The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform

Bharat Bhushan - One of the best experts on this subject based on the ideXlab platform.

  • nanotribological properties of novel lubricants for Magnetic Tapes
    Ultramicroscopy, 2009
    Co-Authors: Manuel Palacio, Bharat Bhushan
    Abstract:

    Two classes of novel lubricants, perfluoropolyethers (PFPE) and ionic liquids (ILs), were deposited on metal film Magnetic Tapes. The adhesive force and coefficient of friction of lubricated and unlubricated Tapes were investigated at the nanoscale with an atomic force microscope (AFM) as a function of various humidity and temperature conditions. Microscale tests with a ball-on-flat tribometer were also performed in order to study the length-scale effects on friction. Wear at ultralow loads was simulated and the lubricant removal mechanism was investigated by monitoring the friction force, surface potential and contact resistance with the AFM. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) experiments were conducted to determine the chemical species that affect intermolecular bonding and as an aid in interpreting how the lubricant film tribological properties vary with the environmental conditions. Z-TETRAOL, one of the PFPEs, was found to exhibit the lowest adhesion and friction among the lubricant films studied. The ionic liquid 1,1'-(pentane-1,5-diyl)bis(3-hydroxyethyl-1H-imidazolium-1-yl) di[bis(trifluoromethanesulfonyl)imide)] exhibited comparable nanotribological properties with the PFPEs. This is attributed to the presence of hydroxyl groups at its chain ends, which can hydrogen bond with the surface similar to PFPEs.

  • nanotribological characterization and lubricant degradation studies of metal film Magnetic Tapes using novel lubricants
    Journal of Tribology-transactions of The Asme, 2007
    Co-Authors: Bharat Bhushan, M Cichomski, Zhenhua Tao, Nang T Tran, Todd L Ethen, Chris Merton, Richard E Jewett
    Abstract:

    In order to improve the durability of metal-film Magnetic Tapes, novel lubricants, A20H, X-1P, and X, a modified phosphazene, were deposited on the Tapes. The adhesion, friction, and wear of the unlubricated/lubricated Tapes were investigated using an atomic force microscope (AFM). The degradation of the lubricants was studied using a mass spectrometer in high vacuum. The durability of various unlubricated/lubricated Tapes was compared in ambient and in humid air. The AFM test results show that the A20H lubricated tape exhibited lower adhesion and friction than X-1P and X lubricated Tapes. The lubricants were believed to be mainly degraded by tribochemical reaction and mechanical shear in high vacuum. In high humidity air, the various lubricated Tapes exhibit higher friction than in ambient air. By comparing the tribological performances of the various lubricated Tapes to metal particle (MP) tape, it was found that the lubricated metal-film Tapes exhibit lower adhesion, friction, and wear than the MP tape.

  • effects of different Magnetic Tapes and operating parameters on lateral tape motion in a linear tape drive
    Tribology Transactions, 2006
    Co-Authors: Andrew E Wright, Bharat Bhushan
    Abstract:

    The need for increased storage capacity in today's data storage technology has created a continuing need to study the tribological performance of Magnetic tape. Lateral tape motion (LTM) is one important area of ongoing tribological research. The objective of the study presented in this article is to determine the effects different Magnetic Tapes and operating parameters have on LTM. Specifically, the research focuses on LTM in five different tape samples and the effects the varying operating parameters have on LTM. The Tapes studied include metal particulate (MP), thin MP, and three advanced metal evaporated (AME) Tapes, as well as MP Tapes with different edge quality and Tapes from staggered packs. The operating parameters studied include tension, speed, and head and bearing setup. Experimental methods used to collect and analyze the LTM data are discussed and the findings are presented.

  • in situ study of nano cracking in multilayered Magnetic Tapes under monotonic and fatigue loading using an afm
    Ultramicroscopy, 2004
    Co-Authors: Nikhil Subhashchandra Tambe, Bharat Bhushan
    Abstract:

    Atomic force microscopy (AFM) techniques are increasingly used for tribological studies of engineering surfaces on micro- to nano-scales. In situ surface characterization of local deformation of materials and thin coatings helps to develop a better understanding of failure mechanisms. In this study, an AFM-based technique has been developed for in situ monitoring of nano-crack formation and progression under fatigue loading. To conduct monotonic and fatigue loading tests, a tensile stage is used to mount samples on the AFM base and the same area on the sample surface is scanned intermittently during the loading process. Crack growth under monotonic and fatigue loading for multilayered Magnetic Tapes is studied and a crack growth mechanism for metallic Magnetic Tapes under monotonic loading is proposed. Fatigue strength for the metallic Magnetic Tapes is measured and a mathematical model based on theory of elasticity for fatigue life prediction is developed.

  • mechanical hygroscopic and thermal properties of ultrathin polymeric substrates for Magnetic Tapes
    Journal of Applied Polymer Science, 2003
    Co-Authors: Bharat Bhushan
    Abstract:

    Mechanical, hygroscopic, and thermal properties of improved ultrathin polymeric films for Magnetic Tapes are presented. These films include poly(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN), and aromatic polyamide (ARAMID). PET films are currently the most commonly used polymeric substrate material for Magnetic Tapes, followed by PEN and ARAMID. The thickness of the films ranges from 6.2 to 4.8 μm. Tensile tests were run to obtain the Young's modulus, F5 value, strain at yield, breaking strength, and strain at break. The storage modulus, E′, and the loss tangent, tan δ, were measured using a dynamic mechanical analyzer (DMA) at temperature ranges of −50 to 150°C (for PET) and −50 to 210°C (for PEN and ARAMID) and at a frequency range of 0.016–28 Hz. Frequency–temperature superposition was used to predict the dynamic mechanical behavior of the films over a 28-decade frequency range. Short-term longitudinal creep behavior of the films during 10, 30, 60, and 300 s, 7 MPa, were measured at 25 and 55°C. Long-term longitudinal creep measurements were performed at 25, 40, and 55°C for 100 h. The Poisson's ratio and 50-h long-term lateral creep were measured at 25°C/15% RH, 25°C/50% RH, 25°C/80% RH, and 40°C/50% RH. The in-plane coefficient of hygroscopic expansion (CHE) at 25°C/20–80% RH and the coefficient of thermal expansion (CTE) at 30–70°C were measured for all the samples. The properties for all films are summarized. The relationship between the polymeric structure and the mechanical and physical properties are discussed, based on the molecular structure, crystallinity, and molecular orientation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3052–3080, 2003

Michael Mello - One of the best experts on this subject based on the ideXlab platform.

