Ethylene epoxidation in a low-temperature parallel plate dielectric barrier discharge system with two frosted glass plates

Ethylene Epoxidation in a Low-Temperature Parallel Plate Dielectric Barrier Discharge System: Effect of Oxygen Source

“…The gap distance between the two electrodes was fixed at 7 mm. Microdischarge was generated by applying an alternating current (AC) across the electrodes at an applied voltage of 23 kV and a frequency of 500 Hz, which were previously found to be the optimum conditions . A domestic AC power (220 V, 50 Hz supply) was converted to high voltage AC by a three-step power supply system, as described previously .…”

“…Dielectric barrier discharge (DBD) is a type of nonequilibrium low temperature plasma that has high electron temperatures (10 4 –10 5 K) with a bulk gas temperature close to room temperature. , As a consequence, the energy consumption used for operating the plasma system for various chemical reactions is lower compared to conventional catalytic processes. Accordingly, DBD has been employed for several studies, including chemical synthesis, such as hydrogen (H 2 ) production by methane (CH 4 ) reforming − and ethylene epoxidation, − ozone generation, − soil remediation, − wastewater treatment, , and surface treatment. − …”

“…For the gas-phase ethylene epoxidation, the molar ratio of oxygen (O 2 ) to C 2 H 4 significantly affects the pathway reactions . Fundamentally, the oxidative combustion of hydrocarbons occurs with excess O 2 , while partial oxidation, especially ethylene epoxidation, markedly occurs under a lean O 2 condition. − ,, Both the type and amount of oxygen species have been reported to affect the chemical reactions. Studies of alternative oxidants in the form of various oxygen-containing molecules, such as nitrous oxide (N 2 O), O 2 , and hydrogen peroxide (H 2 O 2 ) were investigated for a number of chemical reactions, including propylene epoxidation. − Hence, N 2 O was, for the first time of its kind, investigated for the ethylene epoxidation reaction in the present study.…”

Plasma Catalytical Reactors for Atmospheric Gas Conversions

“…Therefore, it can support the adjustment of selectivity. This is observed by Chavadej et al , who varied the frequency of an AC‐corona discharge within the range of 100 – 700 Hz for the oxidation of benzene in air. It is observed, that higher frequencies lead to less total oxidation and less conversion of benzene, which tends to the formation of more CO. Less energy is transferred to the system intended by a smaller measured current.…”

“…One reason therefore might be the simple implementation of the annular DBD setup with a laboratory glass tube and the standard gas connections without the appearance of leackages. One example for the plate‐to‐plate setup is the ethylene oxidation in air with two frosted glass plates .…”