scholarly journals Flotation of Chromite as Pre-Treatment of Olivine Before Carbonation for CO2 Sequestration

2017 ◽  
Vol 11 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Laura Turri ◽  
Hervé Muhr ◽  
Cristielen Rech ◽  
François Lapicque
Keyword(s):  
Co2 Sequestration ◽  
High Performance ◽  
Gas Flow ◽  
Separation Efficiency ◽  
Particle Diameter ◽  
Flow Conditions ◽  
Flotation Process ◽  
Industrial Grade ◽  
Chemical Sequestration ◽  
Pre Treatment

Background and Objective:For the sake of optimal beneficiation of the products formed in the chemical sequestration of CO2on silicates, extraction of the chromite has been carried out prior to carbonation, by flotation in a lab-scale column.Method:Industrial-grade olivine and serpentine were tested. Flow conditionse.g. gas flow rate, stirring, particle diameter of silicates, and physicochemical considerations (composition if the electrolyte solution) have been examined to optimize the separation efficiency in terms of chromite recovery or enrichment factor.Result:The high performance observed with chromite-enriched olivine allows a multistage flotation process from low-chromite minerals blends to be designed.Conclusion:The lower performance with native olivine was attributed to the existence of mixed chromite-silicate particles.

Experimental Studies Concerning the Semipermeable Membrane Separation Efficiency for 134Cs, 137Cs, 57Co, 58Co, 60Co, 54Mn in Liquid Radioactive Waste I. Treatment of secondary waste from POD decontamination procedure

2008 ◽  
Vol 59 (5) ◽  
Author(s):  
Mirela Dulama ◽  
Nicoleta Deneanu ◽  
Cristian Dulama ◽  
Margarit Pavelescu
Keyword(s):  
Membrane Separation ◽  
Separation Efficiency ◽  
Liquid Radioactive Waste ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Suspended Solid ◽  
Process Efficiency ◽  
Active Charcoal ◽  
Precipitation Process ◽  
Pre Treatment

The paper presents the experimental tests concerning the treatment by membrane techniques of radioactive aqueous waste. Solutions, which have been treated by using the bench-scale installation, were radioactive simulated secondary wastes from the decontamination process with modified POD. Generally, an increasing of the retention is observed for most of the contaminants in the reverse osmosis experiments with pre-treatment steps. The main reason for taking a chemical treatment approach was to selectively remove soluble contaminants from the waste. In the optimization part of the precipitation step, several precipitation processes were compared. Based on this comparison, mixed [Fe(CN)6]4-/Al3+/Fe2+ was selected as a precipitation process applicable for precipitation of radionuclides and flocculation of suspended solid. Increased efficiencies for cesium radionuclides removal were obtained in natural zeolite adsorption pre-treatment stages and this was due to the fact that volcanic tuff used has a special affinity for this element. Usually, the addition of powdered active charcoal serves as an advanced purifying method used to remove organic compounds and residual radionuclides; thus by analyzing the experimental data (for POD wastes) one can observe a decreasing of about 50% for cobalt isotopes subsequently to the active charcoal adsorption.. The semipermeable membranes were used, which were prepared by the researchers from the Research Center for Macromolecular Materials and Membranes, Bucharest. The process efficiency was monitored by gamma spectrometry.

High Performance Thin Layer Chromatography (HPTLC) for the Investigation of Medicinal Plants

2020 ◽  
Vol 16 ◽  
Author(s):  
Alper Gökbulut
Keyword(s):  
Medicinal Plants ◽  
High Performance ◽  
Separation Efficiency ◽  
Rapid Development ◽  
Herbal Remedies ◽  
Qualitative And Quantitative ◽  
Powerful Analytical Tool ◽  
Quantitative Examination ◽  
Data Acquisition And Processing ◽  
Layer Chromatography

Background: Chromatographic techniques such as TLC basically and, HPLC, GC, HPTLC equipped with various detectors are most frequently used for the qualitative and quantitative examination of herbals. Method: An overview of the recent literature concerning the usage of HPTLC for the analysis of medicinal plants has been reviewed. Results: During the last decade/s, HPTLC, a modern, sophisticated and automatized TLC technique with better and advanced separation efficiency, detection limit, data acquisition and processing, has been used for the analysis of herbal materials and preparations since the rapid development of technology in chromatography world. HPTLC with various detectors is a powerful analytical tool especially for the phytochemical applications such as herbal drug quantification and fingerprint analysis. Conclusion: In this review, a latest perspective has been established and some of the previous studies were summarized for the usage of HPTLC in the analysis of herbal remedies, dietary supplements and nutraceuticals.

