桦甸油页岩有机岩相特征及其富集特性

为了研究油页岩中有机组分结合特性对有机质分离富集的影响,利用薄片透射光、反射单偏光、反射荧光等煤岩学研究手段研究桦甸油页岩中有机组分的种类、含量及赋存状态,并利用两种密度分离手段研究油页岩中有机质的解离特性.结果表明,桦甸油页岩有机质的变质程度较低,有机显微组分以沥青质体为主,占85.8%,镜质组和惰质组含量较低;有机质与矿物结合紧密,形成有机-矿物复合体,密度分离方法对有机质与矿物质分离效果有限;浮沉实验小于1.40g/cm³密度级样品的热解失重量及失重速率均低于较高密度级产物,这与颗粒状镜质组、惰质组与矿物质结合程度相对较差,在较低密度级产物中富集有关.     

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.     

油页岩裂解色谱质谱分析

油页岩是一种含油有机质的沉积岩,从油页岩提炼可得到页岩油,是石油的部分替代能源.随着原油储量的日趋减少,油页岩的研究及利用将会受到更多的重视.油页岩热加工得到的页岩油类似天然石油,但与石油相比,其不饱和烃和杂原子化合物含量较高,定性极差,但这些非烃化合物是宝贵的化工原料.对页岩油的烃类、非烃类杂原子化合物进行深入的研究,对页岩油的进一步加工以及非烃化合物的综合利用,都是非常必要的.     

桦甸油页岩热解特性的研究

在热分析仪上进行了桦甸油页岩的热解特性研究,升温速率分别为10℃/min、20℃/min、30℃/min和40℃/min,终温为900℃。实验表明油页岩的热解是分两步进行的。在低温段主要是油页岩中可挥发性的气体溢出引起热解失重;高温段则主要是一些有机质、固定碳的热解过程。低温段的热解是主要的,它基本上热解掉了油页岩重量的15％－27％左右,油页岩挥发分含量很高且具有集中析出的特性,在400℃－530℃区间内可挥发物质迅速热解守比,其在高温段的热解产率很小,只有总重量的10％左右。随着升温速率的增加低温段的高温段热解的区分更加明显,且使油页岩的热解产率提高。文中给出了不同升温速率下的桦甸油页岩热解特性数据和化学反应动力学参数。     

贵阳污灌区菜地土壤团聚体中有机碳和重金属的含量特征及相关性分析

以贵阳某污灌区菜地土壤为研究对象,分别采用微波消解-电感耦合等离子体质谱(ICP-MS)法和水合热重铬酸钾氧化分光光度法分析不同粒径土壤团聚体中重金属和有机碳的含量特征,并对有机碳和重金属的相关性进行分析。结果表明,以2mm粒径团聚体的含量为最高,约占75%。Cu、Zn、Cd和Pb在0.25～0.5mm粒径团聚体中含量最高,Cr在5～8mm粒径团聚体中含量最高,As在不同粒径团聚体中的含量变化不大,重金属含量随土层深度增大而减小。土壤重金属富集因子表现为CuPbCdZnCrAs,Cu、Zn、Cd和Pb在0.25～0.5mm粒径团聚体中分布因子最高,而在5～8mm粒径团聚体中重金属的质量负载因子最大。土壤有机碳含量随团聚体粒径的增大表现为先增大后减小,不同粒径团聚体中Cu、Cd、Pb和As含量与有机碳含量均呈显著正相关(p0.05)。污灌区菜地土壤Cr、As在5～8mm粒径团聚体中富集现象显著,Cu、Zn、Cd、Pb在0.25～0.5mm粒径团聚体中均表现出显著的富集特征。6种重金属在5～8mm粒径团聚体中的质量负载因子均为最高,表明6种重金属在5～8mm粒径团聚体中的贡献最大。     

油页岩电化学氧化的研究

在2.5V、70℃下,电解氧化黄县油页岩碱性水浆液,制得含氧有机产品。产品为富含正构饱和一元酸及二元酸的混合物,其收率约13%,油页岩有机碳有效利用率为28.87%。生产每公斤产品需电能5kWh,同时,阴极可得高纯氢气0.83Nm~3。文中对电压、温度、浆液浓度、电解质浓度及种类和油页岩粒径等六个操作因素进行了考察。实验表明,黄县油页岩较茂名、抚顺油页岩更适宜于作电解氧化原料。经初步分析认为,本法为颇有希望的工艺过程。     

