岩石圈深部温度压力条件下褐煤与水的热模拟研究

在压力高达1—3GPa、温度为400—700℃的条件下，在密闭体系中进行了褐煤加水的模拟实验。分析了实验产物中液态烃的变化规律，并讨论了压力、温度及恒温时间对有机质演化的影响。实验结果表明，热模拟液态产物氯仿沥青“A”的有机碳含量为0．91％-2．55％，2GPa条件下其高峰值后移至700℃，说明高压抑制了液态烃的生成，同时压力升高有利于有机质降解产物的环化、聚合和芳构化。在400—600℃条件下，温度升高或恒温时间增长，OEP和Pr／Ph值均减小；而在700℃的恒温条件下，压力增高，OEP和Pr／Ph值均增大。说明有机质的成熟度与温度和加热时间成正相关，而压力增加抑制了有机质的成熟演化。在高压条件下，芳烃演化的主要趋势是甲基化作用，压力升高有利于甲基化反应和甲基重排。     

塔里木盆地煤系有机质热模拟实验中液态烃特征研究

通过对塔里木盆地满加尔凹陷侏罗系演化程度较低的(RO=0.40%)煤岩和煤岩加水进行了从250～550℃(50℃为一温阶,恒温72h)的热模拟实验,用氯仿抽提获得了赋存在固体残余物中的可溶液态有机物,即饱和烃、芳烃和非烃。实验结果表明:煤岩在各演化阶段的液态物产率均低于煤岩原样;饱和烃随演化程度升高逐步增加,而芳烃减少,反映出非烃沥青质,甚至不溶有机质向相对稳定的饱和烃转化以及芳烃随演化程度升高的高聚合作用;沥青质随演化程度升高亦有增大的趋势,而非烃比例变化不大,反映出高温下非烃向饱和烃和沥青质转化的两极分化作用;烷/芳值随着演化程度的升高而增加,反映出高演化期芳烃的聚合作用。在煤岩加水热模拟实验中,液态烃产率随温度升高而逐步增加且芳烃是主体产物。在实验的低温阶段,水的加入使得煤岩样中可溶有机质向气态和不溶有机质转化,从而使得可溶有机质组分呈降低趋势,而在高温阶段时煤岩加水后可溶有机质有所增加。在煤岩加水热模拟实验中,烷/芳值均小于1,再一次说明了水对芳烃缩聚的抑制作用及对烷烃形成的促进作用。     

塔里木盆地煤岩显微组分热模拟实验中液态烃特征研究

对塔里木盆地满加尔凹陷侏罗系演化程度较低(Ro=0.40%)的煤岩显微组分进行了从250℃到550℃(50℃为一温阶,恒温72h)的热模拟实验。用氯仿抽提获得了赋存在固体残余物中的可溶液态有机物,即饱和烃、芳烃和非烃。实验结果表明:1组成煤岩的显微组分产液态物时具有镜质组较早(主要发生在350℃时)、壳质组略晚(发生在400℃)且显微组分产率大小顺序为壳质组(1)>壳质组(2)>镜质组的特征;2各显微组分的液态烃产率均表现为壳质组>镜质组的特征,镜质组和壳质组均存在一个明显的产液态烃高峰,壳质组是煤岩中液态物质的主力贡献者,其产液态物率是镜质组的5～15倍;3在显微组分中,低演化阶段具低总烃、高非烃+沥青质的特征,随着煤化作用的加强,总烃有大于非烃+沥青质趋势。同时,在液态物产率高峰,饱和烃一般都占优势,不同显微组分液态物质的产程有所不同,因此,尽管在煤岩中壳质组是液态烃的主要来源,但由于其在煤岩中所占比较较小,难以肯定其为主力源,而尽管镜质组产液态物率低于壳质组,但因其是煤岩的主体部分,且具有广泛的分布,因此,应该是重视的对象;4不同显微组分的烷/芳值大于1,且壳质组的烷/芳值具有两阶段性。     

煤岩热模拟产物演化特征与煤层气形成关系

为探讨煤岩中煤层气的热演化特征,选取柴达木盆地侏罗系未成熟煤岩样品进行加水热模拟实验,分析了煤岩气、液态产物及固体有机质的热演化特征。实验结果表明,气态烃可以形成于煤岩热演化的各个阶段,液态烃主要在生油窗范围内生成且生成量相对低。生油高峰时烃类气体中甲烷产率较低,之后迅速增加;重烃气体在大量生油阶段和高成熟阶段早期产率相对较高,之后开始降低。非烃类气体中二氧化碳的体积分数明显高于氮气的体积分数,均主要形成于生油阶段;氢气的体积分数普遍较高,随温度升高先降低后增高,最小值出现于生油高峰之后。煤岩能够生成气态烃和液态烃,总体具有较高的甲烷产率,远高于一般煤层实测的含气量,具备形成煤层气的物质基础。     

