scholarly journals LABORATORY STUDIES OF THE PROPERTIES OF IN-SITU BURN RESIDUES

1997 ◽  
Vol 1997 (1) ◽  
pp. 149-156 ◽  
Author(s):  
Ian Buist ◽  
Ken Trudel ◽  
Jake Morrison ◽  
Don Aurand

ABSTRACT This study investigated the physical and chemical properties of the residue from in-situ burns of thick oil slicks. It involved burning small-diameter slicks of oil on water and analyzing the properties of the residues. The objective of the work was to identify the burn conditions that might produce residues that sink. Eight oils were selected for the project: (1) Alaska North Slope crude; (2) Alberta Sweet Mixed Blend crude; (3) Arabian Heavy crude; (4) Arabian Light crude; (5) Bonny Light crude; (6) Iranian Heavy crude; (7) Mayan crude; and (8) automotive diesel. Burn tests were conducted on all eight oils when fresh and on two of the oils when weathered. Experiments involved burning slicks of three thicknesses (5, 10, and 15 cm) on saltwater at room temperature (15°C). Residue density, water content, pour point, and viscosity were measured. Samples of parent oils and burn residues were fractionated into three boiling point ranges, and each was analyzed to quantify total saturates, aromatics, resins, and asphaltenes. The results showed that the residues from burns of thicker slicks of heavier crudes and weathered crudes may sink in fresh water or saltwater once they cool to ambient temperatures, whereas burn residues of lighter oils may not sink. Burn residues of all crudes were more dense than their parent oils and were solid or semisolid. Residue density was related to the density of the parent oil, the state of weathering, and slick thickness. Chemical analysis showed that the burn residues were composed almost exclusively of the higher boiling point (HBP) fraction; virtually all of the lower boiling point fraction and almost all of the middle boiling point fraction had been removed. Most, but not all, of the HBP fraction, which included all of the asphaltenes and resins, was preserved in the burn residue. The in-situ burning process appears to be neither a pure equilibrium flash vaporization nor a pure batch distillation, but rather a process lying somewhere between the two ideals. The results of the burns of automotive diesel contrasted strongly with those of crude oils. Diesel burns were far more efficient than those of crude oils, leaving only a few millimeters of residue regardless of the thickness of the original slick. The chemical composition of the residue and its properties were changed only slightly from those of the parent oil. Research on the use of in-situ burning as a marine oil spill countermeasure has resulted in a rapidly growing acceptance of the technique as an option for spill cleanup. However, one area of concern with in-situ

Fuel ◽  
2021 ◽  
pp. 122707
Author(s):  
Cesar Ovalles ◽  
Estrella Rogel ◽  
Janie Vien ◽  
Harris Morazan ◽  
Lante Carbognani-Ortega ◽  
...  

2017 ◽  
Vol 2017 (1) ◽  
pp. 985-1005
Author(s):  
Laurens van Gelderen ◽  
Ulises Rojas Alva ◽  
Pierrick Mindykowski ◽  
Grunde Jomaas

ABSTRACT The thermal properties and burning efficiencies of fresh and weathered crude oils and a refined fuel oil were studied in order to improve the available input data for field ignition systems for the in-situ burning of crude oil on water. The time to ignition, surface temperature upon ignition, heat release rate, burning rate and burning efficiency of two fresh crude oils (DUC, a light crude and Grane, a heavy crude), one fresh refined fuel oil (IFO 180) and weathered DUC (30–40 wt% evaporated and 40 wt% evaporated with 40 vol% water) were tested. Experiments were conducted in a newly designed water-cooled holder for a cone calorimeter under incident heat fluxes of 0, 5, 10, 20, 30, 40 and 50 kW/m2. The results clearly showed that the weathered oils were the hardest to ignite, with increased ignition times and critical heat fluxes of 5–10 kW/m2. Evaporation and emulsification were shown to be the determining factors increasing the critical heat flux compared to the physical properties of the oils. Boilover was observed for both emulsified DUC and fresh Grane and dominated the energy released by these oils. These results provided further evidence that the boilover phenomenon is correlated to the superheating of relatively volatile components such as water (DUC emulsion) or light hydrocarbons (Grane). Boilovers can thus occur due to inherent properties of the burning oil and should therefore be taken into account in the safety planning of in-situ burning operations. Maximum burning efficiencies of 85–90% were obtained for heat fluxes of 40–50 kW/m2 for the crude oils and 80% at 30 kW/m2 for IFO 180. The heat feedback in large scale fires, however, was estimated to be about 17 kW/m2, for which the burning efficiencies were < 80%. These results indicate that the increased heat feedback to the fuel surface is not the only factor that increases the burning efficiency for large scale fires compared to laboratory experiments. Additional factors such as feeding of surrounding oil into the fire by buoyancy induced wind flows into the hot smoke plume are probably also contributing to these increased burning efficiencies.


Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.


Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1239
Author(s):  
Manuel Ramos ◽  
Félix Galindo-Hernández ◽  
Brenda Torres ◽  
José Manuel Domínguez-Esquivel ◽  
Martin Heilmaier

We report the thermal stability of spherically shaped cobalt-promoted molybdenum disulfide (Co/MoS2) nano-catalysts from in-situ heating under electron irradiation in the scanning transmission electron microscope (STEM) from room temperature to 550 °C ± 50 °C with aid of Fusion® holder (Protochip©, Inc.). The catalytic nanoparticles were synthesized via a hydrothermal method using sodium molybdate (Na2MoO4·2H2O) with thioacetamide (CH3CSNH2) and cobalt chloride (CoCl2) as promoter agent. The results indicate that the layered molybdenum disulfide structure with interplanar distance of ~0.62 nm remains stable even at temperatures of 550 °C, as observed in STEM mode. Subsequently, the samples were subjected to catalytic tests in a Robinson Mahoney Reactor using 30 g of Heavy Crude Oil (AGT-72) from the golden lane (Mexico’s east coast) at 50 atm using (ultrahigh purity) UHP hydrogen under 1000 rpm stirring at 350 °C for 8 h. It was found that there is no damage on the laminar stacking of Co/MoS2 with temperature, with interlayer spacing remaining at 0.62 nm; these sulfided catalytic materials led to aromatics rise of 22.65% and diminution of asphaltenes and resins by 15.87 and 3.53%, respectively.


2021 ◽  
Vol 11 (2) ◽  
pp. 620
Author(s):  
Magdalena Dyda ◽  
Agnieszka Laudy ◽  
Przemyslaw Decewicz ◽  
Krzysztof Romaniuk ◽  
Martyna Ciezkowska ◽  
...  

The aim of the presented investigation was to describe seasonal changes of microbial community composition in situ in different biocenoses on historical sandstone of the Northern Pergola in the Museum of King John III’s Palace at Wilanow (Poland). The microbial biodiversity was analyzed by the application of Illumina-based next-generation sequencing methods. The metabarcoding analysis allowed for detecting lichenized fungi taxa with the clear domination of two genera: Lecania and Rhinocladiella. It was also observed that, during winter, the richness of fungal communities increased in the biocenoses dominated by lichens and mosses. The metabarcoding analysis showed 34 bacterial genera, with a clear domination of Sphingomonas spp. across almost all biocenoses. Acidophilic bacteria from Acidobacteriaceae and Acetobacteraceae families were also identified, and the results showed that a significant number of bacterial strains isolated during the summer displayed the ability to acidification in contrast to strains isolated in winter, when a large number of isolates displayed alkalizing activity. Other bacteria capable of nitrogen fixation and hydrocarbon utilization (including aromatic hydrocarbons) as well as halophilic microorganisms were also found. The diversity of organisms in the biofilm ensures its stability throughout the year despite the differences recorded between winter and summer.


2021 ◽  
Vol 5 (7) ◽  
pp. 191
Author(s):  
Yanshuai Wang ◽  
Siyao Guo ◽  
Biqin Dong ◽  
Feng Xing

The functionalization of graphene has been reported widely, showing special physical and chemical properties. However, due to the lack of surface functional groups, the poor dispersibility of graphene in solvents strongly limits its engineering applications. This paper develops a novel green “in-situ titania intercalation” method to prepare a highly dispersed graphene, which is enabled by the generation of the titania precursor between the layer of graphene at room temperature to yield titania-graphene nanocomposites (TiO2-RGO). The precursor of titania will produce amounts of nano titania between the graphene interlayers, which can effectively resist the interfacial van der Waals force of the interlamination in graphene for improved dispersion state. Such highly dispersed TiO2-RGO nanocomposites were used to modify epoxy resin. Surprisingly, significant enhancement of the mechanical performance of epoxy resin was observed when incorporating the titania-graphene nanocomposites, especially the improvements in tensile strength and elongation at break, with 75.54% and 176.61% increases at optimal usage compared to the pure epoxy, respectively. The approach presented herein is easy and economical for industry production, which can be potentially applied to the research of high mechanical property graphene/epoxy composite system.


2021 ◽  
pp. 118250
Author(s):  
Hamed Peidayesh ◽  
Abolfazl Heydari ◽  
Katarína Mosnáčková ◽  
Ivan Chodák

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Houssine Benabdelhalim ◽  
David Brutin

AbstractBlood pools can spread on several types of substrates depending on the surrounding environment and conditions. Understanding the influence of these parameters on the spreading of blood pools can provide crime scene investigators with useful information. The focus of the present study is on phase separation, that is, when the serum spreads outside the main blood pool. For this purpose, blood pools with constant initial masses on wooden floors that were either varnished or not were created at ambient temperatures of $$21~^{\circ }\hbox {C}$$ 21 ∘ C , $$29~^{\circ }\hbox {C}$$ 29 ∘ C , and $$37~^{\circ }\hbox {C}$$ 37 ∘ C with a relative humidity varying from 20 to 90%. The range $$21~^{\circ }\hbox {C}$$ 21 ∘ C to $$37~^{\circ }\hbox {C}$$ 37 ∘ C covers almost all worldwide indoor cases. The same whole blood from the same donor was used for all experiments. As a result, an increase in relative humidity was found to result in an increase in the final pool area. In addition, at the three different experimental temperatures, the serum spread outside the main pool at relative humidity levels above 50%. This phase separation is more significant on varnished substrates, and does not lead to any changes in the drying morphology. This phenomenon is explained by the competition between coagulation and evaporation.


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