A Seminar Report
Isopropyl Alcohol
SR. NO
COTENTS
PAGE NO.
1
ABSTRACT
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2
INTRODUCTION
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3
PROPERTIES
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DIFFERENT PRODUCT FROM IPA
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DIFFERENT PROCESSES
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IPA BY INDIRECT HYDRATION
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PROCESS FLOW DIAGRAM
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USES
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SAFETY
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TOXICOLOGY
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REFERENCES
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MGMCET, Kamothe
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A Seminar Report
Isopropyl Alcohol
ABSTRACT: The objective of the report is to study the process of production of isopropyl alcohol by using indirect hydration method. An improved process for indirect hydration of propylene to form Diisopropyl Ether and Isopropyl Alcohol is provided in which propylene is absorbed in Sulphuric acid to form an extract. It is withdrawn from the absorbing zone; water in carefully controlled amounts is mixed with the extract. While the resulting mixture is passed to an ether generating zone to form a vaporous ether product and a bottoms product depleted in Diisopropyl Ether containing Sulphuric acid in a concentration at least equal to the acid concentration in the extract withdrawn from the absorbing zone. The withdrawn bottoms is the divided into two portions: a first portion is recycled to the absorber; and the second such portion is mixed with sufficient water to hydrate absorbed olefin values and the resulting mixture is fed to an alcohol generator for formation of isopropyl alcohol as overhead product and dilute Sulphuric acid as bottoms product.
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A Seminar Report
Isopropyl Alcohol
INTRODUCTION: The IUPAC name for chemical compound with the molecular formula of C3H8O is propan-2-ol. Other common names for this compound are isopropyl alcohol, isopropanol, 2propanol and rubbing alcohol. It is the simplest example of a secondary alcohol which the hydroxyl group (OH-) is attached to a carbon atom that is also attached to two other carbon atoms sometimes shown as (CH3)2CHOH. Besides, it is a structural isomer of propanol and in industry, the isopropyl alcohol is well known as IPA.
IPA has a several industrial application such as it is used for manufacturing of aceton by dehydrogenation of ipa. It having several other uses such as a solvent , as a cleaning agent for cleaning number of electronics divices. Isopropyl alcohol is esterified to give isopropyl acetate, another solvent. It reacts with carbon disulfide to give sodium isopropylxanthate, a weed killer. Isopropyl alcohol reacts with titanium tetrachloride and aluminium metal to give titanium and aluminum isopropoxides respectively, the former a catalyst, and the latter a chemical reagent. It is also used for medical purpose as a disinfectant.
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Isopropyl Alcohol
PROPERTIES OF ISOPROPYL ALCOHAL: 1) Physical Properties of IPA: Some of the physical properties of isopropyl alcohol are it is colorless liquid at room temperature, the molar mass is approximately 60.09 g mol−1, have strong rubbing alcohol odor, miscible in water, soluble in some organic solvent but insoluble in salt solution and it is also fairly volatile (evaporates easily). The melting point of this chemical compound is -890C whereas the boiling point is 82.50C. Anhydrous IPA has density about 0.7854g/cm3 whereas the 91% volume. IPA have a density of 0.8173 g/cm3.
2) Chemical properties of IPA Chemical properties of isopropyl alcohol are determined by its functional hydroxyl group in the secondary position. Except for the production of acetone, most isopropyl alcohol chemistry involves the introduction of the isopropyl or isopropoxy group into other organic molecules by the breaking of the C–OH or the O–H bonding the isopropyl alcohol molecule. Isopropyl alcohol undergoes reactions typical of an active secondary alcohol. Some of the chemical property of this alcohol is it can be separated from its aqueous solutions by adding a salt such as sodium chloride, potassium chloride, or any of several other inorganic salts. This is due to solubility of this alcohol in saline which is less compared to its solubility in salt-free water.
