Propylene oxide yield

Hydrogenolysis of propylene oxide yields primary and secondary alcohols as well as the isomeri2ation products of acetone and propionaldehyde. Pd and Pt catalysts favor acetone and 2-propanol formation (83—85). Ni and Cu catalysts favor propionaldehyde and 1-propanol formation (86,87). 

Virtually all of the organo derivatives of CA are produced by reactions characteristic of a cycHc imide, wherein isocyanurate nitrogen (frequendy as the anion) nucleophilically attacks a positively polarized carbon of the second reactant. Cyanuric acid and ethylene oxide react neady quantitatively at 100°C to form tris(2-hydroxyethyl)isocyanurate [839-90-7] (THEIC) (48—52). Substitution of propylene oxide yields the hydroxypropyl analogue (48,49). At elevated temperatures (- 200° C). CA and alkylene oxides react in inert solvent to give A/-hydroxyalkyloxazohdones in approximately 70% yield (53). Alternatively, THEIC can be prepared by reaction of CA and 2-chloroethanol in aqueous caustic (52). THEIC can react further via its hydroxyl fiinctionahty to form esters, ethers, urethanes, phosphites, etc (54). Reaction of CA with epichlorohydrin in alkaline dioxane solution gives... 

In 1618 Abderhalden and Eichwald0 made the curious observation that dextrorotatory propylene oxide yields levorotatory l-bromo-2-propanol on treatment with hydrogen bromide- Subsequent work by Levene and Walti1016 confirmed this particular finding, but at the Bairn time called attention to certain defects in the previous study. There... 

Conjugated propylene epoxidation with hydrogen peroxide is the main reaction proceeding in the temperature range of 500-580 °C under optimal conditions the average propylene oxide yield reaches 50%. 

In fact, the experimental data [124] show that all other factors being equal in the reaction mixture, propylene oxide yield is higher than ethylene oxide yield. This is explained by the... 

Figure 7.12 Dependencies of allyl alcohol and propylene oxide yields on the contact time on PPFe3+0H/Al203 catalyst. T = 160°C C3Hg 20% H202 = 1 1 (1 propylene oxide 2 propionic aldehyde 3 allyl alcohol 4 acetone and 5 total propylene conversion).

EBITP conversion was defined as the percentage of EBHP in the feed that had reacted. Propylene oxide yield was defined as the moles of PO formed per mole of... 

EBHP in the feed. Propylene oxide selectivity was defined as the percentage of EBHP reacfed fo PO (i.e., propylene oxide selectivity = propylene oxide yield/EBHP conversion). 

FIGURE 14.1 Influence of TiCU deposition time on ethylbenzene hydroperoxide (EBHP) conversion and propylene oxide yield for Ti/Si02 catalysts. 

Vapor-phase epoxidation of propylene using H2 and O2 was carried out over gold catalysts supported on mesoporous ordered (MCM-41) and disordered titanosilicates prepared hydrothermally or by modified sol-gel method. Gold nanoparticles were homogeneously dispersed on the titanosilicate supports by deposition-precipitation (DP) method. The catalysts and support materials were characterized by XRD, UV-Vis, surface area measurements (N2 adsorption) and TEM. NaOH was found to be the best precipitant to prepare Au catalysts with optimum propylene oxide yields and H2 efficiency. The extent of catalysts washing during preparation was found to affect the activity of the catalyst. The activity and hydrogen efficiency was found to depend on the type of mesoporous support used. 

The direct oxidation of propylene by molecular oxygen is a low-selective reaction. The propylene oxide yield can be raised by limiting the conversion rate to a low value, about 10 to 15 per cent, by using more selective catalysts, or by achieving co-oxidation with a more oxidizable compound than propylene (acetaldehyde, isobutyraldehyde etc.). Many patents have been Hied concerning this process, but without any industrial implementation. Among them is the liquid phase oxidation of propylene on a rare earth oxide catalyst deposited on silica gel (USSR), or in the presence of molybdenum complexes in chlorobenzene or benzene (JFP Instiiut Francois du Petrole. Jefferson ChemicalX vapor phase oxidation on modified silver catalysts (BP British Petroleum IFP, or on ... 

Hazbum [2.129] in a U.S. patent, reported ethane and propane partial oxidation to ethylene and propylene oxides using a TiYSZ mixed O Velectron conducting membrane with silver deposited on the hydrocarbon side of the membrane as a catalyst. For the ethane partial oxidation reaction catalyst at 250-400 C, the ethylene oxide selectivity was (>75 %) but the ethane conversion was low (<10 %), limited by the low membrane oxygen flux at these temperatures. For the partial oxidation reaction to propylene oxide yields close to 5 % were reported. Using porous membranes Santamaria and coworkers (Mallada et al. [2.252, 2.253, 2.254, 2.255]), Mota et al. [2.256], and Xue and Ross [2.257] recently studied the oxidation of butane into maleic anhydride. 

