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。     

石长沟油页岩的热解特性及动力学

通过热重、元素和XRD分析,研究了新疆吉木萨尔县石长沟矿区油页岩在不同升温速率下的热解特性及热解机理. 结果表明,油页岩中有机质热解生成页岩油和热解煤气的反应主要集中在300~550℃;升温速率从3℃/min增至15℃/min,热解反应向高温区移动,有机质完全热解温度从530℃升至575℃. 油页岩有机质的热解动力学分析显示,升温速率从3℃/min增至15℃/min,直接Arrhenius法计算的有机质热解活化能从243.52 kJ/mol增至257.32 kJ/mol;反应转化率从0.02增至0.97,Friedman法计算的活化能从96.39 kJ/mol增至292.84 kJ/mol.     

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.     

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。     

水介质中的天然胶乳氯化反应动力学

研究水介质中胶乳氯化反应历程,根据氯化反应的两个阶段分别建立了动力学方程,对水介质中天然橡胶乳氯化反应的进行程度用氯含量分析法进行跟踪.结果表明,两个阶段的反应均为一级反应,第二阶段反应活化能Ea为1 122.468 24 J/mol,指前因子为0.202 3 h-1.提出第二阶段光氯化反应机理,推导的反应速率方程与经验速率方程一致.     

升温速率对油页岩热解特性的影响

采用热分析方法,在非等温条件下对茂名和桦甸的油页岩进行了热解试验研究。研究了从常温到900℃之间不同升温速率(10,20,40,50,100℃/m in)对油页岩热分解反应的影响以及油页岩的H/C,O/C,Cdaf,Vdaf等因素与(dw/dt)m ax之间的关系。根据试验数据建立了热解动力学模型,利用积分法求得表观活化能和频率因子等动力学参数。试验结果表明,油页岩热解可分为3个阶段,其中第2阶段(200—600℃)是热解反应最激烈的区域,挥发份几乎全部析出。而第3阶段是碳酸盐热解阶段,茂名油页岩由于碳酸盐含量低,此阶段变化甚微。     

油页岩热解的FG-DVC模型

为研究油页岩结构与热解反应性之间的关系,在TG-FTIR分析仪上对甘肃油页岩在不同升温速率条件下(5、20、50℃·min-1)进行了热解实验研究,对CH4、CO、CO2、H2O和页岩油进行了定量分析,并采用非线性最小二乘拟合方法求解各组分析出的动力学参数,同时采用基于燃料化学结构的FG-DVC模型对各组分的析出过程进行了模拟。结果表明:油页岩的脱挥发分过程主要发生在200~600℃之间;油页岩中有机质所含官能团以脂肪烃为主;由于各官能团活性不同,导致气态产物的析出有先后顺序;由非线性最小二乘拟合方法获得的各种产物析出的活化能E分布在188~239 kJ·mol-1之间,而指前因子A在109~1013 s-1之间;各产物的FG-DVC模拟结果与实验数据较为相符,这说明用FG-DVC模型来描述甘肃油页岩的热解脱挥发分过程是比较合适的。     

水中臭氧的分解动力学研究

在尽可能地排除UV、传质及自由基吸收剂等影响的情况下,在 293.2~298.5K和pH3.2~13.0条件下,用Stopped-Flow光谱仪研究了O3在水中分解反应动力学。pH3.2~13.0条件下,O3分解相对于O3的反应级数为1级。在pH 10.1~10.3之间,OH-或pH对O3分解的影响可能有一个突变点。pH 10.1~10.3以下(含pH 10.1点),O3分解相对于OH-反应级数平均为0.13, 在pH 10.1~10.3以上(含pH 10.3点),O3分解相对于OH-反应级数为1.37。在pH 10.1~10. 3以下时,O3分解活化能为146.7kJ穖ol-1。     

油页岩热解的FG-DVC模型

为研究油页岩结构与热解反应性之间的关系,在TG-FTIR分析仪上对甘肃油页岩在不同升温速率条件下（5、20、50℃·min^-1）进行了热解实验研究,对CH₄、CO、CO₂、H₂O和页岩油进行了定量分析,并采用非线性最小二乘拟合方法求解各组分析出的动力学参数,同时采用基于燃料化学结构的FG-DVC模型对各组分的析出过程进行了模拟。结果表明：油页岩的脱挥发分过程主要发生在200～600℃之间;油页岩中有机质所含官能团以脂肪烃为主;由于各官能团活性不同,导致气态产物的析出有先后顺序;由非线性最小二乘拟合方法获得的各种产物析出的活化能E分布在188～239 kJ·mol^-1之间,而指前因子A在10⁹～10¹³ s^-1之间;各产物的FG-DVC模拟结果与实验数据较为相符,这说明用FG-DVC模型来描述甘肃油页岩的热解脱挥发分过程是比较合适的。     

不同介质条件下竹材的液化反应动力学

采用非等温差热分析(DTA)技术,分析了竹材在苯酚和酚油介质条件下液化反应动力学的影响。运用Kissinger方程在不同的升温速率下进行动力学研究,并由动态DTA曲线求出固化反应动力学参数,进而建立体系的液化反应动力学模型。实验结果表明,苯酚竹材液化体系(PLB)和酚油竹材液化体系(POLB)反应级数分别为0.905 9和0.950 5,平均活化能分别为68.95 kJ/mol和105.43 kJ/mol,指前因子分别为4.08×104s-1和8.91×104s-1;两者的反应级数较为接近,说明PLB和POLB的液化反应模式基本相同;与POLB相比,PLB液化体系液化能耗和液化温度相对较低。由外推法得出竹材液化反应最佳工艺为:液化介质为苯酚,初始液化温度为70.4℃,液化峰高温为110.5℃,液化峰终温为126.8℃。     

Kinetics of Colorado oil shale pyrolysis in a fluidized-bed reactor

Previous hydrocarbon evolution data were reanalysed to determine improved rate expressions for oil generation from Colorado oil shale under rapid pyrolysis conditions. Contributions from low-molecular-weight gases were subtracted from flame-ionization detector data to obtain the rate of oil generation alone. Equally good fits to the data were obtained using two parallel first-order reactions or a single reaction with an effective reaction order of 1.51. The latter expression was easier to incorporate into global process models. The rate expressions were independent of shale source (Anvil Points or Tract C-a) and particle size (0.5–2.4 mm). The kinetic data were consistent with the previous conclusion that the small incremental oil yield possible for fluidized-bed pyrolysis requires a longer residence time than that estimated by kinetic expressions derived from slow-heating data.     

