scholarly journals A Review on Adsorbents In Chromatography

2019 ◽  
pp. 36-42
Author(s):  
Rajeshwar V. Chavan ◽  
Manohar D. Kengar ◽  
Archna R. Dhole ◽  
Vijay R. Salunkhe
Keyword(s):  
Stationary Phase ◽  
Storage Capacity ◽  
Cold Water ◽  
Waste Heat ◽  
Industrial Applications ◽  
Adsorption Chromatography ◽  
Aqueous Systems ◽  
Small Particles ◽  
Chemical Systems ◽  
Adsorption Sites

The Adsorption chromatography only differs from adsorption in how the process operates, not the principle of separation. For adsorption chromatography, the adsorbent is used as the stationary phase. The solute binds to the adsorbent via van der Waal forces and steric interactions. Since the adsorption sites are typical only on the outer surface of the stationary phase, fairly small particles are used as the stationary phase. The technique of chromatography used presently is limited to a few adsorbents and usually to non-aqueous systems, due to the difficulty of elution of the adsorbate. However, aqueous systems could be used if adsorbents were available which permitted adsorption and desorption to be controlled by pH adjustment. Adsorption is present in many natural physical, biological, and chemical systems and is widely used in industrial applications such as activated charcoal, capturing and using waste heat to provide cold water for air conditioning and other process requirements, synthetic resins, increase storage capacity of carbide-derived carbons for tunable nanoporous carbon and water purification.

scholarly journals Morphological and Elemental Investigations on Co–Fe–B–O Thin Films Deposited by Pulsed Laser Deposition for Alkaline Water Oxidation: Charge Exchange Efficiency as the Prevailing Factor in Comparison with the Adsorption Process

2021 ◽  
Author(s):  
Y. Popat ◽  
M. Orlandi ◽  
S. Gupta ◽  
N. Bazzanella ◽  
S. Pillai ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Water Oxidation ◽  
Active Sites ◽  
High Surface ◽  
Pulsed Laser ◽  
Industrial Applications ◽  
Active Species ◽  
Laser Deposition ◽  
Core Shell ◽  
Adsorption Sites

Abstract Mixed transition-metals oxide electrocatalysts have shown huge potential for electrochemical water oxidation due to their earth abundance, low cost and excellent electrocatalytic activity. Here we present Co–Fe–B–O coatings as oxygen evolution catalyst synthesized by Pulsed Laser Deposition (PLD) which provided flexibility to investigate the effect of morphology and structural transformation on the catalytic activity. As an unusual behaviour, nanomorphology of 3D-urchin-like particles assembled with crystallized CoFe2O4 nanowires, acquiring high surface area, displayed inferior performance as compared to core–shell particles with partially crystalline shell containing boron. The best electrochemical activity towards water oxidation in alkaline medium with an overpotential of 315 mV at 10 mA/cm2 along with a Tafel slope of 31.5 mV/dec was recorded with core–shell particle morphology. Systematic comparison with control samples highlighted the role of all the elements, with Co being the active element, boron prevents the complete oxidation of Co to form Co3+ active species (CoOOH), while Fe assists in reducing Co3+ to Co2+ so that these species are regenerated in the successive cycles. Thorough observation of results also indicates that the activity of the active sites play a dominating role in determining the performance of the electrocatalyst over the number of adsorption sites. The synthesized Co–Fe–B–O coatings displayed good stability and recyclability thereby showcasing potential for industrial applications. Graphic Abstract

scholarly journals Functionalized Carbon Nanotubes (CNTs) for Water and Wastewater Treatment: Preparation to Application

2021 ◽  
Vol 13 (10) ◽  
pp. 5717
Author(s):  
Mian Muhammad-Ahson Aslam ◽  
Hsion-Wen Kuo ◽  
Walter Den ◽  
Muhammad Usman ◽  
Muhammad Sultan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Wastewater Treatment ◽  
Water Resources ◽  
Large Scale ◽  
Industrial Applications ◽  
Biological Species ◽  
Special Focus ◽  
Water And Wastewater Treatment ◽  
Adsorption Sites ◽  
Water And Wastewater

