An investigation of the hydrophilic/oleophilic nature of various coals

Adams-Viola, M.; Botsaris, Gregory D.; Glazman, Yu. M.

doi:10.1016/0166-6622(81)80075-3

Cited by 7 publications

(3 citation statements)

References 8 publications

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“…The ultimate and proximate analysis of these coals may be found elsewhere (Adams-Viola, 1981). The surface properties and namely the hydrophilic/oleophilic behavior of these coals have also been evaluated (AdamsViola, 1981;Adams-Viola et al, 1981). The degree of hydrophilicity of these coals (in order of increasing hydrophilicity) is as follows: Buck Mountain < Pittsburgh Bituminous < Pocahontas Bituminous < Sewell Bituminous < Illinois Bituminous < North Dakota.…”

Section: Methodsmentioning

confidence: 99%

The sedimentation of coal in model oils: The effect of the viscosity and composition of the oil

Adams-Viola

Botsaris

1982

AIChE Journal

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The results of batch settling tests with various coal powders in model oils indicated that the viscosity and the aromatic/paraffinic nature of the oil influences G. 0. BOTSARlS and YULl GLAZMAN the sedimentation and the aggregation rate of the particles. Oxidation of paraffin oil may result in the generation of surface active agents which retards the sedimentation of certain coals. Department of Chemical EngineeringTufts University Medford, MA 02155 SCOPEA coal-oil mixture (C0M)-a dispersion of finely pulverized coal in No. 6 fuel oil-is an alternative fuel to be used as an interim measure to reduce oil imports without requiring major renovations to existing oil-fired power facilities. A question which has been raised is how significant the variability of the chemical and physical properties of the residual oil is to the sedimentation behavior of the coal-oil slurry. This variability includes differences in the content of aromatic compounds, in the content of asphaltenes and in the content of naturally occurring or deliberately added surface active agents (Dodd et al., 1952). Ekmann and Bienstock (1979) have compared the sedimentation of Pittsburgh Seam coal in several different No. 6 oils. A regression analysis was performed with the settling data and various oil characteristics. The results indicated to a level of 99% confidence that the oxygen/nitrogen ratio of the asphaltenes, the nitrogen/carbon ratio of the asphaltenes and the kinematic viscosity are correlated to the sedimentaton kinetics of the slurry. The complexity of No. 6 oil required a statistical approach to the interpretation of the data. With this in mind and with the appreciation that even the meaningful characterization of No. 6 oil is in itself a current problem, an experimental scheme was developed in this work using model oils such as hexane, toluene, kerosene and paraffin oil and their mixtures rather than No. 6 oil itself. The use of these model oils, unlike the black and opaque No. 6 oil, also permitted the rapid evaluation of the sedimentation kinetics.The COM prepared with model oil were employed to study the effect of the viscosity and the paraffinic/aromatic composition of the oil on the settling behavior of the coal. The effect of viscosity was studied by comparing the settling rates of suspensions of four different coals having closely matched particle size distributions (including a lignite and three bituminous coals) in hexane and kerosene at 22°C and in paraffin oil at 45OC and 70°C. The slurries in paraffin oil were prepared using both a mechanical dispersator and an ultrasonic dispersator. The effect of the chemical composition (paraffinic/aromatic nature) of the oil was investigated by comparing the settling velocities of six coals having closely matched particle size distributions (including an anthracite, four bituminous samples and a lignite) in toluene, in hexane and in the three toluene/hexane mixtures at room temperature. CONCLUSIONS AND SIGNIFICANCEThe experimental data indicated that variations of the oil viscosity...

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Section: Methodsmentioning

confidence: 99%

The sedimentation of coal in model oils: The effect of the viscosity and composition of the oil

Adams-Viola

Botsaris

1982

AIChE Journal

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“…This applies also to the coals. However, the ratio of the hydrophobic part of the surface to the total surface, the hydrophobicity, can vary between less than 50% to up to 95% and depends on the exact material composition (Adams-Viola et al 1981;Groszek & Partyka 1993;Xia & Xie 2014). For the materials used in our study, the hydrophobicity was not measured, but it should be kept in mind that hydrophilic parts can influence the tensile strength if water molecules stick to the particles and change their surface properties (Kimura et al 2015).…”

Section: Selected Materialsmentioning

confidence: 97%

Sticky or not sticky? Measurements of the tensile strength of microgranular organic materials

Bischoff

Kreuzig

Haack

et al. 2020

Monthly Notices of the Royal Astronomical Society

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Knowledge of the mechanical properties of protoplanetary and cometary matter is of key importance to better understand the activity of comets and the early stages of planet formation. The tensile strength determines the required pressure to lift off grains, pebbles and agglomerates from the cometary surface and also describes how much strain a macroscopic body can withstand before material failure occurs. As organic materials are ubiquitous in space, they could have played an important role during the planet formation process. This work provides new data on the tensile strength of five different micro-granular organic materials, namely, humic acid, paraffin, brown coal, charcoal and graphite. These materials are investigated by the so-called Brazilian Disc Test and the resulting tensile strength values are normalised to a standard grain size and volume filling factor. We find that the tensile strength of these materials ranges over four orders of magnitude. Graphite and paraffin possess tensile strengths much higher than silica, whereas coals have very low tensile strength values. This work demonstrates that organic materials are not generally stickier than silicates, or water ice, as often believed.

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“…i.e., an oil-in-water emulsion is formed with hydrophilic (90 > q > 0 ) particles and water-in-oil emulsion forms when particles are oleophilic (hydrophobic; q > 90 ). 33…”

Section: Fine Particle Partitionmentioning

confidence: 99%

Hydrophilic and superhydrophilic surfaces and materials

et al. 2011

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The term superhydrophilicity is only 11-12 years old and was introduced just after the explosion of research on superhydrophobic surfaces, in response to the demand for surfaces and coatings with exceptionally strong affinity to water. The definition of superhydrophilic substrates has not been clarified yet, and unrestricted use of this term to hydrophilic surfaces has stirred controversy in the last few years in the surface chemistry community. In this review, we take a close look into major definitions of hydrophilic surfaces used in the past, before we review the physics behind the superhydrophilic phenomenon and make recommendation on defining superhydrophilic surfaces and coatings. We also review chemical and physical methods used in the fabrication of substrates on surfaces of which water spreads completely. Several applications of superhydrophilic surfaces, including examples from the authors' own research, conclude this review.

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An investigation of the hydrophilic/oleophilic nature of various coals

Cited by 7 publications

References 8 publications

The sedimentation of coal in model oils: The effect of the viscosity and composition of the oil

The sedimentation of coal in model oils: The effect of the viscosity and composition of the oil

Sticky or not sticky? Measurements of the tensile strength of microgranular organic materials

Hydrophilic and superhydrophilic surfaces and materials

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