  • In Situ Nanoscale In-Plane Deformation Studies of Ultrathin Polymeric Films During Tensile Deformation Using Atomic Force Microscopy and Digital Image Correlation Techniques
    IEEE Transactions on Nanotechnology, 2007
    Co-Authors: Xiaodong Li, Weijie Xu, Michael A. Sutton, Michael Mello
    Abstract:

    The local, nanoscale deformation behavior of ultrathin polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) films used as substrates in Magnetic Tapes was studied by atomic force microscopy (AFM) and digital image correlation (DIC) techniques. A custom-designed tensile stage was integrated with the AFM to perform uniaxial tension tests on the polymeric films in situ where the film surfaces were imaged simultaneously by AFM. The surface features on the PET and PEN films were used as reference patterns for the DIC processing. To improve the accuracy of the AFM imaging system for the application of the DIC method, a simple, cost-effective experimental procedure was established. Axial and transverse strain fields and Poisson's ratio maps with a spatial resolution of 78.13 nm were constructed via processing the AFM images of unstretched and stretched samples with the DIC software. Results from the AFM studies indicate that the deformation in both PET and PEN is nonuniform at the nanoscale. The nanoscale deformation mechanisms are discussed in conjunction with the structure of the PET and PEN films

  • nanoscale deformation and cracking studies of advanced metal evaporated Magnetic Tapes using atomic force microscopy and digital image correlation techniques
    Materials Science and Technology, 2006
    Co-Authors: Michael A. Sutton, Michael Mello
    Abstract:

    Abstract A custom designed microtensile tester was integrated with an atomic force microscopy (AFM) to perform in situ tensile tests on two advanced metal evaporated (ME) Magnetic Tapes – ME/polyethylene terephthalate (PET) (with PET as a substrate) and ME/polyethylene naphthalate (PEN) (with PEN as a substrate) where the tape surfaces were imaged simultaneously by AFM during tensile loading. The digital image correlation technique was used to process the AFM images and quantitatively measure local, nanoscale deformation for both front coat and back coat of the ME Tapes subjected to uniaxial tensile loading. The surface morphology change, strain distribution evolution and crack initiation and propagation during tensile loading are discussed with the structures and mechanical properties of the ME Tapes.

Michael A. Sutton - One of the best experts on this subject based on the ideXlab platform.

  • In Situ Nanoscale In-Plane Deformation Studies of Ultrathin Polymeric Films During Tensile Deformation Using Atomic Force Microscopy and Digital Image Correlation Techniques
    IEEE Transactions on Nanotechnology, 2007
    Co-Authors: Xiaodong Li, Weijie Xu, Michael A. Sutton, Michael Mello
    Abstract:

    The local, nanoscale deformation behavior of ultrathin polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) films used as substrates in Magnetic Tapes was studied by atomic force microscopy (AFM) and digital image correlation (DIC) techniques. A custom-designed tensile stage was integrated with the AFM to perform uniaxial tension tests on the polymeric films in situ where the film surfaces were imaged simultaneously by AFM. The surface features on the PET and PEN films were used as reference patterns for the DIC processing. To improve the accuracy of the AFM imaging system for the application of the DIC method, a simple, cost-effective experimental procedure was established. Axial and transverse strain fields and Poisson's ratio maps with a spatial resolution of 78.13 nm were constructed via processing the AFM images of unstretched and stretched samples with the DIC software. Results from the AFM studies indicate that the deformation in both PET and PEN is nonuniform at the nanoscale. The nanoscale deformation mechanisms are discussed in conjunction with the structure of the PET and PEN films

  • nanoscale deformation and cracking studies of advanced metal evaporated Magnetic Tapes using atomic force microscopy and digital image correlation techniques
    Materials Science and Technology, 2006
    Co-Authors: Michael A. Sutton, Michael Mello
    Abstract:

    Abstract A custom designed microtensile tester was integrated with an atomic force microscopy (AFM) to perform in situ tensile tests on two advanced metal evaporated (ME) Magnetic Tapes – ME/polyethylene terephthalate (PET) (with PET as a substrate) and ME/polyethylene naphthalate (PEN) (with PEN as a substrate) where the tape surfaces were imaged simultaneously by AFM during tensile loading. The digital image correlation technique was used to process the AFM images and quantitatively measure local, nanoscale deformation for both front coat and back coat of the ME Tapes subjected to uniaxial tensile loading. The surface morphology change, strain distribution evolution and crack initiation and propagation during tensile loading are discussed with the structures and mechanical properties of the ME Tapes.

Asu Subhasis - One of the best experts on this subject based on the ideXlab platform.

  • :“Design a plant to manufacture 1×〖10〗^7 kg per year of Methyl Ethyl Ketone (MEK) from Butyl alcohol.”
    iojert, 2017
    Co-Authors: Asu Subhasis
    Abstract:

    SYNOPSIS Name: Mr. Subhasis Basu, Roll No:11/S11/451,Registration No: S/111/16/20. Title: “Design a plant to manufacture 1×〖10〗 7kg per year of Methyl Ethyl Ketone (MEK) from Butyl alcohol.”   Title:“Design a plant to manufacture 1×〖10〗^7 kg per year of Methyl Ethyl Ketone (MEK) from Butyl alcohol.” By Mr.SubhasisBasu, Associate Membership Examination Roll No:11/S11/451, Registration No: S/111/16/20. (Indian Institute of Chemical Engineers (IIChE). A Proposal is to be submitted for the partial fulfilment of Part-III(Home Paper) of The Indian Institute Of Chemical Engineers (IIChE)-Associate Membership Examination). Contents: The Synopsis has been prepared on the basis of following details A brief outline of the process. A summary of raw material requirements. A summary of the process design equipment. A summary of the mechanical design. A summary of safety and pollution consideration of the plant Elaborating the whole idea of design Report has to be prepared on the following topics: 1. Literacy Survey. 2. Detailed flow sheet. 3. Material and energy balance of the plant. 4. Design of vaporizer including mechanical details. 5. Design of catalytic reactor using the rate equation from references. 6. Instrumentation and process control of the reactor. 7. Plant layout. 8. Safety and pollution abatement aspects 9. Cost estimation. 10. Detailed engineering drawing of the reactor and vaporizer. A brief outline of the process. Abstract STATEMENT OF PROBLEM FORM Design a plant to manufacture 1×〖10〗^7 kg per year of Methyl Ethyl Ketone(MEK) from Butyl alcohol. The butyl alcohol is supplied to a steam heated in preheater and then to a vaporizer heated by the reaction products. The vapour leaving the vaporizer is heated to its reaction temperature by the flue gases which have previously has been used as reactor heating medium. The vapour leaving the vaporizer is heated to its reaction temperature by the flue gases which have previously been used as reactor heating medium. The superheated butyl alcohol is fed to the reaction system at 400°C to 500° C where 90% is converted on a zinc oxide brass catalyst to methyl ethyl ketone (MEK), Hydrogen, and other reaction products. The reaction products are cooled to a suitable temperature and separate the MEK by absorption in aqueous ethanol. The hydrogen off- gas is dried and used as a furnace fuel. The liquors leaving the absorbers are passed to a solvent extraction column, where MEK is recovered using trichloroethane. The raffinate from this column is returned to absorber and the extract is passed to distillation unit where the MEK is recovered. The trichloroethane is recycled to the extract plant. Secondary butyl alcohol can be used as feed stock. Dry saturated steam is available at 140° C, cooling water is at 24°C and Flue gases at 540°C. Out let condensate temperature is 32°C and vapour and liquid are in equilibrium at the condenser out let. Calorific value of MEK is 41800 Kj/kg. Assume any missing data suitably if required. A summary of raw material requirements LITERATURE REVIEW Introduction and Background: Nature of methyl ethyl ketone (product description) Methyl ethyl ketone, also known as 2-butanone, is a colourless organic liquid with an acetone-like odour and a low boiling point. It is partially miscible with water and many conventional organic solvents and forms zoetrope with a number of organic liquids. MEK is distinguished by its exceptional solvency, which enables it to formulate higher-solids protective coatings. The molecular formula of methyl ethyl ketone is CH3COCH2CH3; Its molecular structure is represented as: Some physical and chemical properties of MEK are presented in below Applications As a solvent Butanone is an effective and common solvent and is used in processes involving gums, resins, cellulose acetate and nitrocellulose coatings and in vinyl films. For this reason it finds use in the manufacture of plastics, textiles, in the production of paraffin wax, and in household products such as lacquer, varnishes, paint remover, a denaturing agent for denatured alcohol, glues, and as a cleaning agent. It has similar solvent properties to acetone but boils at a higher temperature and has a significantly slower evaporation rate. Butanone is also used in dry erase markers as the solvent of the erasable dye. As a plastic welding agent As butanone dissolves polystyrene and many other plastics, it is sold as "model cement" for use in connecting parts of model kits. Though often considered an adhesive, it is actually functioning as a welding agent in this context. Other uses Butanone is the precursor to methyl ethyl ketone peroxide, which is a catalyst for some polymerization reactions such as cross linking of unsaturated polyester resins as an absorbent which absorb MEK and alcohol and leave from the bottom of the absorber. The off gases from the absorber containing all hydrogen, negligible water, MEK and alcohol are dried and used in a plant fuel system. The liquid discharged from the absorber is sent to a liquid-liquid extraction column where trichloroethane is used to extract the MEK and alcohol and there affinate contains water is recycled back to the absorber along with the small amount of makeup water. The extract from the liquid-liquid extraction column is sent to a solvent recovery column where trichloroethane is recovered at the bottom and is recycled back to a liquid-liquid extraction column. The top product from the solvent recovery unit is sent to a distillation column along with the condensate from the partial condenser. In the distillation column, 99% pure MEK is obtained as distillate and send to storage where as the butyl alcohol obtained as a bottom product, is recycled back and mix with a fresh feed for reprocessing.PumpReactorPartial CondenserLiq-Liq Extraction Column Solvent Recovery Column Distillation Column MEK Storage safety. Table 1: Physical and chemical properties of MEK Property Value Structural Formula CH3COCH2CH3 Molecular weight (grams) 72.1 Melting point, °C -86.3 Boiling point, °C 79.6 Density at 20°C, g/L 804.5 Vapour density (air at 101 KPa, 0°C = 1) 2.41 Critical temperature, °C 260 Property Value Critical pressure, MPa 4.4 Surface tension at 20°C, dyne/cm 24.6 Dielectric constant at 20°C 15.45 Heat of combustion at 25°C, kJ/mol 2435 Heat of fusion, kJ/(kg*K) 103.3 Heat of formulation at constant pressure, kJ/mol 279.5 Specific heat:vapor at 137°C, J/(kg*K)liquid at 20°C, J/(kg*K 1732 2084 Property Value Latent heat of vaporization at 101.3 KPa, kJ/mol 32.8 Flashpoint (closed cup), °C -6.6 Ignition temperature, °C 515.5 Explosive limits, volume % MEK in air lower upper 2 12 Property and Property Value Vapour pressure at 20°C, mm 77.5 Viscosity, MPa*s (=cP) at 0°C at 20°C at 40°C 0.54 0.41 0.34 Solubility at 90°C, g/L of water 190 With the above uses this compound is easily be manufactured or isolable with good yield from various readily found cheap compounds. Because of MEK’s high reactivity, it is estimated to have a short atmospheric lifetime of approximately eleven hours. Atmospheric lifetime is defined as the time required for the concentration to decay to 1/e(37percent) of its original value. Overview of production and use Generally, Methyl ethyl ketone production is accomplished by one of the available processes: (1)Vapour phase Dehydrogenation of secondary butyl alcohol (2) As a by-product of butane oxidation. (Liquid phase oxidation or Direct oxidations which may be Hoechest-Wacker or Maruzen processes) I have selected the dehydrogenation process for MEK production because of following advantage process.(process selection) 1. In dehydrogenation hydrogen as a by-product is obtained that can be used as a furnace fuel. 2. In dehydrogenation process, there is the feasibility of separating the MEK from the reaction products. 3. The dehydrogenation process can easily be carried out at moderate temperature and at atmospheric pressure. 4. In dehydrogenation process, 90% of MEK can easily be converted to MEK. 5. Selective oxidation process require controlled conditions so it becomes uneconomical. 6. Chromic acid and sulphuric acid in aqueous acetone is required for selective oxidation of butanol while only brass is required for dehydrogenation of butanol. 7. The dehydrogenation reaction is a single step reaction and there are negligible chances of producing by product while oxidation is a three step reaction. 8. From the literature survey, it can be found that the dehydrogenation process is the most economical process. (1)Raw materials (1) Secondary butyl alcohol. (2) Catalyst. Cu, Zn or Bronze are used as catalyst. A summary of the process design equipment. Design has been made on the basis of following ideas: MEK Production and use Tree Data Process Data: Outlet condenser temperature = 32°C, Vapour and liquid are in equilibrium at the condenser outlet. Calorific value of MEK= 41800KJ/Kg. Cost Data: Selling Prices of MEK= Rs 760 to 800 per 100 kg. Steam raising Cost= Rs 40 to 45 per per 10 6Kg. Cost of tower shell=Rs 16000 to 18000. Cost of plates= Rs 20000 to 215000. Cost of Reboiler= Rs 15000 to 18000. Cost of heat exchanger (per distillation Column)=RS 640000 TO 650000. Cost of solvent extraction auxiliaries= Rs 80000. Cost of absorption and distillation column packing, supports and distributors=Rs 16000 to 18000 Cost of tanks (Surge, etc)= Rs80000 to100000. Cost of control of whole plant= Rs 720000 to 750000. Cost of Instrumentation for control of recovery section=Rs 360000 to 400000 Cost of electricity for pumps= Rs400000 to 425000 Pump Cost (Total)= Rs240000 to 250000 Cost of Cooling water for whole plant= 400000 Reactor Data: The “short –cut” method proposed in Ref may be used only to obtain a preliminary estimate of the height of catalyst required in the reactor. The reactor should be designed from the principles using the rate equation below: rA=[C.