Geochemical Characteristics and Significance of Organic Matter in Hydrate-Bearing Sediments from Shenhu Area,South China Sea

Rock-Eval pyrolysis and the biomarker composition of organic matter were systematically studied in hydrate-bearing sediments from the Shenhu area, South China Sea. The n-alkane distribution patterns revealed that the organic matter in the sediments appeared to originate from mixed sources of marine autochthonous input, terrestrial higher plants, and ancient reworked organic matter. The low total organic carbon contents (average < 0.5%) and the low hydrogen index (HI, <80 mg HC/g TOC) suggested the poor hydrocarbon-generation potential of the deposited organic matter at a surrounding temperature of <20 °C in unconsolidated sediments. The abnormally high production index and the fossil-originated unresolved complex mixture (UCM) accompanied by sterane and hopane of high maturity indicated the contribution of deep hydrocarbon reservoirs. Preliminary oil-to-source correlation for the extracts implied that the allochthonous hydrocarbons in the W01B and W02B sediments might have originated from the terrestrial source rocks of mature Enping and Wenchang formations, while those of W03B seem to be derived from more reduced and immature marine source rocks such as the Zhuhai formation. The results of the organic extracts supported the previous identification of source rocks based on the isotopic composition of C₂₊ hydrate-bound gases. The biomarker of methanogens, squalane, was recognized in the sediments of this study, possibly suggesting the generation of secondary microbial gases which are coupled with the biodegradation of the deep allochthonous hydrocarbons.     

Chromatographic study of the organic matter from Moroccan Rif bituminous rocks

The bituminous rocks of the Upper Cretaceous in the Moroccan Rif have been assessed and characterized in detail using organic geochemical techniques and a variety of organic geochemical parameters. The organic matter from 4 sites was studied in order to determine its thermal maturity and its depositional environments. The organic extracts (bitumens) were fractionated on silica-potassium hydroxide column according to the aliphatic hydrocarbons, acid compounds and polar compounds. Aliphatic hydrocarbons were identified by gas chromatography and mass spectrometry (GC/MS).The distribution of the aliphatic hydrocarbon fractions, and the various organic geochemical parameters (pristane/phytane, isoprenoids/n-alkanes, CPI, C₂₇:C₂₈:C₂₉ regular, C₂₉20S/(20S+20R), C₂₉ββ/(ββ+αα), C₂₉/C₃₀ hopanes and Ts/Tm) showed that the studied samples were generally mature. Two of the 4 samples appeared to be derived from source rocks deposited under anoxic conditions while suboxic to oxic conditions seemed to have been dominant for the remaining two samples. Rock–Eval pyrolysis data in addition to GC results suggested types II, III and IV kerogens for the studied samples.     

Origin of Ketones in Sediments of Qinghai Lake

This paper analysed the ketone fractions in sediments and living organisms of Qinghai Lake using GC-MS and discussed their origin,n-Alkan-2-ones detected in the sediments ranged from C_(12) to C_(33) with a maximum at n-C_(25) or n-C_(29) and showed a strong odd predominance, n-Alkan-2-ones in the living organisms analysed ranged from C_(15) to C_(31) with a maximum at n-C_(27).The authors believed that ketones in modern sediments may directly derive from biosynthesis.     

低煤级煤热解H2生成动力学及其与第一次煤化作用跃变的关系

用开放体系的热重-质谱联用仪(TG/MS)研究了7种低煤级煤的热解特征、H2的生成动力学特征以及它们与第一次煤化作用跃变的关系. 结果显示, 煤热解失重率在碳含量(Cdaf)为80%(质量分数)和镜质组最大反射率(R0max)为0.60%附近发生转折; 氢气生成的特征温度参数以及动力学参数均在Cdaf为80%(R0max为0.60%)左右表现为最低; 氢气的总产率在此处最大. 这些特征参数的极值点刚好与第一次煤化作用跃变点一致, 说明这些参数可以反映第一次煤化作用跃变的发生. 结合傅立叶变换红外(FTIR)光谱法获得的煤结构特征, 对影响机制进行了分析解释, 认为是由以下3个方面的原因导致的: (1)煤中脂肪类含氧官能团的演化特征; (2)可溶有机质的低温热缩聚作用; (3)有机质的“两极分化”作用.     

