Steam enhanced carbon dioxide reforming of methane in DBD plasma reactor

摘要

Considering the inevitable high energy input to implement the CO_2 reforming of methane under high-temperature operation using conventional catalysis method, the low temperature conversion of CO_2 and methane in the coaxial dielectric barrier discharge (DBD) plasma reactor was investigated in this work. Steam was introduced to enhance the CO_2 reforming of methane with synergetic catalysis effect by cold plasma and catalyst. The experimental results showed that a certain percent of steam could promote the conversion of both CH_4 and CO_2. Meanwhile, the carbon deposition was evidently reduced compared with the dry reforming of methane. With the increase of steam input, the steam reforming occurred predominantly. As a result, the hydrogen volume percentage in the product gases increased. In this way, the products with different H_2/CO ratio could be achieved by changing the mole ratio of CH_4/CO_2/H_2O at the reactor inlet. In particular, when the mole ratio of H_2O/CH_4 increased to almost 3 corresponding to the pure steam reforming process, the conversion of CH_4 reached almost 0.95 and the selectivity to H_2 was almost 0.99 at 773K.