9 research outputs found
On the resolution of constant isosteric heat of propylene adsorptionon graphite in the sub-monolayer coverage region
An early experimental study by Bezus, Dreving and Kiselev [1] on the adsorption of propylene on Spheron-6 carbon black (graphitized at ∼3000C) reported a plot of constant isosteric heat versus loading in the sub-monolayer region. This contrasts with their report of a linear increase in isosteric heat for propane, a similar molecule to propylene. In this paper, we report extensive Grand Canonical Monte Carlo (GCMC) simulations and a high-resolution experimental study of propylene adsorption on Carbopack F, a highly graphitized thermal carbon black, over the same temperature range studied by Bezus et al. From this combined simulation and experimental study we conclude that propylene also shows a linear increase in the isosteric heat versus loading in the sub-monolayer region, indicating that the linear increase in the fluid-fluid interaction in this region more than compensates for the decrease in the solid-fluid interaction that results from the change in orientation of the adsorbate molecules. Our study contradicts the propylene results of Bezus et al., and careful inspection of their isotherm in the sub-monolayer region shows that it does not follow Henry’s law. This calls into question their argument that π-π interactions between propylene molecules are an explanation for the constant heat
Heavy metal recovery from electric arc furnace steel slag by using hydrochloric acid leaching
Electric Arc Furnace steel slag (EAFS) is the waste produced in steelmaking industry. Environmental problem such as pollution will occur when dumping the steel slag waste into the landfill. These steel slags have properties that are suitable for various applications such as water treatment and wastewater. The objective of this study is to develop efficient and economical chlorination route for EAFS extraction by using leaching process. Various parameters such as concentration of hydrochloric acid, particle size of steel slag, reaction time and reaction temperature are investigated to determine the optimum conditions. As a result, the dissolution rate can be determined by changing the parameters, such as concentration of hydrochloric acid, particle size of steel slag, reaction time and reaction temperature. The optimum conditions for dissolution rates for the leaching process is at 3.0 M hydrochloric acid, particle size of 1.18 mm, reaction time of 2.5 hour and the temperature of 90˚C
On the resolution of constant isosteric heat of propylene adsorption on graphite in the sub-monolayer coverage region
An early experimental study by Bezus, Dreving and Kiselev [1] on the adsorption of propylene on Spheron-6 carbon black (graphitized at ∼3000C) reported a plot of constant isosteric heat versus loading in the sub-monolayer region. This contrasts with their report of a linear increase in isosteric heat for propane, a similar molecule to propylene. In this paper, we report extensive Grand Canonical Monte Carlo (GCMC) simulations and a high-resolution experimental study of propylene adsorption on Carbopack F, a highly graphitized thermal carbon black, over the same temperature range studied by Bezus et al. From this combined simulation and experimental study we conclude that propylene also shows a linear increase in the isosteric heat versus loading in the sub-monolayer region, indicating that the linear increase in the fluid-fluid interaction in this region more than compensates for the decrease in the solid-fluid interaction that results from the change in orientation of the adsorbate molecules. Our study contradicts the propylene results of Bezus et al., and careful inspection of their isotherm in the sub-monolayer region shows that it does not follow Henry's law. This calls into question their argument that π-π interactions between propylene molecules are an explanation for the constant heat
Nitrogen doped graphene-supported trimetallic CuNiRu nanoparticles catalyst for catalytic dehydrogenation of cyclohexanol to cyclohexanone