广西合山石村矿超高有机硫煤饱和烃特征分析

以合山石村矿超高有机硫煤为研究对象,利用带能谱的扫描电镜(SEM-EDX)及气相色谱(GC)和色谱-质谱联用(GC-MS)分析技术,综合分析探讨了研究区样品中有机质来源、沉积环境及物源输入。结果表明,研究区样品镜质体反射率均值1.76%,全硫含量均值6.01%,其中有机硫含量占比达94.3%,为高成熟度的超高有机硫煤。饱和烃色谱图中未分辨的复杂混合物(UCM)鼓包明显,前峰及双峰型均有分布,前峰型主峰碳为C_(16)、C_(18)、C_(21),双峰型主峰碳为C_(18)、C_(27),化合物降姥鲛烷、脱氢松香烷、咔达烯均有发现,规则甾烷C_(27)、C_(28)、C_(29)均呈"V"型分布,说明沉积母质受藻类等低等水生生物与高等植物双重输入的影响。姥植比参数、C_(31-35)藿烷呈阶梯式递减的分布特征表明在海相碳酸盐台地成煤带中存在一定的氧化条件。扫描电镜中拍摄到的铁含氧硫酸盐、细胞充填环状黄铁矿说明在沉积质晚期成岩阶段受到一定程度热液作用影响。     

Origin of Aldehydes in Sediments of Qinghai Lake

This paper has analysed the aldehyde fractions in sediments and living organisms of Qinghai Lake using GC-MS and discussed their origin, n-Aldehydes detected in the sediments ranged from C_(16) to C_(32) with a maximum at C_(22) C_(24) or C_(26) and showed a strong even over odd predominance. n-Aldehydes in the living organisms analysed ranged from C_(16) to C_(32) with a maximum at C_(26) or C_(28). The authors believed that aldehydes in modern sediments may directly derive from biosynthesis.     

Devolatilisation characteristics of coal and biomass blends

The characterisation of the initial devolatilisation products could provide important information for understanding synergistic effects and subsequently the formation routes leading to toxic organic compounds and soot during co-combustion. Initial devolatilisation characteristics of the fuels have been characterised following co-pyrolysis experiments. This paper investigates the devolatilisation behaviour during co-pyrolysis of pinewood together with one of three coals of different rank, lignite or high-volatile bituminous of different origin. A range of pyrolysis experiments has been performed over a temperature range from 400 to 900 °C using pyrolysis–GC–MS (py–GC–MS) and thermogravimetric analysis (TGA). Larger scale batch pyrolysis experiments of the hv bituminous coal–pine mixture have been performed enabling collection of the evolved tars. These tars have then been characterised by GC–MS and size exclusion chromatography (SEC). For these batch pyrolysis tests, synergy (non-additive behaviour) was observed and the blend pyrolysis oil contained a decrease in aromatics and an increase in phenols than would be expected for additive behaviour. The molecular weight distributions of the evolved tars also show non-additive behaviour. For the TGA experiments, additive behaviour was seen for all the coal–pine blends studied. Similarly, no obvious synergy was observed by py–GC–MS for the bituminous coal–pine blends, or for model compound–coal and coal–biomass component blends. Non-additive combustion behaviour is not easily explained by studying devolatilisation because of the difficulty in replicating the conditions of temperature profile and residence time experienced by the volatiles. Thus, conflicting behaviour is exhibited depending upon pyrolysis technique.     

