Kinetics of oil generation from oil shale from Liaoning province of China

The intrinsic kinetics of oil generation from 0.124 dm³ kg^?1 Chinese oil shale were determined by a non-isothermal method. Overall first-order kinetics satisfactorily represented the mechanism of kerogen decomposition. The kinetic parameters were determined as 142.8 kJ mol^?1 and 7.495 × 10⁶ s^?1 for activation energy and pre-exponential factor, respectively.     

Physical behaviour of oil shale at various temperatures and compressive loads: 2. Thermal expansion under various loads

The thermal expansion of oil shale for various applied compressive loads, grades and orientations of the bedding plane to the applied load have been measured. It was determined that increasing the compressive load decreases the maximum expansion. Under loads <4.827 MPa the expansions of oil shale specimens with perpendicular and parallel orientations increased with grade. Under loads of 0.345–4.827 MPa increasing the grade decreased the expansion of 45 ° orientated specimens.     

Acoustic wave propagation in oil shale: 1. Experiments

This study examines the propagation characteristics of compressional (P) and shear (S) acoustic waves through cored and broken Green River oil shale specimens. Both compressional and shear wave velocities (V_p and V_s) are sensitive to shale organic content, showing a monotonic decrease with increasing organic content in the range 30–200 L/t. Trends in the dependence of V_p and V_s on temperature are explained by thermal alterations in the shale matrix which include release of free and bound water molecules, pyrolysis of organic matter and re-cementation of the shale matrix by the products of pyrolysis. The temperature dependence of V_p and V_s is less pronounced when the acoustic energy propagates in a plane parallel to the shale bedding planes. Channelling of acoustic energy via mineral-rich layers has been invoked to explain the anisotropy. The degree of anisotropy is also dependent on shale organic content; the differences becoming less pronounced at high levels of organic content. Data on V_p and V_s for burnt and retorted shales show minimal temperature dependence, although these values are sensitive to the initial organic content of the material. Finally, measurements on broken pieces of shale reveal the expected increase in V_p and V_s with increasing compaction pressure. The decrease in V_pand V_s with decreasing particle size down to 0.6?0.3 mm is rather anomalous and can be explained only by the presence of a large number of narrow voids in the material.     

Physical behaviour of oil shale at various temperatures and compressive loads: 1. Free thermal expansion

The effects of grade and specimen orientation on the free thermal expansion of oil shale were investigated. The expansion was found to increase with the grade of the specimen and to be dependent on orientation. The change in heating rate from 1.0 K min⁻¹ to 3.5 K min⁻¹ had little effect on the expansion of oil shale. It was found that many of the oil shale specimens would settle under their own weight once kerogen left the oil shale. The thermal expansion coefficients in the temperature range 373–473 K were determined to be little affected by increases in grade. A polynomial correlation of expansion versus grade and temperature in the temperature range 298–698 K is presented. The behaviour at temperature up to 1000–4000 K was also investigated.     

Thermogravimetry and decomposition kinetics of British Kimmeridge Clay oil shale

The characteristics of volatile matter evolution and the kinetics of thermal decomposition of British Kimmeridge Clay oil shale have been examined by thermogravimetry. TG has provided an alternative to the Fischer assay for shale grade estimation. The following relation has been derived relating TG % volatiles yield to the shale gravimetric oil yield: oil yield (g kg^?1) = (TG volatiles, % × 5.82) ? 28.1 ± 14.5 g kg^?1. A relationship has also been established for volumetric oil yield estimation: oil yield (cm³ kg^?1) = (TG volatiles, % × 4.97) – 5.43. TG is considered to give a satisfactory estimation of shale oil yield except in certain circumstances. It is found to be less reliable for low yield shales producing <≈40 cm³ kg^?1 of oil (≈10 gal ton^?1) where oil content of the TG volatiles is low: volumetric yield estimation accuracy is affected by variations in shale oil specific gravity. First order rate constants, k = 4.82 × 10^?5s^?1 (346.3 cm³ kg^?1shale) and k = 6.78 × 10^?5s^?1 (44.6cm³ kg^?1shale) have been obtained for the devolatilization of two Kimmeridge oil shales at 280 °C using isothermal TG. Using published pre-exponential frequency factors, an activation energy of ≈57.9 kJ mol^?1 is calculated for the decomposition. Preliminary kinetic studies using temperature programmed TG suggest at least a two stage process in the thermal decomposition, with two maxima in the volatiles evolution rate at ≈450 and 325 °C being obtained for some samples. Use of published pre-exponential frequency factors gives activation energies of ≈212 and 43 kJ mol^?1 for these two stages in the decomposition.     

