Abstract: Useful energy is derived from steam flashed from hot geothermal brine having a tendency to deposit amorphous silica or calcite upon a reduction in the pressure or temperature of the brine. Steam condensate produced from the flashed steam is pressurized, acidified and preheated, and the acidified preheated steam condensate is mixed with the hot geothermal brine at a point upstream of the flash stage so as to form a hot aqueous mixture with a reduced tendency for deposition of amorphous silica or calcite.

Abstract: A method for capping an idle geothermal steam well so as to prevent hydrogen sulfide emissions and well damage due to steam condensation includes replacing geothermal steam in a well borehole with gas, perferably an inert gas such as nitrogen, and sealing the well at the wellhead. Thereafter additional quantities of the gas are bled into the well borehole at a rate that substantially prevents steam condensation in the borehole. The method includes purging the well bore with air sufficiently to assure all steam is swept out of the well before the gas is introduced.

Abstract: A process for stabilizing silica-rich geothermal brine to prevent silica scaling comprises selectively providing a supply of ferric ions, allowing the silica-rich brine to combine with the ferric ions to form insoluble, iron-rich siliceous material and separating the insoluble siliceous material from the brine to form a brine having a silica content which is reduced below the saturation level required for substantially scale-free handling of the brine. In one embodiment of the process in which the brine contains sufficient dissolved ferrous ions, the process comprises selectively contacting the brine with an oxidizing agent, preferably by aerating the brine, to oxidize a selected portion of the ferrous ions to ferric ions, which then combine with silica to form the insoluble iron-rich siliceous material. The ferric ion content of an iron-deficient brine may be augmented by adding ferric and/or ferrous ions to the brine.

Abstract: An integrated method for the derivation of useful energy from steam containing both hydrogen sulfide and an alkaline acting component, such as ammonia, while substantially reducing the emission of sulfur-containing compounds to the atmosphere. Pretreatment of the steam to selectively remove the alkaline acting components results in the concentration of hydrogen sulfide in the uncondensed vapor as the steam is condensed during energy derivation. The uncondensed vapor is separated from the steam condensate and then is treated to produce an environmentally acceptable vent gas.

Abstract: A process for treating and deriving useful energy from a two-phase geothermal brine containing non-condensible gases, including hydrogen sulfide, and also containing heavy and/or transition metals in solution, wherein the non-condensible gases are separated from the geothermal brine. Substantially all of the hydrogen sulfide contained in the non-condensible gas is converted to sulfur dioxide and at least a portion of the sulfur dioxide is removed from the non-condensible gas thereby rendering the same environmentally acceptable for discharge. The separated geothermal brine is flashed to a high quality steam utilized for energy derivation. The portion of sulfur dioxide removed from the non-condensible gas is added to the remaining brine for reinjection into the subterranean geothermal reservoir.

Abstract: An inline motionless mixer for mounting in a fluid-conducting conduit having a removable housing which facilitates cleaning of the internal mixing elements.