Patent ID: 8486165

Claim:
A gasification system, comprising: a gasifier configured to produce a black water and syngas from a fuel source; a black water processing system fluidly coupled to the gasifier via a first flow path, wherein the black water processing system is configured to produce a grey water stream from the black water, and the black water processing system comprises: a first flash tank disposed along the first flow path and downstream from the gasifier, wherein the first flash tank is configured to separate gases from the black water to produce a first discharge of the black water and a second discharge of first separated gases; and a second flash tank disposed along the first flow path downstream of and in series with the first flash tank, wherein the second flash tank is configured to separate gases from the first discharge of the black water to produce a third discharge of the black water and a fourth discharge of second separated gases; and a deaerator fluidly coupled to the black water processing system via the first flow path, wherein the deaerator is configured to receive and remove gases from the grey water stream produced by the black water processing system; and an indirect heat exchanger configured to transfer heat from the fourth discharge to a process stream of the gasification system, wherein the process stream comprises a makeup water stream for the deaerator or the grey water stream flowing from the black water processing system to the deaerator.