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Isopropyl Alcohol
DIFFERENT PRODUCT FROM IPA Besides, IPA may undergo dehydrogenation process. Dehydrogenation of isopropyl alcohol to acetone was the most widely practiced production method in industry. This reaction is endothermic reaction means it absorbs about 66.5 kJ/mol of heat and occurs at temperature range between 300-5000C and pressure 100 – 200 kPa. The most useful catalyst contains Cu, Zn, Cr, and Ni as oxides can be used to increase the reaction rate. The balance chemical equation of the dehydrogenation process: (CH3)2CHOH
→ CH3COCH3
+ H2
Chemically, secondary alcohol can be catalytically oxidized using air or oxygen at high temperature (400−6000C) to form respectively ketone and water. Here, when isopropyl alcohol undergoes oxidation process, the product is acetone. The preferred catalyst for this reaction is zinc chloride, ZnO. The oxidation process is highly exothermic which means this reaction releases large amount of energy usually in the form of heat Oxidation Reaction (CH3)2CHOH + 0.5O2 → CH3COCH3
+ H2O
Furthermore IPA reacts with active metal such as potassium to form alkoxides. Next, isopropyl alcohol can be dehydrated in either the liquid phase over acidic catalysts, eg, sulfuric acid, or in the vapor phase over acidic aluminas to give diisopropyl ether. This reaction is known as etherification. IPA also undergoes halogenation chemical reaction with halogen compound. Normally, 2halopropane derivatives are prepared from isopropyl alcohol most economically by reaction with the corresponding acid halide. However, under appropriate conditions, other reagents, eg, phosphorus halides and elemental halogen also react by replacement of the hydroxyl group to give the halide. Normally, this reaction temperature is about 650C.
3(CH3)2CHOH + PBr3 MGMCET, Kamothe
→ (CH3)2CHBr + H3PO3 5
A Seminar Report
Isopropyl Alcohol
DIFFERENT PROCESS FOR MANUFACTURING OF IPA Indirect hydration The indirect process reacts propene with sulfuric acid to form a mixture of sulfate esters. Subsequent hydrolysis of these esters by steam produces isopropyl alcohol, which is distilled. Diisopropyl ether is a significant by-product of this process; it is recycled back to the process and hydrolyzed to give the desired product.
Direct hydration Direct hydration reacts propene and water, either in gas or liquid phases, at high pressures in the presence of solid or supported acidic catalysts. Higher purity propylene (> 90 %) tends to be required for this type of process. Both processes require that the isopropyl alcohol be separated from water and other by-products by distillation. Isopropyl alcohol and water form an azeotrope and simple distillation gives a material which is 87.9% by weight isopropyl alcohol and 12.1% by weight water. Pure (anhydrous) isopropyl alcohol is made by azeotropic distillation of the wet isopropyl alcohol using either diisopropyl ether or cyclohexane as azeotroping agents.
Hydrogenation of acetone Crude acetone is hydrogenated in the liquid phase over Raney nickel or a mixture of copper and chromium oxide to give isopropyl alcohol. This process is useful when coupled with excess acetone production, such as the cumene process.
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Isopropyl Alcohol
IPA BY INDIRECT HYDRATION OF PROPYLENE Process description Propylene, mixed with other C2 and C3 hydrocarbons, is absorbed in 70-75% H2SO4 in a packed or sieve tray absorption tower or in series of agitator reactors operating at 20-25 atms. The strongly exothermic sulfation reaction is kept at 20-30
0
C by refrigerated brine
circulation.the solution is hydrolysed in asteam stripper which removes the organic phase as a vapour. The weak acid bottoms are sent to the H2SO4 concentration plant after neutralization in a caustic solution. The product vapour is fractionally condensed ,with the non-condensable olefin fraction return to sulfation step. The crude isopropanol is distilled to remove the more volatile isopropyl ether. A portion of the reflux is shunted to a decanter where the ether rich top layer is pumped back to a sulfation or dried for product sales. The water –alcohol bottom layer is returned to the reflux-column feed. Ether columns bottoms are pumped to the isopropanol column where an 87% IPA azeotrope is taken as top. this can be sold as a product or sent to a ternary azeotropic distillation column where isopropyl ether removes the water as overhead and the bottoms are 99% absolute isopropanol.
