JPS61222922A - Extraction of hydrogen sulfide from geothermal steam, and utilization of extracted material - Google Patents

Abstract

PURPOSE:To extract hydrogen sulfide contained in geothermal steam as iron sulfide or copper sulfide useful as an agricultural chemical, easily, by placing a reaction column filled with slab containing iron scraps or copper scraps, etc., to the path of geothermal steam, thereby reacting the hydrogen sulfide with the iron scrap, copper scrap, etc. CONSTITUTION:A fluid mixture of vapor and water obtained from the production well 1 is introduced to the part 2 for the treatment of geothermal fluid to extract steam, which is transferred to the reaction column 3 filed with slabs containing iron scraps, copper scraps, etc. The hydrogen sulfide contained in the geothermal steam is made to react with the iron scraps or copper scraps according to the reaction formulas I and II, and the produced iron sulfide or copper sulfide is extracted from the system. The steam free of hydrogen sulfide is sent to the steam-utilization system 4 and used as a hot spring, a heat source, etc., and the condensed hot water is returned to the reinjection well 5. Since hydrogen sulfide can be removed surely from the geothermal steam, the problems such as environmental pollution and the corrosion of power generator, etc., can be prevented, and furthermore, iron sulfide and copper sulfide, etc., useful as a raw material of agricultural chemicals can be produced at a low cost.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention aims to easily and inexpensively extract hydrogen sulfide, which is harmful to air pollution turbines, etc. from geothermal steam, and to utilize it. It concerns a method for extracting and utilizing hydrogen.

[Conventional technology]

The most important chemical measure for environmental conservation in geothermal power plants is the removal of nts (hydrogen sulfide) and the like discharged from the plants. The main components of non-condensable gases contained in geothermal steam (those in hot water are often returned underground in reinjection wells) are CO□ (carbon dioxide gas) and HlS.
Although various other substances are included, the main polluting component in geothermal power plants in Japan is HIS. Therefore, the most required chemical measure for environmental conservation in geothermal power generation in Japan is the removal of H2S, and it is important to treat the H2S so that it is not discharged from the plant. There are the following methods for removing HzS.

(1) Remove Hts from the steam at the turbine inlet.

(2) Remove at the outlet of the condenser gas discharger or gas extrusion steam ejector.

(3) From the cooling tower outlet, HzS contained in the hot water of the condenser is separated from the hot water in the cooling tower and discharged together with air, so it is removed from the air or hot water.

In Japan, H and S removal technology is being developed under the Sunshine Project. Here, a method for recovering sulfur as a single substance from UZS is being researched, taking into account transportation issues and sales channels for recovered materials. In Japan, the soft Claus method and Red method are being considered, while in the United States, The Geysers is considering the Streadford method. For example, the soft Claus method uses the following reaction, and basic research is progressing, but it has not yet reached the stage of constructing a viroft removal plant. The Geysers Power Plant in the United States has taken the lead in environmental measures by installing removal equipment at the power plant itself, and has implemented iron catalyst methods and other methods in a full-scale plant with an output of approximately 10,000 liters. here,
Although the removal rate of His is high, there is a problem of corrosion of materials such as condensers, and the Streadford method removal equipment using the following reaction has an output of 135,000 - No. 13, 110,000 kW.
Buildings attached to No. 14 are being constructed.

ths+co! -, :! 1. s −+HCO! -2H
5-+ 4VO3-+ 4HCO3--→2S + V
'aOq-' 4CO3-+ 3H2O The regeneration reaction of this is V40q-+O1+HzO+2co=-1-4VO3-
+2HCO2-, and this method is said to have a removal efficiency of about 99%, and since this device is independent of the power generation unit, it can be used independently of the operation of the power plant. However, the Geysers Power Plant, a geothermal power plant, contains NH in its gas, and it is necessary to consider the effect of NH3 on the recovery rate.
There are doubts as to whether it can be immediately used in power plants that do not contain a large amount of carbon dioxide.

FIG. 2 is a diagram showing an example of the configuration of a typical conventional geothermal power generation system, in which 11 is a production well, 12 is a steam separator, 13 is a generator, 14 is a turbine, 15 is a flash orifice, and 16 is a A flasher 117 is a condenser, 18 and 19 are pumps, 20 is a gas exhaust fan, 21 is a cooling tower, and 22 is a reinjection well.

When a steam/water mixed fluid is obtained from a geothermal production well, as shown in Fig. 2, the geothermal fluid obtained from the production well 11 is first
Steam and hot water are separated by a steam separator 12, and the steam is sent to a high pressure stage of a turbine 14, and the hot water is sent to a flasher 16. The steam obtained by the flasher 16 is sent to the intermediate pressure stage of the turbine 14, and the hot water separated by the flasher 16 is returned underground from the reinjection well 22. On the other hand,
The hot water condensed in the condenser 17 is sent to the upper part of the cooling tower 21 by the pump 18, and while falling from the upper part, it comes into contact with the atmosphere and is cooled to become cold water. This cold water is pumped 19
After being pressurized, it is ejected from the upper part of the condenser 17 as a thin jet, and comes into direct contact with the steam discharged from the turbine 14 to condense it. In addition, steam
Ai 7! The S gas is extracted by a gas exhaust fan 20, an ejector, etc., and released into the atmosphere.