scholarly journals Enhancing Pervaporation Membrane Selectivity by Incorporating Star Macromolecules Modified with Ionic Liquid for Intensification of Lactic Acid Dehydration

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1811
Author(s):  
Valeriia Rostovtseva ◽  
Alexandra Pulyalina ◽  
Roman Dubovenko ◽  
Ilya Faykov ◽  
Kseniya Subbotina ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Lactic Acid ◽  
Polymer Matrix ◽  
Separation Factor ◽  
Membrane Structure ◽  
High Performance ◽  
Separation Efficiency ◽  
Pharmaceutical Chemical ◽  
Permeate Flux ◽  
Membrane Components

Modification of polymer matrix by hybrid fillers is a promising way to produce membranes with excellent separation efficiency due to variations in membrane structure. High-performance membranes for the pervaporation dehydration were produced by modifying poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) to facilitate lactic acid purification. Ionic liquid (IL), heteroarm star macromolecules (HSM), and their combination (IL:HSM) were employed as additives to the polymer matrix. The composition and structure of hybrid membranes were characterized by X-ray diffraction and FTIR spectroscopy. Scanning electron microscopy was used to investigate the membranes surface and cross-section morphology. It was established that the inclusion of modifiers in the polymer matrix leads to the change of membrane structure. The influence of IL:HSM was also studied via sorption experiments and pervaporation of water‒lactic acid mixtures. Lactic acid is an essential compound in many industries, including food, pharmaceutical, chemical, while the recovering and purifying account for approximately 50% of its production cost. It was found that the membranes selectively remove water from the feed. Quantum mechanical calculations determine the favorable interactions between various membrane components and the liquid mixture. With IL:HSM addition, the separation factor and performance in lactic acid dehydration were improved compared with pure polymer membrane. The best performance was found for (HSM: IL)-PPO/UPM composite membrane, where the permeate flux and the separation factor of about 0.06 kg m−2 h−1 and 749, respectively, were obtained. The research results demonstrated that ionic liquids in combination with star macromolecules for membrane modification could be a promising approach for membrane design.

scholarly journals Investigation on influences of loose gas on gas-solid flows in a circulating fluidized bed (CFB) reactor using full-loop numerical simulation

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Pengju Huo ◽  
Xiaohong Li ◽  
Yang Liu ◽  
Haiying Qi
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Separation Efficiency ◽  
Circulation Rate ◽  
Solid Mass ◽  
Gas Flow Rate ◽  
Gas Leakage ◽  
Mass Circulation

AbstractThe influences of loose gas on gas-solid flows in a large-scale circulating fluidized bed (CFB) gasification reactor were investigated using full-loop numerical simulation. The two-fluid model was coupled with the QC-energy minimization in multi-scale theory (EMMS) gas-solid drag model to simulate the fluidization in the CFB reactor. Effects of the loose gas flow rate, Q, on the solid mass circulation rate and the cyclone separation efficiency were analyzed. The study found different effects depending on Q: First, the particles in the loop seal and the standpipe tended to become more densely packed with decreasing loose gas flow rate, leading to the reduction in the overall circulation rate. The minimum Q that can affect the solid mass circulation rate is about 2.5% of the fluidized gas flow rate. Second, the sealing gas capability of the particles is enhanced as the loose gas flow rate decreases, which reduces the gas leakage into the cyclones and improves their separation efficiency. The best loose gas flow rates are equal to 2.5% of the fluidized gas flow rate at the various supply positions. In addition, the cyclone separation efficiency is correlated with the gas leakage to predict the separation efficiency during industrial operation.

Diabatic Nozzle Flow with Constant Small Stage Efficiency

1960 ◽  
Vol 64 (598) ◽  
pp. 632-635 ◽  
Author(s):  
R. A. A. Bryant
Keyword(s):  
Gas Flow ◽  
Nozzle Flow ◽  
Flow Conditions ◽  
One Dimensional ◽  
Real Flow ◽  
Stage Efficiency ◽  
Frictional Effects

The concept of small stage efficiency is introduced when studying one-dimensional gas flow in nozzles in order to permit a closer approximation of real flow conditions than is possible from an isentropic analysis. It is more or less conventional to assume the flow conditions are adiabatic whenever the small stage efficiency is used. That is to say, small stage efficiency is generally considered in relation to flows contained within adiabatic boundaries, in which case it becomes a measure of the heat generated by internal frictional effects alone.