(PA,i - PK,i.PH,i/K)]/[PK,i(1+KAPA,i +KAK.PAi /PK,i)] Where PA,i, PH,i and PK,i are the interfacial quantities are as specified by the semi entered equations below: log10C= -5964/Ti + 8.464. log10 KA = -3425/Ti + 5.231. log10 KAK = + 486/Ti– 0.1968. In these equations, the interfacial temperature Ti is in Kelvin, the constant Kmol/m2. h. KA in /bar. And K AK is dimensionless. The equilibrium constant, K is given in Ref.22( although the original sources) by the equation : log10 K =- 2790/Ti+ 1.510 log 10 Ti + 1.871 Where K is in bar. Useful general in formations will be found in Ref 24. MEK concentration in the reaction mixture increases and reaches in the maximum at about 350°C. Cu, Zn or Bronze are used as catalyst in the gas phase dehydration process. Commercially used catalyst are reactivated by oxidation after 3 to 6 months use. They have several years of life expectancy. Sec-butyl alcohol is dehydrogenated in a multiple tube reactor, the reaction heat being supplied by heat transfer oil. The reaction product leave the reactor as gas and are split into crude MEK and H2 on cooling. The H2 is purified by further cooling. The crude MEK is separated from un reacted reactants and by-products by distillation. A summary of the mechanical design. Design of the plant to produce1×〖10〗^7 kg per year of Methyl Ethyl Ketone (MEK) from Butyl alcohol.Feed Stock: Secondary butyl alcohol. Services available: Cooling water at 24°C.Electricity at 440V three phase 50 Hz. Flue gases at 540°C. (2) List of Process design of the equipment: Steam heated pre heater.(b)Vaporizer.(mainly thermo syphon type) (c)reactor(mainly multi-tube)for achieving reaction temperature.(d)Extraction plant- solvent extraction column.(e) Dehydrogenation unit. (f) Condenser.(g) Furnace for fuel generation.(h) Dryer for hydrogen. (i)Cooler for MEK. (j)Distillation unit. (k)Absorber. (l) Recycled pump.(m) Extraction unit (n) Product storage and loading unit.(o)Scrubber.(p)Feed tank. Etc. Production of Methyl Ethyl Ketone from secondary Butyl Alcohol by Dehydration Process (flow sheet.) in the following figure PROCESS DESCRIPTION WITH THE USE OF MECHANICAL DESIGN AND USED RAW MATERIALS: The cold feed of secondary butyl alcohol is pumped from the storage to a steam heater and then to a vertical thermo-syphon reboiler (vaporizer) in which the alcohol is vaporized. The thermo-syphon reboiler will be heated by the reaction products discharge from the reactor and the wet alcohol vapours will be passed to a knock-out drum (separator) to remove any entrained liquid. The liquid separated will be recycled and the dry alcohol vapours will be fed to a super heater 1 where they are super-heated to a temperature of 573 K. The super-heated vapours are then compressed to a second super heater 2 where they are heated to a temperature of 773 K. In the supper heaters, the vapours are heated with the help of flue gases at high temperature. The superheated butyl alcohol vapours are fed to the reactor at 400-500 ºC where 90% is converted on a zinc oxide- brass catalyst to methyl ethyl ketone and hydrogen. Production Butanone may be produced by oxidation of 2-butanol. The dehydrogenation of 2-butanol (SBA) using a catalyst is catalysed by copper, zinc, or bronze: CH3CH(OH)CH2CH3 → CH3C(O)CH2CH3 + H2 This is used to produce approximately up to 700 million kilograms yearly or may be used as projected pant as per given in the problem. Other syntheses that have been examined but not implemented include Wacker oxidation of 2-butene and oxidation of isobutyl benzene, which is analogous to the industrial production of acetone. Both liquid-phase oxidation of heavy naphtha and the Fischer-Tropsch reaction produce mixed oxygenate streams, from which 2-butanone is extracted by fractionation. Butanone is biosynthesized by some trees and found in some fruits and vegetables in small amounts. It is released to the air from car and truck exhausts. MEK is prepared by vapour phase dehydrogenation of 2- butanol. A 2 step process from butanes, which first hydrated to2-butanol, is used. The Dehydrogenation of butanol is an exothermic reaction(51 KJ/Kg mol).Cu, Zn or Bronze are used as catalysts. The reaction is, CH3CH2 – CHOH – CH3 CH3CH2-CO-CH3+ H2 (2- Butanol) (Methyl ethyl ketone) (Hydrogen) The reaction products are then cooled in a vaporizer where there heat is utilized to vaporize the butanol feed liquid. The cooled products gases are then condensed in a water cool partial condenser where almost 80% of the MEK and unreacted butanol is condensed and the condensate is passed to a distillation unit. The gases effluent from the partial condenser is send to the absorber to recover remaining uncondensed MEK and alcohol. In the absorber, water is used By the application of the above reaction as illustrated in the production and use of MEK, the major end-users of MEK include protective coating solvents (61 percent), adhesives (13 percent), and Magnetic Tapes (10 percent) .Vinyl are the primary resins that employ MEK as a solvent. Methyl ethyl ketone is commonly used as a solvent in rubber cements, as well as in natural and synthetic resins for adhesive use. It is also the preferred extraction solvent for dew axing lube oil and is used in printing inks. Overall, the projected use of MEK is expected to gradually decline. The growing trend towards water-based, higher-solids, and solvent-less protective coatings, inks and adhesives is reducing the demand for MEK. The installation of solvent recycling facilities will also reduce requirements for fresh solvent production. Although MEK is favoured as a solvent due to its low density, low viscosity, and high solvency, its addition on the EPA’s hazardous air pollutants list will likely cause potential users to consider other comparative solvents such as ethyl acetate. Scope of Design Work required: Material balance need to prepare Material flow diagram of the preferred process. Heat balance diagram of the preheated –vaporiser-super heater –reactor system. A design of pre heater –vaporiser –super heater –reactor system need to be produced. A mechanical design of the butyl alcohol vaporiser and make a dimensioned sketch suitable for submission to a drawing office. A summary of safety and pollution consideration of the plant Flammability Butanone can react with most oxidizing materials, and can produce fires. It is moderately explosive; it requires only a small flame or spark to cause a vigorous reaction. Butanone fires should be extinguished with carbon dioxide, dry agents, or alcohol-resistant foam. Concentrations in the air high enough to be flammable are intolerable to humans due to the irritating nature of the vapour. Health effects Butanone is an irritant, causing irritation to the eyes and nose of humans. Serious health effects in animals have been seen only at very high levels. These included skeletal birth defects and low birth weight in mice, when they inhaled MEK at the highest dose tested (3000 ppm for 7 hours/day).There are no long-term studies with animals breathing or drinking MEK. and no studies for carcinogenicity in animals breathing or drinking MEK. There is some evidence that methyl ethyl ketone can potentiate the toxicity of other solvents, in contrast to the calculation of mixed solvent exposures by simple addition of exposures. As of 2010, some reviewers advised caution in using methyl ethyl ketone because of reports of neuropsychological effects. Butanone is listed as a Table II precursor under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances. Regulation Emission of butanone was regulated in the US as a hazardous air pollutant, because it is a volatile organic compound contributing to the formation of troposphere (ground-level) ozone. In 2005, the U. S. Environmental Protection Agency removed butanone from the list of hazardous air pollutants (HAPs). Reference: 1.S.K.Ghosal, S.K.Sanyal, S.Datta, Introduction to Chemical Engineering, Tata Mc- Graw Hill Publishing Company Limited, New Delhi.ISBN:0-07-460140. 2. "NIOSH Pocket Guide to Chemical Hazards #0069".National Institute for Occupational Safety and Health (NIOSH). 3. "2-Butanone". Immediately Dangerous to Life and Health. National (NIOSH). 4. Wilhelm Neier, GünterStrehlke "2-Butanone" in Ullmann's Encyclopaedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. 5. Turner, Charles F.; McCrery, Joseph W. (1981). The Chemistry of Fire and Hazardous Materials. Boston, Massachusetts: Alyn and Bacon, Inc. p. 118. ISBN 0-205-06912-6. 6. Ashford's Dictionary of Industrial Chemicals, Third edition, 2011,ISBN 978-0-9522674-3-0, pages 6013-47. Apps, E. A. (1958). Printing Ink Technology. London: Leonard Hill [Books] Limited. p. 101. 7. Fairhall, Lawrence T. (1957). Industrial Toxicology. Baltimore: The Williams and Wilkins Company. p. 172–173. 8. Schwetz; et al. (1991). "Developmental toxicity of inhaled methyl ethyl ketone in Swiss mice". Fund. Appl. Toxicol. 16 (4): 742–748. doi:10.1016/0272-0590(91)90160-6. 9. "Methyl ethyl ketone (MEK) (CASRN 78-93-3)". Integrated Risk Information System (IRIS). EPA. 26 September 2003. Retrieved 16 March 2015. 10. "U.S.Toxicological review of Methyl ethyl ketone In Support of Summary Information on the Integrated Risk Information System (IRIS)" (PDF). U.S. Environmental Protection Agency. September 2003. p. 152. Retrieved 16 March 2015. 11. F D Dick. Solvent neurotoxicity, Occup Environ Med. 2006 Mar; 63(3): 221–226. doi: 10.1136/oem.2005.022400, PMCID: PMC2078137 12. Thompson, S.B.N. “Implications for cognitive rehabilitation and brain injury from exposure to Methyl Ethyl Ketone (MEK): a review.” Journal of Cognitive Rehabilitation 2010; 28(Winter): 4-14. doi: jofcr.com/vol284/v28i4thompson.pdf. 13. List of Precursors and Chemicals Frequently Used in the Illicit Manufacture of Narcotic Drugs and Psychotropic Substances under International Control, International Narcotics Control Board. 14. Barbara Kanegsberg (n.d.). "MEK No Longer a HAP". Bfksolutions newsletter. Retrieved 2 April 2015. After technical review and consideration of public comments, EPA concluded that potential exposures to butanone emitted from industrial processes may not reasonably be anticipated to cause human health or environmental problems. 15. "EPA De-Lists MEK from CAA HAP List". www.pcimag.com. Retrieved 2016-07-30.18. Personal, J.J.andTho dose, G., AICHE Journal, 3, 230, (1957)19. Kolb, H.J.and Burwell, R.L. (Jr.) Am. Chem. Soc., 67, 1084, (1945)20. Encyclopaedia of Chemical Technology, by Kirk- Other 5th Edn.John Wiley, Newcastle York. 21. Rudd, D.F. and Watson, C.C., Strategy of Process Engineering, John Wiley & Sons Inc. NY, (1968). 16. Austin G.T,"Shreve' Chemical Process Industries", McCartney Graw Hills Book Company, Newcastle Delhi 5th Edn.John.(1986). 17. Shukla S D and Pandy G N , " A text book of Chemical Technology vol I & II", Visas Publishing House Pvt. Ltd., Newcastle Delhi. 18.M.Gopala Rao & Marshall Sitting, 3rd Edition Carls E.Dryden,Out lines of Chemicals Techonology-2nd Edition p-389-392, East-West Press(2004). 19. Plant design and Economics foe Chemical Engineering by M.S Peters, K.D. Timmerhaus, 4th Edition, McGraw-Hill International. 20. Chemical Engineering Kinetics by J.M.Smith 3rd Edition, McGraw Hill. 27. Separations Processes by King.C.J , 2nd Edition, McGraw Hill Book Co.,Ne