油页岩制油技术中的红外测温研究

针对油页岩制油气反应炉炉内温度场的分布、变化及反应炉布料图像的实时监测问题,提出一种基于红外测温和红外图像处理的反应炉温度场检测方法,探索反应炉炉内温度场与炉外温度场之间的变化关系和变化机理,揭示反应炉内的温度变化规律,实现对油页岩反应炉不同位置温度场变化的实时监控。通过反应炉不同位置、时段温度场的分析和再现,实现对油页岩及相关物料的最佳优化利用,达到对现有工艺条件、工艺过程进行有效监控和改进,实现油页岩反应炉温度检测的自动化,温度分析处理的及时化、可视化。     

煤与油页岩热预处理特性及对热解的影响

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。     

用热分析方法研究药物降解过程及动力学

用热重法（TG），微分热重法（DTG）。和差热分析法（DTA）研究药物甲磺酸多沙唑嗪（C24H29N5O8S）在空气流中的热氧降解过程和热氧降解动力学，发现该药物的热氧降解过程由四个紧连步骤组成。用Coats-Redrern方程进行动力学处理，确定该药物热氧降解的表观反应级数分别为1.1 1.5 1.5 1.2和反应活性能为353.7KJ/mol 239.5KJ/mol 229.9KJ/mol 167.2KJ/mol。     

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.     

Detailed kinetic analysis of oil shale pyrolysis TGA data

There are significant resources of oil shale in the western United States, which if exploited in an environmentally responsible manner would provide secure access to transportation fuels. Understanding the kinetics of kerogen decomposition to oil is critical to designing a viable process. A dataset of thermogravimetric analysis (TGA) of the Green River oil shale is provided and two distinct data analysis approaches—advanced isoconversional method and parameter fitting are used to analyze the data. Activation energy distributions with conversion calculated using the isoconversional method (along with uncertainties) ranged between 93 and 245 kJ/mol. Root mean square errors between the model and experimental data were the lowest for the isoconversional method, but the distributed reactivity models also produced reasonable results. When using parameter fitting approaches, a number of models produce similar results making model choice difficult. Advanced isoconversional method is better in this regard, but maybe applicable to a limited number of reaction pathways. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

油页岩半焦燃烧动力学研究

燃烧动力学是研究油页岩半焦颗粒燃烧特性的基础。利用热重分析仪对油页岩半焦进行了恒温燃烧实验研究,在排除外扩散影响的基础上,分析了燃烧温度、氧气浓度对油页岩半焦燃烧过程的影响。在实验范围内,氧气浓度和燃烧温度均能对油页岩半焦燃烧速率产生重要影响,更高的氧气浓度和燃烧温度可以加快油页岩半焦燃烧速率。结合实验结果,建立了考虑氧气浓度影响的油页岩半焦燃烧动力学模型,发现油页岩半焦燃烧速率与氧气浓度的0.97次方呈线性关系。模型计算结果与实验结果符合较好,为进一步研究油页岩半焦大颗粒燃烧特性提供了燃烧动力学基础。     

油页岩过热蒸汽的干燥动力学

以油页岩颗粒作为干燥物料,以过热蒸汽和热空气分别作为干燥介质,进行了油页岩干燥实验的研究。当颗粒粒径减小时,油页岩干燥速率越大;过热蒸汽和热空气温度增大时,干燥速率也越大。对比相同条件下过热蒸汽和热空气干燥油页岩的平均干燥速率,发现当干燥介质温度超过逆转点温度时,过热蒸汽条件下的平均干燥速率大于热空气下的数值。实验得出粒径分别为9,7,5 mm的油页岩颗粒逆转点温度值分别是154,179,177℃;逆转点温度值是个变量,随颗粒粒径大小变化而变化。颗粒粒径越大时逆转点温度值越小,粒径较小时逆转点变化不大。采用薄层干燥模型对油页岩的干燥数据进行动力学模拟,可得修正Page模型(Ⅱ)干基水分比w模拟值与实验值的最大绝对偏差是12%,综合比较发现修正Page模型(Ⅱ)能较好地描述油页岩在过热蒸汽条件下的干燥过程。     

