Acetone process

Worldwide, approximately 85% of acetone is produced as a coproduct with phenol. The remaining 17% is produced by on-purpose acetone processes such as the hydration of propylene to 2-propanol and the dehydrogenation of 2-propanol to acetone. The cost of production of 2-propanol sets the floor price of acetone as long as the acetone demand exceeds the coproduct acetone supply. However, there is a disparity in the growth rates of phenol and acetone, with phenol demand projected at 3.0%/yr and acetone demand at 2.0%/yr. If this continues, the coproduct supply of acetone will exceed the total acetone demand and on-purpose production of acetone will be forced to shut down the price of acetone is expected to fall below the floor price set by the on-purpose cost production. Projections indicate that such a situation might occur in the world market by 2010. To forestall such a situation, companies such as Mitsui Petrochemical and Shinnippon (Nippon Steel) have built plants without the coproduction of acetone. 

Production of a-methylstyrene (AMS) from cumene by dehydrogenation was practiced commercially by Dow until 1977. It is now produced as a by-product in the production of phenol and acetone from cumene. Cumene is manufactured by alkylation of benzene with propylene. In the phenol—acetone process, cumene is oxidized in the Hquid phase thermally to cumene hydroperoxide. The hydroperoxide is spHt into phenol and acetone by a cleavage reaction catalyzed by sulfur dioxide. Up to 2% of the cumene is converted to a-methylstyrene. Phenol and acetone are large-volume chemicals and the supply of the by-product a-methylstyrene is weU in excess of its demand. Producers are forced to hydrogenate it back to cumene for recycle to the phenol—acetone plant. Estimated plant capacities of the U.S. producers of a-methylstyrene are Hsted in Table 13 (80). 

Ketones.have the characteristic -C- signature group imbedded in them. Acetone, CH3COCH3, comes from two different routes. It is a by-product in the cumene to phenol/acetone process. It is the on-purpose product of the catalytic dehydrogenation of isopropyl alcohol. Acetone is popular as a solvent and as a chemical intermediate for the manufacture of MIBK, methyl methacrylate, and Bisphenol A. 

A large number of compounds related to styrene have been reported in the literature, Those having the vinyl group CH2=CH—attached to the aromatic ring are referred to as styienic monomers, Several of them have been used for manufacturing small-volume specialty polymers. The specialty styreme monomers that arc manufactured in commercial quantities arc vinyl toluene, /r, -methylstyrene, or-methylstyrene. and divinylbenzene. In addition, 4-fert-butylstyrene (TBS) is a specialty monomer that is superior to vinyltoluene and pnra-methylstyrene in many applications. Other styrenic monomers produced in small quantities include chlorostyrene and vinylbenzene chloride. With the exception of a-methylstyrene, which is a by-product of the phenol-acetone process, these specialty monomers are more difficult and expensive to manufacture than styrene... 

The stability of an acetal or a ketal may depend on the catalyst employed in its synthesis. For this and other reasons, Fischer and Taube20 recommended the use of zinc chloride, rather than a mineral acid, as the catalyst in acetonation processes. Presumably the instability of the products prepared with the aid of strong acids is due to the difficulty of ensuring complete removal of the catalysts. 

UOP/Chiyoda Corp. Bisphenol-A Phenol and acetone Process has highest product purity, high selectivity/conversion using proprietary cation-ion resin catalyst, low operating/capital investment costs 3 1998... 

Figure 15.1 Phenol-acetone process to produce a-methylstyrene...

Derivation By heating acetone or ethanol with bromine and alkali hydroxide and recovery by distillation (similar to acetone process of chloroform). 

The larger dichloro precursors needed to make the diiodides by the sodium iodide/acetone process are generally not available. On the other hand, the ditosylate derivatives of the available tetra- and pentaethylene glycols can be produced and reacted directly with the amine to form the aza-15-crown-5 and aza-18-crown-6 ligands. The ditosylates also can be converted to the more reactive diiodides by reaction with sodium iodide in acetone or acetonitrile. 

