Reactors atmospheric pressure apparatus

Atmospheric pressure apparatus. Isomerization experiments at atmospheric pressure were carried out in an all-glass system equipped with greaseless values, a flow meter, a U-shaped silica reactor, a double TCD system recording the pressure of reactant (provided by a saturator) before the reactor and the pressure of the products after the reactor, a system to extract the products for GC analysis and a needle valve to regulate gas flow. The catalyst was placed on a silica fritted disc and the reactor was operated as a fixed bed at constant pressure and temperature. Hydrocarbons were introduced at a set pressure and hydrogen was used as complement to the atmospheric pressure on the catalyst. 

A thermal plasma system has been developed for the decomposition of methane. A schematic diagram of the experimental apparatus is shown in Fig. 1. The system consists primarily of D.C. plasma torch, plasma reactor and filter assembly. Plasma was discharged between a tungsten cathode and a copper anode using N2 gas. All the experiments were carried out at atmospheric pressure at 6 kW input electric power and N2 flow rate of 10 to 12 1/min. The feed gas (CH4) flow rates were varied from 3 to 15 1/min depending on the operating conditions, shown in Table. 1. 

Figure 1. An ultrahigh vacuum apparatus used for the study of single crystal catalysis before and after operation at atmospheric pressure in a catalytic reactor.

Calibration process consists of a few steps. At first we have to obtain advisable pressnre (usually about 10 atm) of argon in a calibrated volnme and atmospheric pressure in the rest of the system (reactor and connections). Then by opening calibrated volume cut-off valve and by pressnre rednction to the value the total volume of the system for the apparatus with the relative transducer can be calculated using the formula ... 

Catalytic tests were performed in an isothermal flow quartz reactor apparatus under atmospheric pressure, provided with on-line gas chromatographic (GC) analysis of the reagent and products by two GC instrument equipped with flame ionization and thermoconducibility detectors. The activity data reported refers to the behavior after at least two hours of time on stream, but generally the catalytic behavior was found to be rather constant in a time scale of around 20 hours. 

See Ref. 5. Catalysts supported metals, 0.8-5%. Apparatus pulse reactor, at atmospheric pressure of H2. Multiple splitting hydrocarbon is split off into C, pieces (CHJ before it leaves the catalyst surface. Terminal splitting always one C, fragment is split off during one adsorption sojourn on the surface. 

Figure 6. Block drawing of the pilot installation for the production of trichloromethyl chloroformate by exhaustive photochlorination [39] 1 Dryer for gaseous Cl2 (H2S04 cone.). 2 Safety tank. 3 Thermoregulated immersion-type photochemical reactor. 4 Raschig column. 5 Cl2 detection system (1,2,4-trichlorobenzene). 6 Neutralization tank (20% NaOH). 7 Reservoir of 20% NaOH. 8 Buffer to atmospheric pressure (20% NaOH). 9 Active carbon filter. 10 Reservoir of crude trichloromethyl chloroformate. 11 Buffer to normal atmosphere via CaCl2 filter and direct entry for trichloromethyl chloroformate to be distilled. 12 Distillation flask with Vigreux column. 13 Exit to vacuum pump. 14 Solid NaOH filter before pump. 15 Cooling water alarm linked to power supply of the light source. 16 Medium pressure mercury arc. 17 Heater for distillation apparatus. 18 Magnetic stirrers. /T thermometer /P manometer.

Apparatus and Procedure - The experiments with the solid feedstocks and the initial experiments on liquid samples were carried out in the apparatus shown in Figure 1A. The vapors from a stainless steel, stirred-bed carbonizer/vaporizer at 873°K were cracked at atmospheric pressure in a tube reactor heated in a platinum-wound furnace. The reactor was 30 mm ID and had a 100 mm long hot zone within 20°K of the maximum reactor temperature. Solid feedstocks were introduced at about 1 g min. from a vibratory table through a water-cooled port. Liquids were injected at the same point from a mechanically driven syringe at 0.1-0.8 ml min. The amount fed was determined by weighing the feeders. 

Experimental Apparatus and Procedures. The amorphous alloys of about 15 microns thick and 3 mm wide ribbons were prepared by the disk method (8), the details of which have been described elsewhere (5). The important step of the method is the impinging of the molten mother alloy, held in a quartz tube with a small nozzle, onto the surface of a rotating disk of stainless steel. A flow type of a reactor apparatus, previously described (5), was used for the catalytic reaction. The reaction was carried out under atmospheric pressure and at temperatures from 220 to 370°C. The catalysts were pretreated with a stream of hydrogen in advance of a run. A gas chromatography was used for analyzing the hydrocarbons methane, ethylene, ethane, propylene, propane, butenes, butanes, total C5 hydrocarbons, and higher hydrocarbons (C6 to Cj0, not separated), as well as carbon monoxide, carbon dioxide and water. Alcohols and aldehydes could be detected by the gas chro-motography but were not found to be produced in sizable amounts. 

