Photo-induced ignition phenomenon of carbon nanotubes by Xenon pulsed light: Ignition tests analysis, automotive and new potential applications, future developments

Abstract

The possibility to use carbon nanotubes (CNTs) enriched with a certain amount of metal nanoparticles for photo-inducing the combustion of liquid fuel sprays, gaseous and solid fuels was investigated in different research works. CNTs photo-ignition phenomenon has been used to trigger the combustion of different fuel typologies, demonstrating better features compared with those obtained by employing a traditional spark-plug. These improvements are due to the presence of distributed ignition nuclei inside the combustion chamber, so obtaining better values of the peak pressure, ignition delay and combustion duration. In this work, the CNTs photo-ignition phenomenon has been analyzed in order to find the minimum energy values needed to trigger the ignition, by varying the light pulse parameters and the nanoparticles concentration, Multi Wall CNTs (MWCNTs)-ferrocene, by weight. Afterwards, the results of combustion processes, triggered by using the nanoparticles, are shown comparing them with those obtained by means the spark plug and with results already published related to other fuel typologies. Hence, an overview of the possible applications of this photo-ignition phenomenon, beside that of the automotive field, is presented, also considering the disadvantages of the Xe-lamp based triggering system. Therefore, after a critical discussion on the light source typology until now used (Xenon lamp), by reporting the possible contraindications deriving from the use of this light source in most of the applicative fields, a solution is here proposed. It involves the substitution of the Xe lamp with LED sources, showing also the related experimental setup. This solution is also strengthened by the our experimental observations of CNTs photo-ignition by using high-power white LEDs as light source, never reported up to now in the literature, and by better characteristics of adaptability, robustness, easy driving and benefits provided by the LEDs rather than the Xenon lamp.

Improved Photo-Ignition of Carbon Nanotubes/Ferrocene Using a Lipophilic Porphyrin under White Power LED Irradiation

“…In fact, the solution adopted in this research work undergoes huge luminous intensity leakages (about 70% with respect to the luminous intensity emitted from “naked” LED) due to the high F-Number, namely the ratio between lens’ focal length and diameter (because of the small dimensions of used lenses). Therefore, a trade-off is needed between the high energy densities, obtained by collimating the emitted light as much as possible, and the luminous intensity leakages [ 41 ].…”