High Performance MEMS Thermal Gyroscope

2012 ◽  
Author(s):  
Nilgoon Zarei ◽  
Albert M. Leung ◽  
John D. Jones
Keyword(s):  
External Force ◽  
High Performance ◽  
Gas Flow ◽  
Element Model ◽  
Minimal Impact ◽  
Mems Gyroscope ◽  
Force Finding ◽  
Dimensional Finite Element ◽  
To Come ◽  
The Impact

This paper reports modeling a new design of Thermal MEMS gyroscope through the use of the Comsol Multiphysics software package. Being very small and having no movable parts have made thermal MEMS gyroscope very practical. Previously designed Thermal MEMS gyroscope shows some limitation such as being vulnerable to gravity force. Finding a technique to increase the range of thermal MEMS gyroscope reliability motivated us to come up with a new design that we will refer to as the ‘Forced Convection MEMS gyroscope’. A two-dimensional finite-element model of the device has been developed to investigate its performance. An external force has been introduced to the system to create a higher-velocity hot gas stream that will be deviated more in response to rotation. The external force should be great enough that convection currents resulting from gravity or acceleration will have minimal impact on the gyroscope sensitivity. A heating element can still be used, but its primary purpose is now to warm the flowing gas so that it can be detected by the sensors. In this paper we will also show that, in order to completely eliminate the impact of gravity and increase the sensitivity of the gyroscope, it is possible to eliminate the heaters entirely and instead use heated sensors to detect gas currents. In other words, the sensors are working as hot-wire anemometers. Our simulations suggest that this design variant results in higher sensitivity. We have also carried out optimization studies to identify the best location for the heaters and sensors. A prototype of this device has been fabricated based on MEMS techniques, and an external pump is used to produce an oscillating gas flow within the device.

Determination of Nitrate in Water by HPLC

2013 ◽  
Vol 448-453 ◽  
pp. 406-408
Author(s):  
Jing Liu ◽  
Xiao Na Ji ◽  
Qing Kai Ren ◽  
Sheng Shu Ai ◽  
Li Jun Wan ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Recovery Rate ◽  
High Performance ◽  
Separation Efficiency ◽  
Fast Analysis ◽  
Relative Standard

We established a method fordetermination of nitrate in water by High Performance Liquid Chromatography(HPLC). The sample was analysed by HPLC-ADA and was quantitated by externalstandard method after being simply processed. This methd has the advantages ofhigh separation efficiency and fast analysis. The experiment result showed thatthe linearly dependent coefficient was0.994, the recovery rate was between 98.7%～105.7%,the relative standard deviation（RSD）wasless than 2.1 %, and the lowest detectable limit is 0.01ng (S/N=1.6).

scholarly journals Statistical Modelling of Oil Removal from Surfactant/Polymer Flooding Produced Water by Using Flotation Column

2020 ◽  
Vol 20 (2) ◽  
pp. 360
Author(s):  
Ku Esyra Hani ◽  
Mohammed Abdalla Ayoub
Keyword(s):  
Flow Rate ◽  
Surfactant Concentration ◽  
Gas Flow ◽  
Produced Water ◽  
Polymer Concentration ◽  
Statistical Modelling ◽  
Oil Removal ◽  
Gas Flow Rate ◽  
Flotation Process ◽  
Flotation Column

The objective of this study was to investigate the effect of polymer (GLP-100) and surfactant (MFOMAX) towards the efficiency of oil removal in a flotation column by using the Response Surface Methodology (RSM). Various concentrations of surfactant (250, 372 and 500 ppm) and polymer (450, 670, and 900 ppm) produced water were prepared. Dulang crude oil was used in the experiments. Flotation operating parameters such as gas flow rate (1–3 L/min) and duration of flotation (2–10 min) were also investigated. The efficiency of oil removal was calculated based on the difference between the initial concentration of oil and the final concentration of oil after the flotation process. From the ANOVA analysis, it was found that the gas flow rate, surfactant concentration, and polymer concentration contributed significantly to the efficiency of oil removal. Extra experiments were conducted to verify the developed equation at a randomly selected point using 450 ppm of polymer concentration, 250 ppm of surfactant concentration, 3 L/min gas flowrate and duration of 10 min. From these extra experiments, a low standard deviation of 1.96 was discovered. From this value, it indicates that the equation can be used to predict the efficiency of oil removal in the presence of surfactant and polymer (SP) by using a laboratory flotation column.

Sign in / Sign up

Export Citation Format

Share Document