Steam Gasification of Coal at Low-Medium (600-800 °C) Temperature with Simultaneous CO2 Capture in Fluidized Bed at Atmospheric Pressure: The Effect of Inorganic Species. 1. Literature Review and Comments

This paper addresses the H2 production with simultaneous CO2 capture by steam gasification of coal in a fluidized bed, at low/medium temperatures (600-800 °C) and atmospheric pressure. This work is mainly aimed at reviewing the effects of the inorganic species present in the matrix of the coal or added to the gasifier bed. The most promising species seems to be the calcined limestone (CaO), which intervenes in the overall gasification reaction network in at least five different types of reactions. The effectiveness of the CaO for CO2 capture in the coal gasifier is, therefore, affected/influenced by the other four simultaneous or competitive types of reactions in the gasifier. The effects of the temperature in the gasifier and of the (CaO/coal) ratio fed to the gasifier are finally reviewed and discussed in detail.