Apparatus for utilizing impure steam with extraction of one or more

Abstract

Certain impure steams, especially those from geothermal sources, are contaminated with gaseous substances such as hydrogen sulfide, ammomia, carbon dioxide, substances comprising boron, arsenic and mercury, other gases, as well as finely divided particulate solid matter in a form resembling dust or smoke. These contaminants reduce the efficiency of the steam as a heat transfer fluid and are detrimental to equipment utilizing steam as an energy source. Furthermore, discharges from the utilization of such impure steams result in pollution of the environment or necessitate expensive requirements for limiting the same. The present invention describes apparatus wherein so contaminated steam is selectively processed at superatmospheric pressure for removing one or more of said contaminants and, after reduction of its energy content by pressure reduction and/or condensation of the steam, gases substantially free of hydrogen sulfide are discharged to the atmosphere. The apparatus includes means for contacting the impure steam with an aqueous liquid containing reactant capable of reacting with at least one of said contaminants in the steam, e.g. hydrogen sulfide, to form non-gaseous reaction products including solids, e.g. metal sulfides, and for separating and removing solids from the aqueous liquid phase. Means are also described for recycling untreacted reactant and/or for regeneration of reactant from metal sulfide, and for recovering byproducts from the reaction products. By use of the described apparatus, the utility of impure steam may be improved and pollution of the environment from emission of hydrogen sulfide and other contaminants may be avoided.