Propylene isopropanol

Isopropanol, also called rubbing alcohol, is prepared industrially via the acid-catalyzed hydration of propylene. Isopropanol has antibacterial properties and is used as a local antiseptic. Sterihzing pads typically contain a solution of isopropanol in water. Isopropanol is also used as an industrial solvent and as a gasoHne additive. 

Conversions of ca 75% are obtained for propylene hydration over cation-exchange resins in a trickle-bed reactor (102). Excess Hquid water and gaseous propylene are fed concurrentiy into a downflow, fixed-bed reactor at 400 K and 3.0—10.0 MPa (30—100 atm). Selectivity to isopropanol is ca 92%, and the product alcohol is recovered by azeotropic distillation with benzene. 

Propylene can be polymerized alone or copolymerized with other monomers such as ethylene. Many important chemicals are based on propylene such as isopropanol, allyl alcohol, glycerol, and acrylonitrile. Chapter 8 discusses the production of these chemicals. U.S. production of proplylene was approximately 27.5 billion lbs in 1997. ... 

Other routes for obtaining glycerol are also based on propylene. It can be produced from allyl chloride or from acrolein and isopropanol (see following sections). 

The production of isopropanol from propylene occurs by either a direct hydration reaction (the newer method) or by the older sulfation reaction followed by hydrolysis. 

In the liquid-phase process, high pressures in the range of 80-100 atmospheres are used. A sulfonated polystyrene cation exchange resin is the catalyst commonly used at about 150°C. An isopropanol yield of 93.5% can be realized at 75% propylene conversion. The only important byproduct is diisopropyl ether (about 5%). Figure 8-4 is a flow diagram of the propylene hydration process. ... 

Figure 8-4. A flow diagram for the hydration of propylene to isopropanol (1) propylene recovery column, (2) reactor, (3) residual gas separation column, (4) aqueous - isopropanol azeotropic distillation column, (5) drying column, (6) isopropyl ether separator, (7) isopropyl ether extraction.

The direct oxidation of propylene with oxygen is a noncatalytic reaction occurring at approximately 90-140°C and 15-20 atmospheres. In this reaction hydrogen peroxide is coproduced with acetone. At 15% isopropanol conversion, the approximate yield of acetone is 93% and that for H2O2 is 87% ... 

The hydroxypropyl derivative of guar GaM (HPG) was prepared with propylene oxide in the presence of an alkaline catalyst. HPG was subsequently etherified as such with docosylglycidyl ether in isopropanol and presence of an alkaline catalyst [432]. The peculiar features of the long-chain hydrophobic derivatives were ascribed to a balance between inter- and intramolecular interactions, which is mainly governed by the local stress field. 

Three major non-polymer propylene derivatives are isopropanol, acetone, and acrylic acid. Isopropanol (isopropyl alcohol) is used mainly as a solvent. It has been made from propylene by reaction with sulfuric acid and water for at least the last 75 years, making its manufacture the oldest, still-running commercial organic chemical process. It is used in household rubbing alcohol because, unlike ethanol, it is unfit for human consumption even in small amounts. About 25 % of the isopropanol produced is used for making acetone, in competition with a route based on isopropylbenzene. 

The hydration of propylene with sulfuric acid catalyst in high-temperature water was investigated using a flow reaction system.31 The major product is isopropanol. A biopolymer-metal complex, wool-supported palladium-iron complex (wool-Pd-Fe), has been found to be a highly active catalyst for the hydration of some alkenes to the corresponding alcohols. The yield is greatly affected by the Pd/Fe molar ratio in the wool-Pd-Fe complex catalyst and the catalyst can be reused several times without remarkable change in the catalytic activity.32... 

Solvents (LD, DW, ADW, HC, FC) Prevent separation or deterioration of ingredients in liquid products, dissolve soils, clean without leaving residues Ability to dissolve ingredients Cost Ethanol Isopropanol Propylene glycol 0-50% 0-50% 0-5%... 

Uses Preparation of propylene and dipropylene glycols, poly (propylene oxide), lubricants, oil demulsifiers, surfactants, isopropanol amines, polyols for urethane foams solvent soil sterilant fumigant. 

Another problem with fermentation products is often the limited outlet. The primary fermentation products such as alcohols require chemical transformations to convert them into species acceptable by the chemical industry as intermediates. This can normally occur through dehydration reactions [77]. For example, ethanol may need to be dehydrated into ethylene, isopropanol into propylene and n-butanol into n-butylene. These reactions are reversed petrochemical reactions and normally lead to products that have a lower selling price than the starting materials under the present structure of the chemical industry. For this reason, bioethanol is still used unchanged as an oxygenated gasoline additive. 

Propanol, 2 Isopropyl Alcohol Isopropanol under Secondary Alcohols Propazine under Aromatic Amines and Diamines Propylene under Alkenes, Cyclic Alkenes, and Dienes Propylene Glycol under Glycols... 

