Parr autoclave

All reactions involving lactic acids were performed in 300 mL Parr Autoclave batch reactor. All reagents, including the resin catalyst, were charged into the reactor and heated up to the desired reaction temperature. Stirring was commenced once the desired temperature was reached this was noted as zero reaction time. Reaction sample were withdrawn periodically over the course of reaction and analysed for ester, water and alcohol using a Varian 3700 gas chromatograph with a thermal conductivity detector (TCD) and a stainless steel... 

More recently, cells using total internal reflectance (TIR) probes have become readily available. The spectrum in Figure 5.3 was obtained, again at temperature and pressure, from an Ir catalysed carbonylation of methanol in a Parr autoclave modified to take a Sentinel IR probe. 

C. Large-scale oxidation protocol. The large-scale oxidations reactions were carried out in a 300mL Parr autoclave equipped with an injection port, a thermocouple port, a septa sealed addition port and port connected to the volumetric measurement and gas supply module. The module consists of a forward pressure regulator and a calibrated ballast reservoir. The pressure in the reactor and in the ballast reservoir is monitored constantly and the pressure drop in the ballast reservoir is constantly converted into moles of oxygen uptake recorded vs. the time. 

Synthesis of Acid-Prepared Mesoporous Spheres (APMS).3 Tetraethylorthosilicate (TEOS, 5.65 g, 27.1 mmol) was added to a solution of cetyltrimethylammonium bromide (CTAB, 1.20 g, 3.30 mmol) in aqueous acid (4.40 g cone. HC1, 55.5 g H20). This mixture was stirred for 1 hour and then transferred to a teflon-lined Parr autoclave and heated at 150 °C for 40 minutes. The mixture was cooled and filtered to recover a white powder. APMS could also be prepared at temperatures between 80 and 230 °C by adjusting the heating time (lower temperatures, longer times). 

Figure 8.4 The ASI ReactIR 1000 reaction analysis system with a stainless-steel Parr autoclave modified with permanently mounted ATR crystal (SiComp) at the bottom of the reactor (purchased from Mettler Toledo).

The oxidation of m-cresol was carried out in Parr autoclave at 353 K using a 3 1 mixture of H2O and acetonitrile as solvent and Sn-silicalites with Si/Sn ratio of 70 as catalysts. A slightly higher efficiency for H2O2 is seen with Sn-ZSM-12 sample (Table 4). The dihydroxylated products, viz., 2-methylhydroquinone and 4-methylcatechol are found to be in excess over the products of side chain oxidation, viz., 3-hydroxybenzyl alcohol and the aldehyde in the product mkture. The aromatic hydroxylation on Sn-silicalites may follow an ionic mechanism as both the -CH3 and -OH groups in m-cresol are favourably placed for electrophilic substitution reaction. Interestingly, the product distribution on all the three Sn-molecular sieves is almost similar. This shows that in all the three types, the Sn ions are dispersed uniformly and possess identical catalytic property due to similar environment around them. 

Reaction conditions Catalyst/m-xylene = 20 g mol l m-Xylene/H202(niole) = 3 Solvent (acetonitrile)/m-xylene(mole) = 20 Temp. = 353 K Time = 24 h Reaction carried out in Parr autoclave. 

A 100 ml thermostated Parr autoclave was charged with the reactant (5ml), rhodium montmorillonite catalyst (100 mg) and with 200 psi of hydrogen at room temperature. The autoclave was purged with hydrogen before charging at room temperature. The autoclave was then heated at 100°C for 20 hours. The reaction mixture was then cooled, separated from the catalyst and analysed by GC. GC analysis was carried out on a Hewlett Packard model 5890 gas chromatograph using FID and HP-101 column. 

Hydrogenation experiments of binary mixtures of the olefins were carried out in 100 ml Parr autoclave. The catalyst amount was 100 mg whereas the amount of each reactant taken was 0.06 moles (Table 2). 

The enhancement in catalytic activity of cations such as Zn(II) which has been achieved both through ion exchange as well as deposition of Zn(II) salts onto clay surfaces led to studies of the acidity and catalytic activity of such ions when incorporated directly into the lattice sites of synthetic clay minerals. Luca et al. showed that Lewis acid sites are generated on Zn2+-substituted fluoro-hectorite.27 The Zn2+-substituted fluorohectorite was synthesised by a sol-gel route. The sol was allowed to crystallise in a Parr autoclave at 250 °C for 24 hours. The Lewis acid sites were identified as Zn2+ at the edges of the fluorohectorite crystallites and were active towards the Friedel-Crafts alkylation of benzene with benzyl chloride. 

