Organic geochemistry of sediments from sapropel 94 of ODP Hole 161-974C

Analysis of the molecular composition of the organic matter (OM) from whole sediment samples can avoid analytical bias that might result from isolation of components from the sediment matrix, but has its own analytical challenges. We evaluated the use of GC * GC-ToFMS to analyze the pyrolysis products of six whole sediment samples obtained from above, within and below a 1 million year old OM-rich Mediterranean sapropel layer. We found differences in pyrolysis products

(Table 1) Low molecular weight hydrocarbon concentrations and organic carbon contents at DSDP Hole 71-511

C2-C8 hydrocarbons (36 compounds identified) from 56 shipboard sealed, deep-frozen core samples of DSDP Leg 71, Site 511, Falkland Plateau, South Atlantic, were analyzed by a combined hydrogen stripping-thermovaporization method. Concentrations, which represent hydrocarbons dissolved in the pore water and adsorbed to the mineral surfaces of the sediment, vary from 24 ng/g of dry weight sediment in Lithologic Unit 4 to 17,400 ng/g in Lithologic Unit 6 ("black shale" unit). Likewise, the organic carbon normalized C2-C8 hydrocarbon concentrations range from 104 to 3.5 x 105 ng/g Corg. The latter value is more than one order of magnitude lower than expected for petroleum source beds in the main phase of oil generation. The low maturity at 600 meters depth is further supported by light hydrocarbon concentration ratios. The change of the kerogen type from Lithologic Unit 5 (Type III) to 6 (Type II) is evidenced by changes in the C6 and C7 hydrocarbon composition. Redistribution phenomena are observed close to the Tertiary-Cretaceous unconformity and at the contact between the "black shale" unit and the overlying Cretaceous chalks and claystones. Otherwise, the low molecular weight hydrocarbons in Hole 511 are formed in situ and remain at their place of formation. The core samples turned out to be contaminated by large quantities of acetone, which is routinely used as a solvent during sampling procedures onboard Glomar Challenger.

(Table 1) C1 - C8 volatile compounds in sediments from DSDP Leg 63 Holes

Low-temperature diagenetic reactions (less than 50°C) are held responsible for the generation of small amounts of C1-C8 hydrocarbons (less than 100 ng hydrocarbon/g dry weight of sediment) at outer continental shelf Deep Sea Drilling Project Sites 468 and 469 (sub-bottom depths 415 m and 454 m, respectively). In contrast, Site 471 shows an exponential rise in hydrocarbon yields at depths greater than 500 meters. The high yields of C4-C8 hydrocarbons (up to 30 ng hydrocarbon/g dry weight of sediment) in this area of high geothermal and volcanic activity suggest the penetration of an active petroleum-generating zone. Similar arguments apply to Site 467, where relatively high levels (up to 3 µg hydrocarbon/g dry weight sediment) occurred in very shallow (250-600 m) sediments.

C1-C8 hydrocarbons in marine sediments

Light hydrocarbon (C1-C8) profiles are compared for three wells of varying maturities: two immature DSDP wells (Site 397 near the Canary Islands and Site 530A near the Walvis Ridge in the south-east Atlantic) and a mature well, the East Cameron well in the Texas Gulf Coast. Primary migration of C1 and C2 appears to be occurring in all of the sedimentary rocks examined. Primary migration of C3+ components becomes important only as fine-grained sedimentary rocks enter the catagenetic hydrocarbon generation zone or over short distances in more permeable sections. Lateral migration along bedding planes was more important than vertical migration in sedimentary rocks of all maturities. The lightest (methane, ethane and propane gases) hydrocarbon show greater fractionation than do the C4-C8 alkanes which generally show minimal fractionation during the migrational process. Subsurface diffusion coefficients for these p.p.b. quantities of C2-C5 alkanes from immature sediments from DSDP Site 530 are estimated to be several orders of magnitude less than values reported in the literature for diffusion of much larger amounts of these compounds from mature water wet sediments into air or sandstones. Since our calculations suggest light hydrocarbons are present in amounts less than their reported solubilities in pure water at 25°C, we postulate that the sediment organic matter has a substantial effect on retarding the movement of these light hydrocarbons.