半开放体系下流体压力对烃源岩HTHP模拟产物产率及镜质体反射率的影响

为探究半开放体系中流体压力对烃源岩热演化和成烃过程的影响,利用高温高压（HTHP）模拟仪,在一定半开放体系中,对采自钻孔的泥岩样品进行恒压和增压2个系列的生烃模拟实验。恒压实验中沥青、热解油和气态烃产率高峰分别出现在350℃、450℃和520℃,产率依次为1.82mg/g、4.86mg/g和2.67mL/g,对应镜质体反射率（R_O）分别为0.68%、1.72%和3.0%。增压实验中,沥青、热解油和气态烃产率高峰也分别出现在350℃、450℃和520℃,产率依次为0.56mg/g、5.41mg/g和2.61mL/g,对应R_O值分别为0.56%、2.42%和2.74%。表明在半开放体系中,流体压力的升高虽不利于沥青形成,但可能会通过促进热解油的形成,从而使总液态烃产率升高。同时,流体压力的升高可能不利于气态烃的形成,会降低气态烃产率。指示在不同的热演化阶段,流体压力对有机质热演化和成烃过程有不同的影响。此外,增压实验中所得残渣总有机碳（TOC）含量均低于恒压实验,表征生烃潜力的相关指标S₂、I_H、H/C也均低于恒压实验,表明高流体压力虽可提高有机质成烃效率,但在促进有机质成油的同时也降低了残渣的生烃潜力。不同热演化阶段流体压力对有机质成熟度的相关指标T_max值和R_O值也有不同影响,热解油大量生成阶段T_max值、R_O值随流体压力升高明显增加。     

塔里木盆地S74井稠油热模拟实验研究(二)——沥青生烃潜力探讨

根据塔里木盆地S74井稠油热模拟实验中油气产率、模拟产物地球化学特征探讨了降解-氧化沥青的产烃率模式。研究表明,降解-氧化沥青生烃作用主要发生于生油窗内,高成熟演化阶段也有一定的生烃潜力,过成熟演化阶段生烃潜力有限;在产物组成上,350℃(R_o=1.24%)之前以生油为主,产油率约245 kg/t,而之后则以生气为主。据降解-氧化沥青产烃率模式,对塔里木盆地沙雅隆起、卡塔克隆起志留系沥青砂岩生烃量的粗略估算表明,其生烃量巨大,可能是塔里木盆地海西晚期及以后的重要油源。     

鄂尔多斯盆地西缘上古生界泥岩饱和烃Pr/Ph值特征及其地质应用

通过对鄂尔多斯盆地西缘上古生界泥岩有机母质类型、有机母质热演化程度、有机质沉积环境等方面与泥岩饱和烃Pr/Ph值之间关系的分析,首次认识到西缘上古生界泥岩饱和烃姥鲛烷与植烷的比值（Pr/Ph值）小于1.0,并且主要受沉积环境水体咸度的影响,与有机母质类型、有机母质热演化程度的关系不明显。应用泥岩、煤岩饱和烃Pr/Ph值特征对盆地西缘上古生界凝析油的来源进行判识,指出上古生界凝析油主要来源于煤系地层,进而认为煤系地层在上古生界天然气成藏中起着决定性的作用。     

热模拟实验中煤岩及显微组分饱和烃甾烷系列化合物有机地球化学特征

通过对塔里木盆地煤岩与壳质组的热模拟实验产物饱和烃进行色-质分析指出，在全煤和壳质组中检测出了丰富的甾族系列化合物，且以C₂₉甾烷占优势；煤岩中异常高的αββ构型异构化甾烷的检出反映了该煤在成岩早期经受过微生物改造；利用C_29-5αββ/(αα+ββ)与C₂₉ααα20S/(20S+20R)关系可以判识原油是否为未熟或成熟。孕甾烷/甾烷值与温度之间的关系表明孕甾烷可能不是甾烷的热降解产物；热模拟中Σ重排甾烷/Σ甾烷值在400℃开始降低和C₂₉αα20R/C₂₇αα20R值在400℃达到最大反映了甾烷骨架在该温度点以后发生开环裂解效应。     

