Highly selective catalysts for the oxidative dehydrogenation of ethane have been developed at the Zelinsky Institute

Ethylene is the base molecule for the production of a wide range of important industrial chemicals such as polyethylene, vinyl chloride, ethylene oxide, ethylene glycol, ethylbenzene, styrene, and ethanol. The main methods for producing industrial ethylene are steam cracking and thermal cracking of naphtha, liquefied petroleum gas or hydrocarbons. Cracking is one of the most energy-intensive and environmentally unfriendly processes in the modern chemical industry. The key challenge of our time is to develop approaches that can reduce the environmental impact of large-scale chemical production. In this regard, one of the most promising processes for the energy efficient and highly selective production of olefins is the catalytic oxidative dehydrogenation of light alkanes using O2 and CO2 oxidants. The technology for producing ethylene using CO2 as a mild oxidant is preferable.

Scientists from the Laboratory of Heterogeneous Catalysis and Processes in Supercritical Media of the ZIOC have developed new selective heterogeneous iron-chromium catalysts supported on a Sibunit® carbon carrier for the process of oxidative ethane dehydrogenation (ODHE) using CO2. A prerequisite for the development of heterogeneous catalysts was the discovered fact that during long-term operation of a catalytic flow-through tubular reactor made of stainless steel, active Fe, Cr, Ni oxide phases are formed on the inner wall for the direct non-oxidative dehydrogenation of light hydrocarbons into the corresponding olefins. The phase composition of the inner surface of the steel reactor was carefully analyzed by SEM and XFA using synchrotron radiation methods. Based on these data, new selective heterogeneous Fe-Cr/C catalysts for the oxidative dehydrogenation of ethane were developed using CO2 as an oxidizing agent at temperatures of 650-750°C. A detailed study of the catalyst by physicochemical methods (XRD, magnetometry, XPS, high-resolution TEM) before and after the reaction showed the formation of an iron chromite FeCr2O4 phase, which determines the activation and entrainment of CO2 in ODHE.

Source:

Igor I. Mishanin, Tatyana V. Bogdan, Aleksey E. Koklin, Viktor I. Bogdan. Design of highly selective heterogeneous catalyst for CO2-mediated ethane oxidative dehydrogenation based on nonoxidative catalysis in stainless-steel reactor. Chem. Eng. J., 2022, 446, 137184. DOI: 10.1016/j.cej.2022.137184.