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Isopropyl Alcohol
PROCESS FLOW DIAGRAM
MGMCET, Kamothe
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A Seminar Report
Isopropyl Alcohol
USES OF ISOPROPYL ALCOHOL AS A SOLVENT Isopropyl alcohol dissolves a wide range of non-polar compounds. It also evaporates quickly and is relatively non-toxic, compared to alternative solvents. Thus it is used widely as a solvent and as a cleaning fluid, especially for dissolving oils. Examples of this application include cleaning electronic devices such as contact pins (like those on ROM cartridges), magnetic tape and disk heads (such as those in audio and video tape recorders and floppy disk drives), the lenses of lasers in optical disc drives (e.g. CD, DVD) and removing thermal paste from heatsinks and IC packages (such as CPUs) Isopropyl alcohol is used in keyboard, LCD and laptop cleaning, is sold commercially as a whiteboard cleaner, and is a strong but safer alternative to common household cleaning products. It is used to clean LCD and glass computer monitor screens (at some risk to the anti-reflection coating on some screens), and used to give second-hand or worn non-vinyl phonograph records newer-looking sheen. Isopropyl alcohol should not be used to clean vinyl records as it may leach plasticizer from the vinyl making it more rigid. It is effective at removing residual glue from some sticky labels although some other adhesives used on tapes and paper labels are resistant to it. It can also be used to remove stains from most fabrics, wood, cotton, etc. In addition it can also be used to clean paintballs or other oil based products so that they may be reused, commonly known as "repainting".
Intermediate Isopropyl alcohol is esterified to give isopropyl acetate, another solvent. It reacts with carbon disulfide to give sodium isopropylxanthate, a weed killer. Isopropyl alcohol reacts with titanium tetrachloride and aluminium metal to give titanium and aluminium isopropoxides
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Isopropyl Alcohol
respectively, the former a catalyst, and the latter a chemical reagent. This compound may serve as a chemical reagent in itself, by acting as a dihydrogen donor in transfer hydrogenation.
Medical Disinfecting pads typically contain a 60–70% solution of isopropyl alcohol in water. A 75 % v/v solution in water may be used as a hand sanitizer. Isopropyl alcohol is used as a waterdrying aid for the prevention of otitis externa, better known as swimmer's ear.
Automotive Isopropyl alcohol is a major ingredient in "gas dryer" fuel additives. In significant quantities, water is a problem in fuel tanks, as it separates from the gasoline, and can freeze in the supply lines at cold temperatures. It does not remove water from gasoline; rather, the alcohol solubilizes water in gasoline. Once soluble, water does not pose the same risk as insoluble water as it will no longer accumulate in the supply lines and freeze. Isopropyl alcohol is often sold in aerosol cans as a windscreen de-icer. Isopropyl alcohol is also used to remove brake fluid traces from hydraulic braking systems, so that the brake fluid (usually DOT 3, DOT 4 or mineral oil) does not contaminate the brake pads, which would result in poor braking.
Laboratory As a biological specimen preservative, isopropyl alcohol provides a comparatively nontoxic alternative to formaldehyde and other synthetic preservatives. Isopropyl alcohol solutions of 90–99% are used to preserve specimens. Isopropyl alcohol is often used in DNA extraction. It is added to a DNA solution in order to precipitate the DNA into a 'pellet' after centrifuging the DNA. This is possible because DNA is insoluble in isopropyl alcohol.
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Isopropyl Alcohol
SAFETY Isopropyl alcohol vapor is denser than air and is highly flammable with a very wide combustible range. It should be kept away from heat and open flame. When mixed with air or other oxidizers it can explode through deflagration.Isopropyl alcohol has also been reported to form explosive peroxides. Like many organic solvents, long term application to the skin can cause defatting
Toxicology Isopropyl alcohol and its metabolite, acetone, act as central nervous system (CNS) depressants. Symptoms of isopropyl alcohol poisoning include flushing, headache, dizziness, CNS depression, nausea, vomiting, anesthesia, and coma. Poisoning can occur from ingestion, inhalation, or absorption; therefore, well-ventilated areas and protective gloves are recommended. Around 15 g of isopropyl alcohol can have a toxic effect on a 70 kg human if left untreated. However, it is not nearly as toxic as methanol or ethylene glycol. Isopropyl alcohol does not cause an anion gap acidosis (in which as lowered blood serum pH causes depletion of bicarbonate anion) unlike ethanol and methanol. Isopropyl alcohol does however, produce an osmolal gap between the calculated and measured osmolalities of serum, as do the other alcohols. Overdoses may cause a fruity odor on the breath as a result of its metabolism to acetone, which is further metabolized to produce the nutrients acetate and glucose.[15] Isopropyl alcohol is oxidized to form acetone by alcohol dehydrogenase in the liver.
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Isopropyl Alcohol
REFERENCES 1) Outlines of chemical technology By Charles E. Dryden
2) http://en.wikipedia.org/wiki/Isopropyl_alcohol 3) http://www.wisegeek.com/what-is-isopropyl-alcohol.htm
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