Experimental investigation of a non-catalytic cold plasma water-gas shift reaction

Abstract

Abstract This work explores the use of an atmospheric pressure, low temperature, cold non-thermal plasma (obtained by dielectric barrier discharge (DBD)) to achieve a water-gas shift (WGS) reaction (CO + H 2 O H 2 + CO 2 ). This work establishes the use of a DBD to generate hydroxyl radicals that initiate and enhance the WGS reaction at low temperatures. The effect of the steam to CO molar ratio (MR) and the gas residence time on the CO conversion ( X CO ) to H 2 is studied. The results show that, at an MR of 20, with 2600 ms of gas residence time and a plasma power of 70 W, a maximum CO conversion of 63 ± 4% can be achieved with an H 2 concentration of 48 ± 2 mol% in the product. Preliminary studies of reaction pathways for the enhanced hydrogen formation confirm the role of C formed from the CO 2 dissociation. A reaction mechanism for the plasma WGS reaction is proposed and the hydrogen yield is calculated.