从烃源岩热模拟实验讨论其生烃特征

采用开放体系下进行的全岩热模拟实验,对塔里木盆地哈2井三叠系的黑色泥岩开展了产气率变化特征的研究.并结合成熟度及其显微组分的变化,探讨了烃源岩的生排烃过程.模拟实验结果表明:加温在400℃以前,Ro值低于0.8%,累积产气率仅1.04 mL/g.所产烃气仅占总产气率的8.2%;加温到600℃时,累积产气率达9.23 mL/g,占总产气率的72.7%;生烃高峰在500～600℃之间.此时阶段产气率为6.23 mL/g,占总产气率的49.1%,大致相当于Ro,值为1.24%～1.78%,此阶段所生烃气约占总产气率的一半;700℃以后镜质组等腐殖组分仍可生成相当数量烃气,但已进入干气阶段,大量生烃阶段基本结束.     

流体压力对半开放体系有机质模拟生烃产率和镜质体反射率的影响

为了解压力对有机质热演化和成烃过程的影响,利用高压生烃模拟仪,在一定半开放体系中,对采自钻孔的泥质烃源岩样品进行了恒压与增压2个系列的生烃模拟实验。恒压系列中,沥青、热解油和气态烃产率高峰分别出现在350℃、520℃和520℃,产率依次为6.17mg/g、12.07mg/g和4.14mL/g,对应镜质体反射率(R_O)分别为0.9%、3.0%和3.0%,排烃次数分别为4次、21次和21次。增压系列中,沥青、热解油和气态烃产率高峰分别出现在350℃、500℃和520℃,产率依次为12.56mg/g、24.87mg/g和2.59mL/g,对应R_O值分别为1.1%、3.1%和3.1%,对应排烃次数分别为5次、43次和44次。表明在半开放体系中,排烃次数受到温度和排烃压力阈值的共同控制,温度升高引起生烃强度增加,在同一排烃压力阈值条件下,体系内压力不断上升,达到排烃压力阈值上限,导致排烃次数增加,而排烃次数增加可能有利于液态烃的形成。流体压力的升高可能会促进沥青和热解油的形成,导致液态烃产率升高。同时,流体压力的升高也可能不利于气态烃的形成,会降低气态烃产率。流体压力对有机质R_O值的影响在不同温度阶段不尽相同,400~500℃区间R_O值随流体压力升高明显增加。     

EFFECTS OF HEATING RATE AND PARTICLE SIZE ON THE PRODUCTS YIELDS FROM RAPID PYROLYSIS OF BEECH-WOOD

ABSTRACT

Effects of pyrolysis temperature (300–1000 ^°C), heating rates (100, 500, 1000, and 10,000 ^°C/s), and particle sizes (53–63,104–120,177–270, and 270–500 urn) on the yields and formation rates of tar, light oils, total gases, and char from pyrolysis of beech-wood under 1 atm helium pressure were studied. Wood particles were pyrolyzed in strips of stainless steel wire mesh in a captive sample apparatus; and yields of products were measured in weight percent of original wood as a function of temperature for different heating rates and particle sizes. The overall weight loss achieved from pyrolysis of this wood was about 90%. The total yields of tar and light oils from pyrolysis of this wood accounted for up to 80% of the original wood above 400 ^°C. Due to the post-pyrolysis reactions of tar and light oils, the tar and light oils yields go through a maximum with pyrolysis temperature for all particle sizes and most heating rates studied here. As particle size increases from 53–63 μm to 270–500 μm the maximum tar yield decreases from 53% to about 38%. The maximum tar yield also decreases with increasing the heating rate from 70% at 100 ^°C/s to 48% at 10,000 ^°C/s heating rate. Theses results indicate that as the intra-panicle post-pyrolysis cracking reactions of tar increases at higher heating rates and with larger particles the tar yield decreases. Tar was also analyzed with GPC for the effects of above pyrolysis parameters on the tar molecular weight. The tar average molecular weight. remains relatively constant (M_w = 300 amu, M_n = 155 amu, and M_z = 483 amu) under helium atmosphere with pyrolysis temperature at 1000 ^°C/s heating rate and with 53/63 u m particle size. The average molecular weight of tar does not significantly varies with heaung rate, but it decreases as the particle size increases.     

