Critical temperatures and pressures of C40, C44, and C60 normal alkanes measured by the pulse-heating technique

• Critical temperatures and pressures of C40, C44, and C60n-alkanes were measured.
• These alkanes decompose at near-critical temperatures.
• Pulse-heating method with short residence times was used.

The critical pressures and the critical temperatures of normal alkanes CnH2n+2 with carbon numbers 40, 44, and 60 have been measured by the pulse-heating technique. A new method of calculation of the correction factors in pulse-heating experiments has been suggested. The results of earlier experiments (E.D. Nikitin, P.A. Pavlov, A.P. Popov, Fluid Phase Equilib., 141, 1997, pp. 155–164.) for n-alkanes with n = 19, 20, 21, 22, 23, 24, 26, 28, 30, and 36 have been recalculated using this method. Equations for the estimation of the critical temperatures and pressures of normal alkanes (n ≥ 5) have been suggested. The experimental critical properties have been compared with the estimations made by the Constantinou/Gani method and equations developed by Lemmon and Goodwin.