窑街油页岩热解动力学研究

利用差热分析仪对窑街油页岩进行不同恒速升温速率的热解实验,考察升温速率对热解的影响,随着升温速率加快,失重曲线和最大热解速率向高温区。建立Friedman动力学模型对热解数据进行了数学处理,得到了活化能的变化范围为120～190kJ·mol^-1,而且活化能E与频率因子A的对数呈良好的线性关系,对认识油页岩干酪根的热解机理和化学结构提供重要信息。     

油页岩热解特性的研究

为了能够高效利用油页岩资源,本文对油页岩的热解特性进行了全面深入的理论与试验研究,为再次振兴油页岩产业,提供有力的理论依据。在TG—DTA、TG—DSC联机分析仪上进行桦甸油页岩的热解特性的研究,得到了在升温速率为20℃/min时,颗粒粒度分别为≤0.3 mm;0.3～0.6 mm;0.6～1 mm;1～3 mm的油页岩的热解TG、DTG以及DTA曲线。结果表明,油页岩的热解是分两步进行的,油页岩在低温段的热解,随着颗粒粒度的减小,油页岩的热解特性趋好。通过各项数据分析,得到了油页岩在不同阶段的热解反应动力学参数。     

油页岩颗粒的热解模型

以实验为依据,分析了油页岩的热解机理及特性,并充分考虑了油页岩中挥发分在整个热解过程的作用,在此基础上建立了与油页岩固有热解特性相适应的热解模型。在能量方程中考虑了油页岩挥发分的热解反应吸热量及其挥发分的释放对油页岩固体颗粒质量的影响,并根据油页岩的热解特性,采用分阶段模型来描述油页岩的热解过程,以减小一步本征动力学方程带来的较大误差,还对模型进行了实验验证。     

大庆油页岩热解特性及动力学研究

采用热分析方法对大庆油页岩热解特性进行研究,考察了升温速率和热解终温对油页岩热解特性的影响.结果表明,温度是影响热解的最主要因素,随着温度的升高,挥发分产率增大;随着升温速率的增大,油页岩的热解特征温度和最大热解速率都明显提高.根据热失重曲线建立了大庆油页岩热解动力学模型,采用傅立叶红外光谱分析对油页岩及热解半焦官能团变化情况进行分析,发现油页岩的主要官能团与煤接近;随着热解终温的升高,半焦含氧官能团的吸收峰逐渐减弱.     

油页岩循环流化床燃烧特性研究

摘要:在循环流化床燃烧试验台上对油页岩的着火、稳定燃烧、燃尽特性等燃烧特性进行详细地试验方案分析,同时提出了油页岩循环流化床锅炉的设计与运行的特点。根据拟做试验方案进行试验研究,可以测试出油页岩的燃烧特性,为油页岩CFB锅炉燃烧特性的试验研究,以及大型化油页岩循环流化床锅炉的设计提供了借鉴。     

油页岩半焦热解特性

利用热重分析仪对油页岩半焦热解特性进行了研究.综合考虑制取半焦所获得的页岩油品质、半焦成分、发热量和循环流化床设计,认为干馏温度介于500～600℃为宜;干馏度对半焦热解初析温度和低温段热解过程有影响,但对高温段热解影响不明显,高温干馏所制取的半焦其热解过程包含于低温所制取的半焦热解过程中;随升温速率的提高,相同温度下的半焦热解度降低,当升温速率超过40℃•min^-1后,升温速率对半焦热解过程影响不大;最后采用Coasts法计算了油页岩半焦热解动力学参数,计算结果可供数值仿真和工程设计参考.     