  • :“Design a plant to manufacture 1×〖10〗^7 kg per year of Methyl Ethyl Ketone (MEK) from Butyl alcohol.”
    iojert, 2017
    Co-Authors: Asu Subhasis
    Abstract:

    SYNOPSIS\ud Name: Mr. Subhasis Basu, Roll No:11/S11/451,Registration No: S/111/16/20. Title: “Design a plant to manufacture 1×〖10〗 7kg per year of Methyl Ethyl Ketone (MEK) from Butyl alcohol.”\ud \ud  \ud Title:“Design a plant to manufacture 1×〖10〗^7 kg per year of Methyl Ethyl Ketone (MEK) from Butyl alcohol.”\ud \ud By\ud \ud \ud \ud \ud \ud Mr.SubhasisBasu,\ud Associate Membership Examination Roll No:11/S11/451,\ud Registration No: S/111/16/20.\ud \ud (Indian Institute of Chemical Engineers (IIChE).\ud \ud \ud \ud \ud \ud \ud \ud \ud \ud A Proposal is to be submitted for the partial fulfilment of Part-III(Home Paper) of The Indian Institute Of Chemical Engineers (IIChE)-Associate Membership Examination).\ud \ud \ud Contents:\ud \ud The Synopsis has been prepared on the basis of following details\ud A brief outline of the process.\ud A summary of raw material requirements.\ud A summary of the process design equipment.\ud A summary of the mechanical design.\ud A summary of safety and pollution consideration of the plant \ud \ud Elaborating the whole idea of design Report has to be prepared on the following topics:\ud 1. Literacy Survey.\ud 2. Detailed flow sheet.\ud 3. Material and energy balance of the plant.\ud 4. Design of vaporizer including mechanical details.\ud 5. Design of catalytic reactor using the rate equation from references.\ud 6. Instrumentation and process control of the reactor.\ud 7. Plant layout.\ud 8. Safety and pollution abatement aspects \ud 9. Cost estimation.\ud 10. Detailed engineering drawing of the reactor and vaporizer.\ud \ud \ud \ud \ud \ud \ud \ud \ud \ud A brief outline of the process.\ud \ud Abstract\ud \ud STATEMENT OF PROBLEM FORM\ud \ud Design a plant to manufacture 1×〖10〗^7 kg per year of Methyl Ethyl Ketone(MEK) from Butyl alcohol.\ud The butyl alcohol is supplied to a steam heated in preheater and then to a vaporizer heated by the reaction products. The vapour leaving the vaporizer is heated to its reaction temperature by the flue gases which have previously has been used as reactor heating medium. The vapour leaving the vaporizer is heated to its reaction temperature by the flue gases which have previously been used as reactor heating medium. The superheated butyl alcohol is fed to the reaction system at 400°C to 500° C where 90% is converted on a zinc oxide brass catalyst to methyl ethyl ketone (MEK), Hydrogen, and other reaction products. The reaction products are cooled to a suitable temperature and separate the MEK by absorption in aqueous ethanol. The hydrogen off- gas is dried and used as a furnace fuel. The liquors leaving the absorbers are passed to a solvent extraction column, where MEK is recovered using trichloroethane. The raffinate from this column is returned to absorber and the extract is passed to distillation unit where the MEK is recovered. The trichloroethane is recycled to the extract plant. Secondary butyl alcohol can be used as feed stock. Dry saturated steam is available at 140° C, cooling water is at 24°C and Flue gases at 540°C. Out let condensate temperature is 32°C and vapour and liquid are in equilibrium at the condenser out let. Calorific value of MEK is 41800 Kj/kg. Assume any missing data suitably if required.\ud \ud \ud A summary of raw material requirements\ud \ud LITERATURE REVIEW\ud Introduction and Background:\ud Nature of methyl ethyl ketone (product description) Methyl ethyl ketone, also known as 2-butanone, is a colourless organic liquid with an acetone-like odour and a low boiling point. It is partially miscible with water and many conventional organic solvents and forms zoetrope with a number of organic liquids. MEK is distinguished by its exceptional solvency, which enables it to formulate higher-solids protective coatings.\ud The molecular formula of methyl ethyl ketone is CH3COCH2CH3; Its molecular structure is represented as: Some physical and chemical properties of MEK are presented in below \ud Applications\ud \ud \ud As a solvent\ud Butanone is an effective and common solvent and is used in processes involving gums, resins, cellulose acetate and nitrocellulose coatings and in vinyl films. For this reason it finds use in the manufacture of plastics, textiles, in the production of paraffin wax, and in household products such as lacquer, varnishes, paint remover, a denaturing agent for denatured alcohol, glues, and as a cleaning agent. It has similar solvent properties to acetone but boils at a higher temperature and has a significantly slower evaporation rate. Butanone is also used in dry erase markers as the solvent of the erasable dye.\ud \ud As a plastic welding agent\ud As butanone dissolves polystyrene and many other plastics, it is sold as "model cement" for use in connecting parts of model kits. Though often considered an adhesive, it is actually functioning as a welding agent in this context.\ud \ud Other uses\ud Butanone is the precursor to methyl ethyl ketone peroxide, which is a catalyst for some polymerization reactions such as cross linking of unsaturated polyester resins as an absorbent which absorb MEK and alcohol and leave from the bottom of the absorber. The off gases from the absorber containing all hydrogen, negligible water, MEK and alcohol are dried and used in a plant fuel system. The liquid discharged from the absorber is sent to a liquid-liquid extraction column where trichloroethane is used to extract the MEK and alcohol and there affinate contains water is recycled back to the absorber along with the small amount of makeup water. The extract from the liquid-liquid extraction column is sent to a solvent recovery column where trichloroethane is recovered at the bottom and is recycled back to a liquid-liquid extraction column. The top product from the solvent recovery unit is sent to a distillation column along with the condensate from the partial condenser. In the distillation column, 99% pure MEK is obtained as distillate and send to storage where as the butyl alcohol obtained as a bottom product, is recycled back and mix with a fresh feed for reprocessing.PumpReactorPartial CondenserLiq-Liq Extraction Column Solvent Recovery Column Distillation Column MEK Storage safety.\ud \ud \ud \ud Table 1: Physical and chemical properties of MEK\ud Property Value\ud Structural Formula CH3COCH2CH3 \ud Molecular weight (grams) 72.1\ud Melting point, °C -86.3\ud Boiling point, °C 79.6\ud Density at 20°C, g/L 804.5\ud Vapour density (air at 101 KPa, 0°C = 1) 2.41\ud Critical temperature, °C 260\ud \ud \ud Property Value\ud Critical pressure, MPa 4.4\ud Surface tension at 20°C, dyne/cm 24.6\ud Dielectric constant at 20°C 15.45\ud Heat of combustion at 25°C, kJ/mol 2435\ud Heat of fusion, kJ/(kg*K) 103.3\ud Heat of formulation at constant pressure, kJ/mol 279.5\ud Specific heat:vapor at 137°C, J/(kg*K)liquid at 20°C, J/(kg*K 1732\ud 2084\ud \ud \ud Property Value\ud Latent heat of vaporization at 101.3 KPa, kJ/mol 32.8\ud Flashpoint (closed cup), °C -6.6\ud Ignition temperature, °C 515.5\ud Explosive limits, volume % MEK in air\ud lower\ud upper \ud 2\ud 12\ud Property and Property Value\ud Vapour pressure at 20°C, mm 77.5\ud Viscosity, MPa*s (=cP)\ud at 0°C\ud at 20°C\ud at 40°C \ud 0.54\ud 0.41\ud 0.34\ud Solubility at 90°C, g/L of water 190\ud \ud \ud \ud \ud With the above uses this compound is easily be manufactured or isolable with good yield from various readily found cheap compounds.