Effect of O2/n-C5H12 Ratio on Oxygenates Production from Plasma N-pentane Partial Oxidation

Abstract

Objective: Non-thermal plasma is a promising method for producing clean fuels. This work provides a deeper understanding of the impact of O2/n-C5H12 ratio on the partial oxidation of n-pentane from both physical and chemical perspectives. Moreover, this work offers insight into improving fuel combustion efficiency and technical support for the preparation of clean fuels. Methods: An experimental system based on dielectric barrier discharge plasma was established. The discharge characteristics and product generation status of n-pentane partial oxidation were measured by changing the concentration of oxygen and n-pentane to evaluate different O2/n-C5H12 ratios. Results: Research on discharge characteristics showed that the O2/n-C5H12 ratio did not affect the discharge mode, and typical Lissajous shapes were present at different ratios. Changing the O2/n-C5H12 ratio affected the oxygen concentration, average electron energy or electron density, and background temperature. As the O2/n-C5H12 ratio increased, the conversion of the n-pentane partial oxidation reaction increased. However, changing the O2/n-C5H12 ratio did not affect the type of generated products. The oxygenates exhibited a volcano curve, and an O2/n-C5H12 ratio of 1.00 achieved the highest selectivity of 35.1%. As the O2/n-C5H12 ratio continued to increase, the selectivity of oxygenates decreased and the selectivity of CO2 increased. This was potentially due to a shift from partial oxidation toward complete oxidation, which led to the generation of secondary pollutants. Thus, higher O2/n-C5H12 ratios were not conducive to clean fuel production and environmental friendliness. Conclusion: In the partial oxidation of n-pentane, the highest clean fuel production rate was achieved when the O2/n-C5H12 ratio was 1.00. When this ratio exceeded 1.00, the reaction shifted toward complete oxidation, producing secondary pollutants. This study provides ideas for improving fuel combustion efficiency and technical support for the preparation of clean fuels.