Heterogeneous liquid discharge cracking of n-hexadecane as a heavy oil model compound: A way to generate plasma in liquid hydrocarbons at low voltage

Abstract

Plasma is an excellent way of coupling renewable power resources and poor-quality heavy oil resources into high value petrochemicals. In order to achieve discharge in liquid hydrocarbons under low-voltage operating conditions, it was proposed a new liquid-phase discharge mode - heterogeneous liquid discharge. The aqueous-phase feedstock was injected into n-hexadecane as a heavy oil model compound through a pin electrode, and plasma was generated directly in the liquid feedstocks at room temperature, atmospheric pressure, and low voltage to achieve the in-situ reforming of n-hexadecane and the generation of syngas, C2 hydrocarbons, and other high value-added chemicals. The effects of injection of water and ethanol solution on the gaseous and liquid products, and feedstocks conversion were discussed, and the distribution of various products was explored in detail. Gas production increased with the concentration of injected ethanol up to a maximum of 110.8 mL/min. A n-hexadecane conversion of 2.0% was obtained on injection of 50% ethanol, 4.56 kV, and discharge for 2 min. Varying the ethanol concentration can regulate the composition of the product. The auxiliary effects of water and ethanol on n-hexadecane cracking and the origin of the main gaseous products were examined in the mechanistic analysis section.