Partial oxidation process

Abstract

Sensible heat in the hot effluent gas stream leaving a partial oxidation gas generator for the production of gaseous mixtures comprising H.sub.2 +CO i.e. synthesis gas, reducing gas, or fuel gas, is used at maximum temperature to heat a stream of gaseous heat transfer fluid comprising a portion of the product gas circulating in the substantially closed loop. The heat transfer fluid serves as the working fluid in a turbine that produces mechanical work, electrical energy, or both. Further, the heat transfer fluid leaving the turbine may be used to preheat hydrocarbonaceous feed and free-oxygen containing gas which is then introduced into the gas generator. Optionally, by-product superheated steam may be produced at high temperature levels for use in the gas generator and as the working fluid in an expansion turbine. The high steam superheat temperatures result in higher conversion efficiencies. A shell and tube heat exchanger in which cleaned and optionally purified generator gas is continuously bled from inside the tubes to the outside, or the reverse is employed. By this means a continuously flowing protective sheath or curtain of the comparatively cooler bleedstream is placed between the surfaces of the tubes and headers, if any, in the heat exchanger and the surrounding hot effluent gas stream from the gas generator which enters the heat exchanger at maximum temperature. The surfaces of the tubes and headers, if any, are thereby protected against corrosive gas attack and deposits of ash, slag, and soot. The bleedstream mixes with the effluent gas stream passing through the heat exchanger and a portion of this mixture is recycled as make-up.