Closed reactor

Figure A3.14.4. P-T ignition limit diagram for H2 + O2 system showing first, second and third limits as appropriate to a closed reactor. The first and second limits have similar positions in a typical flow reactor, for which there is also a region of oscillatory ignition as indicated.

The concept of macroscopic kinetics avoids the difficulties of microscopic kinetics [46, 47] This method allows a very compact description of different non-thennal plasma chemical reactors working with continuous gas flows or closed reactor systems. The state of the plasma chemical reaction is investigated, not in the active plasma zone, but... 

For steam jacketed, agitated closed reactor ketdes, the overall U usually will range from 40-60 Btu/hr (ft ) ( F). Of course, the significant variables are the degree or type of internal wall turbulence and the viscosity and thermal characteristics of the internal fluid. For water or other liquid cooling in the reactor jacket, the U value usually ranges from 20-30. 

A CVD reaction can occur in one of two basic systems the closed reactor or the open reactor (also known as close or open tube). The closed-reactor system, also known as chemical transport, was the first typetobeusedforthe purification of metals. It is a hybrid process which combines vapor-phase transfer with solid-state diffusion. As the name implies, the chemicals are loaded in a container which is then tightly closed. A temperature differential is then applied which provides the driving force for the reaction. 

As opposed to closed-reactor CVD, is the other CVD system is known as open-reactor or flowing-gas CVD, where the reactants are introduced continuously and flow through the reactor. Closed-reactor CVD is by far the most common system and will be referred to simply as CVD. It comprises three interrelated components ... 

Example 15.10 Use residence time theory to predict the fraction unreacted for a closed reactor governed by the axial dispersion model. 

Ethylene glycol reacts dangerously with sodium hydroxide at a temperature starting at 230°C a highly exothermic decomposition, which emits a lot of hydrogen occurs. If the reaction takes place in a closed reactor, the apparatus detonates systematically. 

Reaction run in batch configuration (in closed reactor) without water removal 85°C, 50 50 oUiMeOH 5% catalyst, 60 min. ... 

Let m moles of the gaseous substance AB be heated in a closed reactor of volume V. A state of equilibrium is reached by the time % moles of AB are dissociated into the constituents. Since 1 mole of AB dissociates into 1 mole of A and 1 mole of B, x moles of AB will yield % moles of A and x moles of B. Thus at equilibrium,... 

The adiabatic temperature increase (ATadiab) is defined as the temperature increase that is established in a reactive process system when the process goes to completion without heat or mass exchange with the environment (e.g., following complete failure of cooling in a closed reactor). 

A similar procedure was used to degrade aqueous azo dyes solutions (Red M5B and Blue MR) by means of Fenton s reagent in a stirred closed reactor. The effect of the catalyst amount (Fe ) was evaluated for an aqueous solution containing 250 mg f of Red M5B and 500 mg f of H2O2. It can be seen from Figure 2 (adapted from Swaminathan et al. 2003) that the minimal catalyst amoimt needed, for the maximum COD abatement for the dye solution, is about 10 mg f of Fe, shown in curve (a). 

Case I (selectivity yj = Pi/Sp. = f ([L]o/lM)o)[M]o=const.) describes the ligand control in catalytic systems using closed reactors (autoclaves, ampoules etc.) [MJo does not change during the reaction the product distribution is determined by the ligand to metal ratio. 

All reactions were run in a Parr stirred autoclave (Model 4561) at 1000 psi H2 and 200°C for 6h. A weighed quantity (0.5 g dry basis) of the catalyst, Ru/C or Ni/Re/C, was introduced into the reactor and reduced at 250 C and 200 psi H2 (Ru/C) or at 280°C and 500 psi H2 (Ni/Re/C) for 13 hours. After cooling, 100ml of solution (l.OM GO and O.l-l.OM KOH) was added to the closed reactor. For reactions in solvent mixtures, entries 1-4 in Table 2, the water/solvent ratio was 1/9 (v/v). When the solvent was either t-BuOH or 1,4-dioxane, 1.5 g of water was added to the solution to facilitate dissolution of KOH, because of its low solubility these solvents. Once steady state was achieved following heatup, samples were taken at 30 minute intervals for the first hour, and then hourly, and analyzed via HPLC. The HPLC column was a BIORAD Aminex HPX-87H run at 65 C with 5mM H2SO4 as the mobile phase at a flow rate of 0.6mFmin, using both UV (210 nm) and refractive index (RI) detection. 

The wetted surface area of the 2 m3 reactor during two-phase relief has been estimated as 8.6 m2. This is the full surface area of the bottom and the sides of the reactor because, if two-phase relief occurs, this whole area will be wetted inside the reactor with liquid. The heat input rate from the fire is estimated as 252 kW l For a closed reactor containing 793 kg of material, and using the average, specific heat capacity of 2.25 kJ/kg K, the effective rate of temperature rise due to the fire is given by ... 

This method116181 relies on emptying the reactor by two-phase relief in the time taken for the pressure to rise from the relief pressure to the maximum accumulated pressure in an adiabatic closed reactor. This time is defined as the Boyle time and is illustrated in Figure A5.2. 