As the world human population and industrialization keep growing, the water availability issue has forced scientists, engineers, and legislators of water supply industries to better manage water resources. Pollutant removals from wastewaters are crucial to ensure qualities of available water resources (including natural water bodies or reclaimed waters). Diverse techniques have been developed to deal with water quality concerns. Carbon based nanomaterials, especially carbon nanotubes (CNTs) with their high specific surface area and associated adsorption sites, have drawn a special focus in environmental applications, especially water and wastewater treatment. This critical review summarizes recent developments and adsorption behaviors of CNTs used to remove organics or heavy metal ions from contaminated waters via adsorption and inactivation of biological species associated with CNTs. Foci include CNTs synthesis, purification, and surface modifications or functionalization, followed by their characterization methods and the effect of water chemistry on adsorption capacities and removal mechanisms. Functionalized CNTs have been proven to be promising nanomaterials for the decontamination of waters due to their high adsorption capacity. However, most of the functional CNT applications are limited to lab-scale experiments only. Feasibility of their large-scale/industrial applications with cost-effective ways of synthesis and assessments of their toxicity with better simulating adsorption mechanisms still need to be studied.

scholarly journals Energy Recovery from an Industrial Clothes Dryer Using a Condensing Heat Exchanger

2021 ◽  
Author(s):  
Yousuf Farooq
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat Exchanger ◽  
Heat Recovery ◽  
Cold Water ◽  
Waste Heat ◽  
Interface Temperature ◽  
Sensible Heat ◽  
Clothes Dryer ◽  
Condensing Heat Exchanger

The aim of this project was to design a condensing heat exchanger to recover waste heat from an industrial clothes dryer. Industrial cloth dryers are inefficient in their use of energy because almost all of the energy input in the dryer is wasted in the atmosphere, and thus there is great potential for heat recovery. This energy can be used to preheat the incoming cold water, and the conventional heater can then heat the water to a final temperature. The warm moist air from the dryer carries both sensible and latent heat, and in order to design this heat recovery condensing heat exchanger, the heat transfer by both mass and sensible heat has to be accounted for. The basis of this heat and mass transfer problem was the energy balance at the interface, and separate models for the calculation of latent and sensible heat transfer were used. The mass transfer coefficients were obtained from an analogy with heat transfer, and the unknown interface temperature was solved for iteratively. The data for this design was collected from a 20 kW dryer, and the heat recovery from that dryer was observed to be about 17.3%. This heat recovery condensing heat exchanger efficiency can be enhanced by the addition of more coils to the heat exchanger. An improvement in the overall results can be expected if a practical study is done on the condensation heat exchanger for an industrial cloth dryer.

Dominant Factor for the Occurrence of a Steam Explosion

2008 ◽  
Vol 273-276 ◽  
pp. 388-393
Author(s):  
B.T. Min ◽  
S.W. Hong ◽  
J.H. Kim ◽  
I.K. Park ◽  
H.D. Kim
Keyword(s):  
Steam Explosion ◽  
Nuclear Reactor ◽  
Cold Water ◽  
Hydrogen Reduction ◽  
Chemical Compounds ◽  
Hydrogen Gas ◽  
Dominant Factor ◽  
Small Particles ◽  
Debris Particles ◽  
Pure Zro2

For the study of a steam explosion phenomenon in a nuclear reactor, prototypic corium, a mixture of UO2 and ZrO2 was melted in a cold crucible by applying an induction heating technique. The molten corium was then poured into cold water. It was fragmented into very small particles, so called debris, which enables a very rapid heat transfer to the water. Some cases led to steam explosions by thermal expansion of the water. After the tests, all the debris particles were dried and classified by their size. From the analysis by using EPMA, it was shown that the particles generated by a steam explosion had fine and irregular forms. It is known that real corium (including UO2) hardly leads to a steam explosion, different from pure ZrO2 or metal. A reason for this was previously suggested in that the corium generated hydrogen gas during melt-water interaction, and it enclosed the melt drops to prevent a direct contact of the corium and water. In order to confirm this fact, the debris particles were analyzed with ICP-AES for their typical element contents, EPMA for the homogeneity of the solid solution, XRD for the chemical compounds, and TGA and hydrogen reduction analysis for the percentage of the debris oxidation and reduction. These analyses showed that hydrogen was not directly related to steam explosion. Meanwhile, the material characteristics of the corium compositions are newly suggested to be the most probable reason for the occurrence of a steam explosion so far.