矿物质对桦甸油页岩热解产物影响特性

对桦甸油页岩进行逐级酸洗并对原样及各级酸洗样品的热解产物进行了碳平衡计算以及气相色谱和傅里叶红外光谱实验,得到了矿物质对油页岩热解不凝性气体、半焦以及页岩油的影响特性。结果表明,碳酸盐可以促进有机碳和氢向页岩油中转化,而硅酸盐对有机碳和氢向页岩油中转化具有抑制作用,碳酸盐和硅酸盐均可以使得页岩油中氢碳原子比降低。碳酸盐促进了油页岩热解产油并抑制了干酪根向不凝气分解转化,而硅酸盐抑制了油页岩热解产油但对干酪根向不凝气的分解转化具有促进作用。碳酸盐和硅酸盐均可以促进热解不凝气中CO_2和H_2的生成,而对CO的生成具有抑制作用,碳酸盐可以抑制热解不凝气中碳氢化合物的生成,而硅酸盐对其生成具有促进作用。碳酸盐和硅酸盐均可以使得页岩油中脂肪链长度变短及异构化程度变大,并能够提高干酪根热解产物的芳构化程度。     

酸洗对桦甸油页岩矿物质以及有机结构的影响

基于FT-IR和XRD技术研究了逐级酸洗对桦甸油页岩矿物质以及有机结构的影响。结果表明,采用HCl/HF酸洗方法可以有效去除黄铁矿以外的矿物质,但盐酸处理破坏油页岩中高岭石的立体框架结构。油页岩中有机质以脂肪族结构为主,存在形式为无序非晶态聚合体且变质程度较低。酸洗处理对油页岩有机大分子结构影响很小,但对有机结构产生了一定的影响。盐酸处理主要影响含氧官能团和苯环结构,会生成大量羧酸并破坏苯环的多环结构,但对脂肪族化合物的影响较小。氢氟酸处理主要对脂肪族化合物产生影响,破坏脂肪链的桥键结构,脂肪链断裂变短,进而使样品中脂肪族化合物含量降低。盐酸和氢氟酸处理均会破坏油页岩的羟基官能团,尤其对自缔合羟基氢键影响最大。     

中国桦甸油页岩超临界萃取研究

对桦甸北台子油页岩样品,用甲苯、甲苯四氢萘混合溶剂进行丁非等温(升温速率为8 K·min~(-1))的超临界萃取实验(萃取压力为10MPa,终温为550℃)。为选择高转化率和油类产物高产率的萃取条件,进行了样品粒度(1.2—2.5mm)、溶剂流率(2dm~3·h~(-1))以及甲苯中供氢组分含量(分别为10%、20%、30%)的系统实验。甲苯溶剂超临界萃取油类产物产率是一般干馏方法的2倍。在溶剂甲苯中加入少量供氢组分后,油母转化完全,油类产物产率高。超临界萃取可用一级反应描述,文中用积分法求解了动力学参数。     

油页岩中微量元素赋存形态的研究

通过浮沉实验及脱灰实验对抚顺、龙口、茂名3种油页岩样中部分微量元素进行了赋存形态的研究。结果表明,浮沉实验所得微量元素的赋存状态结果与脱灰实验基本一致,抚顺、龙口、茂名3种油页岩中大部分微量元素以无机态赋存,但也有所区别,抚顺、龙口、茂名油页岩中的元素V、Mn、Zn、Sr、Mo、Ta以及抚顺油页岩中的Cr、Te,龙口油页岩中的Cd、Sn,茂名油页岩中的Cd、Sn、Pb,主要赋存于无机矿物中;茂名油页岩中的Cr、Te,抚顺油页岩中的Cd,龙口油页岩中的Pb有相对较多的比例富集于有机质部分;龙口、茂名油页岩中的元素Co,抚顺油页岩中的Co、Sn、Pb,更多地富集于黏土矿中,但也有少部分富集于有机质中。     