Preparation of Polymer Nanoparticles by Ring Opening Metathesis Polymerization in Aqueous Dispersed Systems with Water-Soluble Ruthenium-based Catalyst

Ring opening metathesis polymerization (ROMP) is a variant of olefin metathesis used to polymerize strained cyclic olefins. Ruthenium-based Grubbs’ catalysts are widely used in ROMP to produce industrially important products. While highly efficient in organic solvents such as dichloromethane and toluene, these hydrophobic catalysts are not typically applied in aqueous systems. With the advancements in emulsion and miniemulsion polymerization, it is promising to conduct ROMP in an aqueous dispersed phase to generate well-defined latex nanoparticles while improving heat transfer and reducing the use of volatile organic solvents (VOCs). Herein I report the efforts made using a PEGylated ruthenium alkylidene as the catalyst to initiate ROMP in an oil-in-water miniemulsion. 1H NMR revealed that the synthesized PEGylated catalyst was stable and reactive in water. Using 1,5-cyclooctadiene (COD) as monomer, we showed the highly efficient catalyst yielded colloidally stable polymer latexes with ~ 100% conversion at room temperature. Kinetic studies demonstrated first-order kinetics with good livingness as confirmed by the shift of gel permeation chromatography (GPC) traces. Depending on the surfactants used, the particle sizes ranged from 100 to 300 nm with monomodal distributions. The more strained cyclic olefin norbornene (NB) could also be efficiently polymerized with a PEGylated ruthenium alkylidene in miniemulsion to full conversion and with minimal coagulum formation.

Exceptional activity of gallium(III) chloride and chlorogallate(III) ionic liquids for Baeyer–Villiger oxidation

Baeyer–Villiger oxidation of cyclic ketones, using H2O2 as the oxidising agent, was systematically studied using a range of metal chlorides in different solvents, and in neat chlorogallate(III) ionic liquids. The extremely high activity of GaCl3 in promoting oxidation with H2O2, irrespective of solvent, was reported for the first time. The activity of all other metal chlorides was strongly solvent-dependent. In particular, AlCl3 was very active in a protic solvent (ethanol), and tin chlorides, SnCl4 and SnCl2, were active in aprotic solvents (toluene and dioxane). In order to eliminate the need for volatile organic solvent, a Lewis acidic chlorogallate(III) ionic liquid was used in the place of GaCl3, which afforded typically 89–94% yields of lactones in 1–120 min, at ambient conditions. Raman and 71Ga NMR spectroscopic studies suggest that the active species, in both GaCl3 and chlorogallate(III) ionic liquid systems, are chlorohydroxygallate(III) anions, [GaCl3OH]−, which are the products of partial hydrolysis of GaCl3 and chlorogallate(III) anions; therefore, the presence of water is crucial.

A Non-catalytic Deep Desulphurization Process using Hydrodynamic Cavitation

A novel approach is developed for desulphurization of fuels or organics without use of catalyst. In this process, organic and aqueous phases are mixed in a predefined manner under ambient conditions and passed through a cavitating device. Vapor cavities formed in the cavitating device are then collapsed which generate (in-situ) oxidizing species which react with the sulphur moiety resulting in the removal of sulphur from the organic phase. In this work, vortex diode was used as a cavitating device. Three organic solvents (n-octane, toluene and n-octanol) containing known amount of a model sulphur compound (thiophene) up to initial concentrations of 500 ppm were used to verify the proposed method. A very high removal of sulphur content to the extent of 100% was demonstrated. The nature of organic phase and the ratio of aqueous to organic phase were found to be the most important process parameters. The results were also verified and substantiated using commercial diesel as a solvent. The developed process has great potential for deep of various organics, in general, and for transportation fuels, in particular.

Crystallization on the Mesoscale : Self-Assembly of Iron Oxide Nanocubes into Mesocrystals