Thermal stability of polyurethanes based on vegetable oils

A series of polyurethanes from polyols derived from soybean, corn, safflower, sunflower, peanut, olive, canola, and castor oil were prepared, and their thermal stability in air and nitrogen assessed by thermogravimetric analysis, FTIR, and GC/MS. Oil‐based polyurethanes generally had better initial thermal stability (below 10% weight loss) in air than the polypropylene oxide‐based polyurethane, while the latter was more stable in nitrogen at the initial stage of degradation. If weight loss at a higher conversion is taken as the criterion of stability, then oil polyurethanes have better thermal stability both in air and in nitrogen. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1723–1734, 2000     

Acoustic wave propagation in oil shale: 2. Modelling

Experimental data on acoustic wave propagation through oil shale, summarized in a previous paper¹, were used to develop a semi-empirical model. This model predicts the variation of pressure, effective compressional wave velocity, effective density and acoustic impedance with depth for a modified in-situ oil shale retort. Results from computer simulation of a variety of retort conditions establish the possibility of employing seismic propagation and reflection techniques for mapping of pyrolysis fronts in in-situ oil shale process beds. Such techniques are potentially free from uncertainties associated with proximate sensing of temperature profiles in these beds.     

药物盐酸曲普利啶的热降解过程及动力学研究

研究药物盐酸曲普利啶在氮气流中的热降解过程及热降解动力学 ,发现药物盐酸曲普利啶热降解过程由五个紧连步骤组成。用Coats-Redfern方法进行动力学处理 ,确定药物盐酸曲普利啶热降解的表观反应级数为 1.1、1.1、1.5、1.1、1.5和反应活化能为 85 .7kJ/mol、16 6 .8kJ/mol、2 2 2 .8kJ/mol、2 37.8kJ/mol、2 93.4kJ/mol     

汪清油页岩燃烧反应动力学研究

采用Pyris-1TGA热重分析仪测定汪清油页岩不同升温速率(20,50,80,100℃/min)下的一组燃烧TG曲线,根据Popescu提出的一种新的多重扫描法,将不同机理函数式进行线性回归。结果表明,该油页岩燃烧反应符合三维扩散机理,从而确定了该油页岩机理函数的积分式与微分式,获得了活化能与频率因子的值。取转化率为0.1,0.2,…,0.9,将冉全印-叶素温度积分近似式与所求机理函数结合,利用迭代法求出转化率-温度的理论值。结果发现,理论TG曲线与实验曲线吻合较好,表明了所求得的油页岩燃烧机理函数的合理性。     

Polymethacrylate Networks: Thermodynamics and Kinetics of Thermal Degradation

Abstract

Several types of oligoesteracrylates are synthesized and the crosslinked polymers obtained from these oligomers subjected to thermal decomposition. A detailed study of thermodynamics and kinetics of degradation of these network polymers is presented.     

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。     

铝试剂热氧降解动力学研究

本文在用热分析方法研究了铝试剂的热氧降解历程后＾［１］,用Ｃｏａｔｓ－Ｒｅｄｆｒｎ方程进行动力学处理,确定铝试剂热氧降解的表面反应级数为１．８、１．６、１．５、０．８２和活化能力６０．２ｋＪ／ｍｏｌ、１１３．３ｋＪ／ｍｏｌ、６５．２ｋＪ／ｍｏｌ、２７４．２ｋＪ／ｍｏｌ。     

Thermal degradation of LC epoxy thermosets

A novel liquid crystalline (LC) epoxy monomer was cured with different types of hardeners. The thermal‐degradation properties of cured thermosets were evaluated by thermogravimetric (TG) analysis. Several widely used kinetic models were reviewed and used to fit the TG data. The experimental results showed that the methods from one constant heating rate are insensitive to the magnitude of reaction order n. The Kissinger and Osawa methods from multiple processes would give more confident kinetic parameters in these observed systems. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1514–1521, 2000