In different hydrocarbons reactions, copper based catalysts have industrial importance especially in the synthesis of the cyclohexanone from dehydrogenation of the cyclohexanol. At operating conditions, one of the significant problems in the industrial process is fast deactivation of the copper based catalysts. The present work focuses on the formulation of two types of the supported catalysts namely supported tri metals alloy (CuNiRu/N-rGO) in paper forms and supported copper (Cu/N-rGO), analysing the properties of the synthesised catalyst support (N-rGO) by Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), Temperature-programmed desorption (TPD-NH3), Temperature Programmed Reduction (TPR-H2) and X-ray diffraction (XRD) as well as to investigate the catalytic performance of the two supported catalysts in the dehydrogenation of cyclohexanol to the cyclohexanone. All experiments on the catalytic performance were conducted at moderate temperatures (200–270 °C), 1 atm, 0.1 ml/min cyclohexanol flow rate and ∼8 h time on stream (TOS). The performances of the catalysts were evaluated in the gas phase dehydrogenation of cyclohexanol to the cyclohexanone. The conversion of the cyclohexanol using CuNiRu/N-rGO is 4% higher compare to use of the Cu/N-rGO. The selectivity for cyclohexanone in case of the Cu/N-rGO catalyst is about 83.88%, whilst, the CuNiRu/N-rGO illustrated approximately 6% better performance. The yield of the cyclohexanone using the Cu/N-rGO is about 78%, while by adding the Ni and Ru as promoters with the improvement of the Cu/N-rGO the yield of cyclohexanone was improved by 8%. The duration of the steady state period significantly improved by using CuNiRu/N-rGO which was proposed up to 7 times. This research shows that the CuNiRu/N-rGO catalyst provides the suitable and selective active sites for the dehydrogenation of cyclohexanol to the cyclohexanone reaction
Microscopic analysis of adsorption in slit-like pores: Layer fluctuations of particle number, layer isosteric heat and histogram of particle number
A number of measures are proposed as a microscopic means to analyse adsorption of gas on a surface and in slit pores under subcritical and supercritical conditions. Layer fluctuation of particle number provides us with information on where most of the mass interchange occurs, which can then be used as an indicator of the position of the interface separating the adsorbed phase and gas phase. The layer compressibility can be used to compare the adsorbed phase density with that of the bulk liquid. The layer isosteric heat provides an indication of the relative contribution of each layer to the overall isosteric heat. Finally, a histogram of particle number as a function of fluid–fluid particle energy is utilised to yield valuable information about the energetic structure of the adsorbed phase, for example (1) the number of neighbouring particles and (2) the evolution of the arrangement of particles
Experimental and CFD Modelling: Impact of the Inlet Slug Flow on the Horizontal Gas–Liquid Separator
For a gas-liquid separator sizing, many engineers have neglected the flow pattern of incoming fluids. The impact of inlet slug flow which impeded onto the separator’s liquid phase will cause a separator fails to perform when sloshing happened in the separator. To date, the study on verifying the impact of inlet slug flow in a separator remains limited. In this paper, the impact of inlet momentum and inlet slug flow on the hydrodynamics in a separator for cases without an inlet device were investigated. The experimental and Computational Fluid Dynamics (CFD) results of cavity formation and sloshing occurrence in the separator in this study were compared. A User Defined Function (UDF) was used to describe the inlet slug flow at the separator inlet. Inlet slug flow occurred at inlet momentum from 200 to 1000 Pa, and sloshing occurred in the separator at 1000 Pa. Both experimental and simulated results showed similar phenomena
Heavy metal recovery from electric arc furnace steel slag by using hydrochloric acid leaching
Electric Arc Furnace steel slag (EAFS) is the waste produced in steelmaking industry. Environmental problem such as pollution will occur when dumping the steel slag waste into the landfill. These steel slags have properties that are suitable for various applications such as water treatment and wastewater. The objective of this study is to develop efficient and economical chlorination route for EAFS extraction by using leaching process. Various parameters such as concentration of hydrochloric acid, particle size of steel slag, reaction time and reaction temperature are investigated to determine the optimum conditions. As a result, the dissolution rate can be determined by changing the parameters, such as concentration of hydrochloric acid, particle size of steel slag, reaction time and reaction temperature. The optimum conditions for dissolution rates for the leaching process is at 3.0 M hydrochloric acid, particle size of 1.18 mm, reaction time of 2.5 hour and the temperature of 90°C