The O2-enriched air gasification of coal, plastics and wood in a fluidized bed reactor

The effect of oxygen-enriched air during fluidized bed co-gasification of a mixture of coal, plastics and wood has been investigated. The main components of the obtained syngas were measured by means of on-line analyzers and a gas chromatograph while those of the condensate phase were off-line analysed by means of a gas chromatography-mass spectrometer (GC-MS). The characterization of condensate phase as well as that of the water used as scrubbing medium completed the performed diagnostics. The experimental results were further elaborated in order to provide material and substances flow analyses inside the plant boundaries. These analyses allowed to obtain the main substance distribution between solid, gaseous and condensate phases and to estimate the conversion efficiency of carbon and hydrogen but also to easily visualise the waste streams produced by the process. The process performance was then evaluated on the basis of parameters related to the conversion efficiency of fuels into valuable products (i.e. by considering tar and particulate as process losses) as well as those related to the energy recovery.

► The effect of the O2 in the gasification stream of a BFB gasifier has been studied. ► Main advantage of the O2-enriched air is the increasing of the bed temperature.► No remarkable effects on tar reduction. Decreasing of recognized PAHs. ► Gasification reactions completed inside the dense bed and splashing zone. ► Polycondensation reactions occur mainly in the freeboard region.