Because of its low boiling point and low toxicity, acetone is particularly suitable for preparing polyurethane dispersions. This procedure is therefore called the "acetone process." Although this process is rather uneconomical, it has certain advantages such as a wide scope for variation in structure and particle size, high quality of end products, and good reproducibility. 

Isopropylbenzene (Cumene). Oxidation of isopropylbenzene, cumene, to cumene hydroperoxide and the subsequent decomposition to phenol and acetone have become of significant commercial importance in recent years and have, furthermore, pointed the way as a generally useful new route for potential commercial manufacture of other important chemicals. For use in the phenol-plus-acetone process, cumene is usually obtained by the phosphoric acid-catalyzed alkylation of benzene with propylene. 

Alternate methods a) U.S. authors have used processes involving fractional extraction of the aqueous phase with benzene solutions of diketones [thenoyl trifluoracetone E. H. Huffman and L. J. Beaufait, J. Amer. Chem. Soc. 71, 3179 (1949) trifluoro-acetylacetone B. G. Schultz and E. M. Larsen, J. Amer. Chem. Soc. 12, 3610 (1950)]. One disadvantage of the thenoyl trifluoro-acetone process may be that the Zr, which is usually the major component, is preferentially extracted into the benzene phase. 

In parallel to the Synthetic Products development of the acetone process, Weizmann isolated a microorganism originally named Bacillus granulobacter... 

In practice, the structures shown in Figure 6.3 are partly or fully crosslinked. The two main methods which lead to these structures are the acetone process (historically older) [23] and the prepolymer-ionomer process [24] that is commonly used to manufacture DPUR at present. A combination of these two methods can also be used. 

In the acetone process , the first step is the synthesis of NCO-terminated urethane prepolymer which is then dissolved in acetone and reacted with a di-hydroxy or diamino compound containing groups which are the precursors of ionic groups, e.g., -SO3, -COOH, N=. The next steps are the emulsification of the resulting product in water combined with the formation of ionic groups and distillation of acetone. 

The ketiraine process combines the quality and versatility of the acetone process with the simplicity and economics of the prepolymer mixing process. Ketimines are formed from a ketone and diamines (96). 

The ketimines can then be mixed with NCO prepolymers without inducing a reaction. However, upon the addition of water, a dispersion results and, about the same time, the ketimine is hydrolyzed to free the amine. The amine then undergoes chain extension to produce a material that can also be obtained by the acetone process. 

Linear PU dispersions can be obtained by the so called acetone process . An isocyanate-terminated PU is made in acetone solution from diisocyanate and a diol (or mixture of diols). The chain extension is obtained with a substituted diamine. After dilution with water, acetone is removed by distillation. The crosslinkable PU dispersions can be produced by one-step or by two-step process [71]. 

The acetone process has the disadvantage that the removal of acetone is a time-consuming and expensive step. PUDs can also be made using a low volatility solvent. A(-methylpyrrolidinone (NMP) has been the most widely used solvent. The cost of manufacture is lower but the VOC is obviously higher and the low volatility of NMP requires baking to remove the solvent. There is also concern about the possible carcinogenicity of NMP. 

Oxidation of cumene to cumenehydroxide in the phenol and acetone processes... 

For the isopropyl alcohol to acetone process flowsheet given in Appendix B, Figure B.10.1. list the 2 minimum input information required to obtain mass and energy balances for this process. Using the process simulator available to you, simulate the isopropyl alcohol to acetone process, and compare your results to those given in Table B.10.1. 

Figure 20.10 Reaction Section of Acetone Process fFrom Figure B.9.1 and Table B.9.1.)...

Table B.10.1 Flow Table for Acetone Process in Figure B.10.1...

Table B.10.2 Preliminaiy Equipment Summaiy Table for Acetone Process...

Ketone Dewaxing. This process is a dev opment of the benzene-acetone process by the use of various mixed solvents consisting of benzene, toluene, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, or mixtures of these ketones. The advantages of the lower molecular-weight ketones are high filter rates and low solubility of wax, but they have higher vapor pressures and are somewhat soluble in water. 

---