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1.
The effect of pyrolysis at increasing temperature on sporopollenin, lignite and sporopollenin oxidized at 200°C has been investigated using measured infrared band absorption coefficients.Oxidation of sporopollenin in air at 200°C is marked by a decrease in the content of saturated hydrocarbon chains and a strong increase in the concentration of carboxylic acid groups.Pyrolysis of a thick bed of sporopollenin at increasing temperatures leads to the removal of a large proportion of oxygenated functions, before the removal of hydrocarbons. For lignite and oxidized sporopollenin, the loss of both types of functional groups extends over a broader temperature range. Reorganization of the carbonaceous residue at high temperature is hindered if a sufficiently low content of oxygenated functions, carbonyl and carboxyl as well as hydroxyl and ether groups, is not reached before the elimination of hydrocarbons. 相似文献
2.
Elodie Salmon Adri C.T. van Duin François Lorant Paul-Marie Marquaire William A. Goddard 《Organic Geochemistry》2009,40(3):416-427
This paper reports ReaxFF MD simulation results on pyrolysis of a molecular model of the algaenan Botryococcus braunii race L biopolymer, specifically, ReaxFF predictions on the pyrolysis of prototypical chemical structures involving aliphatic chain esters and aldehydes. These preliminary computational experiments are then used to analyze the thermal cracking process within algaenan race L biopolymers. The simulations indicate that the thermal decomposition of the algaenan biopolymer is initiated by the cleavage of a C–O bond in the ester group, followed by the release of carbon dioxide. We also observe a significant, strongly temperature dependent, release of ethylene. This degradation mechanism leads to products similar to those observed in pyrolysis experiments, validating this computational approach. 相似文献
3.
珠江口盆地番禺低隆起-白云凹陷北坡干酪根热演化模拟与生烃 总被引：1，自引：0，他引：1
通过密封金管-高压釜体系对珠江口盆地番禺低隆起-白云凹陷北坡恩平组炭质泥岩的干酪根(PY),在24.1 MPa压力、20℃/hr(373.5~526℃)和2℃/h(343~489.2℃)两个升温速率条件下进行热模拟生烃实验,分析气态烃(C1 5)和液态烃(C6 14和C14+)的产率,以及沥青质和残余有机质碳同位素组成。同时与Green River页岩(GR)和Woodford泥岩(WF)的干酪根,分别代表典型的I型和II型干酪根进行对比研究。结果显示PY热演化产物中总油气量明显低于GR和WF干酪根,且气态烃(C1 5)最高产率是液态烃的1.5倍,揭示恩平组炭质泥岩主要以形成气态烃为主。在热演化过程中,有机质成熟度和母质类型是控制油气比的主要因素,气态烃和轻烃的产率比值主要受热演化成熟度的影响。干酪根残余有机质碳同位素和沥青质碳同位素在热演化过程中受有机质成熟度的影响较小,δ13C残余和δ13C沥青质可以间接反映原始母质的特征,为高演化烃源岩油气生成提供依据。 相似文献
4.
分步瞬时热解法可以有效的用于研究干酪根（或其他相关样品）结构组分随温度变化而演变的详细特征。利用分步瞬时热解法从300℃到600℃共分七个温度点,依次对绿河页岩干酪根样品进行热模拟分析。结果表明:在300℃时,绿河页岩干酪根样品基本没有热解产物,在350℃时可检测到少量吸附烃但含量极少;400℃、450℃和500℃是热解产物十分丰富的三个温度点,主要产物是成对出现的正构烷烃和直链烯烃,同时含有一定量的异构烷烃和姥鲛-1-烯;随着热解温度升高,异构烷烃和长链烃类的相对含量逐渐减少;姥鲛-1-烯在400℃和450℃一直占据主要地位;550℃出现了长碳链烷烃（C27~C32）,很有可能是绿河页岩干酪根样品中类似于绿藻等的组分经高温裂解产生的;600℃之后热解产物基本消失,说明在低温阶段干酪根裂解作用就基本完全。另外,绿河页岩干酪根样品在不同温度点的瞬时热解均给出了相应的产物组分构成,对比研究发现,其产物种类及相对含量具有逐渐变化的特征,由此将更有利于研究干酪根的热演化及其成烃机制。 相似文献
5.
V. N. Melenevskii 《Geochemistry International》2012,50(5):425-436
The catagenesis of organic matter (OM) was modeled by the hydrous pyrolysis of a Riphean mudstone. Microscopic observations
of the processes operating during kerogen heating to 600°C were conducted in a diamond anvil cell. The results of pyrolysis
in an aqueous environment were used to calculate the activation energies of kerogen cracking and derive chemical kinetic models
for OM catagenesis. Isothermal experiments were carried out for 3 days at temperatures of 300, 310, …, 360, and 370°C. The
maximum bitumen yield was obtained at 330°C followed by thermal cracking at higher temperatures. The aromatic and saturated
hydrocarbons from rock bitumen, hydrous pyrolyzates, and kerogen flash pyrolyzates were analyzed by chromatography-mass spectrometry.
We also discuss the problem of extrapolation of high-temperature pyrolysis results to geologic observations under the conditions
of regional catagenesis. 相似文献
6.
M.H. Engel J. Rafalska-Bloch C.F. Schiefelbein J.E. Zumberge A. Serban 《Organic Geochemistry》1986,10(4-6)
Amino acids and sugars are principal constituents of marine organisms. The condensation of amino acids and sugars is one possible nonenzymatic, early diagenetic pathway for the incorporation of these compounds into more complex geopolymers. In this study, aqueous solutions consisting of l-lysine, l-histidine, l-arginine and d-(+)-glucose were heated (100°C) for up to 288 h. Portions of the melanoidin polymer isolated after heating were reheated in the presence of water (hydrous pyrolysis) for 72 h at 325°C. Reaction products were identified by GC and GC/MS. Stable isotopic (δ13C) and elemental analyses were used to follow thermal evolution.While the initial melanoidin was synthesized from a simple, four component system, the products generated during hydrous pyrolysis are of considerable complexity, and include straightchain and branched alkanes, alkadienes, alkynes, indole, dimethyl indane, ethyl phenol, quinoline, and xylenes, in addition to a multitude of as yet, unidentified components. Stable carbon isotopic values for the reactants and products correspond to trends observed for naturally generated geopolymers and light gases. Elemental analyses of the melanoidin prior and subsequent to hydrous pyrolysis indicate a kerogen evolution pathway similar to that observed for natural samples. Considering the intractable nature of kerogen, laboratory simulation studies of simple systems can provide an alternative approach for elucidating the origins of geopolymers and their potential for hydrocarbon generation. 相似文献
7.
The effects of intrusive thermal stress have been studied on a number of Pleistocene sediment samples obtained from Leg 64 of the DSDP-IPOD program in the Gulf of California. Samples were selected from Sites 477, 478 and 481 where the organic matter was subjected to thermal stress from sill intrusions. For comparison purposes, samples from Sites 474 and 479 were selected as representative of unaltered material.The GC and GC-MS data show that lipids of the thermally unaltered samples were derived from microbial and terrestrial higher-plant detritus. Samples from sill proximities were found to contain thermally-derived distillates and those adjacent to sills contained essentially no lipids. Curie point pyrolysis combined with GC and GC-MS was used to show that kerogens from the unaltered samples reflected their predominantly autochthonous microbial origin. Pyrograms of the altered kerogens were much less complex than the unaltered samples, reflecting the thermal effects. The kerogens adjacent to the sills produce little or no pyrolysis products since these intrusions into unconsolidated, wet sediments resulted in in situ pyrolysis of the organic matter.Examination of the kerogens by ESR showed that spin density and line width pass through a maximum during the course of alteration but ESR g-values show no correlation with maturity. Stable carbon isotope (δ13C) values of kerogens decrease by 1–1.5‰ near the sills at Sites 477 and 481 and the atomic N/C decreases slightly with proximity to a smaller sill at Site 478. Differences in maturation behavior between Site 477 and 481 and Site 478 are attributed to dissimilarities in thermal stress and to chemical and isotopic heterogeneity of Guaymas Basin protokerogen. 相似文献
8.
为了研究不同煤化程度煤的热解气相产物、热解动力参数,采用热重-红外光谱-质谱（TG-IR-MS）联用技术对4种不同热演化程度的煤进行了热解实验。实时记录了4种煤样在30~1 100℃、10/min℃升温速率、氦气气氛下热解过程中释放的各种气体成分及其释放量的变化趋势。研究结果表明,随煤热演化程度升高,煤的失重率和最大失重速率逐渐降低,与煤的干燥无灰基挥发分呈正相关关系;随着热解温度的升高,煤中逐渐释放出水、甲烷、二氧化碳、氢气和二氧化硫等小分子气体,且随着煤化程度的升高,各种气体的释放峰逐渐向高温处偏移,说明煤的热稳定性逐渐升高。不同变质程度煤的热解动力学分析结果表明,随着煤变质程度增高,其活化能逐渐降低,说明其热效应强度和发生热解反应的能力在逐渐降低。 相似文献
9.