桦甸油页岩中稀土元素赋存状态研究

以吉林省桦甸油页岩为研究对象,采用电感耦合等离子质谱( ICP-MS)和化学逐级提取方法相结合,对油页岩中稀土元素的分布特征以及油页岩中稀土元素的赋存状态进行研究.结果表明,相对于中国煤,桦甸油页岩表现为轻稀土元素富集程度高于重稀土元素.油页岩中稀土元素与陆源碎屑岩关系密切,且陆源物质的供应相对比较稳定.轻重稀土间分馏...     

氯化亚铬脱除黄铁矿对桦甸油页岩有机质结构的影响

采用元素分析、~(13)C NMR、XPS和TG-MS技术考察了氯化亚铬(CrCl_2)脱除黄铁矿对桦甸油页岩有机质结构的影响。结果表明,CrCl_2可有效脱除有机质中的黄铁矿,脱除率为96.19%。CrCl_2对有机质的碳骨架结构影响较小,脱除黄铁矿前后有机质中脂碳、芳碳和羧基/羰基碳的相对含量以及有机质的热解特征温度基本保持不变,但CrCl_2可破坏有机质中的C-O键,使C-O/C-OH和O=C-O的含量减少,造成0.98%的有机碳损失和12.54%的有机质损失。CrCl_2处理后,有机质的C含量显著增加,H含量稍有增加,O含量显著降低,使得H/C略微降低,O/C明显降低。另外,CrCl_2处理后,单位质量有机质中脂碳的含量增加了5.28%,使其热解过程中产生了更多的挥发分,残留的氧化铬对有机质的热分解可能也具有促进作用。     

Mineral matter effect on the decomposition of Ca-rich oil shale

Four oil shale samples with different amounts of organic and mineral matter were analysed through non-isothermal thermogravimetric analysis using a heating rate of 50 °C min^?1 in nitrogen. The goal of the paper is to study the supposed catalytic effect of the indigenous and removed minerals. The samples contained 30, 49, 70 and 90% of organic matter, respectively. X-ray diffraction analysis was used to identify the minerals in the samples. Thermal analysis experiments were carried out up to temperatures of 850 °C in pyrolysis conditions. The mass loss data were used to study the variations in the conversion profiles of the organic matter depending on the content of the mineral matter. The obtained data and the comparison of the sample composition show that the effect of the mineral matter amount on the course of the pyrolysis processes is insignificant.     

Thermal decomposition of kerogens: Mechanism and analytical application

Specific features of the chemical structures of organic matter (Lerogen) in oil shales caused by the nature of the starting materials for the formation of shales and the routes of their subsequent alteration are reflected in the composition of shale semicoking (retorting) oil. In order to establish the analytical possibilities of the thermal decomposition method in elucidating the kerogen structure and to obtain more data on the mechanism of the pyrolysis of kerogens, the effect of a series of factors (rate of heating, pressure, presence of carrier gases, water and mineral matter of shale, treatment with reagents) on the yield and composition of the pyrolysis products of oil shales was investigated.The yield of shale oil and the phenol content in the latter increase when semicoking is performed in a stream of hydrogen at atmospheric pressure. In shale pyrolysis in the presence of water under pressure, the yield of oil and, in particular, water-soluble organic compounds also increase, as well as the content of neutral heteroatomic compounds in oil. With increasing content of mineral substances in shale, the yield of the semicoking oil (kerogen basis) and the content of polar compounds in it diminish owing to an increasing influence of oil adsorption on the mineral matter and its additional decomposition as a result.In the initial stage of thermal decomposition, both longer aliphatic substituents and side-chains of iso-structures split off and alkenes with a double bond in the middle of the chain (probably the products of elimination and dehydration of the aliphatic substituents with a hydroxyl group) are formed. The formation of n-1-alkenes, particularly those of even carbon number, which originate from the side-chains of odd carbon number by the cleavage of carbon–carbon bonds in the β-position to the cyclic nucleus of kerogen, becomes more pronounced in the final stage of pyrolysis when, owing to significant aromatization of the cyclic part of kerogen, the selectivity of the β-cleavage increases.     

