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Full-Text Articles in Engineering

Analysis Of Individual Molecular Dynamics Snapshots Simulating Wetting Of Surfaces Using Spheroidal Geometric Constructions, Aleksandr Abramov, Stefan Iglauer Aug 2019

Analysis Of Individual Molecular Dynamics Snapshots Simulating Wetting Of Surfaces Using Spheroidal Geometric Constructions, Aleksandr Abramov, Stefan Iglauer

Research outputs 2014 to 2021

Accurate characterization of wettability of minerals is important for efficient oil recovery and carbon geosequestration. In studies where molecular dynamics simulations are used to compute the contact angle, emphasis is often placed on results or theoretical details of the simulations themselves, overlooking potentially applicable methodologies for determination of the contact angle. In this manuscript, a concept of a method utilizing spheroidal geometric constructions to estimate the contact angle of a water droplet on a silica surface in carbon dioxide atmosphere is outlined and applied to the final snapshots of two molecular dynamics simulation runs. Two carbon dioxide pressures and two …


Beneficial Reuse Of Industrial Co2 Emissions Using A Microalgae Photobioreactor: Waste Heat Utilization Assessment, Daniel T. Mohler, Michael H. Wilson, Zhen Fan, John G. Groppo, Mark Crocker Jul 2019

Beneficial Reuse Of Industrial Co2 Emissions Using A Microalgae Photobioreactor: Waste Heat Utilization Assessment, Daniel T. Mohler, Michael H. Wilson, Zhen Fan, John G. Groppo, Mark Crocker

Center for Applied Energy Research Faculty and Staff Publications

Microalgae are a potential means of recycling CO2 from industrial point sources. With this in mind, a novel photobioreactor (PBR) was designed and deployed at a coal-fired power plant. To ascertain the feasibility of using waste heat from the power plant to heat algae cultures during cold periods, two heat transfer models were constructed to quantify PBR cooling times. The first, which was based on tabulated data, material properties and the physical orientation of the PBR tubes, yielded a range of heat transfer coefficients of 19–64 W m−2 K−1 for the PBR at wind speeds of 1–10 …


Application Of The Clayff And The Dreiding Force Fields For Modeling Of Alkylated Quartz Surfaces, Aleksandr Abramov, Stefan Iglauer Apr 2019

Application Of The Clayff And The Dreiding Force Fields For Modeling Of Alkylated Quartz Surfaces, Aleksandr Abramov, Stefan Iglauer

Research outputs 2014 to 2021

To extend applicability and to overcome limitations of combining rules for nonbond potential parameters, in this study, CLAYFF and DREIDING force fields are coupled at the level of atomic site charges to model quartz surfaces with chemisorpt hydrocarbons. Density functional theory and Bader charge analysis are applied to calculate charges of atoms of the OC bond connecting a quartz crystal and an alkyl group. The study demonstrates that the hydrogen atom of the quartz surface hydroxyl group can be removed and its charge can be redistributed among the oxygen and carbon atoms of the OC bond in a manner consistent …


Wettability Of Fully Hydroxylated And Alkylated (001) Α-Quartz Surface In Carbon Dioxide Atmosphere, Aleksandr Abramov, Alireza Keshavarz, Stefan Iglauer Mar 2019

Wettability Of Fully Hydroxylated And Alkylated (001) Α-Quartz Surface In Carbon Dioxide Atmosphere, Aleksandr Abramov, Alireza Keshavarz, Stefan Iglauer

Research outputs 2014 to 2021

Wettability of alkylated quartz surfaces is of primary importance in several technological applications, including the development of oil and gas reservoirs and carbon geo-sequestration. It is intuitively understood and experimentally confirmed that hydroxylated quartz surfaces are hydrophilic. By gradually saturating a hydroxylated (001) α-quartz surface with pentyl groups, we show using molecular dynamics simulations that the surface can also exhibit extreme hydrophobicity. Within a range of surface pentyl group density from 0.29 to 3.18/nm2, the contact angle of a water droplet under 10 MPa pressure of carbon dioxide at 300 K changes from 10–20 to 180°. This study …


Effect Of Pretreatment Process On Scale Formation In The Re-Boiler Section Of Monoethylene Glycol Regeneration Plant, Ammar Al Helal, Adam Soames, Stefan Iglauer, Ahmed Barifcani, Rolf Gubner Jan 2019

Effect Of Pretreatment Process On Scale Formation In The Re-Boiler Section Of Monoethylene Glycol Regeneration Plant, Ammar Al Helal, Adam Soames, Stefan Iglauer, Ahmed Barifcani, Rolf Gubner

Research outputs 2014 to 2021

Monoethylene glycol (MEG) regeneration plants often use pretreatment vessels to precipitate divalent cations, such as Fe2+, Ca2+, and Mg2+, in order to avoid or reduce fouling in downstream reboilers and heat exchangers. This pretreatment process operates under alkaline conditions and moderate temperatures (~ 80 °C) to accelerate the formation of low-solubility divalent salts. The objective of the present research was to determine whether the pretreatment process could be minimized, without negatively impacts on the MEG regeneration process from to the formation of scale on the heater bundle in the presence of low concentrations of …