DESULPHURIZATION OF A TURKISH LIGNITE BY PYROLYSIS COMPARISION OF SLOW AND FLASH PYROLYSIS

ABSTRACT

To observe the effect of the heating rate on the desulphurization. Bolu- Mengen lignite was desulphurized in the temperature range of 450-750 °C using flash and slow pyrolysis methods. A reduction of 57.6 % and 34.2 % In the total sulphur was obtained for the slow and flash pyrolysis at a pyrolysis temperature of 750 °C. respectively. It was observed that the flash pyrolysis is shifted toward higher temperatures with respect to the slow pyrolysis. The flash pyrolysis having high thermal efficiency has a potential as a desulphurization process.     

An upgraded bio-oil produced from sugarcane bagasse via the use of HZSM-5 zeolite catalyst

The pyrolysis upgrading of bio-oil from sugarcane bagasse (SB) using ZSM-5 zeolite catalyst was carried out in a fixed bed reactor to determine the effects of heating rate, temperature, and catalyst/biomass ratio on yield of bio-oil and their chemical compositions. Proximate analysis indicated that SB has 13.2% moisture content. The ultimate analysis carried out established that the percentage of carbon content is higher (48.2%) than oxygen content (44%) while the fibre content analysis showed 26.4% lignin, 33.3% cellulose, 30.1% hemicellulose. The heating rate, temperature and catalyst/biomass ratio were varied in the range of 10–50 °C/min, 400–600 °C and 0.05–0.25 respectively. The non-catalytic pyrolysis gave the maximum percentage yield (45.67 wt%) of bio-oil at a pyrolysis temperature of 600 °C, heating rate of 50 °C/min, sweeping gas flow rate of 40 mL/min and the catalytic pyrolysis gave 40.83 wt% of bio-oil at the same conditions. The FT-IR spectra showed that the non-catalytic bio-oil is dominated by oxygenated compounds (acids, ketones, aldehydes, alcohols), while the catalytic bio-oil had preponderances of desirable compounds (alkanes, alkenes, aromatics, phenols). The chemical composition of the bio-oils was analyzed using GC–MS, which revealed that the quality of the bio-oil has been improved using HZSM-5 catalyzed pyrolysis.     

Reaction behavior of oil sand in fluidized-bed pyrolysis

The reaction behavior of oil sand from Inner Mongolia（China） were studied in a fluidizedbed pyrolysis process,and a comparative study was conducted on the properties of the liquid products obtained through fluidized-bed pyrolysis of oil sand and the native bitumen obtained by solvent extraction.The results indicated that the fluidized-bed pyrolysis,a feasible carbon rejection process,can be used to upgrade oil sand.The reaction temperature and time were found to be the key operating parameters affecting the product distribution and yields in fluidized-bed pyrolysis of oil sand.The optimal temperature was 490℃ and the most suitable reaction time was 5 min.Under these operation conditions,the maximum yield of liquid product was 80wt%.In addition,the pyrolysis kinetics of oil sand at different heating rates of 5,10,20 and 30℃/min was investigated using a thermogravimetric analyzer（TGA）.     

PYROLYSIS OF SUNNYSIDE (UTAH) TAR SAND: CHARACTERIZATION OF VOLATILE COMPOUND EVOLUTION

ABSTRACT

Sunnyside (Utah) tar sand was subjected to programmed temperature pyrolysis and the volatile products were detected by tandem on-line mass spectrometry (MS/MS) in real time analyses. A heating rate of 4°C/min from room temperature to 900°C was employed.

Evolution of hydrogen, light hydrocarbons, nitrogen-, sulfur-, and oxygen-containing compounds was monitored by MS or MS/MS detection. Evolution of volatile organic compounds occurred in two regimes: 1) low temperature (maximum evolution at 150 to 175°C), corresponding to entrained organics, and 2) high temperature (maximum evolution at 440 to 460°C), corresponding to cracking of large organic components. Alkanes and alkenes of two carbons and higher had temperatures of maximum evolution at approximately 440°C, and methane at approximately 474°C. Aromatic hydrocarbons had temperatures of maximum evolution slightly higher, at approximately 450° C. Some nitrogen-, sulfur-, and oxygen-'ccntaining compounds were also detected in the volatile products.

Comparing the Sunnyside pyrolysis to the pyrolysis of other domestic tar sands indicated the following for hydrocarbon evolution: 1) the evolution of entrained organics relative to the total evolution was much less for Sunnyside tar sand, 2) the temperatures of maximum evolution of hydrocarbons due t o cracking reactions were slightly lower, and 3) the temperatures of maximum evolution for benzene and toluene are slightly higher than observed for other tar sands.

