Promotion of hydrogen production by resonant excitation of vibrational levels using spectrally controlled thermal radiation

Abstract

The surface grating technologies enable to control the thermal radiation spectrum. We are applying this technique to promote the chemical reaction to produce hydrogen in the methane steam reforming process by spectrally resonant thermal radiation. The thermal radiation spectrum is adjusted to vibrational absorption bands of methane and water molecules near 3 μm by making a two-dimensional surface grating of period Λ=2.6 μm on the radiative surface. By matching the peak of thermal radiation to the absorption bands of gases, it is clearly observed that the hydrogen production is promoted five times as much as the case without spectrally resonant thermal radiation by the optical excitation of vibrational energy levels of molecules. From a series of experiments and analysis, it is suggested that radiative gas effectively excited the molecules up of high energy vibrational and rotational levels, and this lead to the high production rate of hydrogen in methane steam reforming process.