Investigation of characteristics of gas and coke residue for the regime of quasi- and non-stationary steam gasification of coal in a fluidized bed: Part 1

The steam oxygen-free gasification allows deep processing of coal and obtaining gas with high contents of H2 and CO. The design of dual fluidized bed gasifiers (DFB) is considered promising. There are insufficient experimental data on the steam gasification process in DFB for more accurate mathematical modeling. The paper presents the experimental results in dynamics of the quasi-stationary and non-stationary gasification of two types of coals in a laboratory gasifier. It has been established that when using superheated steam for preliminary and main gasification process, it is possible to obtain a gas with a total content of H2 and CO of more than 75% vol, maximum cold gas efficiency 87%. The conditions for the expedient use of two chambers for gasification of coals of different degrees of metamorphism are identified. The gasification regimes that will increase H2 and CO formation in DFB are determined. This research substantiate the necessarily to use only steam in DFB for improving the synthesis gas quality. [Display omitted] •Coal gasification in steam allows to obtain the gas with high total content of H2 and CO.•The degree of coal metamorphism affects the gasification process significantly.•Increasing of the temperature and the flow rate of steam allows to H2 and CO growth.•It is more preferable to use highly-metamorphosed coals at higher thermal stresses.•Pre-activated using gasifying agents is necessary for low-metamorphosed coals.