MIBK , use

The aldol condensation of acetone to diacetone alcohol is the first step in a three-step process in the traditional method for the production of methyl isobutyl ketone (MIBK). This reaction is catalysed by aqueous NaOH in the liquid phase. (3) The second step involves the acid catalysed dehydration of diacetone alcohol (DAA) to mesityl oxide (MO) by H2S04 at 373 K. Finally the MO is hydrogenated to MIBK using Cu or Ni catalysts at 288 - 473 K and 3- 10 bar (3). 

APDC chelates of certain metals such as manganese are not very stable at room temperature. Therefore, the analysis should be commenced immediately after the extraction. If an emulsion formation occurs at the interface of water and MIBK, use anhydrous Na2S04. 

Saayman N, Lund GJ, Kindermans S. Process for the production of MIBK using catalytic distillation technology. WO 02022542, Catalytic Distillation Technologies, 2002. 

A widely studied example of this kind is the synthesis of methyl isobutyl ketone (MIBK, used as a solvent for inks and lacquers) from acetone. The former was previously prepared from the latter through a catalytic three-step process base-catalysed production of 4-hydroxy-4-methylpentan-2-one, acid dehydration into mesityloxide (MO), then hydrogenation of MO on a Pd catalyst. Since acetone aldolization occurs through acid catalysis as shown over a H-MFI zeolite at 433 K (MO is the main reaction product, the aldolization product being rapidly dehy-drated[5]), it is possible, by associating with the acid catalyst a hydrogenation phase,... 

An aqueous acetone solution is fed at a rate of 32.0 Ibm /h to a stirred tank. A stream of pure methyl isobutyl ketone is also fed to the tank, and the resulting mixture is sent to a settler operating at 25 C. One of the phases formed has a flow rate of 41.0 Ibm/h and contains 70 wt% MIBK. Use Figure 6.6-1 to determine the flow rate and composition of the second product stream and the rate at which MIB K is fed to the unit. 

MIBK used in the uncapped process dissolves the interfacial layer. However, attenuation of DUV light due to the novolac resin in the interfacial layer, coupled with the intrinsic, low sensitivity of PMMA developed in MIBK (see Table 3.6), demands prolonged blanket DUV exposure. This high dose of DUV leads to excessive cross-linking and photooxidation of the novolac resist (53, 166-169) and, consequently, to incomplete removal of the top resist during the development of PMMA in MIBK. Lin et al. (85) reported that a soak in methanol/water (1 1) prior to the MIBK development... 

Lawson, K.H. Nkosi, B. Production of MIBK Using Catalytic Distillation Technology U.S. Patent 6,008,416, Dec 28, 1999. 

KH Lawson, B Nkosi. Production of MIBK using catalytic distillation technology. US Patent. 6,008,416. 1999. 

Chem. Descrip. Kefimine (reaction prod, of ethylenediamine and MIBK) Uses Curing agenf for low-VOC coatings Properties Gardner 8 max. color dens. 7.1 Ib/gal vise. 2-5 cP EEW 55 11-14% amine nitrogen content... 

Chem. Descrip. Thermoset polyester resin In Aromatic 150/MIBK Uses Polyester for interior/exterlor coatings plasticizer for lacquers, coil-applied coatings for metal and containers, baked metal protective coatings... 

Figure 6.28 Synthesis of MIBK using sulphonic acid resin catalyst partially exchanged with Pd. Note three consecutive reactions, the first two catalysed by the third by Pd(0)/H2.

MIBK is a highly effective separating agent for metals from solutions of their salts and is used in the mining industries to extract plutonium from uranium, niobium from tantalum, and zirconium from hafnium (112,113). MIBK is also used in the production of specialty surfactants for inks (qv), paints, and pesticide formulations, examples of which are 2,4,7,9-tetramethyl-5-decyn-4,7-diol and its ethoxylated adduct. Other appHcations include as a solvent for adhesives and wax/oil separation (114), in leather (qv) finishing, textile coating, and as a denaturant for ethanol formulations. 

In addition to DAA s use in the production of MIBK, DAA also finds use as a specialty reaction intermediate. Hydrogenation of DAA at 100°C and 30 MPa (83) yields hexylene glycol ( 1.43/kg, October 1994), widely used in castor oil-based hydrauhc brake fluids and as a solvent. Reaction of /)-phenetidine [156-43-4] with DAA synthesizes Monsanto s Santoquin (ethoxyquin) [91-53-2] (149), an antioxidant used in animal feeds and also as a mbber additive. Diacetone alcohol (acetone-free) was available at 1.32/kg as of October 1994. 

