A filter separator and method, including an annular microfilter and a separation chamber within the microfilter including a plurality of mixing blades circulating fluid upwardly and downward within the chamber. When the apparatus is used to purify syngas, adherent metal oxide particles are circulated in the chamber to adsorb waste oxides. The apparatus is purged by injecting hot CO2 free gas into the chamber through the filter and the filter pores may be expanded during purging.