An apparatus incorporating four fixed-bed and two fluid-bed reactors was employed, as shown in Figure 1. These reactors were operated continuously at atmospheric pressure. 

On its way downwards, the liquid phase is of course depleted with respect to its more volatile component(s) and enriched in its heavier component(s). At the decisive locus, however, where both phases have their final contact (i.e., the top of the column), the composition of the liquid is obviously stationary. For a desired composition of the gas mixture, the appropriate values for the liquid phase composition and the saturator temperature must be found. This is best done in two successive steps, viz. by phase equilibrium calculations followed by experimental refinement of the calculated values. The multicomponent saturator showed an excellent performance, both in a unit for atmospheric pressure [18] and in a high-pressure apparatus [19, 20] So far, the discussion of methods for generating well defined feed mixtures in flow-type units has been restricted to gaseous streams. As a rule, liquid feed streams are much easier to prepare, simply by premixing the reactants in a reservoir and conveying this mixture to the reactor by means of a pump with a pulsation-free characteristic. 

Catalyst agitation in the reactor can by accomplished by stirring, shaking or any other means. The reaction can be run at atmospheric pressure as well as sub-atmospheric or elevated pressures as well. The only criteria to meet for the higher pressure reactions is the need to use a reactor and pressure transducer compatible with the elevated pressures and to have the pressure of the gas before the regulator, 7, higher than the reaction pressure. The reactor vessels shown in Fig. 6.6 are particularly suited for use at low pressures with this apparatus. 

The selective hydrogenation of C2 - C4 alkynes was studied at atmospheric pressure, using a fully computer-controlled flow apparatus. 0.5 g of catalyst was placed In a copper reactor tube (3/8" O.D.) between glass wool plugs. The catalyst was reduced prior to reaction In a stream of 50 % hydrogen in helium (40 ml/tnin) at 250 C for 4 hours. 

Temperature programmed reduction (TPR) of the calcined samples were performed in a RIG-100 In Situ Research Instruments catalyst characterization apparatus. The TPR experiments were performed in a quartz gas flow reactor, from room temperature to 1000°C, with a heating rate of 7.5 °C.min under a stream of 5% v/v H2 in argon (total flow rate 25 ml.min ) at atmospheric pressure. 

Isopropanol dehydration over AI2O3 calcined at different temperatures was studied in a pyrex glass steady state system. The fixed bed (50 mg) tubular reactor was operated at differential regime (% conversion<10), in the 423temperature range and atmospheric pressure. The feed was composed of a N2 (Praxair) stream saturated with isopropanol at room temperature. The analysis of effluents from the reactor was carried out by gas chromatography with a Gow-Mac Series 750 apparatus equipped with a thermal conductivity detector and a Porapak Q packed column. 

Screenings the apparatus consist of a fixed-bed reactor containing Ig of catalyst. Hydrocarbon feed (carbureactor containing 189 ppm RSH) and air (atmospheric pressure) are passed through the reactor with a space velocity of 1.2 h at room temperature. The residual mercaptan content was determined using the silver nitrate potentiometric method norm [23]. 

Methanol oxidation was carried out in a conventional flow apparatus at atmospheric pressure. The feed mixtures were prepared by injecting the liquid methanol into air flow with a Gilson 302 pump. The catalyst was diluted with inert carborundum (1 3 volume ratio) to avoid adverse thermal effects, and placed in a tubular pyrex reactor with a coaxially centred thermowell with thermocouple. The reactor outlet was kept at 403 K, to prevent condensation of liquid products and formaldehyde polymerization, and it was connected with multicolumn Shimadzu GC-8A gas chromatograph with thermal conductivity detector. The column system used (1.5m of Poropak N+1.5m of Poropak T+0.9m of Poropak R) could separate CO2, formaldehyde, dimethylether, water, methylformate, dimethoxymethane and formic acid. The last product was never detected. 

While these low-pressure reactor systems are useful for reactions run at pressures up to about 60 psig (depending on the size of the reactor) they are not adaptable for reactions run at atmospheric pressure. We have, however, designed an apparatus in which gas uptake can be automatically measured while keeping the pressure in the reactor constant at atmospheric (13). This is diagramed in Figure 9 with a picture shown in Figure 10. 

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