16 research outputs found
Molecular and isotopic compositions of bitumens in Silurian tar sands from the Tarim Basin, NW China: Characterizing biodegradation and hydrocarbon charging in an old composite basin
No full textBound hydrocarbons and structure of pyrobitumen rapidly formed by asphaltene cracking: Implications for oil-source correlation
No full textThe pyrobitumen in conventional petroleum reservoirs is a thermally altered product of ancient oil pools, which may provide valuable source information using its molecular and isotopic signatures. Pyrobitumen formation is often associated with thermal alteration of asphaltene or polar-rich components rather than that of oil as a whole. Although asphaltenes are useful in source correlation of altered oils, the geochemical characteristics of asphaltene-derived pyrobitumen are poorly understood. In this study, artificial pyrobitumen formation through oil asphaltene cracking was performed at different thermal simulation (i.e., pyrolysis) temperatures. Systematic variations in the amounts and distributions of extractable and bound hydrocarbons, released by catalytic hydropyrolysis of the artificially produced pyrobitumen were studied. Pyrobitumen production yield was high at pyrolysis temperatures corresponding to post oil peak maturities, with a maximum yield of similar to 70 wt% of asphaltene being reached in the early condensate-wetgas stage. The molecular structure of pyrobitumen varied only slightly over the high maturity range (EasyRo 1.64-2.51%). Compared with the parent asphaltene, the pyrobitumen had a low biomarker (e.g., regular steranes and terpanes) content, and even the carbon isotopic values of the more stable bound n-alkanes were strongly altered. Thermal cracking of asphaltene alone, rather than whole oil, accelerates cross-linking of aromatic units, and cleavage or condensation of molecules bound in the pyrobitumen. These molecular changes suggest that care is needed when using the geochemical characteristics of bound hydrocarbons in natural pyrobitumen for source determinations. Nevertheless, the carbon isotopic ratios of bulk pyrobitumen hydropyrolysate were similar to those of bulk oil or pyrobitumen, even at very high maturities, suggesting these may be reliable indices for source tracing. A comparison of carbon isotopic compositions between pyrobitumen-bound and solvent-extractable n-alkanes could be useful in determining whether they have the same origin. Furthermore, the compositional and isotopic characteristics of bound hydrocarbons in pyrobitumen may provide information on the stage of maturity under geological conditions. The investigation of free and bound molecules may thus elucidate pyrobitumen genesis as related to its source, thermal maturity, and possible later hydrocarbon charging. (C) 2020 Elsevier Ltd. All rights reserved
(55(4):213-221)Effects of Organic and Chemical Fertilizers Suitable for Good Agricultural Practices on Root Yield and Active Ingredients of Boehmeria nivesa
No full text本試驗以每公頃施用(A)雞糞堆肥7,500 kg、(B)含木黴菌雞糞之生物性堆肥7,500 kg、(C)化學肥料(N 80kg٫ P2O5 20 kg٫ K2O 120 Kg)、(D) AR3-2S土壤添加物2,400 kg (N 3.9%，P2O5 2.23%，K2O 1.71%)及無肥對照區(CK)等五種處理參試，所用資材、土壤及水質的重金屬均控制在標準值之下，進行有機與化學肥料對苧麻根產量的影響，結果發現平均每公頃苧麻根之鮮重及乾重分別為A處理14,389 kg及5,568.5 kg；D處理16,486 kg及6,871 kg；C處理11,375 kg及4,449.8 kg；而B及CK處理均較低，分別各為10,056 kg及4,082.7 kg與8,597 kg及3,430.2 kg，但經綜合變方分析結果顯示，處理間均未達5%顯著差異水準◦分析各處理苧麻根之總三萜及總酚類含量變化發現，總三萜含量以A處理之雞糞堆肥區的0.38%最高，其次為B處理之木黴菌堆肥區0.237%次之，分別對其餘三處理達5%顯著差異水準；總酚類含量以不施肥區（對照組）為0.148%最高，含量稍高於施用含木黴菌生物性堆肥區（B處理）及雞糞堆肥區（B處理），且顯著高於C及D處理，達5%顯著差異水準◦The