water can contain high levels of tds tss and organics contaminations the gas and solids flow to the discharge section located low at the vessel in this section the gas flow is deflected and forces a change direction to improve the mixture and to prevent large solid particles possible in a sticky form and possible liquid droplets from discharging with the gas flow out from the system where it can settle in down flow pipe and equipment at the bottom of the vessel there is the fluid bed section d where cold gas 4 circulates and flows upwards to suspend the solids bed solids are discharged from the bottom of the vessel 5 to maintain the bottom fluid bed solids level the up flow velocity above flow 4 in section d and below discharge flow 8 in section c is in the range of 0 2 m sec to 6 m sec to support the upward carry on solids particle size of up to 1 2 mm an outline of the method of the present invention is shown in fig3 fig3 is a diagrammatic outline of the method of the present invention fig4 shows a view of the four steps of the fluid bed up flow combustor of the present invention fuel 1 oxidizer 2 and water 3 are supplied to a high pressure combustor 6 located at section a which is located at the lower section of the vertical vessel the combustion gas flows upward to steam generation section b where low quality water 7 is injected into the up flow combustion gas all.