[PDF] Catalytic Nanofiber Media For Air And Hot Gas Filtration eBook

Author : Sneha Swaminathan
Publisher : LAP Lambert Academic Publishing
Page : 184 pages
File Size : 16,82 MB
Release : 2013
Category :
ISBN : 9783659270307

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For environmental protection, the suppression of automotive exhausts such as nitrogen oxides and carbon monoxide is very important. These gases are potential health hazards and green house gases. Hence this concern triggered the need for stringent environmental regulations which resulted in the introduction of catalytic devices in automobiles. In this book, a novel approach has been developed wherein the noble metal nanocatalysts have been incorporated on ceramic nanofibers by the electrospinning process. The catalysts on ceramic nanofibers increase the overall exposed catalyst area and simultaneously immobilize the catalyst to minimize catalyst loss. A small amount of the catalyst incorporated into ceramic nanofibers was mixed with microfibers to fabricate a filter disk by vacuum molding. This filter disk termed as 'catalytic filter'is a combination of catalytic elements and filter. The catalyzed ceramic nanofiber augmented microfiber filter media can be used for two applications: reduction of NOx and oxidation of CO and for enhanced particulate removal.

Author : Bharath Raghavan
Publisher : LAP Lambert Academic Publishing
Page : 172 pages
File Size : 26,54 MB
Release : 2011-06
Category :
ISBN : 9783844314991

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Nonwoven fibrous media with nanofibers have significant filtration applications in automotive, chemical, transportation, power generation and pharmaceutical/biological industries. Nanofibers have higher capture efficiencies in comparison to microfibers in the submicron particle size range of 100 - 500 nm because of smaller fiber diameter and increased surface area of the fibers. Nanofibers are in the slip flow regime as a consequence of which steep increase in pressure drop is considerably reduced due to slip effect. The economic benefits of using nanofiber filter media are improved filter performance and compact filters. Electrospinning process was used to fabricate polymer and ceramic nanofibers. The electrospun polymer nanofibers were added to the nonwoven fibrous media to improve filter performance for air filtration. This improved filter performance was in consistent with numerical modeling. This book describes the experimental and modeling results of particle loading on fibrous media and application of ceramic nanofibers for hot gas filtration applications.

Author : Bharath Kumar Raghavan
Publisher :
Page : 204 pages
File Size : 41,94 MB
Release : 2010
Category : Air filters
ISBN :

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Nanofibers have higher capture efficiencies in comparison to microfibers in the submicron particle size range of 100-500 nm because of small fiber diameter and increased surface area of the fibers. Pressure drop across the filter increases tremendously with decrease in fiber diameter in the continuum flow regime. Nanofibers with fiber diameter less than 300 nm are in the slip flow regime as a consequence of which steep increase in pressure drop is considerably reduced due to slip effect. The outlet or inlet gases have broad range of particle size distribution varying from few micrometers to nanometers. The economic benefits include capture of a wide range of particle sizes in the gas streams using compact filters composed of nanofibers and microfibers. Electrospinning technique was used to successfully fabricate polymeric and ceramic nanofibers. The nanofibers were long, continuous, and flexible with diameters in the range of 200-300 nm. Nanofibers were added to the filter medium either by mixing microfibers and nanofibers or by directly electrospinning nanofibers as thin layer on the surface of the microfiber filter medium. Experimental results showed that either by mixing Nylon 6 nanofibers with B glass fibers or by electrospinning Nylon 6 nanofibers as a thin layer on the surface of the microfiber medium in the surface area ratio of 1 which is 0.06 g of nanofibers for 2 g of microfibers performed better than microfiber filter media in air filtration tests. This improved performance is consistent with numerical modeling The particle loading on a microfibrous filter were studied for air filtration tests . The experimental and modeling results showed that both pressure drop and capture efficiency increased with loading time. Nanofiber filter media has potential applications in many filtration applications and one of them being hot gas filtration. Ceramic nanofibers made of alumina and titania nanofibers can withstand in the range of 1000°C. Ceramic nanofibers filter media were fabricated by mixing alumina microfibers (SAFFIL) and alumina nanofibers. The appropriate binders were tested for ceramic filter media. The ceramic filter media were tested for aerosol filtration.

Author : Sneha Swaminathan
Publisher :
Page : 317 pages
File Size : 37,5 MB
Release : 2010
Category : Automobiles
ISBN :

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For environmental protection, the suppression of automotive exhausts such as nitrogen oxides (NOx) and carbon monoxide (CO) is very important. These gases are potential health hazards and green house gases. Burning of hydrocarbon (HC) ideally leads to the formation of water and carbon dioxide; however, due to incomplete combustion and temperatures fluctuations reached in the combustion chamber, the exhaust contains significant amounts of pollutants which need to be transformed into harmless compounds. Hence this concern triggered the need for stringent environmental regulations which resulted in the introduction of catalytic devices in automobiles. Traditionally, the catalyst is impregnated onto a porous substrate. The limitation of this method is the difficulty involved in controlling the catalyst particle size during the sintering or reduction steps that result in high temperature agglomeration effects. In the present work, a novel approach has been developed wherein the noble metal nanocatalysts have been incorporated on ceramic nanofibers by the electrospinning process. The catalysts on ceramic nanofibers increase the overall exposed catalyst area and simultaneously immobilize the catalyst to minimize catalyst loss. A small amount of the catalyst incorporated into ceramic nanofibers was mixed with microfibers to fabricate a filter disk by vacuum molding technique. This filter disk termed as 'catalytic filter' is a combination of catalytic elements and filter. The catalyzed ceramic nanofiber augmented microfiber filter media can be used for two applications: reduction of NOx and oxidation of CO and for enhanced particulate removal. This filter would include advantages such as light weight structure, optimization of precious metals, high capture efficiency, high surface area, highly interconnected network of pores and high permeability. The key aspects in this dissertation can be divided into six parts: fabrication of catalytic filters and their optimization, fabrication of three-way catalysts and oxygen storage catalysts, crosslinking of nanofibers as an intermediate step to ceramic nanofiber manufacture, comparison of catalytic filter with the traditional methods and conventional catalytic converter, particle size reduction and studying the deactivation using water and H2S. All the types of catalytic filter which were fabricated were successful in reducing NO and oxidizing CO completely. The degradation temperature of NO and CO depended on the type, amount and loading of the catalyst nanoparticles on the alumina nanofiber.

