Ceramics in non-thermal plasma discharge for hydrogen generation

Recent interest in hydrogen as an energy source has resulted in development of new technologies such as non-thermal plasma processing of natural gas. We report the development of a process yielding hydrogen from natural gas that generates no green house gases and thus meets the Kyoto accord targets.; In this process, natural gas is treated in a dielectric barrier discharge (DBD) yielding hydrogen and solid carbon according to the following reaction: CH4 (g) → 2H2 (g) + C (s). The direct cracking of the hydrocarbon is possible if the natural gas is injected in the plasma zone, created by the presence of a dielectric ceramic material.; It was found that the dielectric material plays an important role on plasma intensity. The change in ceramic properties affects the parameters of the discharge. It was discovered that the number of micro-discharges increased when a ceramic with a higher dielectric constant was used. Furthermore, the ceramic relative permittivity or dielectric constant has a direct influence on the hydrogen yield.; However, the challenge is that when using a commercial high dielectric ceramic as barrier they tend to break in the plasma environment. In the attempt of improving the process efficiency medium permittivity dielectric ceramics (9 < K' <166) were fabricated and successfully tested in the discharge reactor. A broad variety of ceramics (from low to high permittivity) were tested and the results suggested that the CH4 conversion using high dielectric constant barrier is much higher than using conventional barrier material such as A12O3.