Phosgene synthesis

Phosgene is used in the production of diisocyanates, starting materials for polyurethanes, and in other organic syntheses. Commercially, phosgene is obtained from carbon monoxide and chlorine 

An experimental study of kinetics of reaction (368) on activated charcoal (139) preceding our investigation was carried out at 30-65°C (i.e., at temperatures below those used in industrial reactors). This promoted us to reinvestigate the kinetics of this reaction (140). 

The utilization of a flow circulation system for laboratory experiments was made difficult by the toxicity of all three gases, CO, Cl2, and COCl2. For this reason, in contrast to other reactions, we studied reaction (368) in a closed system. The experimental apparatus was equipped with a circulation pump so that the gas mixture continuously passed through the catalyst bed in the reactor. The reaction rate was determined from the change in total 

The experiments were done at 70, 100, and 130°C and at pressures somewhat lower than atmospheric. Under these conditions reaction (368) is practically irreversible. Activated charcoal of the trademark Bayer AKT-4 ground to grain size 0.25-0.5 mm served as a catalyst. Estimation of the efficiency factor on the basis of the determination of the effective difusion coefficient of hydrogen in nitrogen or helium has shown that for this grain size the results of reaction rate measurements refer to the kinetic region. Estimation of relaxation time of the reaction rate from (67) showed the reaction to be quasi-steady at the condition of our experiments in the closed system. 

Activated charcoal is a hydrocarbon rather than an elemental carbon because it contains hydrogen chemically bound to carbon. We observed that when exposed to chlorine, activated charcoal evolves HC1 the substitution of hydrogen by chlorine, i.e., the reaction of the type 

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Example 3 Phosgene Synthesis Rate data were obtained by Potter... 

An Existing Distributed Small-scale Plant for Phosgene Synthesis... 

DuPont s phosgene synthesis in a micro reactor BASE S vitamin precursor synthesis developments in the bio field prognosis on market volume in 2000 [227]. 

Ajmera, S.K., Losey, M.W., Jensen, K.F., Schmidt, M.A. (2001) Microfabricated Packed-Bed Reactor for Phosgene Synthesis. AIChE Journal, 47, 1639-1647. 

K. F., Schmidt, M. A., Microfabricated packed-bed reactor for phosgene synthesis, AIChEJ. 2001, 47,1639-1647. 

Phosgene synthesis from CO and Cl2 in a multitubular reactor (Fig. 19-225). The activated carbon catalyst is packed inside the tubes with water on the shell side. Reaction by-products include CCl4. The temperature profile in a tube (shown in the figure) is characterized by a hot spot. The position of the hot spot moves toward the exit of the reactor as the catalyst deactivates. 

Example 3 Phosgene Synthesis Rate data were obtained by Potter and Baron (Chem. Eng. Prog, 47, 478 [1951]) for the reaction CO (A) + Ch (B2) COCI2 (C) at 30.6. Three correlations of approximately equal statis-... 

Petroleum refinery flowsketch, 26 PER (plug flow reactor), 55,558 comparison with CSTR, complex reactions, 569 volume ratio to CSTR, 571 Phase diagrams nitrotoluene isomers, 544 salt solutions, 526 use of example, 528 Phenol bv the chlorbenzene process, 34 Phosgene synthesis, 594 PhthMic anhydride synthesis, 593 PID (proportional-integral-derivative) controllers, 41, 42... 

Temperature profiles, reactors ammonia synthesis, 582, 584 cement kiln, 590 cracking of petroleum, 595 endo- and exothermic processes, 584 jacketed tubular reactor, 584 methanol synthesis, 580 phosgene synthesis, 594 reactor with internal heat exchange, 584 sulfur dioxide oxidation, 580... 

A reaction has an elementary rale law if the reaction order of each species is identical with the stoichiometric coefficient of that species for the reaction as written. For example, the oxidation of nitric oxide presented above has an elementary rate law under this definition, while the phosgene synthesis reaction does not. Another example of this type of reaction with an elementary rate law is the gas-phase reaction between hydrogen and iodine to form hydrogen iodide ... 

Phosgene Synthesis The global reaction CO + Cl2 COCl2 proceeds through the following free radical mechanism ... 

A TYPICAL SPECIFICATION FOR CARBON MONOXIDE SUITABLE FOR PHOSGENE SYNTHESIS [311a]... 

Alternatively, phosphine sulfides and/or phosphine seienides have been screened as active catalysts for phosgene synthesis from CO and Clj [2076]. In one example, a mixture of liquid dichlorine, CCl, and PHjS (0.5%, based on the solvent) was loaded into an autoclave under a CO pressure of about 3 MPa. The reaction, maintained at 10 C for 3 h, resulted in a yield of phosgene of 97%. 

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