Thermooxidative decomposition of oil shales

The thermooxidative decomposition of four oil shale samples from Estonia, Jordan, Israel and Morocco and one sample of Estonian oil shale derivative, semicoke, was studied with the aim to determine the characteristics of the process and the differences of it related to the origin of oil shale. The experiments with a Setaram Setsys 1750 thermoanalyzer coupled to a Nicolet 380 FTIR Spectrometer were carried out under non-isothermal conditions up to 1000 °C at the heating rates of 1, 2, 5, 10 and 20 °C min⁻¹ in an oxidizing atmosphere. A model-free kinetic analysis approach based on the differential isoconversional method of Friedman was used to calculate the kinetic parameters. The results of TG–DTA–FTIR analyses and the variation of activation energy E along the reaction progress α indicated the complex character of thermooxidative decomposition of oil shale and semicoke, being at that the most complicated for Estonian and Jordanian oil shale characterized by higher content of organic matter as compared to the other samples studied.     

Some data on transuranium element distribution in particle size fractions of Chernobyl soils

Some Chernobyl soils were collected in the north-west direction. The samples have been separated into particle size fractions 1–2; 0.5–1; 0.25–0.5; 0.16–0.25; 0.05–0.16; 0.01–0.05; 0.005–0.01; 0.002–0.005; 0.00005–0.002; and less than 0.00005 mm. The fractions were analyzed on^238,239,240Pu,²⁴¹Am,^242,244Cm content. In contrast to the global plutonium fallout, the peak of plutonium activity falls in the particle size range of 0.01–0.05 or 0.005–0.01 mm in Chernobyl soils. Transplutonium elements are more mobile in the soil. As the distance from Chernobyl increases, the trend of their distribution becomes much similar to the global fallout. It is found that the most mobile part of soil with particles of sizes less than 0.05 mm contains 55–70% of plutonium activity and 30–65% of americium and curium activity.     

Effects of retorting factors on combustion properties of shale char

For obtaining high shale oil yield as well as treating shale char efficiently and in an environmentally friendly way in a new comprehensive utilization system of oil shale, a series of fundamental experiments have been conducted for exploring the effects of retorting factors on shale oil yield and shale char characteristics. Based on these previous studies, in this article, combustion experiments of shale chars obtained under various retorting conditions were performed with a Q5000IR thermogravimetric analyzer and a Leitz II-A heatable stage microscope and the effects of retorting factors were discussed on the combustion characteristics of shale char. Among four studied retorting parameters, retorting temperature and residence time exert very significant influence on the combustion characteristics of shale char. Either elevating the retorting temperature from 430 to 520 °C or lengthening the residence time at a low retorting temperature will largely decrease residual organic matters within shale char, resulting in decreasing mass loss in the low-temperature stage of combustion process of shale char, an elevation of ignition temperature and a shift of ignition mechanism from homogeneous to heterogeneous. One set of retorting condition was also recommended as a reference for designing the comprehensive utilization system of oil shale studied in this work: retort temperature of 460–490 °C, residence time of 20–40 min, particle size of <3 mm, and low heating rate of <10 °C/min.     

Effects of acid treatments on Moroccan Tarfaya oil shale and pyrolysis of oil shale and their kerogen

In this study, the kerogen of oil shale from Moroccan Tarfaya deposits was isolated and the changes in the initial organic matter during the removal of the mineral matrix were examined. Chloroform extraction of the oil shale increases the intensity of the peaks in the X-ray diffractograms. Infrared spectra and X-ray diffractograms reveal the presence of mineral, calcite, quartz, kaolinite, and pyrite in the mineral matrix of the oil shale. Hydrochloric and hydrofluoric acids dissolution do not alter the organic matter. The nonisothermal weight loss measurements indicate that thermal decomposition of the isolated kerogen can be described by firstorder reaction. A single kinetic expression is valid over the temperature range of kerogen pyrolysis between 433K and 873K. Furthermore, the results indicate that the removal of mineral matter causes a decrease in the activation energies of the pyrolysis reactions of oil shale.