Characterization of Ammonia–Water Absorption Chiller and Application

2018 ◽  
Vol 26 (04) ◽  
pp. 1850035 ◽  
Author(s):  
Gopalakrishnan Anand ◽  
Donald C. Erickson ◽  
Ellen Makar
Keyword(s):  
Simple Model ◽  
Low Temperatures ◽  
Waste Heat ◽  
Cooling Water ◽  
Industrial Applications ◽  
Absorption Refrigeration ◽  
Potential Applications ◽  
Ammonia Absorption ◽  
Simple Equations

Ammonia-absorption refrigeration units (AARUS) can supply subfreezing refrigeration for many industrial applications. Such units are usually driven by waste heat or renewable energy at relatively low temperatures. The performance of the chiller is highly dependent on the temperatures of the driving heat, the chilling load, and the cooling water. In this paper, the performance of an advanced industrial-scale ammonia-absorption unit is modeled over a representative operating range. The performance is then characterized by a set of simple equations incorporating the three external temperatures. This simple model helps to evaluate potential applications, predict performance, and perform initial optimization. Case studies are presented highlighting the application of the model.

scholarly journals Advanced and Intensified Seawater Flue Gas Desulfurization Processes: Recent Developments and Improvements

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5917 ◽  
Author(s):  
Nguyen Van Duc Long ◽  
Dong Young Lee ◽  
Kim Myung Jin ◽  
Kwag Choongyong ◽  
Lee Young Mok ◽  
...  
Keyword(s):  
Flue Gas ◽  
Gas Flow ◽  
Process Integration ◽  
Waste Heat ◽  
Combined Treatment ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Flue Gas Desulfurization ◽  
Loading Capacity ◽  
Equipment Size

Seawater flue gas desulfurization (SWFGD) is considered to be a viable solution for coastal and naval applications; however, this process has several drawbacks, including its corrosive absorbent; low vapor loading capacity since the solubility of sulfur oxides (SOx) in seawater is lower than that of limestone used in conventional methods; high seawater flowrate; and large equipment size. This has prompted process industries to search for possible advanced and intensified configurations to enhance the performance of SWFGD processes to attain a higher vapor loading capacity, lower seawater flowrate, and smaller equipment size. This paper presents an overview of new developments as well as advanced and intensified configurations of SWFGD processes via process modifications such as modification and optimization of operating conditions, improvement of spray and vapor distributors, adding internal columns, using square or rectangular shape, using a pre-scrubber, multiple scrubber feed; process integration such as combined treatment of SOx and other gases, and waste heat recovery; and process intensification such as the use of electrified sprays, swirling gas flow, and rotating packed beds. A summary of the industrial applications, engineering issues, environmental impacts, challenges, and perspectives on the research and development of advanced and intensified SWFGD processes is presented.

Integrated Steam/Organic Rankine Cycle (ISORC) for Waste Heat Recovery in Distributed Generation and Combined Heat and Power Production

2010 ◽  
Author(s):  
Yaroslav Chudnovsky ◽  
Mikhail Gotovsky ◽  
Valentin Arefiev ◽  
Mark Greenman ◽  
Victor Fomin ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Distributed Generation ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Industrial Applications ◽  
Heat Utilization ◽  
Energy Efficiency Improvement ◽  
Waste Heat Utilization ◽  
Cycle Efficiency

Energy efficiency improvement and waste heat utilization in power generation and energy intensive industrial applications are in the main focus of the researchers and engineers nowadays. A great deal of experience was gained by the industrial leaders such as ORMAT, Siemens, Caterpillar, Turboden, and others. However, the commercially and semi-commercially available systems for waste heat utilization have certain restrictions that limit the utilization cycle efficiency to approximately 18%. The paper presents an innovative concept of waste heat utilization system that allows reaching the utilization cycle efficiency up to 28–30% employing low-boiling media such as butane, propane, pentane and others. Applying such a concept to Distributed Generation systems the overall energy efficiency could be boost up to 58–60% and further up to 90% in case of CHP production.

Study of a Fuel Cell Cogeneration System Applied to a Brazilian Tertiary Sector

2000 ◽  
Author(s):  
Jose Luz Silveira ◽  
Elisângela Martins Leal
Keyword(s):  
Fuel Cell ◽  
Cold Water ◽  
Waste Heat ◽  
Technical Information ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Tertiary Sector ◽  
Computer Center ◽  
Cogeneration System ◽  
Decentralized Energy

Abstract In this paper, a methodology for the study of a molten carbonate fuel cell cogeneration system and applied to a computer center building is developed. This system permits the recovery of waste heat, available between 600°C and 700°C, which can be used to the production of steam, hot and cold water, hot and cold air, depending on the recuperation equipment associated. Initially, some technical information about the most diffusing types of the fuel cell demonstration in the world are presented. In conclusion, the fuel cell cogeneration system may have an excellent opportunity to strengthen the decentralized energy production in the Brazilian tertiary sector.

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