Self-assembly of nanoparticles is a promising route to form complex, nanostructured materials with functional properties. Nanoparticle assemblies characterized by a crystallographic alignment of the nanoparticles on the atomic scale, i.e. mesocrystals, are commonly found in nature with outstanding functional and mechanical properties. This thesis aims to investigate and understand the formation mechanisms of mesocrystals formed by self-assembling iron oxide nanocubes. We have used the thermal decomposition method to synthesize monodisperse, oleate-capped iron oxide nanocubes with average edge lengths between 7 nm and 12 nm and studied the evaporation-induced self-assembly in dilute toluene-based nanocube dispersions. The influence of packing constraints on the alignment of the nanocubes in nanofluidic containers has been investigated with small and wide angle X-ray scattering (SAXS and WAXS, respectively). We found that the nanocubes preferentially orient one of their {100} faces with the confining channel wall and display mesocrystalline alignment irrespective of the channel widths.  We manipulated the solvent evaporation rate of drop-cast dispersions on fluorosilane-functionalized silica substrates in a custom-designed cell. The growth stages of the assembly process were investigated using light microscopy and quartz crystal microbalance with dissipation monitoring (QCM-D). We found that particle transport phenomena, e.g. the coffee ring effect and Marangoni flow, result in complex-shaped arrays near the three-phase contact line of a drying colloidal drop when the nitrogen flow rate is high. Diffusion-driven nanoparticle assembly into large mesocrystals with a well-defined morphology dominates at much lower nitrogen flow rates. Analysis of the time-resolved video microscopy data was used to quantify the mesocrystal growth and establish a particle diffusion-based, three-dimensional growth model. The dissipation obtained from the QCM-D signal reached its maximum value when the microscopy-observed lateral growth of the mesocrystals ceased, which we address to the fluid-like behavior of the mesocrystals and their weak binding to the substrate. Analysis of electron microscopy images and diffraction patterns showed that the formed arrays display significant nanoparticle ordering, regardless of the distinctive formation process.  We followed the two-stage formation mechanism of mesocrystals in levitating colloidal drops with real-time SAXS. Modelling of the SAXS data with the square-well potential together with calculations of van der Waals interactions suggests that the nanocubes initially form disordered clusters, which quickly transform into an ordered phase.

New N-acylamino acids and derivatives from renewable fatty acids: gelation of hydrocarbons and thermal properties

This work reports the synthesis of new fatty N-acylamino acids and N-acylamino esters from the C16:0, C18:0, C18:1, and C18:1(OH) fatty acid families and demonstrates the activity of these compounds as organogel agents. Compounds were heated and dissolved in various solvents (n-hexane, toluene, and gasoline). Only saturated C16:0 and C18:0 derived from alanine were able to form gels in toluene, and saturated C16:0 derived from phenylalanine showed gelation in n-hexane. This is the first evidence that fatty N-acylamino esters and N-acylamino acid derivatives of l-serine and fatty acids C16:0, C18:0, and C18:1 are able to form gels with hexane. This observation confirms the importance of the hydroxyl group in the segment derivative of l-serine in forming good gels.

Design of experiments to optimized the determination of TDIs in agglomerated cork stoppers

Isocyanates are included into a class with an extreme commercial importance because their use in the manufacture of polyurethanes. Polyurethanes are used in several applications such as adhesives, coatings, foams, thermoplastics resins, printing inks, foundry moulds and rubbers. Agglomerated cork stoppers are currently used for still wines, semi-sparkle and gaseous wines, beer and cider. Methylene diphenyl diisocyanate (MDI) is presently the isocyanate used in the production of polyurethane based adhesive in use due to its lowest toxicity comparing with toluene diisocyanate (TDI) previously employed. However, free monomeric TDI or MDI, depending on the based polyurethane, can migrate from agglomerated cork stoppers to beverages therefore it needs to be under control. The presence of these compounds are usually investigated by HPLC with Fluorescence or UV-Vis detector depending on the derivatising agent. Ultra Performance Liquid Chromatography with Diode Array Detector (UPLC-DAD) method is replacing HPLC. The objective of this study is to determine which method is better to analyze isocyanates from agglomerated cork stoppers, essentially TDI to quantify its monomer. A Design of Experiments (DOE) with three factors, column temperature, flow and solvent, at two levels was done. Eight experiments with three replications and two repetitions were developed. Through an ANOVA the significance of the factors was evaluated and the best level’s factors were selected. As the TDI has two isomers and in this method these two isomers were not always separated an ANOVA with results of resolution between peaks was performed. The Design of Experiments reveals to be a suitable statistical tool to determine the best conditions to quantified free isocyanates from agglomerated cork stoppers to real foodstuff. The best level’s factors to maximize area was column temperature at 30ºC, flow to 0,3 mL/min and solvent 0,1% Ammonium Acetate, to maximize resolution was the same except the solvent that was 0,01% Ammonium Acetate.

Toxic metal recovery from spent hydroprocessing catalyst

Spent hydroprocessing catalysts (HPCs) are solid wastes generated in refinery industries and typically contain various hazardous metals, such as Co, Ni, and Mo. These wastes cannot be discharged into the environment due to strict regulations and require proper treatment to remove the hazardous substances. Various options have been proposed and developed for spent catalysts treatment; however, hydrometallurgical processes are considered efficient, cost-effective and environmentally-friendly methods of metal extraction, and have been widely employed for different metal uptake from aqueous leachates of secondary materials. Although there are a large number of studies on hazardous metal extraction from aqueous solutions of various spent catalysts, little information is available on Co, Ni, and Mo removal from spent NiMo hydroprocessing catalysts. In the current study, a solvent extraction process was applied to the spent HPC to specifically remove Co, Ni, and Mo. The spent HPC is dissolved in an acid solution and then the metals are extracted using three different extractants, two of which were aminebased and one which was a quaternary ammonium salt. The main aim of this study was to develop a hydrometallurgical method to remove, and ultimately be able to recover, Co, Ni, and Mo from the spent HPCs produced at the petrochemical plant in Come By Chance, Newfoundland and Labrador. The specific objectives of the study were: (1) characterization of the spent catalyst and the acidic leachate, (2) identifying the most efficient leaching agent to dissolve the metals from the spent catalyst; (3) development of a solvent extraction procedure using the amine-based extractants Alamine308, Alamine336 and the quaternary ammonium salt, Aliquat336 in toluene to remove Co, Ni, and Mo from the spent catalyst; (4) selection of the best reagent for Co, Ni, and Mo extraction based on the required contact time, required extractant concentration, as well as organic:aqueous ratio; and (5) evaluation of the extraction conditions and optimization of the metal extraction process using the Design Expert® software. For the present study, a Central Composite Design (CCD) method was applied as the main method to design the experiments, evaluate the effect of each parameter, provide a statistical model, and optimize the extraction process. Three parameters were considered as the most significant factors affecting the process efficiency: (i) extractant concentration, (ii) the organic:aqueous ratio, and (iii) contact time. Metal extraction efficiencies were calculated based on ICP analysis of the pre- and post–leachates, and the process optimization was conducted with the aid of the Design Expert® software. The obtained results showed that Alamine308 can be considered to be the most effective and suitable extractant for spent HPC examined in the study. Alamine308 is capable of removing all three metals to the maximum amounts. Aliquat336 was found to be not as effective, especially for Ni extraction; however, it is able to separate all of these metals within the first 10 min, unlike Alamine336, which required more than 35 min to do so. Based on the results of this study, a cost-effective and environmentally-friendly solventextraction process was achieved to remove Co, Ni, and Mo from the spent HPCs in a short amount of time and with the low extractant concentration required. This method can be tested and implemented for other hazardous metals from other secondary materials as well. Further investigation may be required; however, the results of this study can be a guide for future research on similar metal extraction processes.

Greener Alternatives to Selected Organic Oxidation Reactions

The study of green chemistry is dedicated to eliminating or reducing toxic waste. One route to accomplish this goal is to explore alternative reaction conditions and parameters resulting in the development of more benign synthetic routes and reagents. The primary focus of this research is to find optimal reaction conditions for the oxidation of a primary alcohol to an aldehyde. As a case study, the oxidation of benzyl alcohol to benzaldehyde, a common industrial process, was examined. Traditionally carried out using the Jones Reagent, commonly referred to as chromium (IV) oxide or chromium trioxide (CrO3) in sulphuric acid, a great deal of research went into utilizing less toxic reagents, such as MnO2 or KMnO4 supported on a clay base. This research has led to an improvement on these alternatives, using a lithium chloride (LiCl) catalyst in a montmorillonite K10 clay solid phase, together with the oxidizing agent hydrogen peroxide, as even greener alternatives to these traditional oxidizing agents. Experiments were carried out to determine the lifetime of this LiCl/clay system as compared to MnO2 and KMnO4, to investigate its ability to catalyze the oxidation of other aromatic alcohols (such as 4-methoxybenzyl alcohol and diphenylmethanol), and to further improve the system’s adherence to green chemistry principles. Green solvent alternatives were examined by replacing the toluene solvent with dimethylcarbonate (DMC), and reaction conditions were optimized to improve product yield. It was determined that the LiCl/H2O2 system was, in most cases, equally as effective at catalyzing the oxidation of benzyl alcohol to benzaldehyde. Although the catalyst and oxidizing agent eliminated the toxic waste generated from chromium reagents, it offered significant challenges in product isolation, because of an aqueous-organic phase separation.