Here, it is desirable to remove H2S upstream of the turbine because it prevents His from being discharged from the cooling tower and also enables the use of a surface condenser to prevent scale discharge. FIG. 3 is a diagram showing an example of a device for separating gas upstream of a turbine, in which 23 is a main body, 24 is a condensate, 25 is a flush valve, and 26 is a pump. It is also possible to separate the turbine inlet steam from the gas by condensing it on a surface whose temperature is slightly lower than that of the steam by providing a structure as shown in FIG. 3.

[Problems to be solved by the invention] However, as mentioned above, in the conventional H2S removal method,
Corrosion of materials such as capacitors became a problem, and the equipment became larger and maintenance costs increased.

The present invention solves the above-mentioned problems, and the present invention extracts H2S contained in geothermal steam using a simple and inexpensive method, and effectively utilizes this to further reduce the extraction unit cost. The purpose of this paper is to provide a method for extracting hydrogen sulfide contained in steam and a method for utilizing the extraction.

[Means for solving problems]

For this reason, the method of extracting hydrogen sulfide contained in geothermal steam according to the present invention involves installing a reaction tower containing a slab containing iron scraps, copper scraps, etc., which were originally discarded, in the middle of the geothermal steam flow path. It is characterized by extracting the hydrogen sulfide contained in geothermal steam as iron sulfide and copper sulfide by reacting it with scrap iron and copper scraps. It is characterized by its use as a raw material.

[Effect]

In the method of extracting hydrogen sulfide contained in geothermal steam and its extraction utilization method of the present invention, when geothermal steam passes through a reaction tower, hydrogen sulfide contained therein reacts with iron scraps and copper scraps in the slab. Hydrogen sulfide is removed from geothermal steam and output.

As a result, iron sulfide and copper sulfide are produced in the reaction tower and are extracted from the reaction tower in the form of sulfides. This sulfide is then used as a raw material for agricultural chemicals.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a diagram for explaining one embodiment of the present invention,
1 is a production well, 2 is a geothermal fluid treatment section, 3 is a reaction tower, 4 is a steam utilization system, and 5 is a return well.

In FIG. 1, a geothermal fluid processing section 2 is a system that extracts steam from a steam/water mixed fluid obtained from a production well 1 and sends it to a reaction tower 3, and includes, for example, a steam/water separator and a flasher. Note that if only steam is obtained from the production well 1, the geothermal fluid processing section 2 may not be provided. The reaction tower 3 is
A slab containing scraps such as iron (Fe) and copper (Cu) is interposed in the steam flow path, and the iron and copper scraps are reacted with hydrogen sulfide (OZS) contained in the steam passing through. It removes hydrogen sulfide from steam utilization system 4.
is a system in which the steam from which hydrogen sulfide has been removed after passing through the reaction tower 3 is used for hot springs, power generation, etc. After being used here, the hot water (hot water) is returned to the reinjection well 5, and the non-condensable gas is released into the atmosphere. released.

In the reaction tower 3, Has+Pe
-* FeS+Ht■zS +Cu -e CuS
Iron sulfide (FeS) and iron sulfide (Cu
S) is generated. The present invention further extracts the sulfide produced here and utilizes it as a raw material for agricultural chemicals. Furthermore, since hydrogen sulfide is removed from the steam using this reaction, the steam can be used as a hot spring without any adverse effects on the human body.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, since the reaction is carried out with the intervention of a slab containing scraps such as Fe and Cu, which were originally discarded, H and S can be easily extracted as iron sulfide and copper sulfide. be able to. Therefore, H from geothermal steam
, S can be reliably removed and pollution problems can be avoided, and iron sulfide and copper sulfide can be effectively used as agricultural chemicals without being discarded. In addition, since the reaction is carried out using a slab containing scraps such as iron and copper, the entire device can be manufactured and installed easily at low cost. Therefore, the total H and S removal cost can be kept low. Furthermore, H2S can be removed by reacting with a slab containing scraps such as iron and copper without adding any chemical substances, so H! The steam after S removal has no adverse effects on the human body and can be used directly as a hot spring.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining one embodiment of the present invention,
FIG. 2 is a diagram showing an example of the configuration of a typical conventional geothermal power generation system, and FIG. 3 is a diagram showing an example of a device for separating gas upstream of a turbine. 1...Production well, 2...Geothermal fluid processing section, 3...Reaction tower, 4...Steam utilization system, 5...Reduction well, 1
1... Production well, 12... Steam water separator, 13... Generator, 14... Turbine, 15... Flash orifice, 16... Flasher-117... Condenser, 18 and 19...Pump, 20...Gas exhaust fan, 21...Cooling tower, 22...Reduction well, 23...Main body, 24...Condensate, 25...Flash valve , 26... pump. Patent applicant: Shimizu Corporation Representative Patent Attorney Ryukichi Abe Figure 1 Figure 2

Claims (2)

[Claims] (1) A reaction tower containing a slab containing iron scraps, copper scraps, etc. is installed in the middle of the geothermal steam flow path, and hydrogen sulfide contained in the geothermal steam is removed by reacting with the iron scraps and copper scraps. A method for extracting hydrogen sulfide contained in geothermal steam, which is characterized by extracting it as copper sulfide. (2) A reaction tower containing a slab containing iron scraps, copper scraps, etc. is installed in the middle of the geothermal steam flow path, and hydrogen sulfide contained in the geothermal steam is removed from iron sulfide by reacting with the iron scraps and copper scraps. A method for extracting and utilizing hydrogen sulfide contained in geothermal steam, characterized by extracting it as iron sulfide and copper sulfide, and using the extracted iron sulfide and copper sulfide as raw materials for agricultural chemicals.