Selective fast pyrolysis of biomass impregnated with ZnCl2 to produce furfural: Analytical Py-GC/MS study

For 20 years ending in the 1990s the city of Barcelona discharged the products from a large primary sewage treatment plant directly into the Mediterranean Sea via underwater conduits. About ca. 3 million m³ of relict sewage sludge, rich in organic matter and heavy metals, has spread over an elongated area offshore, due to successive ruptures of the conduits. The use of the discharge pipes ceased, but the sludge deposit remains in place for the time being.To understand the history and present state of the sludge deposit in advance of future remediation, a program of geophysical mapping, sampling, and analytical work was undertaken. Rock Eval pyrolysis, although created for use in petroleum prospecting, can also be applied to environmental contamination studies. It offers a simple means to effectively delineate the sludge deposit, with the S₂ parameter and the hydrogen and oxygen indices particularly useful. On the molecular level, the sludge flash pyrolysis products notably include relatively abundant C₂₇ and C₂₉ sterenes and steranes, likely produced from the pyrolysis of fecal and other steroids, including coprostanol, in the sewage sludge. Linear alkylbenzenes and trialkylamines, derived from surfactant residues in the sludge, are also detected. The indoles detected are likely the pyrolysis products of proteins, while the alkylnitriles and alkylamides in the pyrolyzate likely derive from bacterial biomass. Principal components analysis aided the interpretation of the large geochemical dataset and a geographic information system enabled the three-dimensional visualization of the results in their geospatial context. The distinctive pyrolysis products and the trace elements would be geochemical markers useful in planning and assessing a future remediation program. The recognition of a distinctive sewage pyrolysis–GC/MS signature in this deposit would facilitate the use of this method in the detection of sewage-contaminated sediments in urban waterways worldwide.     

Effect of Pyrolysis Temperature on the Characterisation of Dissolved Organic Matter from Pyroligneous Acid

Dissolved organic matter (DOM) greatly influences the transformation of nutrients and pollutants in the environment. To investigate the effects of pyrolysis temperatures on the composition and evolution of pyroligneous acid (PA)-derived DOM, DOM solutions extracted from a series of PA derived from eucalyptus at five pyrolysis temperature ranges (240–420 °C) were analysed with Fourier transform infrared spectroscopy, gas chromatography–mass spectroscopy, and fluorescence spectroscopy. Results showed that the dissolved organic carbon content sharply increased (p < 0.05) with an increase in pyrolysis temperature. Analysis of the dissolved organic matter composition showed that humic-acid-like substances (71.34–100%) dominated and other fluorescent components (i.e., fulvic-acid-like, soluble microbial by-products, and proteinlike substances) disappeared at high temperatures (>370 °C). The results of two-dimensional correlation spectroscopic analysis suggested that with increasing pyrolysis temperatures, the humic-acid-like substances became more sensitive than other fluorescent components. This study provides valuable information on the characteristic evolution of PA-derived DOM.     

Microprobe sampling—Photo ionization-time-of-flight mass spectrometry for in situ chemical analysis of pyrolysis and combustion gases: Examination of the thermo-chemical processes within a burning cigarette

A microprobe sampling device (μ-probe) has been developed for in situ on-line photo ionization mass spectrometric analysis of volatile chemical species formed within objects consisting of organic matter during thermal processing. With this approach the chemical signature occurring during heating, pyrolysis, combustion, roasting and charring of organic material within burning objects such as burning fuel particles (e.g., biomass or coal pieces), lit cigarettes or thermally processed food products (e.g., roasting of coffee beans) can be investigated. Due to its dynamic changes between combustion and pyrolysis phases the cigarette smoking process is particularly interesting and has been chosen as first application. For this investigation the tip of the μ-probe is inserted directly into the tobacco rod and volatile organic compounds from inside the burning cigarette are extracted and real-time analyzed as the glowing front (or coal) approaches and passes the μ-probe sampling position. The combination of micro-sampling with photo ionization time-of-flight mass spectrometry (PI-TOFMS) allows on-line intrapuff-resolved analysis of species formation inside a burning cigarette. Monitoring volatile smoke compounds during cigarette puffing and smoldering cycles in this way provides unparalleled insights into formation mechanisms and their time-dependent change. Using this technique the changes from pyrolysis conditions to combustion conditions inside the coal of a cigarette could be observed directly. A comparative analysis of species formation within a burning Kentucky 2R4F reference cigarette with μ-probe analysis reveals different patterns and behaviors for nicotine, and a range of semi-volatile aromatic and aliphatic species.     