The restrictions which apply at equilibrium can also be extended a small way to cover the behaviour near to equilibrium, i.e. at long but not infinitely long times in closed reactors. Even so these rules do not mean that closed... 

If a Safety Interlock System exists, describe what is to happen when shutdown is triggered for example, reactor feed MV closes, reactor vent MV opens, etc.)... 

Gas phase reactions at constant volume and temperature are routinely monitored by pressure measurements when the gas is assumed to behave ideally and a direct proportionality between pressure and concentration can be assumed, but the technique is much less commonly used for reactions in solution. If a gas is evolved or consumed in a reaction, it can be monitored continuously by the change in pressure when the reaction is investigated in a closed reactor at constant volume. An early example is the thermal decomposition of arenediazonium salts with evolution of N2 [61] ... 

After the reactor had been cleaned, evacuated and purged with N2, 1.29 g of 2,5-di-tert-butyl-l,4-benzoquinone (5.85 mmol) were added, taking care that the benzoquinone did not touch the ATR sensor. After the desired jacket temperature had been reached, a reference background infrared spectrum was recorded. Then, 19.2 mL dioxan, 8 mL EtOH and 8 mL tert-butyl hydroperoxide (70% solution in water, 58.5 mmol) were added, the stirrer was turned on to 400 rpm and the desired reaction temperature was set. After degassing the solution for 3 minutes with N2, Triton B (0.8 mL of a 40% solution in methanol, 1.78 mmol) was added within 24 seconds into the closed reactor to start the reaction. 

In chemical reaction engineering, an ideal batch reactor is defined as a closed reactor, meaning there is no addition and no removal of any components during the reaction time. The prototype of this reactor is the autoclave, where all reactants are charged into the reactor at the beginning of the operation (Figure 6.3). The reactor is then closed and heated to reaction temperature, the temperature at which the reaction is allowed to complete or at which a catalyst is added. After the reaction is completed, the reactor is cooled and discharged. It is now ready for a new cycle. 

There are many different physical scenarios to be considered. In the first category, we find scenarios that result from gas compression, such as by liquid transfer into a closed reactor or gas inlet from a line connected to the reactor. With such scenarios, two-phase flow is unlikely to occur. Other common physical scenarios are linked to unwanted heating of the reactor contents, either by fire or by inadvertently heating of the reactor by the heating system. In this case, two-phase flow may occur. 

Closed gassy system gas release in a closed reactor. 

The presence of the intermediate methane in the ethane and propane oxidation experiments, coupled with failure to detect ethane or ethene intermediates in the propane experiments constitutes indirect evidence that the reaction rate constants are in the order k >k >k, This order is confirmed by comparing Tablls°5fnlo tVlan t s rate constants calculated on the assumption of first order kinetics, decrease with percent reaction. This is presumably the consequence of the closed reactor conditions and for this reason, rate constants are not given in the tables. However, on average, the assumption of first order kinetics with respect to... 

Esterification reactions were carried out in a closed reactor with 10 mL of dried n-heptane containing suitable amounts of alcohol and acid. A molecular sieve (aluminum sodium silicate, type 13X BHD Chemicals) was used to removal water. The mixture was incubated at 37°C for 24 h with continuous shaking at 150 rpm. The effects of concentration of immobilized lipase (5-50 mg/mL) molar ratio of reactants (0.5-2.0), acid chain length... 

A stirred suspension of 5 g of (S)-5-(2-oxo-l,3-oxazolidin-4-ylmethyl)-3-[(2-toluen-4-sulphoniloxy)ethyl]-lH-indol-2-carboxylic acid ethyl ester in 30 ml of a 2 N solution of dimethylamine in ethanol was stirred at 50°C for 20 hours in a closed reactor. The solvent was evaporated to dryness, the residue dissolved in 20 ml of 2 N HCI and washed three times with 15 ml of dichloromethane. The washed aqueous phase was cooled and adjusted to pH 12 with a 40% sodium hydroxide solution and extracted three times with 20 ml of dichloromethane. The combined organic phases were washed with brine and dried above anhydrous sodium sulphate. The solvent was evaporated to dryness and the residue recrystallised from ethyl acetate to give 3.4 g (91%) of the title dimethylamine as a yellow solid. Melting point 67°-70°C. 

The high-pressure device is a microautoclave made of tantalum and located in a thermo-regulated oven as shown in Figure 2. It is a closed reactor with a constant volume of 140 cm3. The total expected pressure is about 80 bars for a temperature close to 280°C. Tantalum has been chosen as the reference material for the internal part of the reactor in order to avoid corrosion from the products under study. 

Actually, the technical synthesis of adipic acid dinitrile does not begin with, but proceeds via adipic acid diamide (D). In fact, it starts with the bis(ammoniumcarboxylate) A obtained from adipic acid (B) and two equivalents of ammonia. Upon heating in a closed reactor small amounts of the carboxylic acid and ammonia are regenerated from the salt A and react according to the Bac2 mechanism (Figure 6.24) to give diamide D. 

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