O2 Solubility in C7–C16 n-Alkanes

Oxygen (O₂) solubility in hydrocarbons plays a crucial role to control conversion and product selectivity during liquid phase oxidation of hydrocarbons to produce petrochemicals. In spite of its importance, experimental measurements of O₂ solubility in liquid hydrocarbons are not abundant. Because it is challenging to experimentally determine the oxygen in hydrocarbons following traditional titration method as reagents react with hydrocarbons. In the current study, the O₂ solubility was measured using a differential pressure-based measurement method in n-heptane, n-decane, n-dodecane, n-tetradecane, n-hexadecane, and tetralin at 294 K. Henry constants were calculated and were in the range 0.03–0.40 mol‧m⁻³‧kPa⁻¹. At 140 kPa O₂ pressure, in n-tetradecane and n-hexadecane O₂ solubility was in the range 4–24 mol‧m⁻³, compared to O₂ solubility in n-heptane and n-decane which was in the range 27–57 mol‧m⁻³. The O₂ solubility expressed as a mole fraction of the total liquid appeared to have a slightly decreasing trend with an increase in carbon number in the alkanes.