油页岩循环流化床燃烧室密相区物料颗粒与燃烧特性

在 65t/h油页岩循环流化床锅炉上进行了燃烧室密相区物料特性与燃烧特性的工业试验。得到了极具片状结构特点的油页岩颗粒特性 ,经燃烧破碎磨损后的密相区床料和循环物料的颗粒特性与燃烧特性及相应的锅炉运行参数。试验结果对油页岩循环流化床锅炉的放大设计与运行调节具有一定的参考价值。同时为进一步建立油页岩循环流化床燃烧室密相区的流动、燃烧、传热、磨损、扬析与夹带模型奠定了基础。     

生物质与油页岩混合热解特性研究

为了充分利用油页岩和生物质,以生物质和油页岩按照不同质量比的混合试样作为研究对象,采用TG-DSC联用技术进行了热重实验,分析了热解过程特性曲线并计算热解特性参数,采用差减微分法计算了热解动力学参数。结果表明:混合试样DTG曲线分别在低温段及高温段出现2个峰,前者主要是生物质的纤维素及半纤维素挥发分的热解析出,后者主要为油页岩热解析出挥发分;随混合试样中油页岩含量逐渐增多,热解后期逐渐出现因油页岩无机盐热分解吸热过多而出现DSC曲线吸热峰;混合试样低温段挥发分析出量及挥发分综合释放特性指数均大于高温段的值;生物质含量最高的混合试样(生物质与油页岩的质量比为4∶1)的挥发分初始析出温度最低,其挥发分最大释放速度的峰值及挥发分综合释放特性指数均最大;生物质含量较多的混合试样低温段活化能大于高温段活化能的值,油页岩含量较多的混合试样低温段活化能低于高温段的值。     

油页岩热解特性及其甲烷释放规律研究

为研究油页岩热解特性及热解过程中甲烷的释放规律,采用热重-傅里叶变换红外光谱（TG-FTIR）对龙口（LK）、内蒙（NM）、汪清（WQ）三个地区的典型油页岩进行热解实验,并结合固相红外（FTIR）对油页岩的官能团结构进行分析。研究结果表明,油页岩热解过程可分为四个阶段,热解反应及挥发分释放主要发生在第二阶段（400～600℃）。甲烷的析出与油页岩结构中的脂肪烃（光谱范围3000～2800 cm^-1）密切相关,脂肪烃含量越多,热解过程中释放的甲烷越多。通过对甲烷析出曲线分峰拟合及结合动力学分析,得出甲烷的生成是由一个脱吸附过程和四个化学反应共同作用的结果。     

油页岩与玉米秸秆共热解特性研究

在固定床反应器中,研究了油页岩与玉米秸秆的共热解行为,利用红外和元素分析技术对油品进行比较。结果表明共热解对整体分解率与气产率有促进效果,油产率与玉米秸秆掺混比例有关。当玉米秸秆掺混比例小于等于30%,共热解提高了油产率、高位热值和H/C,抑制了氧含量,当掺混比例大于等于60%时结果相反,油品下降严重。在官能团分布中,共热解油中C=O浓度下降,O-H浓度上升,芳香类物质增加。     

热管式固定床鼓泡反应器返混试验研究

为了研究热管式固定床鼓泡反应器的返混问题,采用脉冲法,在一内径为50mm、高800mm,床内充以多孔填料,内插一根16mm×2mm不锈钢-水热管的固定床反应器中,用并流向上的水和氮气进行返混试验研究。利用轴向扩散模型计算反应器轴向Peclet准数,考察了气相流速、液相流速、多孔介质和热管对返混的影响。研究表明反应器中热管的存在加重了返混。     

加压大型鼓泡床反应器内大小气泡气含率研究

在内径0.3m、高6.6m的加压鼓泡床反应器内采用床层塌落技术测量床层内的大小气泡气含率实验。由于大小气泡上升速度不同,床层塌落曲线存在一水平段,在此基础上,详细考察了表面张力、粘度、系统压力、表观气速对大小气泡气含率的影响,得出大气泡气含率随粘度和表面张力升高而升高,随压力升高而降低;小气泡气含率随粘度和表面张力升高而降低,随压力升高而升高;并根据质量守恒定理,进行了解释。     