\ud \ud Because of MEK’s high reactivity, it is estimated to have a short atmospheric lifetime of approximately eleven hours. Atmospheric lifetime is defined as the time required for the concentration to decay to 1/e(37percent) of its original value. Overview of production and use Generally, Methyl ethyl ketone production is accomplished by one of the available processes:\ud (1)Vapour phase Dehydrogenation of secondary butyl alcohol \ud (2) As a by-product of butane oxidation. (Liquid phase oxidation or Direct oxidations which may be Hoechest-Wacker or Maruzen processes)\ud I have selected the dehydrogenation process for MEK production because of following advantage process.(process selection)\ud 1. In dehydrogenation hydrogen as a by-product is obtained that can be used as a furnace fuel.\ud 2. In dehydrogenation process, there is the feasibility of separating the MEK from the reaction products.\ud 3. The dehydrogenation process can easily be carried out at moderate temperature and at atmospheric pressure.\ud 4. In dehydrogenation process, 90% of MEK can easily be converted to MEK.\ud 5. Selective oxidation process require controlled conditions so it becomes uneconomical.\ud 6. Chromic acid and sulphuric acid in aqueous acetone is required for selective oxidation of butanol while only brass is required for dehydrogenation of butanol.\ud 7. The dehydrogenation reaction is a single step reaction and there are negligible chances of producing by product while oxidation is a three step reaction.\ud 8. From the literature survey, it can be found that the dehydrogenation process is the most economical process.\ud \ud (1)Raw materials\ud (1) Secondary butyl alcohol.\ud (2) Catalyst. Cu, Zn or Bronze are used as catalyst.\ud \ud \ud \ud \ud A summary of the process design equipment.\ud \ud Design has been made on the basis of following ideas:\ud \ud \ud \ud \ud \ud MEK Production and use Tree\ud \ud Data\ud Process Data: \ud Outlet condenser temperature = 32°C,\ud Vapour and liquid are in equilibrium at the condenser outlet.\ud Calorific value of MEK= 41800KJ/Kg.\ud \ud \ud Cost Data:\ud Selling Prices of MEK= Rs 760 to 800 per 100 kg.\ud Steam raising Cost= Rs 40 to 45 per per 10 6Kg.\ud Cost of tower shell=Rs 16000 to 18000.\ud Cost of plates= Rs 20000 to 215000.\ud Cost of Reboiler= Rs 15000 to 18000.\ud Cost of heat exchanger (per distillation Column)=RS 640000 TO 650000.\ud Cost of solvent extraction auxiliaries= Rs 80000.\ud Cost of absorption and distillation column packing, supports and distributors=Rs 16000 to 18000\ud Cost of tanks (Surge, etc)= Rs80000 to100000.\ud Cost of control of whole plant= Rs 720000 to 750000.\ud Cost of Instrumentation for control of recovery section=Rs 360000 to 400000\ud Cost of electricity for pumps= Rs400000 to 425000\ud Pump Cost (Total)= Rs240000 to 250000\ud Cost of Cooling water for whole plant= 400000\ud \ud \ud Reactor Data:\ud The “short –cut” method proposed in Ref may be used only to obtain a preliminary estimate of the height of catalyst required in the reactor. The reactor should be designed from the principles using the rate equation below:\ud rA=[C.(PA,i - PK,i.PH,i/K)]/[PK,i(1+KAPA,i +KAK.PAi /PK,i)]\ud Where PA,i, PH,i and PK,i are the interfacial quantities are as specified by the semi entered equations below:\ud log10C= -5964/Ti + 8.464.\ud log10 KA = -3425/Ti + 5.231.\ud log10 KAK = + 486/Ti– 0.1968.\ud In these equations, the interfacial temperature Ti is in Kelvin, the constant Kmol/m2. h.\ud KA in /bar. And K AK is dimensionless.\ud The equilibrium constant, K is given in Ref.22( although the original sources) by the equation :\ud log10 K =- 2790/Ti+ 1.510 log 10 Ti + 1.871\ud Where K is in bar. Useful general in formations will be found in Ref 24.\ud MEK concentration in the reaction mixture increases and reaches in the maximum at about 350°C. Cu, Zn or Bronze are used as catalyst in the gas phase dehydration process. Commercially used catalyst are reactivated by oxidation after 3 to 6 months use. They have several years of life expectancy. Sec-butyl alcohol is dehydrogenated in a multiple tube reactor, the reaction heat being supplied by heat transfer oil. The reaction product leave the reactor as gas and are split into crude MEK and H2 on cooling. The H2 is purified by further cooling. The crude MEK is separated from un reacted reactants and by-products by distillation.\ud A summary of the mechanical design.\ud Design of the plant to produce1×〖10〗^7 kg per year of Methyl Ethyl Ketone (MEK) from Butyl alcohol.Feed Stock: Secondary butyl alcohol. Services available: Cooling water at 24°C.Electricity at 440V three phase 50 Hz. Flue gases at 540°C.\ud \ud (2) List of Process design of the equipment:\ud Steam heated pre heater.(b)Vaporizer.(mainly thermo syphon type)\ud (c)reactor(mainly multi-tube)for achieving reaction temperature.(d)Extraction plant- solvent extraction column.(e) Dehydrogenation unit. (f) Condenser.(g) Furnace for fuel generation.(h) Dryer for hydrogen. (i)Cooler for MEK. (j)Distillation unit. (k)Absorber. (l) Recycled pump.(m) Extraction unit (n) Product storage and loading unit.(o)Scrubber.(p)Feed tank. Etc.\ud Production of Methyl Ethyl Ketone from secondary Butyl Alcohol by Dehydration Process (flow sheet.) in the following figure\ud \ud \ud \ud PROCESS DESCRIPTION WITH THE USE OF MECHANICAL DESIGN AND USED RAW MATERIALS:\ud \ud The cold feed of secondary butyl alcohol is pumped from the storage to a steam heater and then to a vertical thermo-syphon reboiler (vaporizer) in which the alcohol is vaporized. The thermo-syphon reboiler will be heated by the reaction products discharge from the reactor and the wet alcohol vapours will be passed to a knock-out drum (separator) to remove any entrained liquid. The liquid separated will be recycled and the dry alcohol vapours will be fed to a super heater 1 where they are super-heated to a temperature of 573 K. The super-heated vapours are then compressed to a second super heater 2 where they are heated to a temperature of 773 K. In the supper heaters, the vapours are heated with the help of flue gases at high temperature. The superheated butyl alcohol vapours are fed to the reactor at 400-500 ºC where 90% is converted on a zinc oxide- brass catalyst to methyl ethyl ketone and hydrogen. \ud Production\ud Butanone may be produced by oxidation of 2-butanol. The dehydrogenation of 2-butanol (SBA) using a catalyst is catalysed by copper, zinc, or bronze:\ud CH3CH(OH)CH2CH3 → CH3C(O)CH2CH3 + H2\ud This is used to produce approximately up to 700 million kilograms yearly or may be used as projected pant as per given in the problem.\ud Other syntheses that have been examined but not implemented include Wacker oxidation of 2-butene and oxidation of isobutyl benzene, which is analogous to the industrial production of acetone. Both liquid-phase oxidation of heavy naphtha and the Fischer-Tropsch reaction produce mixed oxygenate streams, from which 2-butanone is extracted by fractionation. Butanone is biosynthesized by some trees and found in some fruits and vegetables in small amounts. It is released to the air from car and truck exhausts.