Energy recovery, sour gas stripping and caustic neutralization using combustion gases containing solids

Abstract

Abstract Combustion gases containing solids, e.g., gases resulting from regeneration of catalyst contact mass such as used in catalytic cracking of hydrocarbons or resulting from production of other materials or substances, e.g., carbon black, are passed to a separation zone, e.g., a cyclone separation zone in which separation of solids together with a substantial proportion of gases are separated resulting in a gas having a reduced solids content amounting to a tolerable maximum for utilization in an expansion zone, e.g., in a turbine to recover energy therefrom and then into a heat recovery unit or zone, e.g., to produce steam, and then pass to disposal, in one embodiment disposal including a combustion to convert trace amounts of hydrogen sulfide to sulfur dioxide; the solids and gas separated in the cyclone being used for heat recovery and then used as stripping medium to strip hydrogen sulfide from hydrogen sulfide containing fluid, e.g., water, to obtain as a bottoms for withdrawal to disposal substantially all of the solids and desoured water, an overhead containing in the gases hydrogen sulfide form the sour water and carbon dioxide, resulting from the combustion as in the regeneration of said catalyst contact mass, said gas being passed into contact with an alkaline medium, e.g., spent caustic to produce a substantially neutral or slightly alkaline readily disposable material and an overhead gas containing sulfur dioxide, carbon dioxide and hydrogen sulfide, in one embodiment a fuel or combustible material being added to the gas to convert therein H 2 S to SO 2 , the latter being more tolerable, ecologically speaking.

Inventors

• 👤 Norris W. Mitchell

Bibliographic Details