1,2-Dichloroethane production by two-step oxychlorination reactions in a fluidized bed reactor

Go, Kang Seok; Kim, Yun; Son, Sung Real; Kim, Sang Done

doi:10.1016/j.ces.2009.02.052

Cited by 20 publications

(5 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ethylene oxychlorination is widely used in the industry, owing to the significant economic benefits by using cheap and abundant feedback and waste HCl produced in EDC cracking. CuCl 2 / γ-Al 2 O 3 -based catalysts are effective in catalyzing ethylene, HCl, and oxygen to produce EDC in ethylene oxychlorination . It has been proved that the reaction follows a three-step redox mechanism where copper is cycled by Cu(II) reduction and Cu(I) oxidation. − …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cluster-Size-Dependent Interaction between Ethylene and CuCl₂ Clusters Supported via γ-Alumina

Fenes

et al. 2020

J. Phys. Chem. C

View full text Add to dashboard Cite

Alumina-supported copper chloride serves as an industrial catalyst for ethylene oxychlorination, resulting from its high activity and selectivity. A better understanding of the detailed active site structure and reaction mechanism is highly desired. The present work aims to explore the dependence of the structure of active sites and the adsorption of ethylene on differently sized (CuCl 2 ) n (n = 1−4) clusters supported by γ-Al 2 O 3 . The effect of the support facets (i.e., ( 110) and ( 100) surfaces) on the interface structures between the active component CuCl 2 and the support was also investigated. The stronger CuCl 2 −support interaction was found on the (110) surface compared to the (100) surface, which is attributed to the stronger Lewis acidity of Al of the (110) surface. The adsorption strength of (CuCl 2 ) n) (n = 1−4) clusters becomes weak with the increment of cluster size on the (110) surface. The cluster size has a profound influence on the interaction between ethylene and the clusters. Ethylene binds to a copper atom on the small clusters (i.e., CuCl 2 and (CuCl 2 ) 2 ), while it extracts two chlorine atoms to form dichloroethane from the large clusters (i.e., (CuCl 2 ) 3 and (CuCl 2 ) 4 ), which explains the high activity of catalysts with high loadings upon exposure to ethylene. The effects of cluster size and alumina facets on the short d-band center and the Bader charge of the active sites result in the distinct formation energy of the chlorine vacancy and the interaction energy between C 2 H 4 and the clusters. Thus, an improved catalyst could be achieved by the modification of the surface electronic structure via finetuning the support or adding promoters.

show abstract

Section: Introductionmentioning

confidence: 99%

“…CuCl 2 / γ-Al 2 O 3 -based catalysts are effective in catalyzing ethylene, HCl, and oxygen to produce EDC in ethylene oxychlorination. 4 It has been proved that the reaction follows a three-step redox mechanism where copper is cycled by Cu(II) reduction and Cu(I) oxidation. 5…”

Section: Introductionmentioning

confidence: 99%

Cluster-Size-Dependent Interaction between Ethylene and CuCl₂ Clusters Supported via γ-Alumina

Fenes

et al. 2020

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…In the oxychlorination process, gaseous ethylene, HCl, and air react together with the CuCl 2 /γ-Al 2 O 3 -based catalyst in a fixed or fluidized bed reactor in a temperature range of 217–257 °C and a 5–6 atm pressure range following eq . ,, The CuCl 2 /γ-Al 2 O 3 catalyst is effective in ethylene oxychlorination (eq ) because CuCl 2 can catalyze the conversion of HCl to chlorine. Further, it has been shown that the overall oxychlorination reaction (eq ) is catalyzed by a highly dispersed CuCl 2 phase following a three-step redox mechanism (eqs –): − …”

Section: Introductionmentioning

confidence: 99%

Highly Active and Stable CeO₂-Promoted CuCl₂/Al₂O₃ Oxychlorination Catalysts Developed by Rational Design Using a Rate Diagram of the Catalytic Cycle

