abstract
A thermodynamic analysis of hydrogen production via steam and autothermal reforming of beef tallow has been carried out via the Gibbs free energy minimization method. Equi- librium calculations are performed at atmospheric pressure with a wide range of temperatures (400e1200 C), steam-to-beef tallow ratios (1e15) and oxygen-to-beef tallow ratios (0.0e2.0).
The results show that the optimum conditions for steam reforming can be achieved at reforming temperatures between 700 C and 900 C and a steam-to-beef tallow ratio of approximately 5. Optimal operating conditions of T 1⁄4 700 C and a steam-to-beef tallow ratio of 5 are proposed. With this condition, a hydrogen yield of 170 moles/kg beef tallow and a CO concentration in the synthesis gas of 4.77% with a trace content of CH4 (0.01%) can be obtained without coke formation.
The most favorable conditions for hydrogen production from autothermal systems are achieved at the temperature, steam-to-beef tallow ratio and oxygen-to-beef tallow ratio of 600e800 C, 3e5 and 0.0e0.45, respectively. Thermoneutral conditions can be accom- plished with an oxygen-to-beef tallow ratio of 0.384e0.427. The recommended conditions are a steam-to-beef tallow ratio of 5, T 1⁄4 600 C and an oxygen-to-beef tallow ratio of 0.422. Under these conditions, 150 moles H2/kg beef tallow can be produced with only 2.92% CO and 0.07% CH4 in the synthesis gas.
Copyright a 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights