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At least 649 records · Page 36

Catalytic conversion of post-consumer recycled high-density polyethylene oil over Zn-impregnated ZSM-5 catalysts

The catalytic conversion of post-consumer recycled high-density polyethylene (PCR-HDPE) pyrolysis oil was investigated using modified ZSM-5 zeolites, prepared under different conditions. The PCR-HDPE oil, obtained through pyrolysis at 500 °C followed by distillation at 165 °C, contained a naphtha fraction hydrocarbons suitable for catalytic upgrading. H/ZSM-5 converts PCR-HDPE naphtha fraction oil primarily into BTX, along with light paraffins and olefins. Introducing mesoporosity led to increased propylene yield at the expense of BTX. Zn impregnation onto H/ZSM-5 and H-meso/ZSM-5 enhanced BTX yield by up to 13 %. However, Zn-meso/ZSM-5 exhibited a lower BTX yield than Zn/ZSM-5 with the same Zn loadings, especially after additional steam treatment at 700 °C. Spent catalysts revealed no noticeable increase in metal contaminants such as calcium and aluminum that were present in the PCR-HDPE. Here, the Zn/ZSM-5 catalyst was stable for more than 50 h time on stream and showed promising potential for upgrading PCR-HDPE naphtha fraction oils.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Lube oil-dependent ash chemistry on soot oxidation reactivity in a gasoline direct-injection engine

Gasoline particulate filters (GPF) are considered an enabling technology to meet stringent particulate matter (PM) regulations for gasoline direct-injection (GDI) engines, which are known to produce significant PM emissions. While ash loading in filters has been recognized to be detrimental in filter performance by increasing back pressure, increased ash fractions in soot were observed to enhance soot oxidation. In this study, GDI soot samples derived from different gasoline/lube oil blends were evaluated to identify potential promoting factors when formulated lube oils were dosed into gasoline fuel. Ca-derived ash enhanced soot oxidation remarkably, while P- and ZDDP-derived ash deteriorated soot oxidation. It is apparent that the promoting effect of lube oil-derived ash is due mainly to the Ca component that is the most abundant among additive components in lube oil. Bulk and surface analyses of these ash compounds indicate that Ca-derived ash would be complex compounds, while the contribution of CaSO 4 , which is one of the most abundant ash compounds from diesel engines, is almost negligible. For the validation of the ash promoting impact in filters, the regeneration experiments were compared for a TWC-coated GPF in a GDI engine before and after ash loading was performed. The pressure drop of the ash-loaded GPF decreased noticeably in the initial regeneration stage and it increased gradually, whereas that of no ash-loaded GPF increased gradually without any reduction. So, it is concluded that the ash layer in the GPF assisted soot oxidation in the early regeneration stage when it was in close contact with soot.

33 ADVANCED PROPULSION SYSTEMS↗

CO 2 Sequestration and Enhanced Oil Recovery at Depleted Oil/Gas Reservoirs

This study presents a quantitative evaluation of the operational and technical risks of an active CO 2 -EOR project. A set of risk factor metrics is defined to post-process the Monte Carlo (MC) simulations for statistical analysis. The risk factors are expressed as measurable quantities that can be used to gain insight into project risk (e.g. environmental and economic risks) without the need to generate a rigorous consequence structure, which include (a) CO 2 injection rate, (b) net CO 2 injection rate, (c) cumulative CO 2 storage, (d) cumulative water injection, (e) oil production rate, (f) cumulative oil production, (g) cumulative CH 4 production, and (h) CO 2 breakthrough time. The Morrow reservoir at the Farnsworth Unit (FWU) site, Texas, is used as an example for studying the multi-scale statistical approach for CO 2 accounting and risk analysis. A set of geostatistical-based MC simulations of CO 2 -oil/gas-water flow and transport in the Morrow formation are conducted for evaluating the risk metrics. A response-surface-based economic model has been derived to calculate the CO 2 -EOR profitability for the FWU site with a current oil price, which suggests that approximately 31% of the 1000 realizations can be profitable. If government carbon-tax credits are available, or the oil price goes up or CO 2 capture and operating expenses reduce, more realizations would be profitable.