As sulfur-containing organic molecules are known catalyst poisons because of strong adsorption, acylation of thioethers is difficult to obtain. The reaction between thioanisole and AAN can, however, be performed in the presence of ion-exchange resins that are more robust to deactiva-tion. The process is carried out in a Parr autoclave in 1,2-dichloro-ethane at 70°C. Under these conditions, other acid catalysts such as sulfated zirconia and KIO clay do not show any noticeable activity. Only the cation exchange resin catalysts, which contain Bronsted sites, are effective. Among these, Amberlyst-15 shows maximum conversion because it... 

Procedure in autoclave. Experiments were performed at 10 bar using a 180 ml Hastelloy C Parr autoclave. A continuous stream of 8% O2 in N2 was passed through the solution. The amount of oxygen consumed during the reaction was monitored by an oxygen meter and plotted against time. 

Screening reactions were carried out with 10-15 wt% solutions of PVOH in a 100 mL stirred stainless steel Parr autoclave. Catalyst (5% Pd/AlaOs 5 wt%, based on PVOH) was added, the reactor was purged and pressiue checked with nitrogen, purged and pressurized with hydrogen, and heated with stirring to the desired tenqterature for the desired time (see Table 1) at the desired pressure (typi-... 

Hydrogenation of benzophenone (0.065 mol) (Loba Chemie, A.R. grade) was carried out in a 100 ml Parr autoclave using appropriate solvents (35.5 ml,... 

The simplest type of batch high-pressure reactor is essentially a hollow cylinder with one or two end caps, often referred to as a pressure bomb. Such vessels can be purchased from a variety of manufacturers, including Parr, Autoclave Engineers, and Pressure Products Industries, to name just a few. These reactors typically are equipped with a stirring system, such as described in an earlier section, a heating jacket, and ports for introduction of a thermocouple, as well as addition or removal of samples. Sizes range typically from 50 mL up to several liters, and pressure and temperature ratings vary from one manufacturer to another. 

In cases where the Parr 4740 autoclave is used as the pressure containment device, multiple quartz reaction ampoules can be used in each run. These autoclaves have the advantage that up to eight quartz ampoules can be run at once. In this case, pressurization can be most conveniently accomplished by hooking up the autoclave directly to a new cylinder of inert gas. Most commercial gas suppliers supply gases in cylinders which are pressurized to 150-170 bar and the Parr autoclave can easily contain these pressures. Direct inlet adapters can be purchased from standard compressed gas dealers. Swage type and NPT connectors are suitable for these connections but any tubing must be medium walled copper or steel. 

The evaluation of catalytic hydrogenation was carried out in batch reactor of 450 mL and under pressure (Parr autoclave). To eliminate the diffusion effects, the reactor was equipped with double-helix stirring device at specific positions near the bottom and on the surface of the reactant (height of the liquid mixture). To visualization of the system. Figure 25.11 presents the reactor used for this example. 

Figure 25.11 Schematic representation of the reactor used in catalytic tests, Parr autoclave (with permission).

University Chemical Laboratory, Lensfield Road, Cambridge, CB2 lEW, United Kingdom. tDepartment of Chemistry, Iowa State University, Ames, lA 5(X)11. tThe checkers carried out the reaction in a 250-mL stainless steel high-pressure Parr autoclave without stirring. 

Benzene (6-17 mL), tetrakis(acetato)dirhodium(II), [Rh(OAc)2]2, and the substrate in the ratio 1 100 were placed in a 100-mL stainless steel Parr autoclave which was then pressurized with a 1 1 molar mixture of carbon monoxide and hydrogen to 500 psi and heated to temperatures between 30 and 100 °C for 5-90 h. The crude reaction mixture were analyzed the H NMR and P immediately after the reaction reached completion, and isomer ratios were determined where appropriate from H NMR spectral data. An alternative method for some reactions involved using benzene (6-10 mL), dodecacarbonyltetrarhodium, Rh4(CO)i2, and the substrate in the ratio 1 200 in the autoclave which was then pressurized with a 1 1 molar mixture of carbon monoxide and hydrogen to 500 psi and heated to temperatures between 40 and 70 °C for 22 h. 

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