Thermodynamic analysis of hydrogen production via glycerol steam reforming with CO2 adsorption

Thermodynamic equilibrium for glycerol steam reforming to hydrogen with carbon dioxide capture was investigated using Gibbs free energy minimization method. Potential advantage of using CaO as CO2 adsorbent is to generate hydrogen-rich gas without a water gas shift (WGS) reactor for proton exchange membrane fuel cell (PEMFC) application. The optimal operation conditions are at 900 K, the water-to-glycerol molar ratio of 4, the CaO-to-glycerol molar ratio of 10 and atmospheric pressure. Under the optimal conditions, complete glycerol conversion and 96.80% H2 and 0.73% CO concentration could be achieved with no coke. In addition, reaction conditions for coke-free and coke-formed regions are also discussed in glycerol steam reforming with or without CO2 separation. Glycerol steam reforming with CO2 adsorption has the higher energy efficiency than that without adsorption under the same reaction conditions.