Kinetics of pyrolysis and combustion of oil shale sample from thermogravimetric data

Thermogravimetric (TG) data of oil shale obtained at MI (Waste to Energy laboratory) were studied to evaluate the kinetic parameters for El-Lujjun oil shale samples. Different heating rates were employed simulating pyrolysis reaction using Nitrogen as purging gas up to ∼800 °C. The extent of char combustion was found out by relating TG data for pyrolysis and combustion with the ultimate analysis. Due to distinct behavior of oil shale during pyrolysis, TG curves were divided into three separate events: moisture release; devolatization; and evolution of fixed carbon/char, where for each event, kinetic parameters, based on Arrhenius theory, were calculated. Three methods were used and compared: integral method; direct Arrhenius plot method; and temperature integral approximation method. Results showed that integral method is closer to the experiment, while no relationship was observed between activation energy and the heating rate.     

Study of pyrolysis kinetics of oil shale

The pyrolysis experiments on oil shale samples from Fushun, Maoming, Huangxian, China, and Colorado, USA, were carried out with the aid of thermogravimetric analyzer (TGA) at a constant heating rate of 5 °C/min. A kinetic model was developed which assumes several parallel first-order reactions with changed activation energies and frequency factors to describe the oil shale pyrolysis. The kinetic parameters of oil shale pyrolysis were determined on the basis of TGA data. The relationship between the kinetic parameters was further investigated and the correlation equations of x_∞-E and ln A-E were obtained. These equations show that the final fractional conversion of each parallel reaction, x_∞(j), can be expressed as an exponential function of the corresponding activation energy. The plot of ln A-E for different reactions becomes a straight line. These relationship equations can provide important information to understand the pyrolysis mechanism and to investigate the chemical structure of oil shale kerogen.     

桦甸油页岩的微波干馏特性

在自行设计的微波干馏装置上研究了桦甸油页岩、半焦及其混合物在微波场中的升温特性。发现油页岩本身是一种微波弱吸收物质,纯油页岩在微波场中升温能力较差;油页岩热解产物半焦在微波场中升温很快,可以作为油页岩微波干馏的微波吸收剂,将油页岩和半焦的混合物放入微波场中能达到良好的热解效果。实验研究了半焦和油页岩的混合比、微波功率、粒径等因素对微波干馏效果的影响,结果发现,随着半焦比例加大,产油率增加,半焦产率降低;在相同时间内,微波功率越大,产油率和气体损失产率越大,半焦产率降低;油页岩粒径对微波热解影响较小,但当粒径小于0.2mm时实验中出现了较严重的夹带现象。     

油页岩热解技术研究进展

针对油页岩热解反应过程复杂,产油率低的问题,进行了油页岩的热解机理和反应过程介绍,探讨了材料特性、炉型种类、催化剂类型、热解温度、加热速率和停留时间对热解转化率的影响及其变化规律。研究发现材料特性影响页岩油产率和品质,粒径尺寸适宜范围在1. 2³ mm;固体干馏炉比气体干馏炉好,其油页岩利用率和油收率最高可达100%;催化剂由于其独特的性质和结构特点能够加速油页岩的热解,增大油页岩热解转化率,提高页岩油产率;此外,热解温度在5203 mm;固体干馏炉比气体干馏炉好,其油页岩利用率和油收率最高可达100%;催化剂由于其独特的性质和结构特点能够加速油页岩的热解,增大油页岩热解转化率,提高页岩油产率;此外,热解温度在520⁵50℃、加热速率在12550℃、加热速率在12¹5℃/min和停留时间在2015℃/min和停留时间在20⁴0 min范围内能够提高页岩油产率,改善页岩油的品质。指出了油页岩热解技术发展趋势,以期为我国非常规、战略接替能源的开发利用提供一定的参考。     

Kinetics of oil generation from Colorado oil shale

Isothermal and nonisothermal methods have been used to investigate the kinetics of oil generation during decomposition of 91.7 ml/kg (22 U.S. gal/short ton) Colorado oil shale. The result from the nonisothermal method gives an apparent activation energy of 219.4 kJ/mol and a frequency factor of 2.81 × 10¹³s^?1. Furthermore, the process is found to be first-order to within experimental error. These results compare favourably with isothermal data reported here and in the literature. The results show the reliability and convenience of nonisothermal kinetic experiments in studying oil-shale decomposition reactions. The principal advantages are short-term experiments and the lack of initial heat-up periods. Moreover, nonisothermal experiments more accurately simulate actual conditions of above-ground and in situ oil-shale retorting. These kinetics are ‘effective’ values and can only properly be used to describe the macroscopic oil-production process rather than the complex microchemistry.     

影响油页岩热分解的因素

介绍了抚顺式干馏炉的工作原理;论述了油页岩的含水量、热稳定性、粘结性、结焦性、粒度组成等性质及干馏加热的温度、速度和时间等不同受热条件对其热分解的影响;总结出干馏炉内油页岩受热条件的控制须根据页岩的各种实际物理性质进行操作。