purpose of this study was to establish a model of good agricultural practices suitable for cultivation of Boehmeria nivesa in the field. The effects of different types of organic and chemical fertilizers on the root yield and active ingredients of this medicinal herb crop were evaluated. The concentrations of heavy metals and mineral elements in the tested organic and chemical fertilizers, and irrigation water were measured before planting. The control measures other than synthetic pesticides were used to manage the diseases and insect pests during plant growth stage. The treatments consisted of (A) chicken manure at 7,500 kg ha^(-1); (B) chicken manure with Tricoderma sp. at 7,500 kg ha^(-1); (C) chemical fertilizer at the rate of N:P2O5:K2O = 80: 20: 120 kg ha^(-1); (D) soil amendment (AR3-2S) with chemical fertilizer (N: P2O5: K2O = 3.9: 2.23: 1.71) at 2400 kg ha^(-1)and (E) non-treated plot used as the control (CK). Each treatment had four replicates in a randomized complete block design (RCBD). The results showed that there were no significant differences in root yield among treatments. The fresh and dry weight of root of B. nivesa were 14,389 kg and 5,568.5 kg in treatment A, 10,056 kg and 4,082.7 kg in treatment B, 11,375 kg and 4,449.8 kg in treatment C, 16,486 kg and 6,871.4 kg in treatment D, and 8,597 kg and 3,430.2 kg in CK, respectively. The triterpenes contents in roots harvested from treatment A and B were 0.38% and 0.237%, respectively, which were significantly (p=0.05) higher than other treatments. The content of total phenolic compounds in roots harvested from CK treatment was 0.148%, which was slight higher than A and B treatments, and significantly (p=0.05) higher than C and D treatments
Bulbophyllum guniuensis W. Y. Ni & J. W. Shao 2022, sp. nov.
No full textBulbophyllum guniuensis W.Y. Ni & J.W. Shao, sp. nov. (牯牛石ā兰, Figs. 1, 2) Diagnosis:— Bulbophyllum guniuensis is similar to Bulbophyllum henanense J. L. Lu (1992: 331) in sharing small pseudobulbs, ovoid oblong leaves, and margin fimbriate-ciliate dorsal sepal, but can be distinguished from it by having longer scape, short and straight side lateral sepals, ovate-triangular petals and ligulate lip. Type:— CHINA. Anhui: Qimen County, Chiling Township, Guniujiang National Nature Reserve, on the stone, under the evergreen broad-leaved forest, elev. 368 m, 28 May 2021, Wei-Yong Ni, Si-Yu Zhang, Ke-Run Zhu, Zheng Jiang & Hao-Tian Wang ANUB08615 (holotype ANUB02284; isotype ANUB02285, PE02354810). Description:— Epiphytic or lithophytic herbs. Rhizome creeping, 1 mm in diam., growing from the base of the pseudobulbs. Pseudobulbs 3–6 mm apart along the rhizome, near spherical, slightly ribbed, ca. 5 mm in diam., with 1 leathery leaf on top. Leaf ovate-oblong, 1–1.5 × 0.5–0.8 cm, sunken midrib, apex obtuse, base narrowing into a 1 mm long petiole. Scape from the base of pseudobulb, erect, 4–6 cm long, raceme shortened, umbel-like, 4–6 flowered. Flowers pale yellow to orange yellow. Bracts membranous, lanceolate, 0.5–1 mm long. Ovary and pedicel 6–8 mm, glabrous. Dorsal sepal ovate-triangular, 4 × 3 mm, apex acuminate, margin fimbriate-ciliate, 3-veined; lateral sepals oblique oblong, 5–6 × 2–3 mm, base adnate to column foot, tip caudate, separate from each other. Petals white, obliquely ovate-triangular, 3 × 2 mm, apex acuminate, margin fimbriate-ciliate, 3-veined. Lip ligulate, fleshy, slightly curved, with orange edges and yellow inside, ca. 3 mm, blunt tip, rough edges, base attached to end of column-foot by a mobile joint; Column ca. 1.5 mm, with 2 extremely small mastoid on the upper part, stelidia subulate, slender, ca. 0.8 mm; anther cap with many dentate projections. Pollinia 4, in 2 pairs. Etymology:— The specific epithet is from the locality of type, Guniujiang National Nature Reserve. Phenology:— Flowering period from May to June, fruiting period in July. Distribution and habitat:— Found in Guniujiang National Nature Reserve, Qimen County, Huangshan City, Anhui Province, China (Fig. 3). It grows on rocks in an evergreen broad-leaved forest at elevation of 300–400 meters, and accompanied by Deutzia ningpoensis Rehd., Cyclobalanopsis glauca (Thunberg) Oersted, Distylium myricoides Hemsl. and Lilium anhuiense D.C.Zhang & J.Z.Shao etc. Conservation status:— At present, we have only found a population in Guniujiang National Nature Reserve, covering an area of about 3 square meters, with a preliminary estimate of nearly 3,000 pseudobulbs. The author transplanted about 10 plants on the rockery in the management station of Guniujiang Nature Reserve and observed for 2 years. The growth is good, indicating that this species has a relatively tenacious vitality. Due to the small size of the plant, the growing area is relatively hidden, and when not flowering, it looks very similar to Lemmaphyllum drymoglossoides (Baker) Ching, and is easily overlooked. Therefore, it cannot be ruled out that there are other unknown populations in the wild. For these reasons, we classified its conservation status as Data Deficient (DD), according to the IUCN Red List Criteria (IUCN 2019). Taxonomic note:— Generally, Bulbophyllum guniuensis is morphologically close to B. henanense. In addition, B. guniuensis and B. hirundinis (Gagnep.) Seidenf. (1973: 76) are somewhat similar in petals, lip and column (Seidenfaden 1973). The morphological comparison between these three species were summarized in Table 1 & Fig. 4.Published as part of Zhang, Si-Yu, Zhu, Ke-Run, Yan, Qi, Wu, Wei, Wang, Bo-Rui, Ni, Wei-Yong & Shao, Jian-Wen, 2022, Bulbophyllum guniuensis (Orchidaceae: Epidendroideae; Malaxideae), a new species from Eastern China, pp. 82-88 in Phytotaxa 543 (1) on pages 82-86, DOI: 10.11646/phytotaxa.543.1.8, http://zenodo.org/record/642440
Composition and pore characteristics of black shales from the Ediacaran Lantian Formation in the Yangtze Block, South China
No full textThe Ediacaran period was critical in the evolution of the biosphere and ocean in the history of the Earth. Shales rich in organic matter (OM) are well developed for this period in the Yangtze Block, China, and have recently been related to shale gas exploration in South China. To date, detailed characterisation of the Ediacaran shales is not available. The present work sets out a detailed investigation of the composition and pore characteristics of samples from a shallow drill core in the Ediacaran Lantian Formation in the Lower Yangtze area, and the effects of shale composition on the pore growth are discussed.
The 90-m-thick Lantian black shales are highly over-mature (equivalent vitrinite reflectance (EVRo) value approximately 4.0%) with a total organic carbon (TOC) content up to 12%. They are dominated by quartz (33-72%), generally with low clay or feldspar content (<20%) and highly varied carbonate content (up to 60%). The Lantian shales are also notable for their high pyrite content (up to 19%), suggesting a depositional environment of an anoxic water body rich in sulphates; greatly enriched OM is facilitated in deep-water environments.
