Hydrogen Enrichment of Low-Calorific Fuels Using Barrier Discharge Enhanced Ni/γ-Al_2O_3 Bed Reactor: Thermal and Nonthermal Effect of Nonequilibrium Plasma

摘要

We have developed a dielectric barrier discharge (DBD) and catalyst hybrid reactor for reforming low-calorific fuels such as biogas at low temperature (300-500℃). This technique allows the use of low-temperature thermal energy wasted from various industries, which ultimately provides a variety of energy utility options. The idea behind the project is that radicals produced by DBD can be decomposed at much lower temperatures than in a normal reforming condition. However, the situation becomes even more complicated because DBD enhances chemical reactions in different ways: (1) Excited species, radicals, and ions decompose on the catalyst at a lower temperature than the stable molecule. (2) Byproducts such as acetylene and ethane decompose at lower temperatures than methane. (3) Heat that is generated by DBD also enhances regular catalytic reforming. A mechanistic study of steam reforming in a plasma hybrid reactor was performed to distinguish their respective contributions to the synergistic effect. Results are discussed on the basis of the catalyst bed temperature, which was measured accurately with an infrared camera with and without DBD. Thermal and nonthermal effects of DBD on the catalytic reforming of methane are discussed extensively.