Methyl ethyl ketone design

A condensible blowdown tank, designed on a similar basis to that described above for phenol, may be provided in other services where a conventional condensible blowdown drum would not be acceptable (e.g., due to effluent water pollution considerations). Examples of such cases are methyl ethyl ketone (MEK) and dimethyl formamide (DMF). A suitable absorbing material is specified (e.g., a lube oil stock for MEK water for DMF), and the design must include consideration of maximum permissible operating temperatures to prevent excessive vapor evolution or the boiling of water. 

The production of methyl ethyl ketone (MEK) is described in Appendix G, problem G.3. A preliminary design has been made for a plant to produce 10,000 tonne per year. The major equipment items required are listed below. The plant attainment will be 8000 hours per year. 

Design a plant to produce 1 x 107 kg/year of methyl ethyl ketone (MEK). 

Numerous studies have been conducted in which animals were exposed to 2-hexanone via inhalation. However, the purpose of many of these studies was to assess the potential effects of combined exposure to 2-hexanone and another substance (usually chloroform or methyl ethyl ketone [MEK]). Study design has consequently involved exposure to only one concentration of 2-hexanone as a control exposure. A single high dose of 2-hexanone was used in several other studies in order to elicit and study histopathological changes in the affected nervous tissue. In addition, the grade or purity of the 2-hexanone administered was not stated in many studies, or in some cases, hexanone with purity as low as 70% was used. As a result of these various complications, the usefulness of the available data is limited. 

Austin, D.G., and Jeffreys, G.V., The Manufacture of Methyl Ethyl Ketone from 2-Butanol (A Worked Solution to a Problem in Chemical Engineering Design), The Institution of Chemical Engineers (UK) and George Godwin Ltd. London (1979). 

Ternary Separation By Distillation. To design a recovery system, a starting composition of 85 mole % water, 7.5 mole % tetrahydrofuran, and 7.5 mole % methyl ethyl ketone was chosen. This assumes 1.5 pounds of steam per pound of solvent are used for regeneration and a blend of equal amounts of the solvents for the polyvinyl chloride processing. 

Methyl ethyl ketone (MEK) is to be recovered from a gas mixture containing 20.0 mole% MEK and 80.0 mole% at 85 C and 3.5 atm. In a proposed process design, a stream of this mixture is fed to a condenser at a rate of 500 Us and is cooled at constant pressure, causing most of the MEK to condense. 

Dimethylacetamine, tetrahydrofuran, dichloromethane, methyl ethyl ketone, N,N-dimethylformamide, N-methylpyrrolidone, cyclopentanone, cyclohexanone, dioxane, and chloroform are the most commonly used solvents. Most of these are hazardous but used because they contribute to highly transparent product which is very desirable in medical devices. Transparent materials can only be made from transparent solutions. These solvents can dissolve polymers well and form clear solutions. Ease of solvent removal from the material is very important in formulation design. Obviously, no traces of solvents should remain in the medical devices since even trace amoimts may interfere with the treatment and the patient s health. An inappropriate solvent selection may cause the formation of crust as the solvent escapes. This leads to material discontinuity (e.g., pinholes) which renders the product inferior. This brings a discussion of solvent evaporation, the rheological properties of formulation, and formation of multilayer materials. 

Some of the denaturants in laboratory use ethanol are cyclohexane (1%) isopropyl alcohol ( 5%) diethyl phthalate (1%) toluene (1-2%) 2-butanone (methyl ethyl ketone) (2%) a mixture of 2-butanone and 4-methyl-2-pentanone (methyl isobutyl ketone) (2% and 0.5%, respectively) methanol (5%), designated SDA Formula 3 ethyl acetate and gasoline (5% and 1%, respectively), designated SDA Formula 1 ethyl acetate, 4-methyl-2-poitanone, and gasoline (each at 1%), designated SDA Formula 1-1 ethyl acetate and methanol (1-2% and 3-5%, respectively) 4-methyl-2-pentanone and ko osene (4% and 1%, respectively), designated Formula CDA 19 and isopropyl alcohol and methanol (5% each). Note that many other denatured ethanols (e.g., bitrex and menthol denatured) are available, typically for use in personal care and cosmetic products. 

Denatured ethanols are not for use in HPLC. They often contain methyl ethyl ketone, ethyl acetate, and a hydrocarbon, each at the 1% level. Reagent alcohol or alcohol is the typical designation for HPLC-quality ethanol. It contains methanol and IPA each at the 3-6% range and the ethanol is present at the 89-95% range. Refer to manufacturer s specifications for details. 

Polymer Characterization. Number average molecular weights (M ) of polymers were determined using an automatic membrane osmometer (Shell Development Design) in toluene solution at 35.5 C. Membranes (Sartorious MembranfiIter, SM 11539) were cautiously conditioned from ethanol into methyl ethyl ketone and finally toluene. Weight... 

Under the lUPAC system the number of carbons in the longest chain carrying the carbonyl carbon establishes the hydrocarbon base, which is followed by -one to identify the ketone as the class of compound. Methyl ethyl ketone, having four carbons, is called butanone. Two isomers of pentanone would be 2-pentanone and 3-pentanone, the number being used to designate the carbonyl carbon ... 

Manufacturing processes for sustainability can be optimized in the context of life cycle analysis (Shoimard and Hiew 2000). It involves definition of the process boundaries and quantifiable sustainability impacts in the form of established metrics, incorporated into process design and optimization. It has been applied to determining waste treatment options, abatement of pollution, and designing the optimal recipe of solvents. Impact indices, such as ozone depletion potential to human toxicity and eco-toxicity, developed by the EPA, can be used. This method has been applied in a methyl ethyl ketone production plant to determine the effect of recycling on the enviromnent (Shonnard and Hiew 2000). 

Special care must be taken in the design and operation of adsorption units handling ketone solvents, such as methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone, because of their reactivity in the presence of activated carbon. Traces of metal compounds in the carbon act as catalysts for decomposition reactions, which are further accelerated by the presence of heat and moisture. The decomposition reactions are exothermic and if allowed to continue can cause hot spots in the bed and ultimately fires. According to Collins (1988), ketone adsorption and recovery can be accomplished safely if these guidelines are followed ... 

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