\ud MEK is prepared by vapour phase dehydrogenation of 2- butanol. A 2 step process from butanes, which first hydrated to2-butanol, is used. The Dehydrogenation of butanol is an exothermic reaction(51 KJ/Kg mol).Cu, Zn or Bronze are used as catalysts.\ud \ud \ud The reaction is,\ud CH3CH2 – CHOH – CH3 CH3CH2-CO-CH3+ H2\ud (2- Butanol) (Methyl ethyl ketone) (Hydrogen)\ud The reaction products are then cooled in a vaporizer where there heat is utilized to vaporize the butanol feed liquid. The cooled products gases are then condensed in a water cool partial condenser where almost 80% of the MEK and unreacted butanol is condensed and the condensate is passed to a distillation unit. The gases effluent from the partial condenser is send to the absorber to recover remaining uncondensed MEK and alcohol. In the absorber, water is used\ud By the application of the above reaction as illustrated in the production and use of MEK, the major end-users of MEK include protective coating solvents (61 percent), adhesives (13 percent), and Magnetic Tapes (10 percent) .Vinyl are the primary resins that employ MEK as a solvent. Methyl ethyl ketone is commonly used as a solvent in rubber cements, as well as in natural and synthetic resins for adhesive use. It is also the preferred extraction solvent for dew axing lube oil and is used in printing inks. Overall, the projected use of MEK is expected to gradually decline. The growing trend towards water-based, higher-solids, and solvent-less protective coatings, inks and adhesives is reducing the demand for MEK. The installation of solvent recycling facilities will also reduce requirements for fresh solvent production. Although MEK is favoured as a solvent due to its low density, low viscosity, and high solvency, its addition on the EPA’s hazardous air pollutants list will likely cause potential users to consider other comparative solvents such as ethyl acetate.\ud Scope of Design Work required:\ud Material balance need to prepare \ud Material flow diagram of the preferred process.\ud Heat balance diagram of the preheated –vaporiser-super heater –reactor system.\ud A design of pre heater –vaporiser –super heater –reactor system need to be produced.\ud A mechanical design of the butyl alcohol vaporiser and make a dimensioned sketch suitable for submission to a drawing office.\ud \ud \ud A summary of safety and pollution consideration of the plant \ud \ud \ud \ud Flammability\ud Butanone can react with most oxidizing materials, and can produce fires. It is moderately explosive; it requires only a small flame or spark to cause a vigorous reaction. Butanone fires should be extinguished with carbon dioxide, dry agents, or alcohol-resistant foam. Concentrations in the air high enough to be flammable are intolerable to humans due to the irritating nature of the vapour.\ud \ud \ud Health effects\ud Butanone is an irritant, causing irritation to the eyes and nose of humans. Serious health effects in animals have been seen only at very high levels. These included skeletal birth defects and low birth weight in mice, when they inhaled MEK at the highest dose tested (3000 ppm for 7 hours/day).There are no long-term studies with animals breathing or drinking MEK. and no studies for carcinogenicity in animals breathing or drinking MEK. There is some evidence that methyl ethyl ketone can potentiate the toxicity of other solvents, in contrast to the calculation of mixed solvent exposures by simple addition of exposures. As of 2010, some reviewers advised caution in using methyl ethyl ketone because of reports of neuropsychological effects. \ud Butanone is listed as a Table II precursor under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances.\ud \ud \ud Regulation\ud Emission of butanone was regulated in the US as a hazardous air pollutant, because it is a volatile organic compound contributing to the formation of troposphere (ground-level) ozone. In 2005, the U. S. Environmental Protection Agency removed butanone from the list of hazardous air pollutants (HAPs). \ud \ud \ud Reference:\ud 1.S.K.Ghosal, S.K.Sanyal, S.Datta, Introduction to Chemical Engineering, Tata Mc- Graw Hill Publishing Company Limited, New Delhi.ISBN:0-07-460140.\ud 2. "NIOSH Pocket Guide to Chemical Hazards #0069".National Institute for Occupational Safety and Health (NIOSH).\ud 3. "2-Butanone". Immediately Dangerous to Life and Health. National (NIOSH).\ud 4. Wilhelm Neier, GünterStrehlke "2-Butanone" in Ullmann's Encyclopaedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002.\ud 5. Turner, Charles F.; McCrery, Joseph W. (1981). The Chemistry of Fire and Hazardous Materials. Boston, Massachusetts: Alyn and Bacon, Inc. p. 118. ISBN 0-205-06912-6.\ud 6. Ashford's Dictionary of Industrial Chemicals, Third edition, 2011,ISBN 978-0-9522674-3-0, pages 6013-47. Apps, E. A. (1958). Printing Ink Technology. London: Leonard Hill [Books] Limited. p. 101.\ud 7. Fairhall, Lawrence T. (1957). Industrial Toxicology. Baltimore: The Williams and Wilkins Company. p. 172–173.\ud 8. Schwetz; et al. (1991). "Developmental toxicity of inhaled methyl ethyl ketone in Swiss mice". Fund. Appl. Toxicol. 16 (4): 742–748. doi:10.1016/0272-0590(91)90160-6.\ud 9. "Methyl ethyl ketone (MEK) (CASRN 78-93-3)". Integrated Risk Information System (IRIS). EPA. 26 September 2003. Retrieved 16 March 2015.\ud 10. "U.S.Toxicological review of Methyl ethyl ketone In Support of Summary Information on the Integrated Risk Information System (IRIS)" (PDF). U.S. Environmental Protection Agency. September 2003. p. 152. Retrieved 16 March 2015.\ud 11. F D Dick. Solvent neurotoxicity, Occup Environ Med. 2006 Mar; 63(3): 221–226. doi: 10.1136/oem.2005.022400, PMCID: PMC2078137\ud 12. Thompson, S.B.N. “Implications for cognitive rehabilitation and brain injury from exposure to Methyl Ethyl Ketone (MEK): a review.” Journal of Cognitive Rehabilitation 2010; 28(Winter): 4-14. doi: jofcr.com/vol284/v28i4thompson.pdf.\ud 13. List of Precursors and Chemicals Frequently Used in the Illicit Manufacture of Narcotic Drugs and Psychotropic Substances under International Control, International Narcotics Control Board.\ud 14. Barbara Kanegsberg (n.d.). "MEK No Longer a HAP". Bfksolutions newsletter. Retrieved 2 April 2015. After technical review and consideration of public comments, EPA concluded that potential exposures to butanone emitted from industrial processes may not reasonably be anticipated to cause human health or environmental problems.\ud 15. "EPA De-Lists MEK from CAA HAP List". www.pcimag.com. Retrieved 2016-07-30.18. Personal, J.J.andTho dose, G., AICHE Journal, 3, 230, (1957)19. Kolb, H.J.and Burwell, R.L. (Jr.) Am. Chem. Soc., 67, 1084, (1945)20. Encyclopaedia of Chemical Technology, by Kirk- Other 5th Edn.John Wiley, Newcastle York. 21. Rudd, D.F. and Watson, C.C., Strategy of Process Engineering, John Wiley & Sons Inc. NY, (1968).\ud 16. Austin G.T,"Shreve' Chemical Process Industries", McCartney Graw Hills Book Company, Newcastle Delhi 5th Edn.John.(1986).\ud 17. Shukla S D an