应用TGA-FTIR测定煤显微组分的生烃动力学参数 总被引：2，自引：0，他引：2
天然气生成的动力学参数的求取一直是天然气勘探盆地模拟技术中的难题。本文应用一套ＴＧＡ－ＦＴＩＲ（热失重与傅利叶红外光谱联用仪）对不同煤显微组分进行了分析，并将结果代入ｌｓｓｌｅｒ的最优化软件系统，求取这些组分的热解产物动力学方程，并对其热解性质进行了探讨。这些动力学方程可直接用于盆地模拟软件系统中，预测甲烷及其它产物的生成史。 相似文献
10.
Pierre Libert André Marchand Marie-France Achard 《Geochimica et cosmochimica acta》1976,40(2):143-148
Two parameters are chosen to characterize the pyrolysis residues of sporopollenin: the first one is the ratio, where d1600 and d1700 are the optical densities of the absorption bands at 1600 and 1700 cm?1, respectively; the second one is the paramagnetic susceptibility χp measured by E.P.R.Those two quantities increase rapidly above 300°C, which confirms previous results that the sporopollenin structure undergoes important modifications at this temperature. A striking similarity is observed between the properties of sporopollenin residues and those of natural kerogens. 相似文献
11.
为了更加客观地了解煤系烃源岩的生气性能,采用半开放体系对塔里木盆地库车坳陷侏罗纪煤、碳质泥岩和煤系泥岩3种等变质煤系烃源岩样品进行了生气热模拟实验。实验结果表明:侏罗纪煤、碳质泥岩和煤系泥岩均具有良好的生气性,但其生气性存在一定的差异,煤和碳质泥岩的生气性要好于煤系泥岩;随着热演化程度的增加,这3种煤系烃源岩生气总产率(C1-5)也相应增加,在高演化阶段时主要产甲烷;煤系烃源岩热解气组分的碳同位素值和热解温度有关,随着热解温度升高,甲烷碳同位素值先降低后增大,乙烷碳同位素值一直增大,且在同一温度点有δ13C1<δ13C2的特征。 相似文献
12.
采用热重与测汞仪联用技术,对5种不同煤化程度的煤进行氧化热解实验,研究不同煤化程度煤的热解过程及煤中汞的释放规律。结果表明:X射线衍射（XRD）曲线中衍射峰的特征可反应煤化程度,衍射峰的高度越高,宽度越窄,煤化程度就越高。不同煤化程度的煤在氧气中热解,质量损失随煤化程度的加深而增大,且随着煤化程度的加深,氧化热解的起始温度、最大热分解温度、终止温度也逐渐升高。随着煤化程度的升高,煤中汞释放所需的时间逐渐增加,且汞释放最大值所对应的热重（TG）曲线热解率最大的温度随煤化程度的加深而升高。 相似文献
13.
Sulfate rocks and organic sulfur from sedimentary organic matter are conventionally assumed as the original sulfur sources for hydrogen sulfide(H_2S) in oil and gas reservoirs. However,a few recent experiments preliminarily indicate that the association of pyrite and hydrocarbons may also have implications for H_2S generation,in which water effects and natural controls on the evolution of pyrite sulfur into OSCs and H_2S have not been evaluated. In this study,laboratory experiments were conducted from 200 to 450° C to investigate chemical interactions between pyrite and hydrocarbons under hydrothermal conditions. Based on the experimental results,preliminary mechanism and geochemical implications were tentatively discussed. Results of the experiments showed that decomposition of pyrite produced H_2S and thiophenes at as low as 330°C in the presence of water and n-pentane. High concentrations of H_2S were generated above 450°C under closed pyrolysis conditions no matter whether there is water in the designed experiments. However,much more organic sulfur compounds(OSCs) were formed in the hydrous pyrolysis than in anhydrous pyrolysis. Generally,most of sulfur liberated from pyrite at elevated temperatures was converted to H_2S. Water was beneficial to breakdown of pyrite and to decomposition of alkanes into olefins but not essential to formation of large amounts of H_2S,given the main hydrogen source derived from hydrocarbons. In addition,cracking of pyrite in the presence of 1-octene under hydrous conditions was found to proceed at 200°C,producing thiols and alkyl sulfides. Unsaturated hydrocarbons would be more reactive intermediates involved in the breakdown of pyrite than alkanes. The geochemistry of OSCs is actually controlled by various geochemical factors such as thermal maturity and the carbon chain length of the alkanes. This study indicates that the scale of H_2S gas generated in deep buried carbonate reservoirs via interactions between pyrite and natural gas should be much smaller than that of thermochemical sulfate reduction(TSR) due to the scarcity of pyrite in carbonate reservoirs and the limited amount of long-chained hydrocarbons in natural gas. Nevertheless,in some cases,OSCs and/or low contents of H_2S found in deep buried reservoirs may be associated with the deposited pyrite-bearing rock and organic matters(hydrocarbons),which still needs further investigation. 相似文献
14.
