Constant rate cylinder reactor

Two purification processes have been employed. In one of these the main condenser is immersed in an oil bath, which can be heated to 220°C after condensation, to allow the mixed chlorides to melt and flow to a displacer unit. This consists of a vertical steel pipe, also at 220°C, about 5 ft long and 3 in. diameter. A steel cylinder is slowly fed from the upper part of the tube to the lower part, the tube being filled with liquid chlorides, so as to displace the latter at a constant rate. The liquid chlorides are then vapourized, as they flow from the displacer unit through a short section of heated pipe, and passed with hydrogen into a horizontal steel reactor about 4 ft long by 9 in. diameter. This reactor is heated to 350 C and allows the ferric chloride impurity to be reduced to the involatile ferrous chloride, i.e. 

Example 4. Depolymerization under Pressure.62 PET resin was depolymerized at pressures which varied from 101 to 620 kPa and temperatures of 190—240° C in a stirred laboratory reactor having a bomb cylinder of2000 mL (Parr Instrument) for reaction times of 0.5, 1, 2, and 3 h and at various ratios of EG to PET. The rate of depolymerization was found to be directly proportional to the pressure, temperature, and EG—PET ratio. The depolymerization rate was proportional to the square of the EG concentration at constant temperature, which indicates that EG acts as both a catalyst and reactant in the chain scission process. 

Here, e is the maximum electron density in the reactor, r is the radial position in the reactor, rt is the radius of the reactor cylinder, z is the axial coordinate, L is the height of the reactor (distance between the two electrodes), and J0 is the zero-order Bessel function of the first kind. Clearly, the electron density is a maximum at the center of the reactor (r = 0, z = L/2). The rate constants are ... 

The design of a typical commercial reactor for large-scale production of materials is similar to the laboratory setup, except that the capacity of the former is larger, up to 30 liters. Since the synthesis of materials produced commercially is well understood, most reactors are not equipped with optical windows to monitor the process. A schematic diagram of such a reactor is shown in Fig. 5. Typically, it is a thick-walled stainless steel cylinder that can be water cooled (Borovinskaya et al., 1991). The green mixture or pressed compacts are loaded inside the vessel, which is then sealed and evacuated by a vacuum pump. After this, the reactor is filled with inert or reactive gas (Ar, He, Nj, O2, CO, C02). Alternatively, a constant flow of gas can also be supplied at a rate such that it permeates the porous reactant mixture. The inner surface of the reactor is lined with an inert material to... 

Fresh catalyst samples were activated prior to each kinetic experiment under dry conditions. The catalyst (5 g) was placed in the reactor and a silver ring packing was installed between the reactor cylinder and the lid. The catalyst was heated to the desired temperature at a rate of 5 °C/min under hydrogen flow (0.5 dm /min). The hydrogen flow (0.75 dm /min) was continued at elevated terrqjerature for 1 h. After this activation, the gas flow was maintained constant, the heating jacket was removed and the reactor was cooled down. 

For a particular experiment in a packed catalytic tubular reactor, the chemical kinetics can be approximated by a zeroth-order rate law where the best value for the zeroth-order rate constant is calculated via the formalism on pages 459 and 460. At what value of the intrapeUet Damkohler number Aa. intrapellet does reactant A occupy 75% by volume of the catalyst if the porous pellets are (a) spherical, (b) long cylinders, and (c) wafer-like ... 

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