John Q Xiao - One of the best experts on this subject based on the ideXlab platform.

  • memory effect in Magnetic nanowire arrays
    Advanced Materials, 2011
    Co-Authors: Randy K Dumas, Qi Lu, Yaping Zhang, Xiaokai Zhang, John Q Xiao
    Abstract:

    www.advmat.de www.MaterialsViews.com Xiaoming Kou , Xin Fan , Randy K. Dumas , Qi Lu , Yaping Zhang , Hao Zhu , Xiaokai Zhang , Kai Liu , and John Q. Xiao* Magnetic materials are widely used for information storage because of their large capacity and low cost. [ 1 ] Storage medium technologies have evolved from analog recording with mag- netic Tapes to high fidelity digital recording with Magnetic hard disks. Nevertheless, both techniques use a Magnetic medium consisting of Magnetic particles, whose sizes have also evolved from micrometers in Magnetic Tapes to nanometers in modern hard disks. In analog recording, signals are converted into mag- netic fields which change the magnetization of a group of mag- netic particles (bit). The magnetization variations represent the stored information which can subsequently be read out. The magnetization, and therefore the stored information, could be changed by an external Magnetic field and/or thermal effects. In digital recording, the bit magnetization can be aligned either left or right in parallel recording or up and down in perpen- dicular recording. [ 2 ] The information is stable as long as the medium is not subjected to a Magnetic field higher than the coercivity, or a temperature higher than the superparaMagnetic limit, of the constituent Magnetic particles. In order to clearly distinguish one bit from another it is advantageous to minimize the dipolar interaction among Magnetic particles, which is typi- cally achieved by creating boundaries between particles. Since the Magnetic dipolar interaction is particularly pronounced in a collection of Magnetic entities, such as Magnetic particles and nanowires, it is scientifically interesting to question whether such a degree of freedom can be exploited in order to create additional memory functions. To answer this question, one needs a Magnetic system with a sizable and preferably control- lable dipolar interaction. The Magnetic nanowire array is an ideal system for this purpose. Magnetic nanowire arrays embedded in an insulating Al 2 O 3 matrix have been intensively studied. [ 3–12 ] When the magnetoc- rystalline anisotropy is negligible, the magnetization direction of the nanowires is preferably aligned along the length of the nanowire because of the shape anisotropy. When nanowires are very close to each other, dipolar interactions play a significant X. Kou, Dr. X. Fan, Q. Lu, Y. Zhang Prof. J. Q. Xiao Department of Physics and Astronomy University of Delaware Newark, DE, 19716, USA E-mail: jqx@udel.edu Dr. R. K. Dumas, Prof. K. Liu Department of Physics University of California Davis, CA, 95616, USA Dr. H. Zhu, Dr. X. Zhang Spectrum Magnetics LLC, 1210 First State Blvd, Wilmington, DE, 19804, USA DOI: 10.1002/adma.201003749 Adv. Mater. 2011, 23, 1393–1397 role in the Magnetic behavior of the nanowire array, leading to rich physical phenomena and great application potentials. [ 7–12 ] Recently, it was demonstrated that the dipolar interaction among Magnetic nanowires could provide zero field ferroMagnetic res- onance (FMR) tunability, which has potential applications in a variety of microwave devices. A double FMR feature caused by the dipolar interaction in a Magnetic nanowire array was also predicted [ 13 ] and verified. [ 14–17 ] In this manuscript, we demon- strate how dipolar interactions can induce an analog memory effect in Magnetic nanowire arrays. Through this effect, the Magnetic nanowire array has the ability to ‘memorize’ the maximum Magnetic field that the array has been exposed to. A novel, low cost, and robust electroMagnetic pulse detecting method is proposed based on this memory effect. Nanowire arrays of Ni 90 Fe 10 and Ni were synthesized by elec- trodeposition into anodized alumina templates. The diameter, center-to-center interpore distance, and length of the nanowires are 35 nm, 60 nm, and 30 μ m, respectively. Figure 1 a shows the hysteresis loop, with a coercivity of 1080 Oe, of a Ni 90 Fe 10 nanowire array with a Magnetic field parallel to the wire (open squares). The loop with the field perpendicular to the wire is shown in the inset. Clearly, a well defined easy axis exists along the wire axis because of the dominant shape anisotropy. The memory effect was demonstrated using a vibrating sample magnetometer. The Ni 90 Fe 10 nanowire array was satu- rated along the wire prior to the measurement. The Magnetic moment of the array was monitored as a series of Magnetic field pulses were applied parallel to the nanowires. Figure 1b displays the series of Magnetic pulses with different magni- tudes and directions. The corresponding change of the mag- netic moment is illustrated in Figure 1c. We find that the Magnetic moment decreases monotonically as the magnitude of the negative pulses increases, while the moment remains the same after the positive pulses. This demonstrates that the maximum negative Magnetic field can be recorded into the nanowire array. However, this is violated for the 800 and 900 Oe field pulses, and this discrepancy will be explained later. The result is also plotted in the Magnetic moment verses applied field ( M – H ) graph, displayed in Figure 1d. Similar prop- erties are also observed in Ni nanowire arrays. This phenomenon is attributed to the dipolar interactions among the nanowires. Previously, using a theoretical model, two assumptions were proposed. [ 13 ] First, each nanowire is a single domain cylinder with a uniform magnetization pointing up or down parallel to the wire. The second assumption is that the number of nanowires with up magnetizations ( N ↑ ) and down magnetizations ( N ↓ ) is determined by the total magnetization M(H) , i.e. (N ↑ – N ↓ )/(N ↑ + N ↓ ) = M(H)/M s , where M s is the saturation magnetization. According to these assumptions, the dipolar field among the nanowires can be written as [ 13 ] © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim wileyonlinelibrary.com COMMUNICATION Memory Effect in Magnetic Nanowire Arrays