Correlations between catalytic activity and a variety of bulk properties of semiconductors have been reported (i) the average band gap of III-V and II-VI semiconductors and activity towards hydrogenation of isopropanol (ii) enthalpy of oxides and their activity towards oxidation of propylene and (iii) number of d-electrons (and crystal field stabilization energy) or 3rf-metal oxides and their activity towards N2O decomposition. The last correlation, due to Dowden (1972), is important since it provides a connection between heterogeneous catalysis and coordination chemistry of transition-metal compounds. A correlation between the catalytic activity of transition-metal sulphides towards hydrodesulphurization of aromatic compounds and the position of the transition metal in the periodic table has been made by Whittingham ... 

Dovonex (calcipotriene solution) scalp solution 0.005%, is a colorless topical solution containing 0.005% calcipotriene in a vehicle of isopropanol (51% v/v) propylene... 

Isopropanol is manufactured in the United States by the indirect hydration of propylene in processes which may involve the use of concentrated or dilute sulfuric acid, whereas, in European countries and Japan, a direct hydration process is used in which propylene reacts with water in the presence of a catalyst. It is used mainly for the production of acetone, but also as a solvent and in the manufacture of other chemicals and in pharmaceutical and cosmetic formulations (lARC, 1977). 

Diisopropyl sulfate is an intermediate in the indirect hydration (strong- or weak-acid) process for the preparation of isopropanol from propylene. It has no other known industrial use. No data were available on levels of occupational exposure to diisopropyl sulfate (lARC, 1992). 

Isopropyl oils are produced as by-products in the reaction of propylene with sulfuric acid during the manufacture of isopropanol and consist of the residue after distillation. They do not appear to have been used commercially (lARC, 1977). 

By far the largest prodn of acet in the USA is from petroleum-derived propylene by way of isopropanol (Refs 31 48). Another method is to pass acetylene and steam over FeaOj-ZnO catalyst at elevated tempsfRef 48). In Germany acet was produced in 95% yield from AcOH by a vapor-phase catalytic process using a cerium oxide catalyst at 400 Ref 31) There are also other methods of prepn(Refs 1,2,3,4,10,14,31,33,42,47, ... 

Table 2 shows the conversion of isopropanol to propylene over PSM and AMM samples. The reactivity of isopropanol on PSM is very low due to the lack of acid sites on PSM. The conversion is less than 1% at temperatures lower than 200 °C and only 10% at 250°C. However, all AMM samples show considerable activities for the dehydration of isopropanol to propylene. Having only 0.1 wt.% loading of AI2O3 on the sample, the conversion of isopropanol on AMM-0.1 reaches 79.6 % at 200°C and reaches complete conversion at 250°C. With the increase of A1 content, the catalytic activity is found to be increased. The conversion of isopropanol at 200°C is over 90% on AMM-1 and 100% on AMM-5 and AMM-10. 

Table 2. Conversion (%) of isopropanol to propylene over PSM and AMM samples...

Post-synthesis alumination using A1(N03)3 as the precursor improves the acidity of siliceous MCM-41 materials significantly. FTIR results show that both Bronsted and Lewis acid sites are increased upon alumination. The number of acid sites increases with the Al content on MCM-41. NH3-TPD reveals the mild strength of these created acid sites. Due to the improved acidity, the catalytic activity for dehydration of isopropanol to propylene over these alumina-modified MCM-41 materials is considerably promoted by post-synthesis alumination. The results of XRD and N2 adsorption show that the enhancement of acidity for siliceous MCM-41 by postsynthesis alumination does not cause any serious structural deformation of the resulting material. 

Ion exchange resins are used widely as heterogeneous catalysts of processes that require acid or base catalysis, for example, hydration of propylene to isopropanol, reaction of isobutylene with acetonitrile, and many others. The same kind of equipment is suitable as for ion exchange, but usually regeneration is not necessary, although some degradation of the resin naturally occurs over a period of time. 

Two basic methods of production are in commercial use 11) jhsnrption of propylene in sulfuric acid to form alkyl hydrogen sulfate, followed by the hydrolysis of the estei and (2) by direct hydration with water, using a catalyst. An inherent disadvantage in the lirst process is the need lo handle sulfuric acid. Further, the first process yields liuic more ihan 7() f isopropanol as compared with the second process, in which liquid propylene is used as the charge stock. All direct-hydration processes can he represented by CiH + HO) — CiFLOH + heat. 

Friedel-Crafts alkylation of benzo[6]thiophene has received little attention. The published results, which deserve reexamination, indicate that exclusive 3-substitution occurs in some cases, whereas in others, 2-substitution predominates. Benzo[6]thiophene is alkylated with isopropyl chloride, isopropanol, or propene in the presence of various acid catalysts under a variety of reaction conditions to give a mixture of 2- and 3-isopropylbenzo[6]thiophene in which the 2-isomer predominates (78-92%).358 410 In contrast, alkylation with isobutene in the presence of either 80% sulfuric acid415 or 100% phosphoric acid416 is said to afford exclusively 3-/er<-butylbenzo[6]thiophene in yields of 100 and 75%, respectively. In neither case was the structure of the product rigorously confirmed. Likewise, 3-Jeri-amylbenzo [63-thiophene is the exclusive product of alkylation with tert-amyl alcohol in the presence of stannic chloride414 alkylation with pent-l-ene, hex-l-ene, and a Ci8 propylene polymer is also claimed to give... 

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