Another solvent extraction scheme uses the mixed anhydrous chlorides from a chlorination process as the feed (28). The chlorides, which are mostly of niobium, tantalum, and iron, are dissolved in an organic phase and are extracted with 12 Ai hydrochloric acid. The best separation occurs from a mixture of MIBK and diisobutyl ketone (DIBK). The tantalum transfers to the hydrochloric acid leaving the niobium and iron, the DIBK enhancing the separation factor in the organic phase. Niobium and iron are stripped with hot 14—20 wt % H2SO4 which is boiled to precipitate niobic acid, leaving the iron in solution. 

Solvents used for dewaxing are naphtha, propane, sulfur dioxide, acetone—benzene, trichloroethylene, ethylenedichloride—benzene (Barisol), methyl ethyl ketone—benzene (benzol), methyl -butyl ketone, and methyl / -propyl ketone. Other solvents in commercial use for dewaxing include /V-methylpyrrolidinone, MEK—MIBK (methyl isobutyl ketone), dichloroethane—methylene dichloride, and propfyene—acetone. 

Formulator s Dilemma. The regulatory discussion included a listing of solvents designated as HAP compounds. Emissions of these solvents are to be significantly reduced. For many appHcations this means that less is to be allowed. In a situation where the allowed VOC emission levels are also being reduced, the formulator would like to use the most effective solvents available. In the past, MEK and MIBK were frequently used as active solvents and aromatic hydrocarbons as diluents. These solvents have been popular because they are cost-effective. 

Reformulating to reduce HAP solvents frequently means that solvent blend costs increase. The newer blends are generally not be as effective. For example, many coatings were usually formulated using ketones as the active solvents with aromatic hydrocarbons as diluents. This combination produced the most cost-effective formulations. However, when MEK, MIBK, toluene, and xylene became HAP compounds, less-effective solvents had to be used for reformulation. Esters are the most common ketone replacements, and aUphatic diluents would replace the aromatic hydrocarbons. In this situation, more strong solvent is required compared to the ketone/aromatic formulation and costs increase. The combination of reduced VOC emissions and composition constraints in the form of HAP restrictions have compHcated the formulator s task. 

In the initial thiocyanate-complex Hquid—Hquid extraction process (42,43), the thiocyanate complexes of hafnium and zirconium were extracted with ether from a dilute sulfuric acid solution of zirconium and hafnium to obtain hafnium. This process was modified in 1949—1950 by an Oak Ridge team and is stiH used in the United States. A solution of thiocyanic acid in methyl isobutyl ketone (MIBK) is used to extract hafnium preferentially from a concentrated zirconium—hafnium oxide chloride solution which also contains thiocyanic acid. The separated metals are recovered by precipitation as basic zirconium sulfate and hydrous hafnium oxide, respectively, and calcined to the oxide (44,45). This process is used by Teledyne Wah Chang Albany Corporation and Western Zirconium Division of Westinghouse, and was used by Carbomndum Metals Company, Reactive Metals Inc., AMAX Specialty Metals, Toyo Zirconium in Japan, and Pechiney Ugine Kuhlmann in France. 

Table 61 presents some important and useful properties of MIBK, TBP and 2-Octanol [72, 458, 474 - 476]. 

Sometimes it may become necessary to change the solvent. An example of phosphinyl acetic acid may be cited where crystallization from the aqueous phase did not provide a rugged process, whereas the use of methyl wo-butyl ketone (MIBK) as a solvent did. 

The reductive alkylation of DAP with acetone led to high conversions and selectivity to the dialkylated product over Al, Bl, and BS2 catalysts. The ASl catalyst, which typically has lower activity than the Al or Pt-based catalysts showed greater formation of heterocycles. These results indicate that a more active catalyst, a shorter reaction time, a higher operating temperature, or sterically hindered amines/ketones will help minimize the formation of the heterocycles. Similar high selectivities were obtained with DAP-MIBK reaction over BSl and BS2 catalysts with no heterocycles being formed. However, over Al, the undesired heterocyclic compound was over 15%. This indicates that the reaction between diamines and ketones has a significant potential to form heterocyclic compounds unless the interaction between these is kept to a minimum by the use of a continuous flow reactor as proposed by Speranza et al. (16) or by other methods. 

The present economic and environmental incentives for the development of a viable one-step process for MIBK production provide an excellent opportunity for the application of catalytic distillation (CD) technology. Here, the use of CD technology for the synthesis of MIBK from acetone is described and recent progress on this process development is reported. Specifically, the results of a study on the liquid phase kinetics of the liquid phase hydrogenation of mesityl oxide (MO) in acetone are presented. Our preliminary spectroscopic results suggest that MO exists as a diadsorbed species with both the carbonyl and olefin groups coordinated to the catalyst. An empirical kinetic model was developed which will be incorporated into our three-phase non-equilibrium rate-based model for the simulation of yield and selectivity for the one step synthesis of MIBK via CD. 

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