Síntese de novos N-acilaminoácidos graxos: estudo das propriedades gelificantes

Neste trabalho é descrita a síntese de novos N-acilaminoácidos e Nacilaminoésteres graxos derivados de ácidos graxos saturados e insaturados como, por exemplo, esteárico e ricinoléico, respectivamente. Após, foi avaliada a capacidade destes compostos para a gelificação de hidrocarbonetos e as propriedades dos géis formados foram estudadas pelas técnicas de Espectroscopia de Infravermelho (IV) e Calorimetria de Varredura Diferencial (DSC). A síntese dos N-acilaminoésteres graxos foi realizada na presença de DCC, DMAP e dos respectivos aminoésteres e ácidos graxos. Os N-acilaminoésteres graxos 11-15a-d foram isolados em rendimentos que variaram de 50-84%, após 12h de reação a temperatura ambiente. Os N-acilaminoácidos graxos 16-20a-d foram obtidos a partir da hidrólise básica de 11-15a-d realizada a temperatura ambiente, em rendimentos que variaram de 34-80%. A seguir foi realizado o estudo de gelificação com todos os compostos sintetizados para verificar a influência das diferentes cadeias graxas e dos grupos laterais dos aminoácidos e aminoésteres na gelificação de tolueno, hexano e gasolina. As análises de DSC e IV mostraram que a estabilidade dos géis dependeu do tipo e do tamanho da cadeia lipofílica e também da natureza dos grupos laterais ligados ao átomo de nitrogênio. Dentre os compostos testados os compostos 17a-b de cadeia satura (C16:0 e C18:0) e 19a (C16:0), derivados da alanina e da fenilalanina, respectivamente, formaram géis em hexano, gasolina e tolueno. Pela primeira vez foram citadas as capacidades de gelificação de hidrocarbonetos pelos Nacilaminoésteres graxos 15a-b de cadeia saturada, derivados da serina, sendo os géis derivados destes compostos os mais estáveis termicamente dentre todos os obtidos.

Adsorption of aromatic compound by multi-walled carbon nanotube from sea water

It is global concern that soil and water were contaminated with organic substances such as BTEX (benzene) (B), toluene (T) and xylene (x) .The presence of excessive amounts of BTEX in aqueous surroundings may have a greatly adverse impact on water quality and thus endanger public health and welfare. Carbon nanotubes (CNT) have aroused widespread attention as a new type of adsorptions due to their outstanding ability for the removal of various inorganic and organic pollutants from large volume of wastewater. Due to variety of adsorbent and their ability to adsorb pollutant, it is possible to reduce expenses and completely omit pollutant. In this CNT is used as a new adsorbent for removal pollutant such as benzene, toluene, and xylene. The result in the area of adsorbing benzene, toluene, and xylene is as follows: the changes of pH don’t affect the capacity of adsorption and the greatest amount of adsorption occurs in pH. The greatest amount of adsorption occurs when using 0.01gr CNT oxidized. Comparing CNT with CNT oxidized in term of adsorption capacity, it is proved that the adsorption capacity of CNT oxidized is much more than CNT. The result of comparing the percentage of adsorption of mentioned elements (B, X, T) is as follows; the amount of adsorption of xylene is more than toluene and toluene is more than benzene. It should be mentioned that in this research the percentage of adsorption to measure is between to 70-80.

Análise de compostos orgânicos voláteis (BTEX) no ar da Cidade de Évora

A poluição atmosférica é um dos principais factores de degradação da qualidade de vida da população. O conjunto BTEX (benzeno, tolueno, etilbenzeno e xilenos) constitui o grupo mais importante dos compostos orgânicos voláteis (VOCs) na atmosfera uma vez que participam na química da atmosfera e constituem um perigo para a saúde, nomeadamente o benzeno, por ser altamente cancerígeno. São maioritariamente libertados pelo tráfego automóvel. Neste trabalho foi determinada a concentração dos BTEX em nove pontos da cidade de Évora no período de 21 Março a 1 de Julho de 2009 tendo-se recorrido à técnica de amostragem passiva, com amostradores Radiello™, seguida de desadsorção líquida, usando CS2, e subsequente análise por GC-MS. A concentração de benzeno no ar da cidade de Évora não excedeu o valor legislado de 5 g/m3 neste período de amostragem, sendo as concentrações obtidas para os poluentes em geral muito baixas e na sua maioria inferiores ao LOQ do método analítico. ABSTRACT; Air pollution is the major factor in the degradation of the population quality of life. BTEX (benzene, toluene, ethylbenzene and xylenes) is the most important group of volatile organic compounds (VOCs) in the atmosphere because of their role in atmospheric chemistry and the risk they posed to human health, with benzene, being a highly carcinogenic compound. BTEX are released mainly by road traffic. Concentrations of BTEX were determined at nine sampling points in the city of Évora in the period from 21 March to 1 July 2009, using passive samplers Radiello™, followed by liquid desorption with CS2, and subsequent analysis by GC-MS. During the sampling period, the concentration of benzene in the outdoor air of Évora city did not exceed 5 g/m3, the maximum value admissible by legislation. The concentrations measured of the other pollutants were, in general, very low and mostly below the LOQ of the analytical method.