A synthesis of the marine antibiotic (-)-malyngolide from D-glucose

(-)_Malyngolide, an antibiotic from the marine blue-green alga Lyngbya majuscula, was synthesized in about 30% yield from ethyl 4,6-0-benzylidene-2-deoxy-α-D-erythro-hexopyranosid-3-ulose, a chiral synthon easily derived from commercially available methyl α-D-glucopyranoside.     

Aqueous photolysis of the sunscreen agent octyl-dimethyl-p-aminobenzoic acid. Formation of disinfection byproducts in chlorinated swimming pool water

The photochemical behavior of the sunscreen agent octyl-dimethyl-p-aminobenzoic acid (ODPABA) was studied in different aqueous solutions and under different conditions. ODPABA photolysis was performed under laboratory conditions using a xenon light source and under natural sunlight conditions in sea, swimming pool as well as in distilled water. The influence of dissolved organic matter (DOM) on the degradation kinetics was also studied in the presence of various concentrations of humic acids (HA). The phototransformation was shown to proceed via pseudo-first-order reaction in all cases and the reaction rates followed the order: distilled water > swimming pool water > seawater, depending mainly on the presence of dissolved organic matter that retarded the photolysis reaction. Kinetic experiments were monitored with HPLC/UV-DAD and the half-lives (t 1/2) varied between 1.6 and 39 h in simulated solar irradiation and between 27 and 39 h in natural sunlight conditions. The product distribution during illumination was strongly dependent on the constitution of the irradiated media. Irradiation of the aqueous ODPABA solutions gave rise to several transformation products that were isolated by means of solid-phase extraction (SPE) and identified using GC-MS techniques. These were formed mainly through dealkylation and hydroxylation reactions and were detected in all aqueous solutions investigated. In the case of swimming pool water some additional byproducts were isolated and were tentatively identified as chlorinated intermediates, formed by the subsequent chlorination of the parent molecule as well as other intermediates.     

Use of a GC/MS/MS technique in determination of biomarkers in regional petroleum

The optimum conditions of a GC/MS/MS operation based on the covariant scan of electrostatic-magnetic fields on the trisector double focusing mass spectrometer JMS-HX100 have been searched for and procured. The distribution of C(29) sterane biomarkers in Arabian Medium crude oil is obtained by utilizing the best acquired parameter settings.     

有机阴离子柱撑水滑石催化酯交换合成碳酸二苯酯

 A series of organic anion-pillared hydrotalcites were synthesized by the ion exchange method and characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The hydrotalcite precursor and pillared hydrotalcites with different anions was tested as catalysts in transesterification of dimethyl carbonate (DMC) with phenol. The results show that the catalytic selectivity of this transesterification reaction over these organic anion-pillared hydrotalcites is significantly improved. The catalytic selectivities of C4H4O4-, C6H8O4-, C10H16O4-, 1,4-C8H4O4-, and C7H5O2-pillared hydrotalcites for transesterified products (diphenyl carbonate and methyl phenyl carbonate) are all greater than 90%, at least 10% higher than that of the hydrotalcite precursor. Under the conditions of n(phenol)/n(DMC)=4, catalyst amount=1.5%, and t=10 h, the C6H8O4-pillared hydrotalcite presents the best catalytic performance, and the DMC conversion and the selectivity for transesterified products reach 43.8% and 93.2%, respectively.     

