其比表面积提高4倍、孔体积提高5倍以上，而神木煤的孔隙结构则减少了，特别是孔径大于1 nm的孔体积减少了近60%、比表面积减少了近80%，而其1 nm以下的孔则相对稳定，孔体积和比表面积分别只减少了10%左右。低于400℃时热预处理过程中除脱去吸附水外，其他挥发分也有一定析出，并以CO₂为主，另有少量CO，但挥发分总失重量不超过5%。固定床慢速升温热解研究表明，经热预处理后，油页岩的油产率最高提高了22.7%，而水和气的产率则相应降低，气体中CH₄增加而H₂降低。热预处理对煤的热解油产率影响不明显，但热解水产率降低而热解气产率增加且其中CH₄增多而H₂降少。

关键词: 油页岩, 煤, 热预处理, 热解