Method and apparatus for treating synthesis gas and recovering a clean liquid condensate

摘要

An apparatus and method for recovering a clean liquid condensate from a synthesis gas at elevated temperatures and pressures. The apparatus includes at least one heat exchanger for reducing the temperature of the synthesis gas down to below 200° F. (93° C.) so as to form a syngas condensate at elevated pressure. The syngas condensate is flashed so that it separates into a liquid phase condensate and a gas phase. The liquid phase condensate is primarily water, dissolved ammonia and particulates. The gas phase contains carbon monoxide, carbon dioxide, various sulfur containing compounds and trace amounts of other compounds that may have been dissolved in the syngas condensate. The gas phase is removed from the flash tank and sent to a sour gas treatment unit and/or flare. The liquid phase condensate is then filtered so as to remove larger sized particulates. This clean liquid condensate is sufficiently free of large particulates and potentially corrosive materials that it may be used to flush pumps and purge instrumentation used in the gasification process. The process reduces the amount of clean make-up water that must be added to the system as well we the amount of waste water that must be treated and disposed. In addition, ammonia that is typically added to gasification systems to maintain a safe pH is not completely evolved from the liquid condensate and thus need not be recovered or replaced.