Author : Agasthiyaraj L
Publisher : Mohammed Abdul Sattar
Page : 0 pages
File Size : 35,94 MB
Release : 2024-02-13
Category : Nature
ISBN :

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Human health is harmed by both brief and prolonged period exposure to PM2.5 pollution. Particulate Matter (PM) is commonly divided into two groups, PM2.5 is particles with an aerodynamic diameter lower than 2.5 μm, and if the particles' aerodynamic diameter is between 2.5 to 10 μm then it is PM10. PM2.5 particles are generated by different man-made and natural sources such as vehicular emissions, industrial emissions, power generation emissions, cooking, house cleaning, forest fire, volcano eruption etc. Especially, PM2.5 particles are critically dangerous particles which is capable to interpenetrate into human lungs and bronchi; which causes respiratory diseases like cardiovascular disease, stroke, chronic bronchitis, asthma etc., to human beings. Thus one-third of the effects of PM2.5 pollution is associated with lung cancer, stroke, and chronic vascular disease. Majority of the particulate pollutants consist of organic compounds, such as carbon-derived compounds and also nitrogen and sulfur-based inorganic compounds. Some other sort of primary pollutant is bio-aerosols, which include bacteria, viruses, and fungi. Because they are easily spread by contaminated air, this significantly enhances the risk to human health. These biological pollutants will induce toxigenic, allergic, infectious, and other disorders in both chronic and acute forms. To protect humans from PM2.5 pollution filtration of the air is the best preservation. Resultantly, interest in high-proficiency air filtration technologies which could collect dangerous particles, toxic gases and biological contaminants all at the same time is growing. Also, these high-efficiency air filter media with different multi functionalities that can work in various temperature and humidity conditions for real-time applications is gathering a lot of attention in the past few years.

Author : Hua Fen Han
Publisher :
Page : 298 pages
File Size : 23,43 MB
Release : 2016-08-01
Category :
ISBN : 9781681175287

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With the prompt development of nanoscience and nanotechnology over the last years, great progress has been made not only in the preparation and characterisation of nanomaterials, but also in their functional applications. As an important one-dimensional nanomaterial, nanofibres have enormously high specific surface area because of their small diameters, and nanofiber membranes are extremely porous with excellent pore interconnectivity. These unique characteristics plus the functionalities from the materials themselves impart nanofibres with a number of novel properties for applications in areas as various as biomedical engineering, wound healing, drug delivery and release control, catalyst and enzyme carriers, filtration, environment protection, composite reinforcement, sensors, optics, energy harvest and storage , and many others. Special properties of nanofibres make them suitable for a wide range of applications from medical to consumer products and industrial to high-tech applications for aerospace, capacitors, transistors, drug delivery systems, battery separators, energy storage, fuel cells, and information technology. Nanofibres have significant applications in the area of filtration since their surface area is substantially greater and have smaller micropores than melt blown (MB) webs. High porous structure with high surface area makes them ideally suited for many filtration applications. Nanofibres are ideally suited for filtering submicron particles from air or water. This book provides an up-to-date coverage of nanofiber preparation, properties and functional applications. The text will be of immense useful for anyone allied with the discipline of nanofibres.

Author : Bin Ding
Publisher : Springer Science & Business Media
Page : 518 pages
File Size : 33,36 MB
Release : 2014-04-10
Category : Technology & Engineering
ISBN : 3642541607

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This book offers a comprehensive review of the latest advances in developing functional electrospun nanofibers for energy and environmental applications, which include fuel cells, lithium-ion batteries, solar cells, supercapacitors, energy storage materials, sensors, filtration materials, protective clothing, catalysis, structurally-colored fibers, oil spill cleanup, self-cleaning materials, adsorbents, and electromagnetic shielding. This book is aimed at both newcomers and experienced researchers in the field of nanomaterials, especially those who are interested in addressing energy-related and environmental problems with the help of electrospun nanofibers. Bin Ding, PhD, and Jianyong Yu, PhD, are both Professors at the College of Materials Science and Engineering, Donghua University, China.

Author : Dominique Thomas
Publisher : Elsevier
Page : 228 pages
File Size : 50,51 MB
Release : 2016-11-30
Category : Science
ISBN : 008102116X

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Filtration of aerosols is omnipresent in our daily lives, in areas as diverse as health, the protection of people and the environment, and air treatment inside buildings. However, the collection of particles within a filter media is not, contrary to popular belief, linked to a simple screen effect. The phenomena involved are much more complex and require the consideration of aerosol interactions, filter media and process conditions to select the best fiber filter for a given application. Aerosol Filtration, book for students, hygiene or process engineers, fibrous media manufacturers, designers, and filtration system suppliers or users addresses the filtration of aerosols in six chapters. These chapters cover physics and aerosol characterization, the fibrous media, and efficiency and filter clogging by solid or liquid aerosols, with special attention to the filtration of the nanoparticles. Analyses the behavior of fibrous media against solid and liquid aerosols Presents models of efficiency and pressure drop Introduces computing elements for estimating the lifetime of filters Provides guidance for designing filters and predicting their behavior over time