02 PETROLEUM↗

Oil extraction in the Amazon basin and exposure to metals in indigenous populations

Highlights: • We assessed the body burdens of metals in two kukama communities after oil spills. • Median Hg levels were above values recommended by the Peruvian Ministry of Health. • 50% of the population had Hg levels higher than those recommended. • 17% of the study population had Cd levels higher than those recommended. • Oil spills may be a source of exposure to metals but other sources may contribute. Most oil extraction areas in the Peruvian Amazon are within indigenous territories. Poor environmental practices have exposed the indigenous population to metals. We conducted a survey in two indigenous Kukama communities to assess body burdens of metals after the occurrence of two major oil spills in 2014. Urine levels above those recommended by the Peruvian Ministry of Health were observed in 50% and 17% of the study population for mercury and cadmium, respectively.

54 ENVIRONMENTAL SCIENCES↗

Iodine 125 Brachytherapy With Vitrectomy and Silicone Oil in the Treatment of Uveal Melanoma: 1-to-1 Matched Case-Control Series

Purpose: We initially reported the radiation-attenuating effect of silicone oil 1000 centistokes for iodine 125. The purpose of this report was to compare the clinical outcomes in case patients who had iodine 125 brachytherapy with vitrectomy and silicone oil 1000 centistokes with the outcomes in matched control patients who underwent brachytherapy alone. Methods and Materials: Consecutive patients with uveal melanoma who were treated with iodine 125 plaque brachytherapy and vitrectomy with silicone oil with minimum 1-year follow-up were included. Control patients who underwent brachytherapy alone were matched for tumor size, location, and sex. Baseline patient and tumor characteristics and tumor response to radiation, final visual acuity, macular status, central macular thickness by ocular coherence tomography (OCT), cataract progression, and metastasis at last follow-up visit were compared. Surgical complications were also determined. Results: Twenty case patients met the inclusion criteria. The average follow-up time was 22.1 months in case patients and 19.4 months in control patients. The final logMAR vision was 0.81 in case patients and 1.1 in control patients (P=.071); 8 case patients and 16 control patients had abnormal macular findings (P=.011); and the average central macular thickness by OCT was 293.2 μm in case patients and 408.5 μm in control patients (P=.016). Eleven case patients (55%) and 1 control patient (5%) had required cataract surgery at last follow-up (P=.002). Four patients in the case group and 1 patient in the control group experienced metastasis (P=.18). Among the cases, intraoperative retinal tear occurred in 3 patients; total serous retinal detachment and macular hole developed in 1 case patient each. There was no case of rhegmatogenous retinal detachment, treatment failure, or local tumor dissemination in case patients or control patients. Conclusions: With up to 3 years of clinical follow-up, silicone oil during brachytherapy for the treatment of uveal melanoma resulted in fewer abnormal maculas, lower central macular thickness on OCT, and a trend toward better final visual acuity in comparison with matched control patients who underwent brachytherapy alone.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Generation of camelina mid-oleic acid seed oil by identification and stacking of fatty acid biosynthetic mutants

