A rate-based model for CO2 regeneration in an ammonia-based CO2 capture process was developed and validated against the experimental results in a pilot plant at the Munmorah power station. The Redlich-Kwong equation of state and the Pitzer method were used to calculate properties of the vapour and liquid phase. The effects of operating conditions on the regeneration process were investigated. It was found regeneration energy as low as 3MJ/kg CO2 was achievable under optimized operating conditions, showing that ammonia-based CO2 capture technology is competitive in energy requirement with conventional amine based CO2 capture technology.