Immature Torbanite and the resistant biopolymer (PRB A) isolated from extant B. braunii were previously compared using bulk spectroscopic methods. In the present work, analysis of 400°C pyrolysis products and pyrolysis residues provided further information on their structure and possible relationships. It appears that such polymers are based upon unbranched, saturated, cross-linked hydrocarbon chains up to C31. In addition to these bridging structures, a substantial part of the alkyl chains is singly bound, as esters of unbranched, saturated or cis unsaturated, even fatty acids. These esters are sterically protected, against chemical degradations, by the network of the bioand geopolymer.Quantitative and qualitative observations derived from 400°C pyrolysis confirm that the chemical structure of PRB A and immature Torbanite are closely related. The pyrolysis residues show a similar evolution and numerous common features are noted, with respect to the nature and the distribution of the major constituents of the pyrolysates (hydrocarbons and fatty acids). Accordingly, Botryococcus provides what seems to be the first example of a close structural relationship between a biopolymer produced in large amounts by an extant alga and the geopolymer of an immature kerogen. The essential role of PRB A in Torbanite formation is ascertained. Moreover, it is found that the resistant biopolymer does not undergo important structural changes during the first stages of diagenesis. Thus, owing to steric protection, the esters of immature Torbanite show a distribution quite close to the one of PRB A esters, with exclusively even constituents and a large contribution of unsaturated acids.Recent observations pointed to the possible genesis of some algal kerogens principally by selective preservation of resistant macromolecules. Such a type of formation is clearly predominant in Torbanite, where the bulk of the fossil organic matter corresponds to a selectively preserved and weakly altered, resistant biopolymer, while incorporation of lipids into the kerogen structure during diagenesis seems to play a minor role. 相似文献
15.
利用干酪根热解动力学模拟实验研究塔里木盆地下古生界古地温 总被引：9，自引：0，他引：9
通过热解动力学模拟实验，对塔里木盆地塔参1井奥陶系干酪根的热演化过程进行了模拟，以此基础上利用KINETICS软件求取干酪根镜质体反射率（R0）的生成动力学参数，并结合塔参1井的沉积埋藏史，计算塔参1井寒武－奥陶系的古地温，这对于研究塔里木盆地下古生界高过成熟烃源岩的古地温是一种新方法。 相似文献
16.
The natural thermal evolution of type III coals (Humic origin) is expressed during diagenesis by a loss of oxygen as CO2 and H2O. Other phenomena such as oxidation can cause extensive geochemical modifications and may complicate the effects of simple maturation.Humic coals from the Jurassic in southeastern Utah were studied by elemental analysis, Rock-Eval pyrolysis and infrared spectroscopy. In a van Krevelen diagram (atomic H/C vs atomic O/C), the samples fall within the envelope defined by 860 reference humic coals covering the entire range of diagenesis. Nevertheless, various criteria (geochemical, petrographic, geological and microscopic) cast doubt upon the interpretation that such a distribution of coal composition results from thermal maturation.The same criteria indicate the intervention of redox phenomena. Comparison of our results with those from artificial and natural oxidation shows that these coals were subjected to an oxidation process different from ordinary late alteration. This process was probably due to circulation of highly oxidizing saline water causing oxygen fixation and the transformation of carboxyls into carboxylate anions. The cations that were fixed are oxygenated and certainly contain calcium, but also uranium and perhaps several other cations (V, Mo, Fe...). Emphasis is placed on possible mechanisms that cause such phenomena. 相似文献
17.
