Study on n-hexadecane cracking with introducing water by pulsed discharge in liquid

Abstract

A hollow needle-plate pulsed plasma reactor was designed to figure out a suitable discharge type for heavy oil model compound (n-hexadecane) cracking. The characteristics of n-hexadecane under the action of pulsed discharge in liquid after the injection of water were explored. The results show that three types of discharge can be obtained through U-I waveform and discharge images: corona discharge, spark-like discharge, and spark discharge. Based on these discharge types, the influence of applied voltage and electrode distance on the liquid conversion rate and selectivity is further explored. Considering these two indicators, the electrode distance of 5.5 mm and spark-like discharge of 9–14 kV are the most suitable conditions. The conversion and the selectivity of treated liquid hydrocarbons are 5.27% and 75.42% when the duration time of plasma treatment is 7 min, respectively. According to the distribution of hydrocarbons in the liquid product, it is found that the formation of dodecane and pentadecane can be used as one of the signals of upgrading. This research provides a new method for heavy hydrocarbon cracking and discovers a new type of discharge between corona and spark discharge.