Heating rate effect on the DSC kinetics of oil shales

This research was aimed to investigate the combustion and kinetics of oil shale samples (Mengen and Himmetoğlu) by differential scanning calorimetry (DSC). Experiments were performed in air atmosphere up to 600°C at five different heating rates. The DSC curves clearly demonstrate distinct reaction regions in the oil shale samples studied. Reaction intervals, peak and burn-out temperatures of the oil shale samples are also determined. Arrhenius kinetic method was used to analyze the DSC data and it was observed that the activation energies of the samples are varied in the range of 22.4–127.3 kJ mol⁻¹ depending on the oil shale type and heating rate.     

油页岩固定床热解反应器中内构件强化作用

在内构件(传热板和中心集气管)外热式固定床反应器中研究了油页岩热解产物生成特性,并与无内构件的相同常规固定床反应器内的油页岩热解行为对比,考察了两反应器中油页岩升温特性、热解产物分布、页岩油品质以及气体产物组成的变化规律.结果表明,内置传热板和中心集气管显著强化了反应器内的传热,相对于无内构件常规固定床反应器,料层升温速率提高了约2倍.对于依兰油页岩,其热解页岩油产率明显提高,最高达11.1 wt%(干燥基),明显高于无构件常规固定床反应器获得的页岩油产率.随着外加热炉温度的升高,内构件固定床反应器的页岩油产率逐渐增加,而无内构件常规固定床反应器的页岩油产率则明显降低.当外加热炉温度为1000℃时,前者页岩油产率是后者的2.3倍,并且内构件固定床反应器的热解水产率较低.两反应器中热解气产物组成相近,其H2与CH4之和占气体总量的70 vol%左右,热值为4406~5400 kcal/Nm3.     

CO2-水-页岩相互作用的研究现状及展望

简要综述了CO2、水和页岩间矿物的相互作用,分析了CO2注入到地下进入页岩层后,地下含水层pH值的变化,并根据页岩层的矿物学组成分为黏土矿物和脆性矿物,较为详细地描述了CO2与黏土矿物和脆性矿物之间发生的地球化学反应,概述了此反应对页岩层孔隙度和渗透率的影响。同时,也讨论了CO2增强页岩气开采的现实问题及发展趋势,为今后的研究提供了参考。     

X射线荧光光谱法直接测定油页岩中微量元素

本文提出用微晶纤维素与GSD等国家一级系列标样按不同比例混合制备标准样品。油页岩样品不经前处理,直接粉末法压片,经验系数法校正元素间效应,直接测定油页岩中V、Co、Ni、Cr、Cu、Zn、Sr、Ba和Rb等元素的X射线荧光光谱法。样品分析结果与ICP-AES法分析结果基本一致,本法具有简单、准确、实用的特点。     

抚顺页岩油的高分辨核磁共振研究

用高分辨液体核磁共振氢谱、碳谱、二维碳氢相关谱和DEPT谱(无畸变极化转移增强法)对我国抚顺页岩油的不同组分进行了详细研究,得出了一些结构信息和变化规律。     

The role of MgO in the binding of SO<Subscript>2 </Subscript>by lime-containing materials

Summary The results of investigation of MgO participation in the binding of SO₂ with lime-containing materials as sorbents are presented. Experiments of SO₂ binding into solid phase using model samples of reactive grade MgO and CaO varying the mole ratio of MgO/CaO from 9:1 to 1:9 were carried out. Besides, dolomite and limestone samples with different MgO/CaO mole ratio (from 1.24 to 0.13) and samples of ashes formed at combustion of Estonian oil shale (containing 35-40% of carbonates) and its semicoke were studied Initial samples, intermediate and final products were subjected to chemical, IR-spectroscopy, X-ray and BET specific surface area analyses. The results of the present study confirmed the active participation of MgO in the binding of SO₂ into the solid phase. In addition to CaSO₄ the formation of Ca,Mg-double sulphate CaMg₃(SO₄)₄ and -MgSO₄ was observed. The presence of CaMg₃(SO₄)₄ was fixed in a large temperature range 400-900°C and that of -MgSO₄ in between 500-700°C. The optimum temperature range for formation and durability of CaMg₃(SO₄)₄ was 700-800°C.     

