RU2287056C1 - Method for electric power generation in situ - Google Patents

Abstract

FIELD: mining, particularly to generate electric power during standard or non-standard coal field development.

SUBSTANCE: method involves performing simultaneous degassing and carbonification of coal bed in different areas; directing gas obtained in underground gas generator to mechanical and chemical treating means; treating cleaned gas with water in carbonyl metal presence and in alkaline medium; mixing obtained gas with methane and directing the mixture to means, which treats the mixture with water stream over nickel catalyst; cooling gas mixture and directing thereof into filter filled with calcium oxide; transferring the gas mixture to steam-gas turbogenerator to generate electric power.

EFFECT: increased efficiency of coal and methane usage, decreased coal combustion gas emission in atmosphere.

2 cl, 1 dwg

Description

The invention relates to the mining industry and can be used to produce electrical energy during the operation of coal deposits with conditioned and substandard reserves with a sufficiently high gas content (more than 8-10 m ³ / t).

There is a method of gasification of coal with subsequent generation of electricity, including producing generator gas and synthesized methane, which are energy carriers for generating electricity [1].

The disadvantage of this method is that this energy carrier contains a significant amount of carbon dioxide, which reduces its energy value.

A known method of generating electricity at a bed of coal seams, including drilling injection and gas wells, degassing the seams by sucking methane through the wells in one section of the formation with simultaneous gasification in an underground gas generator in another section of the formation, mechanically and chemically cleaning the generator gas, mixing the purified gas with degassing methane and power generation in a combined cycle gas turbine generator [2].

The disadvantages of this method are:

- low heat of combustion of gas fuel sent to a gas-steam turbine;

- emission of nitrogen oxides into the atmosphere;

- emission of carbon dioxide into the atmosphere;

- low degree of beneficial use of coal energy in the place of its occurrence;

- lack of integrated use of the resulting gas fuel.

The objective of the invention is to increase the efficiency of energy use of coal and methane contained in it, by removing non-combustible components from the mixture of generator gas and degassing methane, as well as a significant reduction in the emissions of gases from the combustion of coal.

This is achieved by the fact that in the method of generating electric power at the bed of coal seams, which includes drilling injection and gas discharge wells, degassing of the seams by suction of methane through the wells in one section of the formation with simultaneous gasification in an underground gas generator in another section of the formation, mechanical and chemical cleaning of the generating gas , mixing purified gas with degassing methane and generating electricity in a steam-gas turbine generator, hydrogen is obtained from the purified generator gas in in the presence of the medium in the presence of metal carbonyl in a low-temperature hydrogen reactor, then the resulting mixture at the outlet of this reactor is enriched with degassing methane, followed by treatment with water vapor at a temperature of 800-900 ° C and in the presence of a nickel catalyst in a high-temperature hydrogen reactor, after which the mixture gases are cooled in a heat exchanger, passed through a filter with calcium oxide and sent to a steam-gas-turbine generator, into which steam from heat exchangers is supplied through a mixer.

In addition, to increase the calorific value of the gas mixture obtained at the outlet of the filter, it is heated to a temperature of 1800-1900 ° C to produce ammonia and its subsequent disposal.

The drawing shows a schematic flow diagram of the production of electrical energy at the bed of coal seams.

The method of generating electricity at the bed of coal seams is as follows.

In one section of the gas-bearing coal seams, gas is degassed with suction of methane through wells 1 drilled from the surface, and in the other section, gasification of coal in the underground gas generator is simultaneously carried out. The process of underground gasification is carried out through injection 2 and gas outlet 3 wells. The obtained crude generator gas (SGH), having a temperature of 1000-1500 ° C, is cooled to atmospheric temperature equal to 15-25 ° C, by means of a heat exchanger 4 and sent for mechanical purification of mineral impurities into the cyclone 5. Next, the generator gas is chemically cleaned in two stages: obtaining hydrogen sulfide (H ₂ S) in the reactor 6 at a temperature of 150-200 ° C by the reaction:

and the allocation of sulfur from hydrogen sulfide by cooling it in the heat exchanger 7, and the connection with the acidic liquid in the absorber 8. Then the generator gas at a temperature of 30-40 ° C is sent to a low-temperature hydrogen reactor (HBP) 9, where in an alkaline medium and in the presence of carbonyl metal [Me (СО) _Π ] carbon monoxide reacts with water:

Next, the resulting gas is mixed with degassing methane by connecting a methane line to the outlet of the HBP 9 reactor, while the mixture contains the following components: N ₂ , H ₂ , CH ₄ and CO ₂ .

To transform methane into hydrogen, this mixture is exposed to steam at a temperature of 800-900 ° C in the presence of a nickel catalyst in a high-temperature hydrogen reactor (WWR) 10, in which the reaction occurs:

At the outlet of WWR 10 there is a mixture consisting of N ₂ , H ₂ and CO ₂ , which is cooled to a temperature of 20-30 ° C in a heat exchanger 11. The resulting mixture at a temperature of 20-30 ° C is sent to a filter 12 with calcium oxide (quick lime), in which the reaction of absorption of carbon dioxide and the formation of calcium carbonate takes place:

which goes to waste.

From the heat exchangers 4, 7, 11, the steam enters the mixer 13 and then to the steam turbine generator 14 to produce electricity. The gas mixture from the outlet of the filter 12, consisting of hydrogen (more than 80%) and nitrogen (less than 20%), is sent to a gas turbine generator 15, which forms an energy block 16 with a steam turbine generator 14. The hydrogen energy carrier has a high calorific value, which can significantly increase production electrical energy.

To purify the hydrogen-nitrogen mixture from nitrogen from the exit from the filter 12, it is sent to a reactor-heater (PH) 17, in which under the influence of a temperature equal to 1800-1900 ° C, a reaction occurs to produce ammonia:

To remove ammonia from a mixture with hydrogen, it is cooled to a temperature of 20-30 ° C by means of a recovery cooler (ХУ) 18 and sent to a reactor 19, in which, in the presence of water, ammonia passes into aqueous ammonia (ammonia) by the reaction:

which goes to recycling. The resulting hydrogen from the reactor 19 is sent to the gas turbine generator 15 and for chemical reactions in the reactors 6 and 17.

Thus, the described method allows to increase the efficiency of using natural energy of coal and methane contained in it, from 8-10 to 27-30%, as well as reduce emissions of harmful and greenhouse gases (NO _x , SO _x , CO ₂ and CH ₄ ) into the atmosphere to international environmental standards.

Information sources

1. Auto No. 1800010 on the square E 21 B 43/295. Bull. No 9 on 09/07/93.

2. RF patent No. 2100588 on the square. E 21 B 43/295. Bull. No. 36 dated 12/27/97 (prototype).

Claims (2)

1. A method of generating electricity at a bed of coal seams, including drilling injection and gas discharge wells, degassing the seams by sucking methane through the wells in one section of the formation with simultaneous gasification in an underground gas generator in another section of the formation, mechanical and chemical cleaning of the generator gas, mixing purified gas with degassing methane and generating electricity in a steam-gas turbine generator, characterized in that hydrogen is obtained from the purified generator gas in an alkaline medium and the presence of metal carbonyl in a low-temperature hydrogen reactor, then the resulting mixture at the outlet of this reactor is enriched with degassing methane, followed by treatment with water vapor at a temperature of 800-900 ° C and in the presence of a nickel catalyst in a high-temperature hydrogen reactor, followed by a mixture of gases cooled in a heat exchanger, passed through a filter with calcium oxide and sent to a steam-gas-turbine generator, into which steam from heat exchangers is supplied through a mixer. 2. The method according to claim 1, characterized in that to increase the calorific value of the gas mixture obtained at the outlet of the filter, it is heated to a temperature of 1800-1900 ° C to produce ammonia and its subsequent disposal.