题名温度分布与油页岩热解二次反应关系研究
作者张喻
学位类别硕士
答辩日期2016-07
授予单位中国科学院研究生院
授予地点北京
导师许光文 ; 高士秋
关键词油页岩 热解 温度分布 二次反应 匹配
学位专业化学工程
中文摘要

本论文基于中心集气管对油页岩外热式固定床热解过程的强化,深入研究了反应器内温度分布对热解产物分布和产品特性的影响。采用了单段固定床反应装置、温度梯度热解装置和两段反应装置分别研究了桦甸油页岩的基本热解特性、反应器内温度分布对热解过程的影响和温度分布影响热解的机理。油页岩在500-700 oC温度范围内的固定床程序升温热解实验表明,油收率在550 oC达到最大值7.91%,约为铝甑油收率的86.07%。在油页岩梯度热实验中,当热解温度分布为900-500 oC时页岩油收率为7.40%,当温度梯度反转为500-900 oC时,页岩油收率降为2.23%,在350-900 oC温度范围内两组热解实验也有相同的规律,表明高温到低温的温度分布有利于高的油收率。两段反应装置进一步研究了温度分布对油页岩热解二次反应影响的作用机理,当初次热解产物通过低温(<450 oC)的半焦床层时会发生在床层颗粒表面的冷凝,被冷凝的油会在后续的升温(至550 oC)过程中释放出来,伴随着初次热解产物在半焦颗粒表面轻微程度的裂解,导致轻微的油损失和高的轻油(沸点低于350 oC)收率,得到的页岩油仍然能保持较高的脂肪烃含量。当初次热解产物通过高温(>550 oC)半焦床层时,会在颗粒表面发生剧烈的二次裂解,将重质组分和轻质组分都转化为气体和积碳,导致油收率和品质大幅降低,油中几乎不含脂肪烃。通过分析初次热解产物通过低温和高温颗粒层时二次反应的趋势,得到温度分布和二次反应之间的匹配关系,即引导初次热解产物从高温区向低温区流动,可以避免发生裂解主导的二次反应,从而实现高页岩油收率和品质。

英文摘要

Based on the enhancement of central gas collecting pipe on oil yield and quality of oil shale pyrolysis in fixed bed reactor, this article investigates the effect of the reactor temperature profile on the distribution and characteristics of the products in fixed bed pyrolysis of oil shale. Experiments have been performed in a one-stage fixed bed reactor, a temperature–gradient pyrolysis reactor and a two-stage fixed bed reactor to study the fundamentals of oil shale pyrolysis, the effect of temperature profiles and the mechanism of the above effect, respectively. In the one-stage fixed bed reactor, shale oil yield reached a maximum value of 7.91%(86.07% of Fischer assay oil yield) at a pyrolysis temperature of 550 oC which is recognized as the end temperature for later pyrolysis experiments. For oil shale pyrolysis with different temperature profiles, shale oil yield reaches 7.40 wt.% with a reactor temperature profile from 900oC to 550 oC, while it reduces to 2.23 wt.%with the reversed temperature profile. The effect of temperature profile is investigated further in the two-stage fixed bed reactor combining a pyrolysis stage operating at 550 oC and a shale char bed operating at different temperatures. At low temperatures (<450 oC) in the shale char bed, the primary oil from the pyrolysis reactor condenses. The condensed oil can be released once re-heating the bed to 550oC, thus causing a slight oil loss but higher light oil (boiling point<350 oC) yield due to oil cracking over shale char. At high temperatures of the shale char bed (>550 oC), severe cracking occurs, converting both heavy and light oil to carbon and gas. After discussed via analyzing the tendency of secondary reactions subject to the temperature of particles contacting with primary volatiles, concluded out that the desirably matched reactor temperature profile for high oil yield is achieved by controlling the pyrolysis volatiles to flow from high-temperature zone to low temperature to avoid the cracking-dominant secondary reactions. 

语种中文
内容类型学位论文
源URL[http://ir.ipe.ac.cn/handle/122111/22860]  
专题过程工程研究所_研究所(批量导入)
推荐引用方式
GB/T 7714
张喻. 温度分布与油页岩热解二次反应关系研究[D]. 北京. 中国科学院研究生院. 2016.
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