Anionic polymerization of a substituted epoxide such as propylene oxide yields only low molecular weight (< 5000) polymers as chain growth is severely restricted by chain transfer to monomer. The transfer reaction becomes more prevalent as the substituent group possesses hydrogen atoms on the a-carbon atom. The chain transfer to propylene oxide monomer occurs by proton abstraction from the methyl group attached to the epoxide ring (Young and Lovell, 1990) ... 

Copolymerization of ethylene oxide and propylene oxide yields quite valuable functional fluids of various sorts. The random copolymers of ethylene and propylene oxides of relatively low molecular weights are water soluble when the proportion of ethylene oxide is at least 40-50% by weight. 

Cationic polymerizations of oxiranes are much less isospecific and regiospecific than are anionic polymerizations. In anionic and coordinated anionic polymerizations, only chiral epoxides, like propylene oxide, yield stereoregular polymers. Both pure enantiomers yield isotactic polymers when the reaction proceeds in a regiospecific manner with the bond cleavage taking place at the primary carbon. 

GC studies) bislactim ethers 2R,5R)-4a, (25,5/ )-4a, (2/f,5/f)-4b, and (2S,5R)-4h were subsequently hydrolyzed with hydrochloric acid at 0°C to jdeld the respective P-(trimethylsilyl)alanine esters (R)-5a and S)-5a and the P-(trimethylgermyl)alanine esters (7 )-5b and (S)-5b. As shown by H-NMR studies using the chiral solvating agent (R>(-)-l-(9-anthryl)-2,2,2-trifluoroethanol, the enantiomeric purities of these esters were >98 % ee. Hydrolysis of the esters (R)-5a, (S)-5a, (R)-5b, and (S -5b in boiling hydrochloric acid and subsequent treatment of the resulting a-amino acid hydrochlorides with propylene oxide yielded the title compounds (R)-la, (S)-la, (R)-lb, and f5)-lb as colorless crystalline solids. 

Reaction conditions , [catalyst] = 0.12 mmol Mo [tBHP] = 10 mmol propene = 238 mmol 1,2-dichloroethane = 22 ml 400 spi He at 80°C. Reaction Time = 1 h. Propylene oxide yield determined as % of BHP consumed, i.e. 10 mmol = 100%. Reaction solution assayed for Mo using ASS (atomic absorption spectroscopy). Detection limit 0.5 ppm. Expressed as a percentage of Mo originally present on resin. 

The P-series glycol ethers are products of the reaction of propylene oxide with various alcohols. Reaction of propylene oxide with methanol in a 1 1 mole ratio yields propylene glycol methyl ether, PM. Further reaction of PM with propylene oxide yields the dipropylene glycol methyl ether, DPM, and the tripropylene glycol methyl ether product, TPM. The aromatic ether analogue of propylene glycol is propylene glycol phenyl ether, PPh. 

In the chlorohydrination step, the reactants propylene and hypochlorous acid (chlorine and water) are converted into two propylene chlorohydrin isomers (90% l-chloro-2-propanol and 10% 2-chloro-l-propanol). Yields of up to 94% can be achieved in modern commercial plants. The main by-products formed in this reaction step are dichloropropane (3-10%), dichloropropanol (0.3-1.2%), and dichlorodiisopropyl ether (0.2-1.7%). In the second step (dehydrochlorination, also called epoxidation or saponification ) the aqueous propylene chlorohydrin solution is treated with slaked lime or caustic soda. Propylene oxide and calcium or sodium chloride are formed. In a commercial process 1.4-1.5 units of chlorine are consumed to produce one unit of propylene oxide. Typical by-products are monopropylene glycol, epichlorohydrin, glycerol monochlorohydrin, glycerol, propanal, and acetone. In dehydrochlorination, propylene oxide yields of up to 96% can be obtained. 

The reactions of ethylene and propylene oxides yield hydroxyethylcellulose and hydroxypropyl-cellulose (equation 6). Hydroxyethylcelluloses have been used in latex paints and in paper. ... 

Typically, a mixture of alkene (10 mmol), a 37.5 wt% solution of TBHP in toluene (14 mmol) and 500 mg of catalyst was magnetically stirred at 90 °C for 24 h. The catalyst was separated by filtration (PTFE filters pore width 0.45 pm) and employed in the next run without reconditioning. The filtrate was analyzed by GC and atomic spectroscopy. Epoxidation of propylene was carried out in a 80-ml steel autoclave charged with 50 mmol TBHP (34.0 wt% in toluene) and 1 g of catalyst. The solution was saturated with propylene and a pressure of 8 bar was adjusted. The reaction mixture was stirred for 24 h at 90 °C (operating pressure ca. 20 bar). Propylene oxide yields were based on peroxide consumption determined by iodometric titration and GC analyses. 

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