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11 Catalytic hydropyrolysis of beech wood was conducted in a fluid bed reactor at 450°C and a total pressure 12 of 26 bar. The differences in hydrodeoxygenation activity, selectivity and the resulting product composition 13 between sulfided Mo/MgAl 2 O 4 , CoMo/MgAl 2 O 4 or NiMo/MgAl 2 O 4 catalysts have been investigated. The 14 acidity and molybdate species in the oxide catalyst precursors were characterized with ammonia 15 temperature programmed desorption (NH 3-TPD) and Raman spectroscopy. The spent sulfided catalysts 16 were also extensively characterized by scanning electron microscopy (SEM) and by scanning transmission 17 electron microscopy (STEM) coupled with energy dispersive X-ray spectroscopy (EDS). The catalytic 18 hydropyrolysis of beech wood produced four kinds of products: Liquid organic and aqueous phases, solid 19 char and gases. The solid char and aqueous phase yields were not affected by the type of catalyst. The sum 20 of condensed organics and C 4+ gas yield varied between 24.3 and 26.4 wt.% on dry, ash free basis (daf) and 21 was highest for the Mo catalyst and lowest for the NiMo catalyst. The NiMo catalyst had the highest 22 hydrogenation, cracking, and de-carbonylation activity. The oxygen content in the condensed organic phase 23 was between 9.0 and 12 wt.% on dry basis (db) and was lowest for the CoMo catalyst and highest for the
A new integrated methodology for forensic oil spill identification is presented. It consists of GC-MS analysis, chromatographic data processing, variable-outlier detection, multivariate data analysis, estimation of uncertainties, and statistical evaluation. The methodology was tested on four groups of diagnostic ratios composed of petroleum biomarkers and ratios within homologous PAH categories. Principal component analysis (PCA) was employed and enabled the simultaneous analysis of many diagnostic ratios. Weathering was taken into account by considering the sampling uncertainties estimated from replicate spill samples. Statistical evaluation ensured an objective matching of oil spill samples with suspected source oils as well as classification into positive match, probable match, and nonmatch. The data analysis is further refined if two or more source oils are classified as probable match by using weighted least squares fitting of the principal components, local PCA models, and additional information relevant to the spill case. The methodology correctly identified the source of two spill samples (i.e., crude oils from Oseberg East and Oseberg Field Centre) and distinguished them from closely related source oils.
The occurrence of heteroaromatic compounds (NSO) and their degradation products in ground water at creosote‐contaminated sites in Denmark was investigated. NSO are of special interest because of their high polarity, toxicity, and adverse organoleptic properties. In total, the content of about 50 organic tar compounds and the chemical redox parameters of ground water from three creosote‐contaminated sites were determined. The organic contamination of ground water varied considerably between sites and wells with concentrations up to mg/L level. The major organic contaminants were NSO, phenols, and monoaromatic hydrocarbons, which are among the most water‐soluble creosote compounds. High concentration (several μg/L) of these compounds were observed downgradient of the contamination source. Within a distance of 50 to 80 m from the source, the concentrations of most compounds were reduced significantly, often below detection limits. The NSO constituted from 0.1 percent to 73 percent of all organic compounds determined by gas chromatography (GC) with an increasing dominance downgradient of the source. Among the 17 studied NSO, carbazole, thiophene, benzothiophene, dibenzothiophene, benzofuran, and dibenzofuran were observed most frequently (detection frequency > 60 percent). High concentrations (>100 μ/L) of some NSO such as benzothiophene, carbazole, hydroxyquinolines, and basic N‐compounds were observed occasionally. Other recent studies on creosote contamination support the present observations of high ground water concentrations of basic N‐compounds and the high detection frequency of the aforementioned NSO. However, unlike the other studies, we did observe thiophene (1‐10 μg/L).
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