| 摘要 |
Hydrogen chloride in superheated steam is neutralized by contacting the steam with a solution containing potassium carbonate. A solution of potassium carbonate will remain liquid when contacted by steam superheated by as much as 40° C. and, unlike sodium carbonate, the degree of superheat of a saturated solution of potassium carbonate increases with temperature. Other highly soluble potassium salts or salt inhibitors can be added to prevent precipitation of solid potassium chloride which may occur under certain conditions, or a small amount of additional water can be added to keep the potassium chloride in solution while allowing the steam to remain superheated. Injection of potassium carbonate solution downhole in a dry steam geothermal well to protect the well casing from corrosion is especially beneficial, because only a small amount of carrier water needs to be injected together with the potassium carbonate, whereby the steam remains superheated and the possibility of localized corrosion is avoided. |
| 主权项 |
1. A method of neutralizing at least part of the acidic impurities present in a superheated steam by contacting the superheated steam with one or more aqueous liquids, wherein:
at least one of said aqueous liquids comprises an alkaline compound of potassium, the superheated steam comes from a geothermal source and contains the acidic impurity hydrogen chloride, the superheated steam is characterized by a temperature and a degree of superheat that is greater than a degree of superheat of steam at equilibrium with a saturated solution of sodium carbonate at said temperature, a volume and composition of said aqueous liquids are predetermined such that:
the superheated steam remains superheated after said contacting step, all of the hydrogen chloride is neutralized, andsaid contacting step does not produce solid deposits of potassium chloride, and if the superheated steam is characterized by a temperature and a degree of superheat that would otherwise produce solid deposits of potassium chloride, then at least one of the following conditions is met:
at least one of said aqueous liquids further comprises a potassium salt capable of supporting at least as much superheat as potassium chloride,at least one of said aqueous liquids further comprises a salt inhibitor, andthe aggregate amount of water in said aqueous liquids is selected to decrease the degree of superheat of the superheated steam by an amount sufficient to prevent solid deposits of potassium chloride from forming. |