Pyrolysis kinetics for Green River oil shale from the saline zone

The nature of the organic and mineral reactions during the pyrolysis of Saline-zone Colorado oil shale containing large amounts of nahcolite and dawsonite has been determined. Results reported include a material-balanced Fischer assay and measurements of gas evolution rate of CH₄, C₂H_x, H₂, CO and CO₂, Stoichiometry and kinetics of the organic pyrolysis reactions are similar to oil shale from the Mahogany zone. X-ray diffraction and thermogravimetric analysis results are used to help determine the characteristics of the mineral reactions. Kinetic expressions are reported for dawsonite decomposition, and it is demonstrated that the temperature of dolomite decomposition is substantially lower than for Mahogany-zone shale because of the presence of the sodium minerals.     

Pyrolysis with partial combustion of oil shale fines in a spouted bed

Pyrolysis with partial combustion of oil shale fines from the Irati Formation in Brazil has been investigated in a 30 cm diameter spouted bed reactor. Experiments were carried out at atmospheric pressure and temperatures between 450 and 600°C. The oi] shale particle size was less than 6.35 mm. Spouting gas temperatures ranged from 20 to 565°C. Three inlet gas pipe diameters and two spouted bed heights were studied. Operation of the process was found to be stable over a wide range of test conditions. Results are presented for oil and gas quality, efficiency of retorting and overall performance of the plant.     

Modeling of vanillin production in a structured bubble column reactor

Vanillin is an important flavour. Semi-synthetic vanillin can be produced by the oxidation of lignin. Experimental studies leading to vanillin production in a batch reactor and a structured bubble column reactor (SBCR) lead us to the conclusion that the SBCR could have non-idealities such as dispersion. The radial and axial liquid-phase dispersion within the packed criss-crossing sandwich structures of Mellapak-750Y had been studied. A 2D model accounting for axial and radial velocities and dispersion was formulated and solved. The model predictions were compared with that of an experimental residence time distribution curve. The axial dispersion coefficient of the liquid phase is of the same order of magnitude as the radial dispersion coefficient. The reaction kinetics available in literature is adopted for the present study. Model for the SBCR was formulated and simulated using commercial modeling software. Simulation experiments were conducted in a SBCR. The effect of the following parameters on the yield of vanillin is studied: lignin concentration, lignin molecular weight, oxygen partial pressure and reaction temperature. It can be said that lignin molecular weight is a crucial parameter in vanillin production.     

美国绿河油页岩中沥青热解特征及动力学

沥青是油页岩中的重要有机质,也是油页岩中油母质热解产油和气过程的重要中间产物,对其热解研究有利于加深油页岩/油母质热解理解。通过索氏萃取提取出了绿河油页岩中的沥青,并对其进行了不同升温速率下热解实验。基于热重（TGA）数据,使用Friedman法计算了沥青热解的活化能,并通过活化能分布特征,推测沥青热解可能包含三个过程。接着,使用双高斯函数对含有交叠峰的DTG曲线进行反褶积处理,分解成三个峰,依次对应每一个过程。使用最小二乘法获得了这三个过程的活化能、指前因子和反应模型通式,并将获得的通式与四类固态物质热解模型中的11种理想模型进行对比,辨识出上述三个过程均遵循n级反应模型。     

Pyrolysis of model compounds on spent oil shales, minerals and charcoal: Implications for shale oil composition

Aliphatic compounds (alkanes, alkenes, alkanoic acids, ketones, alcohols and amines) were passed through beds of spent oil shales (Condor brown, Condor carbonaceous, Julia Creek), minerals (quartz, calcite, K-feldspar, pyrite, kaolinite) and charcoal at temperatures of 300–600 °C and the products were analysed by g.c.m.s. All the materials catalysed isomerization, aromatization and cracking to varying degrees: non-clay minerals < kaolinite ≈ spent oil shales < charcoal. Products included branched alkanes, isomeric alkenes, nitriles, ketones and alkyl-substituted benzenes, naphthalenes, pyridines, phenols, thiophenes and pyrroles. These compounds occur in shale oils and may be derived from secondary reactions of aliphatic products arising from kerogen cracking.