et al. 2016

View full text Add to dashboard Cite

In this study, we have developed a method to predict the steady-state rate and Cu oxidation state during ethylene oxychlorination from a reaction rate diagram of the individual steps involved in the catalytic oxychlorination cycle. The steady state of the redox cycle is represented by a cross point of the reaction rates of the reduction and oxidation steps as a function of the Cu2+ in the rate diagram. Transient kinetics of elementary reactions and steady-state kinetics of the overall catalytic cycle were investigated in an operando study using combined mass and UV–vis-NIR spectrophotometry. The catalytic consequence of the promoters was then evaluated in terms of reduction and oxidation activity as well as number of active sites, site activity, and the catalyst oxidation state at steady state. Results revealed that the neat CuCl2 catalysts operated at low Cu2+ at the steady-state conditions with stoichiometric feed composition, as a result of relatively low oxidation rate of Cu1+. As a consequence of a high content of Cu1+, ethylene conversion and selectivity are low, and the catalyst deactivates rapidly. By the promotion of the CuCl2 catalyst by K, the reactor operates at a high Cu2+ concentration with much improved stability as a result of enhanced oxidation rate, but the catalyst has low activity due to significantly reduced reduction rate. Therefore, the rate diagram has been applied as a tool for a rational design of the CuCl2-based oxychlorination catalysts, and Ce was proposed as the promoter due to its high promotion to the oxidation and low reactivity with Cu ions. It was found that the activity of the Ce-promoted catalysts increased 8 times compared to the neat CuCl2 catalyst and moreover significantly improved the stability for the oxychlorination catalyst at steady state, due to the enhancement of both the rates of the reduction and oxidation. It is anticipated that the methodology developed here paves the way for a general method for catalyst design of heterogeneous catalysts where the catalyst undergoes oxidation state changes, in particular in redox reactions.

show abstract

“…The extent of the reduction is affected by the stoichiometric relation of the reaction and the content of inert gas in the feed. Go et al10 have reported that the total flow, which was 60% inert gas, was needed to avoid defluidization and maintain the stable fluidization state in the oxidation stage of two‐step oxychlorination of ethylene.…”

Section: Introductionmentioning

confidence: 99%

Analysis of fluidization quality of a fluidized bed with staged gas feed for reactions involving gas‐volume reduction

et al. 2010

View full text Add to dashboard Cite

A significant defluidization occurs when carrying out reactions involving a decrease in gas volume in a fluidized catalyst bed. The cause of this phenomenon is a decrease in the gas velocity in the emulsion phase below the minimum fluidization velocity. Fluidization quality is improved by a staged gas feed when hydrogenation of CO 2 is carried out. To evaluate the experimental results, two parameters are introduced; gas-volume reduction rate and gas-volume ratio. Fluidization quality and defluidization zone are indicated as a map using these parameters. The vertical distributions of these parameters are calculated using a reactor model to obtain operating lines. The calculation shows that fluidization quality can be improved by operating the reactor by avoiding the operating lines of the defluidization zone in the map. For this purpose, it is required to control the gas-volume ratio at a level near unity and maintain the gasvolume reduction rate below 0.01/s.

show abstract

1,2-Dichloroethane production by two-step oxychlorination reactions in a fluidized bed reactor

Cited by 20 publications

References 8 publications

Cluster-Size-Dependent Interaction between Ethylene and CuCl₂ Clusters Supported via γ-Alumina

Cluster-Size-Dependent Interaction between Ethylene and CuCl₂ Clusters Supported via γ-Alumina

Highly Active and Stable CeO₂-Promoted CuCl₂/Al₂O₃ Oxychlorination Catalysts Developed by Rational Design Using a Rate Diagram of the Catalytic Cycle

Analysis of fluidization quality of a fluidized bed with staged gas feed for reactions involving gas‐volume reduction

Contact Info

Product

Resources

About

1,2-Dichloroethane production by two-step oxychlorination reactions in a fluidized bed reactor

Cited by 20 publications

References 8 publications

Cluster-Size-Dependent Interaction between Ethylene and CuCl2 Clusters Supported via γ-Alumina

Cluster-Size-Dependent Interaction between Ethylene and CuCl2 Clusters Supported via γ-Alumina

Highly Active and Stable CeO2-Promoted CuCl2/Al2O3 Oxychlorination Catalysts Developed by Rational Design Using a Rate Diagram of the Catalytic Cycle

Analysis of fluidization quality of a fluidized bed with staged gas feed for reactions involving gas‐volume reduction

Contact Info

Product

Resources

About

Cluster-Size-Dependent Interaction between Ethylene and CuCl₂ Clusters Supported via γ-Alumina

Cluster-Size-Dependent Interaction between Ethylene and CuCl₂ Clusters Supported via γ-Alumina

Highly Active and Stable CeO₂-Promoted CuCl₂/Al₂O₃ Oxychlorination Catalysts Developed by Rational Design Using a Rate Diagram of the Catalytic Cycle