The Experts below are selected from a list of 6099 Experts worldwide ranked by ideXlab platform
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, 2017Co-Authors: Asu SubhasisAbstract: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, 2017Co-Authors: Asu SubhasisAbstract: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
Jalel Labidi - One of the best experts on this subject based on the ideXlab platform.
-
agricultural palm oil tree residues as raw material for cellulose lignin and hemicelluloses production by ethylene glycol pulping process
Chemical Engineering Journal, 2009Co-Authors: Gonzalez M Alriols, Ivan Mondragon, Alvaro Tejado, M Blanco, Jalel LabidiAbstract:Agricultural crop residues (palm oil empty fruit bunches—EFB) were used as raw material for cellulose, lignin and hemicelluloses obtaining following sustainable criteria. An organosolv pulping process based on ethylene glycol–water mixtures, which allowed an easy recycling of Solvents as well as the recovery of generated by-products, was used to induce delignification. Computer simulations using commercial software (Aspen Plus) were made on the whole process in order to design the Solvents recovery stages and optimise the operation conditions. Laboratory experiments were carried out with the aim of characterizing raw material, black liquors and released by-products. Considerable high proportion of recycled Solvents (91 wt% ethylene glycol and 88 wt% water) was reached with the proposed scheme. This resulted in 70 and 80 wt% reduction of Fresh Solvent input for ethylene glycol and water respectively, thus reducing the environmental impact of the process. EFB organosolv pulp could be considered an acceptable alternative for producing certain paper qualities with moderate strength requirements while allowing an agricultural residue from a major economic activity (viz. oil palm production) to be exploited.
-
organosolv pulping process simulations
Industrial & Engineering Chemistry Research, 2008Co-Authors: Maria Jesus Gonzalez Gonzalez, Alvaro Tejado, C Pena, Jalel LabidiAbstract:Computer simulations of organosolv pulping processes (ethanol−water and ethylene glycol−water mixtures) using commercial simulation software (ASPEN PLUS) have been developed in order to design the process and to establish its key points (product and byproduct mass flow balances, energy analysis, and Solvent recovery degree) as well as to analyze operation conditions. Laboratory experiments, in which a deciduous wood called leucaena (Leucaena leucocephala) was used as raw material, were carried out to obtain input data for the simulation. The proposed process flow sheets allow the recovery and recycling of a high percentage of used Solvents (97 wt % ethanol and 88 wt % ethylene glycol), which represent a reduction of 66 and 59 wt % of Fresh Solvent input for ethanol and ethylene glycol, respectively.
Hanqi Zhang - One of the best experts on this subject based on the ideXlab platform.
-
dynamic microwave assisted extraction of flavonoids from herba epimedii
Separation and Purification Technology, 2008Co-Authors: Ligang Chen, Chenling Qu, Huarong Zhang, Lan Ding, Juan Li, Hanqi ZhangAbstract:Abstract An apparatus for extraction of flavonoids from Herba Epimedii has been constructed which utilizes a microwave technique for heating in a dynamic mode. A TM 010 microwave resonance cavity was applied to concentrate the microwave energy; the power needed to achieve efficient extraction was significantly reduced. The method has been compared with other extraction methods, such as pressurized microwave-assisted extraction (PMAE), ultrasonic extraction (UE), heat reflux extraction (RE) and Soxhlet extraction (SOX). The four flavonoids in extract were identified by HPLC–MS. The influence of extraction parameters on the extraction yield of flavonoids has been evaluated by comparison with the peak areas of HPLC-DAD spectra in the different extraction methods. The results showed that the extraction yield of flavonoids in Herba Epimedii obtained by dynamic microwave-assisted extraction (DMAE) was higher than that obtained by UE, RE and SOX, and the extraction time is dramatically reduced. The extraction yield obtained by DMAE is similar to that obtained by PMAE. But the flavonoids in Herba Epimedii would not decompose easily when increasing the extraction time in DMAE. This is the benefit of dynamic extraction system which can transfer the analytes extracted from the sample matrix with flowed Fresh Solvent to the out of extraction vessel.
Ligang Chen - One of the best experts on this subject based on the ideXlab platform.
-
dynamic microwave assisted extraction of flavonoids from herba epimedii
Separation and Purification Technology, 2008Co-Authors: Ligang Chen, Chenling Qu, Huarong Zhang, Lan Ding, Juan Li, Hanqi ZhangAbstract:Abstract An apparatus for extraction of flavonoids from Herba Epimedii has been constructed which utilizes a microwave technique for heating in a dynamic mode. A TM 010 microwave resonance cavity was applied to concentrate the microwave energy; the power needed to achieve efficient extraction was significantly reduced. The method has been compared with other extraction methods, such as pressurized microwave-assisted extraction (PMAE), ultrasonic extraction (UE), heat reflux extraction (RE) and Soxhlet extraction (SOX). The four flavonoids in extract were identified by HPLC–MS. The influence of extraction parameters on the extraction yield of flavonoids has been evaluated by comparison with the peak areas of HPLC-DAD spectra in the different extraction methods. The results showed that the extraction yield of flavonoids in Herba Epimedii obtained by dynamic microwave-assisted extraction (DMAE) was higher than that obtained by UE, RE and SOX, and the extraction time is dramatically reduced. The extraction yield obtained by DMAE is similar to that obtained by PMAE. But the flavonoids in Herba Epimedii would not decompose easily when increasing the extraction time in DMAE. This is the benefit of dynamic extraction system which can transfer the analytes extracted from the sample matrix with flowed Fresh Solvent to the out of extraction vessel.
M Luque D De Castro - One of the best experts on this subject based on the ideXlab platform.
-
focused microwave assisted soxhlet an advantageous tool for sample extraction
Analytical Chemistry, 1998Co-Authors: L E Garciaayuso, Ma Del Pilar Laguna Sanchez, Fernandez A De Alba, M Luque D De CastroAbstract:A new type of microwave-assisted Soxhlet is here reported. The device uses conventional Soxhlet glassware for solid sample extraction and a focused-microwave digester for irradiation of the sample cartridge at the required intervals while the Fresh Solvent (condensed vapors from the distillation flask) drips on and passes through the solid sample. In this way breaking of the analyte-matrix bonds is facilitated by application of the appropriate energy. The new approach has been checked in a comparative study by its application to the extraction of analyte families of different polarity (namely, alkanes, polyaromatic hydrocarbons, and herbicides) from the same soil matrix using dichloromethane as extractant. The reduction of the extraction times (from 8 h to 50−60 min, depending on the polarity of the analytes) with efficiency similar to or even higher than that afforded by the conventional Soxhlet technique supports the suitability of the new approach. In addition, recycling of the Solvent during extract p...
