Influence of plasma reactor structure on methanol oxidation

Abstract

Abstract Plasma oxidation of methanol (CH 3 OH) in oxygen and nitrogen was investigated using two dielectric barrier discharge (DBD) reactors with or without Al 2 O 3 as a catalyst and using a DC circle‐to‐plate (CTP) reactor. An AC power supply was used for the DBD reactors to generate corona discharges. A DC power supply, a 20‐MΩ resistor, and a 100‐pF capacitor were used to yield pulselike discharges. CH 3 OH was oxidized to formaldehyde (HCHO), carbon monoxide (CO), and carbon dioxide (CO 2 ). HCHO was the main product when using DBD reactors and without Al 2 O 3 . CO was the main product when using the DBD reactor with Al 2 O 3 and CTP reactor. Al 2 O 3 could inhibit CH 3 OH further oxidation. The energy efficiency of the DBD reactors decreased with increasing power input and power density. The energy efficiency of the CTP reactor peaked with 7 g CH 3 OH/kWh that was three times as high as that with the DBD reactors at the same power input. Furthermore, the power density of the CTP reactor was higher than that of the DBD reactors, implying that the CTP reactor could be used for CH 3 OH oxidation with a small discharge space volume. © 2005 American Institute of Chemical Engineers AIChE J, 2005