基于低场核磁共振的抚顺油页岩孔隙连通性演化研究

油页岩原位注热开采过程中，储层内部孔隙结构的连通性直接影响载热介质的流动行为和传热效率，同时对油气产物的扩散和流动行为起控制作用.本文利用低场核磁共振（LF NMR）技术，考察了不同热解终温（23~650℃）处理时，饱和水及束缚水状态下抚顺油页岩的T₂谱，分析了可动流体T₂截止值、束缚流体孔隙度、饱和流体孔隙度、渗透率等NMR孔隙参数，定量研究了随热解终温升高，抚顺油页岩孔隙结构的连通性演化规律.研究结果表明热解终温对抚顺油页岩孔隙连通性及渗透率的变化起控制作用，且可动流体孔隙度对总孔隙度的增加起主要促进作用，这说明热解终温升高加大了渗透率及油气产物的输运能力.本文为深入认识油页岩原位热解过程中孔隙结构的演化提供了依据.     

抚顺油页岩干酪根热解反应性分子动力学-量子力学模拟

采用MS（Materials Studio 2017）软件中Forcite模块,对自主构建的抚顺油页岩干酪根二维结构模型进行能量最小化分子动力学模拟,通过能量最优化过程得到干酪根初始优化结构。在此基础上进行分子动力学退火模拟,获得全局能量最优化构型,即油页岩干酪根分子三维结构模型。基于密度泛函理论的量子力学模拟方法,计算分析干酪根三维结构模型的动力学、键能、键级、电荷密度等参数,分析化学活性位点,探讨了干酪根热解微观化学演化机理,进而预测了反应性。     

Applicability of equilibrium and kinetic models on the herbicide 4-chloro-2-methyl phenoxyacetic acid adsorption on bituminous shale

Adsorption characteristics of herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) have been evaluated using bituminous shale (BS) as a model adsorbent-containing solid organic matter in a mineral matrix. The adsorption of MCPA on BS has been studied with varying concentration, temperature, pH and contact time, using batch technique. Adsorption ability of BS increases with increasing temperature and decreasing pH in the studied concentration range of (0.6–4.0) × 10⁻⁴ M. Theoretical curves calculated from Freundlich, Dubinin-Radushkevich (D-R), Langmuir and Temkin isotherm equations show a two-step isotherm shape. The results could be explained by assuming the presence of two-type sites with different affinity on adsorbent surface. Adsorption process is endothermic and entropy controlled at the first stage, and exothermic and enthalpy controlled at the second stage. The mechanism proposed based on surface ionization and complexation model is consistent with the pH dependent experimental results. Kinetic data fit well to both Paterson’s and Nernst Planck model based on homogeneous solid phase diffusion (HSPD). The values of particle diffusion coefficients (D _p ) predicted from both models are comparable each other and independent of temperature and concentration.      

基于扩展有限元的页岩水平井多裂缝模拟研究

页岩储层水平井分段多簇压裂簇间距优选是压裂技术的关键,建立了水力压裂流固耦合数学模型,基于扩展有限单元法模拟多条裂缝的扩展过程,研究多条裂缝同时扩展的转向规律,以及应力干扰、水平主应力差、裂缝间距等因素与裂缝转向角度的关系.结果表明:应力干扰作用对裂缝宽度具有限制作用,单条裂缝张开宽度比两条裂缝的大;裂缝转角随应力差的减小而增大,随压裂时间的增加而增大.簇间距越小,应力干扰越强,转角越大,综合主缝均匀扩展、支撑剂填充以及复杂裂缝网络形成等条件,确定最优簇间距为30~40 m.多条裂缝同时扩展时,中间裂缝会受到两边裂缝的限制作用,簇间距越小,限制作用越强,裂缝发育时间越长,扩展速度越慢.