Deacons process

Deacon equilibrium Deacon process Deacon reaction Deactivating groups Deactivation... 

The rate of this reaction is significantly enhanced over catalysts such as copper chloride which is the basis for the Deacon process for producing CI2 from HCl. The relationship between the equilibrium constant and the temperature in Kelvin for the reaction is expressed by equation 19. 

In oxychlorination, ethylene reacts with dry HCl and either air or pure oxygen to produce EDC and water. Various commercial oxychlorination processes differ from one another to some extent because they were developed independentiy by several different vinyl chloride producers (78,83), but in each case the reaction is carried out in the vapor phase in either a fixed- or fluidized-bed reactor containing a modified Deacon catalyst. Unlike the Deacon process for chlorine production, oxychlorination of ethylene occurs readily at temperatures weU below those requited for HCl oxidation. 

Cataljdic reactions performed in fluid beds are not too numerous. Among these are the oxidation of o-xylene to phthalic anhydride, the Deacon process for oxidizing HCl to CI2, producing acrylonitrile from propylene and ammonia in an oxidation, and the ethylene dichloride process. In the petroleum industry, cataljdic cracking and catalyst regeneration is done in fluid beds as well as some hydroforming reactions. 

Again, if we divide the square of the equilibrium constant for hydrogen chloride by that for steam we obtain the equilibrium for the Deacon process of chlorine manufacture ... 

Airco A modification of the Deacon process for oxidizing hydrogen chloride to chlorine. The copper catalyst is modified with lanthanides and used in a reversing flow reactor without the need for external heat. Developed by the Air Reduction Company from the late 1930s. U.S. Patents 2,204,172 2,312,952 2,271,056 2,447,834. 

Hasenclever An improvement to the Deacon process for oxidizing hydrogen chloride to chlorine, in which the hydrogen chloride is first dried with concentrated sulfuric acid. 

Kel-Chlor [Kellogg Chlorine] A non-catalytic version of the Deacon process for making chlorine by oxidizing hydrochloric acid, in which nitrosyl sulfuric acid and nitrosyl chloride are intermediates and concentrated sulfuric acid is used as a dehydrating agent ... 

The process was complicated by the formation of calcium manganite, CaMn206, known as Weldon mud. Invented by W. Weldon in 1866 and developed at St. Helens from 1868 to 1870. Operated in competition with the Deacon process until both were overtaken by the electrolytic process for making chlorine from brine. Weldon mud has been used as a catalyst for oxidizing the hydrogen sulfide in coal gas to elemental sulfur. 

The Deacon process for production of chlorine involves the gas phase reaction... 

As noted IN the preceding chapter, almost all elemental chlorine is made as a by-product of caustic soda production, although the obsolete Deacon process of 1868 has been revived (with improvements) for recycling CI2 onsite in plants where chlorination of hydrocarbons forms gaseous HC1, an objectionable waste product ... 

The reaction is exothermic (see Exercise 12.1), but, since it is very slow, a catalyst is necessary. Nitric oxide, once again, can serve as an oxygen carrier, as in the lead chamber process (Section 10.2) and in reaction 10.8, where (CH3)2S generated in the kraft process is converted to DMSO. Even so, at the elevated temperatures required, reaction 12.1 needs to be forced to completion by absorption of the steam in concentrated sulfuric acid or some other desiccant. In variants of the Deacon process, copper chloride acts as the catalyst or as an intermediate for chlorine regeneration. 

From the data in Appendix C, calculate (a) the enthalpy of reaction and (b) the equilibrium constant for reaction 12.1 (the Deacon process) at standard conditions, (c) Above what temperature does the reaction cease to be thermodynamically favored (i.e., AG° becomes positive), if ACp can be ignored ... 

Ferric Orthoarsenite, FeAs03, was described by Reichard 9 as a rust-yellow powder obtained by adding potassium tetrarsenite to a dilute aqueous solution of ferric chloride. A substance of similar chemical composition has been found in a crystalline deposit formed during the Deacon process of making chlorine. The crystals of the pure salt are monoclinic, their crystallographic elements being 10... 

Figure 17 Operating concept of an unsteady-state Deacon process for chlorine recycling.

U. Nieken, O. Watzenberger, Periodic operation of the Deacon process. 

Closer inspection reveals that this somewhat superficial and largely self-evident evaluation is by no means exhaustive, and concrete experimental studies on adsorptive reactors expose both additional pitfalls and benefits that are often specific for a particular reaction system and decisive for the success or otherwise of adsorptive reactor concepts. Before illustrating this point with the help of four examples with which the author is personally acquainted - the Claus reaction, the direct hydrogen cyanide synthesis from ammonia and carbon monoxide and, to a lesser extent, the water-gas shift reaction and the Deacon process - it is worthwhile briefly reviewing other reaction systems for which the potential of adsorptive reactors has been examined (Tab. 7.2). 

The Deacon process for the heterogeneously catalyzed oxidation of hydrogen chloride to chlorine at around 350 °C represents an energetically and possibly... 

Due to the volatility of some of the chlorides present the temperature must be maintained below 400 °C, which limits the scope for accelerating the rate-limiting oxidative regeneration step by increasing the temperature [19], For the unsteady-state adsorptive Deacon process the catalyst composition had to be modified to reduce volatility and enhance the oxidative of the reaction phase. 

The suitability of regenerating the adsorbent by reactive means can only be judged on a case-by-case basis. With some adsorptive reactors - for example, for the total denitrification of flue gases or the unsteady-state Deacon process - the reactive regeneration is the object of the exercise. The prerequisite that the adsorbate does not undergo further reaction and is adsorbed in reasonable amounts at moderate temperatures means that the molecules being adsorbed tend to be small and stable, and thus do not lend themselves to reactive regeneration. 

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