Determination of diffusion coefficient and concentration change of hydrocarbon fuel in amine fuel

In a motor with a liquid hydrocarbon fuel، the hydrocarbon fuel diffuses into the amine fuel and the fuel concentration changes with time. Therefore، the variation of amine fuel at each time should be predicted to ensure the safe start of the motor and the fuel storage should be recharged if the amine fuel concentration is out of specific range. In this work، the amount of hydrocarbon fuel diffusion in the amine fuel and the variation of the amine fuel concentration at different times was obtained numerically and compared with experimental data. For this reason، the corresponding diffusion coefficient was obtained firstly. The results showed that the diffusion coefficient of 9. 4*10-6cm2/s with an absolute average deviation of 0. 037 has a good conformity with experimental data at 20°C. To investigate the effect of ambient temperature on the diffusion phenomenon، a correlation was proposed to predict the variation of diffusion coefficient with temperature. The predicted concentration with this predicted diffusion coefficient showed a good agreement with experimental data. Ultimately، a correlation was proposed to predict the amine fuel concentration versus a dimensionless parameter ofz/√Dt. The prediction showed a good agreement with empirical data.