Modifying oilseeds to obtain a desired fatty acid composition is often necessary to enable use as feedstocks for specific applications such as food processing, biofuels, or biolubricants. A mutant population of camelina (Camelina sativa), an emerging specialty oilseed crop, was screened by high-throughput gas chromatography for lines with altered seed oil fatty acid composition. By leveraging knowledge of fatty acid synthesis in Arabidopsis thaliana, mutations in orthologs of FATTY ACID ELONGASE1 (FAE1), FATTY ACID DESATURASE2 (FAD2), FATTY ACID DESATURASE3 (FAD3), and β-KETO-ACYL-ACP SYNTHASE II (KASII; FAB1) were identified. The mutations altered conserved amino acid residues in the encoded proteins. The ability of the mutations in FAE1, FAD2 and FAD3 to affect enzyme function was demonstrated by comparing in vivo activities of wild-type and mutant alleles in yeast. In addition, expression of wild-type cDNA in camelina complemented fatty acid phenotypes of these mutants. As camelina has a hexaploid genome, the effect of a mutation in one of the three homeologs for each gene resulted in no or less severe growth phenotypes compared to similar mutations in Arabidopsis. Mid-oleic oils with nearly 40 % oleic acid and reduced very long-chain (≤C20) fatty acid content were obtained by crossing to obtain a fae1c/fad2a/fae1a/fad3a quadruple mutant. Little effect on total seed oil content was observed in the stacked mutant line. Finally, the resulting mid-oleic acid oil had improved oxidative stability due to reductions in polyunsaturated fatty acid content, increasing its utility for biofuels and other applications.

09 BIOMASS FUELS↗

Separation of chemical groups from bio-oil aqueous phase via sequential organic solvent extraction

Bio-oil aqueous phase contains a considerable amount of furans, alcohols, ketones, aldehydes and phenolics besides the major components of organic acids and anhydrosugars. The complexity of bio-oil aqueous phase limits its efficient utilization. To improve the efficiency of bio-oil biorefinery, this study focused on the separation of chemical groups from bio-oil aqueous phase via sequential organic solvent extractions. Due to their high recoverability and low solubility in water, four solvents (hexane, petroleum ether, chloroform, and ethyl acetate) with different polarities were evaluated, and the optimum process conditions for chemical extraction were determined. Chloroform had high extraction efficiency for furans, phenolics, and ketones. In addition to these chemical groups, ethyl acetate had high extraction efficiency for organic acids. The sequential extraction by using chloroform followed by ethyl acetate rendered that 62.2 wt.% of original furans, ketones, alcohols, and phenolics were extracted to chloroform, over 62 wt.% acetic acid was extracted to ethyl acetate, resulting in a high concentration of levoglucosan (~53.0 wt.%) in the final aqueous phase. Chemicals separated via the sequential extraction could be used as feedstocks in biorefinery using processes such as catalytic upgrading of furans and phenolics to hydrocarbons, fermentation of levoglucosan to produce alcohols and diols, and hydrogen production from organic acids via microbial electrolysis.

09 BIOMASS FUELS↗

Episodic hydrocarbon charge in tight Mississippian reservoirs of Central Oklahoma, USA: Insights from oil inclusion geochemistry

The unforeseen discovery of substantial hydrocarbons in ultra-tight Mississippian reservoirs in Oklahoma testifies to the complexity of the hydrocarbon charge across the flanks of the Nemaha Uplift. Based on crude oil and fluid-inclusion chemistry, the hydrocarbons at the western side of the Nemaha Uplift consist of highly-mature, thermally-cracked and less-mature uncracked hydrocarbons (0.50–1.4% calculated vitrinite reflectance, R c ). The oils are less mature on the eastern flank of the structure (0.5–0.7% R c ). Based on distributions of biomarkers and higher diamondoid (composed of three adamantane cages or more) distributions, the hydrocarbons entrapped within reservoir fluid-inclusions are sourced from the Woodford Shale and also from Mississippian carbonates. To our knowledge, this is the first work to describe oil correlations using diamondoids inside fluid inclusions. Petroleum compositions in the ultra-tight Mississippian reservoirs are highly variable, which highlights the need for a thorough assessment of mechanisms controlling charge. By integrating oil and fluid inclusion geochemistry and fluid-inclusion microthermometry with basin modeling, we show that the primary controls are: (1) proximity to the source-rock kitchen(s), (2) episodic charging from Permian through Cretaceous time, and (3) mixing.