颗粒粒径对油页岩热解产油率的影响

以桦甸油页岩为原料研究了颗粒粒径对油页岩热解产油率的影响。将油页岩破碎、筛分得到<0.074、0.074~0.125、0.125~0.25、0.25~0.5、0.5~1和1~3 mm不同粒级样品,再将0.25~0.5、0.5~1和1~3 mm大粒级样品粉碎制得对应的细粉样品,采用低温干馏法和热重分析分别测定表征样品的油产率和有机质含量。结果表明,油产率随着粒径减小逐渐降低,从1~3 mm下的11.92%降到<0.074 mm下的6.14%。热重分析表明,有机质含量随着粒径降低而降低,且油产率与有机质含量有明显的线性关系。0.25~0.5、0.5~1和1~3 mm样品经粉碎后油产率降低、气产率升高,但变化值均小于1%。在破碎过程中有机质选择性地富集在大粒级样品中,且页岩油二次反应程度随着粒径的减小而增大,使得页岩油产率随着粒径的降低而降低,且有机质选择性富集是主导因素。     

Study of the pyrolysis liquids obtained from different sewage sludge

Pyrolysis of sewage sludge in fluidized bed to produce bio-oil is under study as a useful way to valorise this waste. Sewage sludge is the waste produced in the wastewater treatment plants. Its composition may change due to the origin and to the non-standardized treatments in the wastewater treatment plants. The pyrolysis of three samples of anaerobically digested sewage sludge obtained from three different urban wastewater treatment plants was studied in this work. The organic and inorganic matter composition, and the volatile and ash content of these sewage sludge samples were different. The influence of these parameters on the pyrolysis product distribution and on some characteristics of these products was studied. It was determined that the ash content of the raw material had an enormous influence on the sewage sludge pyrolysis. An increase in the ash content of the sewage sludge caused an increase in the gas yield and a decrease in the liquid and the solid yield with the operational conditions studied. The increase of the volatile content of the sewage sludge samples caused an increase in the liquid yield. The H₂ proportion was the most influenced non-condensable gas. It increased significantly with the ash content. The viscosity of the pyrolysis oils decreased when the ash content augmented. On the other hand, the water content depended on the organic composition of the sewage sludge samples. The chemical composition of the pyrolysis oils was also affected by the sewage sludge ash content above all the proportion of polyaromatic hydrocarbons and nitrogen-containing aromatic compounds. These compound groups increased with the augment of the sewage sludge ash content. The oxygen-containing aliphatic compounds and the steroids decreased with the ash content, although its proportion in the sewage sludge liquid was also influenced by the organic matter composition of the sewage sludge samples.     

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.     

Flash Pyrolysis and Kinetic Parameters of Decomposition of Oil Shales

Flash pyrolysis of oil shales, distribution of the organic matter in the volatile products, solidresidue at various pyrolysis temperatures were studied. The concentrations of aliphatic hydrocarbons andnaphthenes + arenes in the volatile products were determined.     

Spatial Distribution of Chemical and Organic Compounds in the Water of Oligotrophic Peatland of Tomsk Region (Western Siberia)

In the central part of Western Siberia a study of the chemical and organic compounds spatial distribution in the water of oligotrophic peatland has been carried out. It was shown that marsh water generally contains exceptionally low total dissolved salinity (TDS), low pH value, high content of organic matter and NH₄, increased content of Fe. The composition of organic matter is characterized by pronounced predominance of organic compounds and the presence of hydrocarbon and oxygen-containing compounds. Features of ionic and organic distribution in water and its ground were investigated.     

矿物质对煤显微组分热解的影响

用常压热天平考察了平朔气煤三种主要显微组分(镜质组、丝质组和稳定组)的热解特性及其原生矿物质和外加无机物对各显微组分热解的影响。用ST-03表面孔径测定仪测定了三种显微组分及焦样的比表面积。研究表明,各显微组分的热解反应性从强到弱的排列顺序为:稳定组>镜质组>丝质组;原生矿物质对各显微组分的热解具有抑制作用,对热解活化能也有影响,并使焦样的比表面积显著增加;外加CaO等无机物及其添加量对不同显微组分的热解有不同的影响,但都使焦样比表面积增加。用分段连续一级反应机理可以较好地描述各显微组分的热解过程,统一形式不同参数的动力学模型为dx_(ij)/dt_(ij)=k_(ij)(1-x_(ij))。