In general, the noncondensible gases, H₂, CO, and CO₂, exhibited evolution associated with hydrocarbon cracking reactions, and high temperature evolution associated with mineral decomposition, the water-gas shift reaction, and gasification reactions. Pyrolysis yields were dominated by the evolution of carbon oxides and water. The CO₂ primarily appeared t o cane from the decomposition of carbonate minerals. Compared t o other domestic tar sands, the gas evolution reflected more mineral decomposition character for Sunnyside tar sand.     

The chemical structure and the kinetics research of oil-wet oil sand from Kazakhstan during pyrolysis process

The pyrolysis experiments on the oil sands from Kazakhstan were carried out in a batch reactor. The FT-IR spectrum and the ¹H-NMR spectrum of pyrolysis oil under different temperatures were carried out to investigate the changes of functional group with temperature. The TGA experiments of oil sand were performed at different heating rates of 5, 10, 15, and 20°C/min up to 600°C. The Coats–Redfern method was accepted to calculate the kinetic parameters (apparent activation energy E and frequency factor A) of the desorption stage and the thermal cracking stage, respectively.     

A kinetic model for pyrolysis of petroleum residue under nonisothermal conditions

Kinetic study on pyrolysis of petroleum residue was carried out by an accurate Arrhenius type equation at heating rate of 0.5–30.0°C/min under nonisothermal conditions. The influence of some critical parameters including temperature, heating rate and activation energy on mass conversion was evaluated. The apparent activation energies for during the pyrolysis process were in the range of 198–361 kJ/mol at various mass conversions of 5–94%. The reaction temperature was introduced as the most important parameter for the improvement of mass conversion, compared to that of other parameters. The pyrolysis of petroleum residue was occurred in a broad temperature range, from 150–650°C, yielding 33 wt% unpyrolyzed residue. It also was found that an increase in heating rate has a minor impact in the process. Model predictions were compared with experimental data, which showed fully good agreement.     

Direct conversion of an agricultural solid waste to hydrocarbon gases via the pyrolysis technique

The increased awareness toward the global warming and the environmental pollution problems has stimulated the utilization of the alternative energy sources since they can positively take part in minimizing such problems. Among these sources, biomass based solid wastes is counted as one of the most promising in the field of energy production. Thus, the current research work focuses on the conversion of rice straw (a biomass-based solid waste) into hydrocarbon gases in general and methane (main constituent of natural gas) in particular. The reduction of the operational temperature and the elevated rate of solid-to-gas conversion are newly presented approaches in this research. Specifically, the used operating temperature, in this study, had been 250?°C while the well-known temperature range for slow pyrolysis is 380–550?°C. Another approach is represented in this work via the orientation of the obtained biogas to become mainly hydrocarbon gases instead of CO, CO₂ and CH₄ mixture, as the common for such pyrolysis processes. The attained high rate of solid-to-gas conversion (80%) while at low temperature is also a new approach of this study since such high rate is just possible in the flash pyrolysis (750–900?°C). The increased conversion rate was achieved via reducing the particles size of the used solid-biomass to a nano-sized range.     

Thermogravimetric analysis and kinetic study of heavy oil pyrolysis

Pyrolysis, so-called devolatilization, is one of the first steps of all thermochemical processes occurring in an inert atmosphere. The authors discuss the main kinetic features of heavy oil pyrolysis, on the basis of the data derived m from a TGA analysis and by using a kinetic model. The samples were heated over a range of temperature from 400 K to 430°C at various heating rates between 10 and 80°C/min. Experimental results showed that the effect of time is considerable in the case of tar conversion, compared to char and gases.     

PRODUCTS FROM FLASH PYROLYSIS OF A TURKISH LIGNITE IN A FREE-FALL REACTOR UNDER VACUUM

ABSTRACT

Flash pyrolysis of a Turkish lignite under vacuum in a free-fall reactor was examined at a temperature range of 400 - 800 °C. Gaseous products were analysed with an on-line GC equipped with a manuel injection valve. Solvent fractionation was applied to the liquid product to separate preasphaltenes, asphaltenes and oils fractions. Two particle distributions of the lignite were used: ?0.315+0.2 mm and ?0.1 mm. The liquid yield increased with temperature up to 650 °C and, thereafter decreased for the larger particles. The maximum liquid yield, excluding pyroltic water, was found to be 8 % wt (dal) at 650 °C. In the case of the smaller particles the liquid yield increased steadily with temperature and the yield of liquid, excluding pyrolytic water, was 5.9 % wt (da) at 850 °C. The gaseous product yield also increased with temperature for both size fractions, and CO and CO₂ in the gaseous products were present in large amounts.