58 GEOSCIENCES↗

Surface engineering of polymeric membranes with metal oxides for improved fouling resistance and superior oil-water separation

Rapid industrial growth has increased the need for efficient membranes to separate oil-water emulsions. Polyvinylidene fluoride (PVDF) membranes, although widely used due to their chemical inertness and favorable mechanical properties, suffer from fouling due to their intrinsic hydrophobicity. Modifying these membranes after fabrication offers a practical solution as it easily fits into existing large-scale manufacturing processes. Atomic layer deposition (ALD), an atomically-precise vapor phase surface modification technique, can create ultrathin metal oxide layers that greatly improve membrane hydrophilicity without significantly affecting the original pore size. However, PVDF's lack of reactive chemical moieties makes ALD challenging. Here, in this study, we present a simple alkali treatment that greatly enhances ALD nucleation and growth on PVDF membranes. This treatment imparts exceptional oil-water emulsion separation capabilities and antifouling behavior in PVDF membranes after just a few ALD cycles, surpassing the performance of PVDF membranes coated with hundreds of ALD cycles. This dramatic reduction in the number of ALD cycles required could enable cost-effective modification of commercial PVDF membranes at scale using spatial, roll-to-roll ALD. These modified membranes outperform reported modified PVDF membranes, with >99 % permeance recovery and <1 % irreversible loss of permeance and >98 % oil rejection from oil-water emulsions over 100 h continuous operation, making them promising for advanced water purification technologies.

Atomic layer deposition↗

Dynamic Life Cycle Assessment for Evaluating the Global Warming Potential of Geothermal Energy Production Using Inactive Oil and Gas Wells for District Heating in Tuttle, Oklahoma

Repurposing abandoned oil and gas infrastructure for geothermal energy production has great potential to reduce greenhouse gas (GHG) emissions. This study quantified the life cycle global warming potential of geothermal energy production using four inactive oil and gas wells repurposed for district heating in Tuttle, Oklahoma. A cradle-to-grave prospective life cycle assessment was performed to compare GHG emissions between the geothermal district heating system and conventional natural gas-fired heating system from 2020 to 2050. For initial implementation of the geothermal system, we investigated two approaches: 1) repurposing abandoned infrastructure from a nearby oil and gas well site, and 2) production and injection well drillings including new construction of a central heat exchange station. Environmental impacts from the geothermal system were estimated for five scenarios where a natural gas peaking boiler is incorporated to supply peak heat demand. The prospective results indicated that cumulative reduction in GHG emissions from transitioning to the geothermal district heating system increase over time as a function of future renewable resource penetration and technological advancements within electricity, fuel, and steel production. Over 30 years, the global warming potential associated with the district heating demand will have been reduced by up to 24 % with the repurposed system. These results imply that repurposing existing oil and gas infrastructure for geothermal energy systems of district heating will bring future climate benefits.

abandoned oil and gas wells↗

Transesterification of waste vegetable oil under pulse sonication using ethanol, methanol and ethanol–methanol mixtures

Highlights: • Pulse sonication effect on transesterification of waste vegetable oil was studied. • Effects of ethanol, methanol, and alcohol mixtures on FAMEs yield were evaluated. • Effect of ultrasonic intensity, power density, and its output rates were evaluated. • Alcohol mixtures resulted in higher biodiesel yields due to better solubility. - Abstract: This study reports on the effects of direct pulse sonication and the type of alcohol (methanol and ethanol) on the transesterification reaction of waste vegetable oil without any external heating or mechanical mixing. Biodiesel yields and optimum process conditions for the transesterification reaction involving ethanol, methanol, and ethanol–methanol mixtures were evaluated. The effects of ultrasonic power densities (by varying sample volumes), power output rates (in W), and ultrasonic intensities (by varying the reactor size) were studied for transesterification reaction with ethanol, methanol and ethanol–methanol (50%-50%) mixtures. The optimum process conditions for ethanol or methanol based transesterification reaction of waste vegetable oil were determined as: 9:1 alcohol to oil ratio, 1% wt. catalyst amount, 1–2 min reaction time at a power output rate between 75 and 150 W. It was shown that the transesterification reactions using ethanol–methanol mixtures resulted in biodiesel yields as high as >99% at lower power density and ultrasound intensity when compared to ethanol or methanol based transesterification reactions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Small-Angle Neutron Scattering Investigation of Oil Recovery in Mineralogically Distinct Wolfcamp Shale Strata