Bulk porosities of the shales range from 1.0% to 7.9%, and are positively correlated with TOC content. High-magnification scanning electron microscopy (SEM) images support the crucial importance of OM content on pore development. Generally, pore volume shows excellent, positive correlation with TOC content for micropores, good correlation for mesopores, and relatively poor correlation for macropores. Two samples with mostly high TOC content showed very low macropore volume and medium mesopore volume. These results suggest a close relationship between OM with relatively small pores, and enhanced compaction effect on large pores in highly OM-enriched shales. (C) 2016 Elsevier Ltd. All rights reserved
Chemical composition, optical properties, and oxidative potential of water- and methanol-soluble organic compounds emitted from the combustion of biomass materials and coal
No full textBiomass burning (BB) and coal combustion (CC) are important sources of brown carbon (BrC) in ambient aerosols. In this study, six biomass materials and five types of coal were combusted to generate fine smoke particles. The BrC fractions, including water-soluble organic carbon (WSOC), humic-like substance carbon (HULIS-C), and methanol-soluble organic carbon (MSOC), were subsequently fractionated, and their optical properties and chemical structures were then comprehensively investigated using UV-visible spectroscopy, proton nuclear magnetic resonance spectroscopy (H-1 NMR), and fluorescence excitation-emission matrix (EEM) spectroscopy combined with parallel factor (PARAFAC) analysis. In addition, the oxidative potential (OP) of BB and CC BrC was measured with the dithiothreitol (DTT) method. The results showed that WSOC, HULIS-C, and MSOC accounted for 2.3%-22%, 0.5%-10%, and 6.4%-73% of the total mass of combustion-derived smoke PM2.5, respectively, with MSOC extracting the highest concentrations of organic compounds. The MSOC fractions had the highest light absorption capacity (mass absorption efficiency at 365 nm (MAE(365)): 1.0-2.7m(2)/gC) for both BB and CC smoke, indicating that MSOC contained more of the strong light-absorbing components. Therefore, MSOC may represent the total BrC better than the water-soluble fractions. Some significant differences were observed between the BrC fractions emitted from BB and CC with more water-soluble BrC fractions with higher MAE(365) and lower absorption Angstrom exponent values detected in smoke emitted from BB than from CC. EEM-PARAFAC identified four fluorophores: two protein-like, one humic-like, and one polyphenol-like fluorophores. The protein-like substances were the dominant components of WSOC (47%-80%), HULIS-C (44%-87%), and MSOC (42%-70%). The H-1-NMR results suggested that BB BrC contained more oxygenated aliphatic functional groups (H-C-O), whereas CC BrC contained more unsaturated fractions (H-C-C= and Ar-H). The DTT assays indicated that BB BrC generally had a stronger oxidative potential (DTTm, 2.6-85 pmol/min/mu g) than CC BrC (DTTm, 0.4-11 pmol/min/mu g), with MSOC having a stronger OP than WSOC and HULIS-C. In addition, HULIS-C contributed more than half of the DTT activity of WSOC (63.1% +/- 15.5%), highlighting that HULIS was a major contributor of reactive oxygen species (ROS) production in WSOC. Furthermore, the principal component analysis and Pearson correlation coefficients indicated that highly oxygenated humic-like fluorophore C4 may be the important DTT active substances in BrC
Distinct evolution trends of nanometer-scale pores displayed by the pyrolysis of organic matter-rich lacustrine shales: Implications for the pore development mechanisms
No full textOrganic matter (OM) compositions greatly affect hydrocarbon generation and expulsion processes, which are critical for the organic porosity development in shale. Lacustrine shale samples of low thermal maturity were pyrolyzed using two pyrolysis systems (closed and semi-closed systems). Pore development was measured by low-pressure gas adsorption and field emission-scanning electron microscopy (FE-SEM), and bulk porosity was modeled utilizing organic geochemical data. The gas adsorption analysis indicated that shale samples of different OM compositions differed in pore volume evolution with thermal maturity, mainly related to the different amounts of hydrocarbon generated and expelled. Residual bitumen significantly reduced the pore volume of OM-rich oil generative shale samples, and restricted the micro-, meso-, and macro-pore volumes to different extents. Calculations and experiments both showed that OM-rich and oil generative shale experienced a greater increase in pore volume after the oil peak. In