Separation of a high temperature (e.g., 300.degree.-1200.degree. C.) and high pressure (e.g., 2-20 bar) solids-gas stream from a pressurized fluidized bed reactor into solids and gas while reducing the pressure of both the gas and solids takes place in a vertical de-entrainment vessel having a packed bed of solids within it. The possibility of fluidization of the solids is minimized by causing the velocity of the gas component of the solids-gas stream to be reduced during, or just prior to, introduction of the gas into the packed bed of solids, e.g., by providing an expanding conical end to the inlet for the solids-gas stream into the vessel. A gas permeable solids impermeable element may also or alternatively be connected to the inlet and extend toward (optionally all the way to) the side wall of the vessel, to substantially prevent fluidization. The fluidization-preventing element may be a perforated plate, ceramic filter, or wire mesh screen, and may have gradually increasing gas permeability from the inlet to the vessel side wall. At least one inlet flows to the vessel, and at least one separated gas and solids outlet leads from the vessel to a low (e.g., atmospheric) pressure area.