Optimization of the Production of Hydrogen From Syngas Using a 1∶7 Mass Ratio of Hematite to Calcium Oxide in a Pressurized Fluidized Bed

Abstract

A set of response surface experiments were designed to determine the optimum conditions for the production of high‐purity hydrogen from wet syngas of composition (44% CO, 23% steam, and 33% hydrogen) using 50 grams of a 1∶7 mass ratio of Fe₂O₃: CaO loaded into the fluidized bed reactor. Pressure was varied between 50 psi and 515 psi and temperature between 725°C and 800°C. Results indicated:

	High purity hydrogen production is possible at reactor conditions of 725°C & 50 psi, as well as 725°C & 250 psi;
	Optimum high purity hydrogen production (largest mass in 15 minutes with no COx) occurred near conditions of 725°C and 250 psi;
	Mass of produced high‐purity hydrogen increased most significantly with pressure;
	Methane production increased linearly with pressure due to the catalytic effect of the high nickel content of the reactor walls;
	The chemical reaction rate is predicted to be a controlling factor in the percentage of CO and CO2 in the outlet at lower pressures.

Keywords:

• High purity hydrogen
• syngas
• hematite
• calcium oxide
• fludidized bed

Acknowledgement

The authors are pleased to acknowledge the U.S. Department of Energy (contracts DE‐FC26‐00FT40974 and DE‐FC26‐03NT41842) and General Electric for their financial support.