Understanding and improving hydrocarbon yields during enhanced oil recovery (EOR) in unconventional reservoirs is complicated by the intrinsic mineralogical and geochemical heterogeneity of shale formations. Here, in this study, we utilized small-angle neutron scattering (SANS) and ultra-small-angle neutron scattering (USANS) to investigate the degree of oil retention and its location in the nanoporous shale matrix for two mineralogically distinct shale samples. The two samples, dubbed “dark” and “light” based on their color, were taken from adjacent strata in a Wolfcamp shale core. While both samples contained kerogen, the dark sample contained more kerogen and clay (43.7 wt %) while the light sample contained more calcite (54.9 wt %). Samples were presaturated with decane, a model hydrocarbon, prior to pressure cycling with methane. Results showed significantly more retention of decane in 1.5–10 nm radius pores of both, likely indicating that oil is retained within kerogen nanopores. Although the dark sample had a higher porosity of 8.7%, versus 3.3% for the light sample, more pores were accessible to decane and a higher percentage of the imbibed decane was removable from the light sample compared to the dark sample. The majority of decane was not recoverable for the dark sample, indicating that EOR with methane can be challenging. These new findings can help to model expected recoveries of in-place oil from heterogeneous shale formations, as well as inform improved EOR strategies.

04 OIL SHALES AND TAR SANDS↗

In Situ Monitoring the Nucleation and Growth of Nanoscale CaCO 3 at the Oil–Water Interface

Interfaces can actively control the nucleation kinetics, orientations, and polymorphs of calcium carbonate (CaCO 3 ). Prior studies have revealed that CaCO 3 formation can be affected by the interplay between chemical functional moieties on solid–liquid or air–liquid interfaces as well as CaCO 3 ’s precursors and facets. Yet little is known about the roles of a liquid–liquid interface, specifically an oil–liquid interface, in directing CaCO 3 mineralization which are common in natural and engineered systems. Here, in this study, by using in situ X-ray scattering techniques to locate a meniscus formed between water and a representative oil, isooctane, we successfully monitored CaCO 3 formation at the pliable isooctane–water interface and systematically investigated the pivotal roles of the interface in the formation of CaCO 3 (i.e., particle size, its spatial distribution with respect to the interface, and its mineral phase). Different from bulk solution, ∼5 nm CaCO 3 nanoparticles form at the isooctane–water interface. They stably exist for a long time (36 h), which can result from interface-stabilized dehydrated prenucleation clusters of CaCO 3 . There is a clear tendency for enhanced amounts and faster crystallization of CaCO 3 at locations closer to isooctane, which is attributed to a higher pH and an easier dehydration environment created by the interface and oil. Our study provides insights into CaCO 3 nucleation at an oil–water interface, which can deepen our understanding of pliable interfaces interacting with CaCO 3 and benefit mineral scaling control during energy-related subsurface operation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Hydroprocessing Bio-oil and Products Separation for Coke Production

Fast pyrolysis of biomass can be used to produce a raw bio-oil product, which can be upgraded by catalytic hydroprocessing to hydrocarbon liquid products. In this study the upgraded products were distilled to recover light naphtha and oils and to produce a distillation resid with useful properties for coker processing and production of renewable, low-sulfur electrode carbon. For this hydroprocessing work, phase separation of the bio-oil was applied as a preparatory step to concentrate the heavier, more phenolic components thus generating a more amenable feedstock for resid production. Low residual oxygen content products were produced by continuous-flow, catalytic hydroprocessing of the phase separated bio-oil.

bio-oil↗

Identification of triacylglycerol remodeling mechanism to synthesize unusual fatty acid containing oils

Abstract Typical plant membranes and storage lipids are comprised of five common fatty acids yet over 450 unusual fatty acids accumulate in seed oils of various plant species. Plant oils are important human and animal nutrients, while some unusual fatty acids such as hydroxylated fatty acids (HFA) are used in the chemical industry (lubricants, paints, polymers, cosmetics, etc.). Most unusual fatty acids are extracted from non-agronomic crops leading to high production costs. Attempts to engineer HFA into crops are unsuccessful due to bottlenecks in the overlapping pathways of oil and membrane lipid synthesis where HFA are not compatible. Physaria fendleri naturally overcomes these bottlenecks through a triacylglycerol (TAG) remodeling mechanism where HFA are incorporated into TAG after initial synthesis. TAG remodeling involves a unique TAG lipase and two diacylglycerol acyltransferases (DGAT) that are selective for different stereochemical and acyl-containing species of diacylglycerol within a synthesis, partial degradation, and resynthesis cycle. The TAG lipase interacts with DGAT1, localizes to the endoplasmic reticulum (with the DGATs) and to puncta around the lipid droplet, likely forming a TAG remodeling metabolon near the lipid droplet-ER junction. Each characterized DGAT and TAG lipase can increase HFA accumulation in engineered seed oils.

59 BASIC BIOLOGICAL SCIENCES↗

Systematic observations of enhanced oil recovery and associated changes at carbonate-brine and carbonate-petroleum interfaces

Enhanced oil recovery (EOR) from carbonates is obtained by injection of controlled ionic strength brines containing “active ions” (e.g., SO 4 2- , Mg 2+ , Ca 2+ ). It is generally believed that this occurs through the interaction of the active ions at the carbonate-brine interface (e.g., within a thin brine layer separating the petroleum and the carbonate phases). Here, in-situ observations show how one active ion, SO 4 2- , alters behavior at the carbonate-petroleum interface. Displacement of petroleum from initially oil-wet carbonate rocks using brines with variable SO 4 concentrations systematically changes oil recovery, in situ contact angles, and connectivity of the oil phase, confirming that the active ion alters interactions at the oil/brine/carbonate interface, as expected. Measurements of model calcite-fluid interfaces show that there is no measurable sorption of SO 4 to carbonate-brine interfaces but reveals that the carbonate-petroleum interface is altered by previous exposure to SO 4 -containing brines. These results suggest that EOR in carbonates is controlled indirectly by active ions. We propose that this may be due to a reduced oleophilicity of the carbonate caused by chemical complexation between the active ion and petroleum’s acidic and basic functional groups. This mechanism explains how both anions and cations act as active ions for EOR in carbonates.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Controllable underwater anisotropic oil-wetting

This Letter demonstrates a simple method to achieve underwater anisotropic oil-wetting using silicon surfaces with a microgroove array produced by femtosecond laser ablation. The oil contact angles along the direction perpendicular to the grooves are consistently larger than those parallel to the microgroove arrays in water because the oil droplet is restricted by the energy barrier that exists between the non-irradiated domain and the trapped water in the laser-ablated microgrooves. This underwater anisotropic oil-wetting is able to be controlled, and the anisotropy can be tuned from 0° to ∼20° by adjusting the period of the microgroove arrays.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Topological and thermal properties of polypropylene composites based on oil palm biomass

Roughness on pristine and polymer composite surfaces is of enormous practical importance for polymer applications. This study deals with the use of varying quantity of oil palm ash as a nanofiller in a polypropylene based matrix. The oil palm ash sample was preprocessed to break the particles into small diameter by using ultra sonication before using microfluidizer for further deduction in size and homogenization. The oil palm ash was made to undergo many passes through the microfluidizer for fine distribution of particles. Polypropylene based composites containing different loading percentage oil palm ash was granulated by twin screw extruder and then injection molded. The surface morphology of the OPA passed through microfluidizer was analyzed by Tapping Mode - Atomic Force Microscopy (TMAFM). Thermal analysis results showed an increase in the activation energy values. The thermal stability of the composite samples showed improvement as compared to the virgin polymer as corroborated by the on-set degradation temperatures and the temperatures at which 50% degradation occurred.

36 MATERIALS SCIENCE↗