Colloidal material in the size range 1.2 nm to 0.4 μm was isolated by ultrafiltration from Chesapeake Bay and Patuxent River waters (U.S.A.). Temperature controlled, stepwise pyrolysis of the freeze-dried material, followed by gas chromatographic-mass spectrometric analyses of the volatile products indicates that the primary organic components of this polymer are carbohydrates and peptides. The major pyrolysis products at the 450°C step are acetic acid, furaldehydes, furoic acid, furanmethanol, diones and lactones characteristic of carbohydrate thermal decomposition. Pyrroles, pyridines, amides and indole (protein derivatives) become more prevalent and dominate the product yield at the 600°C pyrolysis step. Olefins and saturated hydrocarbons, originating from fatty acids, are present only in minor amounts. These results are consistent with the composition of Chesapeake phytoplankton (approximately 50% protein, 30% carbohydrate, 10% lipid and 10% nucleotides by dry weight). The pyrolysis of a cultured phytoplankton and natural particulate samples produced similar oxygen and nitrogencontaining compounds, although the proportions of some components differ relative to the colloidal fraction. There were no lignin derivatives indicative of terrestrial plant detritus in any of these samples. The data suggest that aquatic microorganisms, rather than terrestrial plants, are the dominant source of colloidal organic material in these river and estuarine surface waters. 相似文献
18.
D. Vu
eli&#x; V. Markovi&#x; V. Vu
eli&#x; D. Spiridonovi&#x; B. Jovan
i&#x;evi&#x; D. Vitorovi&#x; 《Organic Geochemistry》1992,19(4-6)
The catalytic effect of indigenous minerals in the pyrolysis of Aleksinac (Yugoslavia) oil shale was studied in this paper. The substrates were prepared by gradual removal of the mineral constituents (carbonates, silicates, pyrite) and the free and bound bitumens. The substrates were analyzed by chemical methods, X-ray diffraction, porosimetry, thermal analysis, 13C NMR, and standard ASTM Micro Activity Test (MAT) designed for the investigation of cracking catalysts. The liquid pyrolysis products were analyzed by organic geochemical techniques as well. Based on the yields of gaseous and liquid products and the coke, conversion degrees, GC analyses (MAT parameters) and weight losses (TG parameter), the catalytic effect of indigenous mineral components in the pyrolysis of Aleksinac oil shale organic matter was found to be very low. The results suggested that principal organic matter changes should be attributed to thermal rather than to catalytic cracking. 相似文献
19.
M. Krzesi&#x;ska U. Szeluga S. Czajkowska J. Muszy&#x;ski J. Zachariasz S. Pusz B. Kwieci&#x;ska A. Koszorek B. Pilawa 《International Journal of Coal Geology》2009,77(3-4):350-355
The objective of this work was to investigate the thermal decomposition of various bituminous coal blends. Three Polish coals of varying rank (82.7, 86.2 and 88.7 wt.% carbon content) and caking ability (weak, moderate and strong) were collected from the Krupiński, Szczygłowice and Zofiówka mines, respectively. These coals were used to prepare binary and ternary blends. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were used. The weight loss and heat flow during pyrolysis, and storage/loss elastic modulus measured as a function of increasing temperature were related to the caking ability of coals. Parameters determined with the TGA and the DSC methods in the binary and ternary blends were correlated with the proportion of strongly-caking-coal concentration in the blend. The weight loss of coal blends was found to be additive parameter. The DSC thermograms of binary blends were found to be different from those of the ternary blends, which suggests a different course for this blend pyrolysis. 相似文献
20.
Hydrous and anhydrous closed-system pyrolysis experiments were conducted on a sample of Mahogany oil shale (Eocene Green River Formation) containing Type-I kerogen to determine whether the role of water had the same effect on petroleum generation as reported for Type-II kerogen in the Woodford Shale. The experiments were conducted at 330 and 350 °C for 72 h to determine the effects of water during kerogen decomposition to polar-rich bitumen and subsequent bitumen decomposition to hydrocarbon-rich oil. The results showed that the role of water was more significant in bitumen decomposition to oil at 350 °C than in kerogen decomposition to bitumen at 330 °C. At 350 °C, the hydrous experiment generated 29% more total hydrocarbon product and 33% more C15+ hydrocarbons than the anhydrous experiment. This is attributed to water dissolved in the bitumen serving as a source of hydrogen to enhance thermal cracking and facilitate the expulsion of immiscible oil. In the absence of water, cross linking is enhanced in the confines of the rock, resulting in formation of pyrobitumen and molecular hydrogen. These differences are also reflected in the color and texture of the recovered rock. Despite confining liquid-water pressure being 7-9 times greater in the hydrous experiments than the confining vapor pressure in the anhydrous experiments, recovered rock from the former had a lighter color and expansion fractures parallel to the bedding fabric of the rock. The absence of these open tensile fractures in the recovered rock from the anhydrous experiments indicates that water promotes net-volume increase reactions like thermal cracking over net-volume decrease reactions like cross linking, which results in pyrobitumen. The results indicate the role of water in hydrocarbon and petroleum formation from Type-I kerogen is significant, as reported for Type-II kerogen. 相似文献