addition, it was observed that variations in the main pore types were associated both with shale compositions and with exerted overburden pressure. Increase in overburden pressure were found to greatly facilitate the development of nanometer-size spongy and complex OM pores in shales containing type II/III kerogens, possibly as a result of the expulsion of gaseous hydrocarbons. By contrast, the shale with abundant type I kerogen tended mainly to develop relatively large pores following oil expulsion regardless of overburden pressure. The modeled organic porosity of pyrolyzed samples of type III OM was similar to the porosity of geological shale, but the porosity of OM-rich oil generative shale samples with high expulsion efficiency at the oil generation stage was two to three times the measured porosity of the geological shale. In some cases, the higher modeled shale porosity might be related to the higher expulsion efficiency. For geological shales of expulsion efficiency comparable to the pyrolyzed samples, geological processes (e.g., compaction and cementation) may have greatly reduced the OM-associated pore volume
Potential of Light Oil and Condensates from Deep Source Rocks Revealed by the Pyrolysis of Type I/II Kerogens after Oil Generation and Expulsion
No full textLight and condensable oils derived from mature kerogen and residual oil in deep source rocks have contributed strongly to a rapid increase in oil production. In this study, oil expulsion from kerogen and shale was simulated by selective solvent extraction (hexane/toluene, 9:1 v/v, instead of the commonly used dichloromethane) and by returning the extracts (so-called "oil a") back into a controlled mass of mature kerogen. The maturity intervals and potential of the light oil and condensates were investigated by analyzing the yields of different hydrocarbons from the subsequent pyrolysis of mature kerogen-"oil a" mixtures. The gas-to-oil ratio was used to constrain the maturity range for the light oil, condensate, and gas stages. The lowest equivalent vitrinite reflectance (EVRo, 1.9-2.1%) for the gas stage was compatible with commonly accepted models. The EVRo cutoff of 1.55-1.75% between light oil and condensate was higher than that in traditional models, although this depended primarily on the generality of the "condensate" definition. An EVRo ranging between 1.35 and 1.55-1.75% was defined in this work as the "light oil/gas" substage within the commonly accepted condensate/wet gas stage. Moreover, yields of hydrocarbons from the cracking of "oil a" were distinctly affected by mature kerogen. This effect showed little difference on the yield of C6-14 hydrocarbons and C15+ hydrocarbons but notable difference for the gases between types I and II kerogens. The release of C6-14 hydrocarbons was promoted when the release of C15+ hydrocarbons was notably inhibited. Approximately linear relationships were established between maximum yields of liquid hydrocarbons and the carbon content of "oil a" (selective solvent extraction products) in the mixtures. This relationship was helpful in estimating both oil and total petroleum potential of deep source rocks that have undergone oil generation and expulsion, but it was dependent on the composition of the solvents used in extraction
Potential of Light Oil and Condensates from Deep Source Rocks Revealed by the Pyrolysis of Type I/II Kerogens after Oil Generation and Expulsion
No full textPy-GC/MS study of lignin pyrolysis and effect of catalysts on product distribution
No full textFast pyrolysis is one of the most promising methods to convert lignin into fuels and chemicals. In the present study, pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was used to evaluate vapor phase product distribution of lignin fast pyrolysis. During the non-catalytic pyrolysis process, lignin was pyrolyzed at 400 degrees C, 500 degrees C and 600 degrees C respectively, finding that the highest yield of aromatic hydrocarbons was obtained at 600 degrees C. Catalytic pyrolysis experiments were also conducted to investigate the effects of catalyst pore structure and acidity on the product distributions. Five different catalysts (HZSM-5, MCM-41, TiO2, ZrO2 and Mg(Al) O) were applied to lignin catalytic pyrolysis, and the catalytic performance was estimated by analyzing the pyrolytic products. The catalysts were characterized by using X-ray diffraction ( XRD), BET, and NH3 (CO2) temperature programmed desorption. Based on these characterizations, discussion was carried out to explain the formation of the produc distributions. Among the five catalysts, HZSM-5 exhibited the best performance on the formation of aromatic hydrocarbons
