The Deacon Process

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

Scheele s discovery of chlorine in 1774 was soon followed by its use to bleach cotton and linen. The Deacon process, which made use of one of the first indus- 

---

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... 

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... 

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). 

Industrial catalysis is an old practice. Catalysts have always been used in the production of wine and beer. Among the first industrial catalytic processes are a few inorganic oxidation processes, viz. the Deacon process (oxidation of HC1 into CI2) and the production of sulphuric acid. These processes were developed before a scientific basis of chemical reactivity was established. Only after the formulation of the theory of chemical equilibria by van t Hoff did a framework for catalyst development become available. This had a major impact on the development of a process for the synthesis of ammonia at the beginning of the twentieth century, allowing a systematic, scientifically based search for a good catalyst to be performed. It also initiated the development of chemical process engineering as we know it today. 

The anhydrous salt has been found as a deposit m the Deacon process for the preparation of chlorine, in the form of black prismatic crystals, belonging to the monoclmic system. Its crystallographic elements are —... 

An arsenate containing copper—namely, CuFe4As4017 or CuO. 2Fe203.2As205—has been found m the form of rhombic crystals as a deposit during the manufacture of chlorine by the Deacon process.4... 

Industrial catalysis is an old practice. Catalysts have always been used in the production of wine and beer. Among the first industrial catalytic processes are a few inorganic oxidation processes, viz. the Deacon process (oxidation of HCl into CI2) and the production of sulphuric acid. These processes were developed... 

The Deacon process solved these problems by replacing manganese dioxide by air as the oxidizer (Eq. 8.55). Further tuning of the Deacon process resulted in the development of the Kel Chlor Cu/heat... 

Another solution, proposed for a long time, consists in reconvening the hydrochloric acid to chlorine by the Deacon process, which can be improved and inserted into the installation scheme variant suggested by Shell). The past two decades, however, have witnessed the simultaneous development of many processes for the direct oxychlorinatkm of ethylene, designed to perform such an operation in situ. They have fed to the construction of most of the large plants currently in operation worldwide. 

The Deacon process for the manufacture of chlorine from hydrochloric acid is a scientific method, whereby hydrochloric acid gas and air are passed over hot brick-work impregnated with copper salts. The products are chlorine gas and water, the copper salts acting merely as carriers of oxygen. The only losses are that of the hydrogen of the hydrochloric acid and the oxygen of the air. 

The electro-motive force of the hydrogen-chlorine gas cell is well known from this the dissociation of hydrochloric acid gas may be derived, knowing the HCl-vapour pressure of the solutions used. With the further assistance of the equilibrium in the Deacon process,... 

---