Method for disposal of carbon dioxide (co2) from underground-coal-gasification-derived gas (ucg-derived gas) |
|
  
IPC classes for russian patent Method for disposal of carbon dioxide (co2) from underground-coal-gasification-derived gas (ucg-derived gas) (RU 2513947):
 Gas emission control method at development of coal bed prone to spontaneous ignition / 2512049
Method refers to the field of mining industry, to coal mining industry in particular, and may be used during development of coal beds prone to spontaneous ignition. The method used during development of coal bed prone to spontaneous ignition includes preparation of extraction section by double workings, ventilation of wide section workings due to mine ventilating pressure drop and coalmine methane extraction from emission source. Methane is extracted first through drilled at superimposed beds methane drainage boreholes with possibility of air inleakage exclusion from bottom-hole region of active stope. Then after displacement of developed bed main roof mine rocks, methane is removed through the rest part of borehole length in modes excluding air inleakage from bottom-hole space of long face. Methane, evolving hard from developed bed zones released from overburden pressure near long face bottom-hole, is offtaken to degassing vacuum network of extraction section through formation wells drilled oriented on working face with methane concentration fit for disposal.
 Procedure for underground gasification of coal / 2490445
Method involves drilling of an air injection hole and gas removal hole in a coal bed, including setting of pipe string, connection of holes in the bed by hydraulic fracturing with formation of a channel. Ferric oxide is loaded into a channel; at that quantity of ferric oxide is equal to 0.25-0.35 of the mass of gasifiable coal bed. Coal ignition is made by coal bed heating up to 300-500°C. Superheated steam of the same temperature is supplied to the channel and combustible gas with hydrogen content of 17-34% and calorific capacity of 6.5-15.2 MJ/m3 depending on the process temperature is removed through the gas removal hole.
 Method for underground gasification / 2477788
Method includes well drilling from ground surface into treated interval of formation, electrodes allocation in wells, voltage supply to electrodes, electric current supply and formation heating. In order to provide maximum output of heat generation in the formation the current frequency is chosen depending upon maximum of angle tangent of dielectric losses of the rock and electric current of chosen frequency is fed through the formation. Heating is done due to dielectric and resistant losses in the formation. In the course of formation heating there performed is a gradual changing of electric current frequency according to the change of maximum of angle tangent of dielectric losses of the rock. Note that wells for electrodes location are drilled by grid-intersection coordinates in points of square network, and gas draw-off wells in the centre of network squares.
 Method to produce hydrogen during underground coal gasification / 2443857
According to the method, air or technical oxygen are supplied as blowing to a hot coal surface of an underground gas generator. Produced gas is discharged via gas-discharge wells ending with coal shafts without pipe casing. Technological process parameters are controlled via gas-discharge wells. The reaction of steam conversion of carbon monoxide is initiated in the reaction channel of the underground gas generator by injection of water vapour or surface water into reaction zones of coal shafts of gas-discharge wells via sections of auxiliary wells having hydraulic connection with the specified reaction zones and perforated in preset areas along the length of rock shafts, and such auxiliary wells are drilled along every gas-discharge well and cased with pipes along the entire length. As the coal bed is mined by gasification, and reaction zones of coal shafts of the gas-discharge wells are displaced, the point of water vapour or surface water supply in rock shafts of auxiliary wells is moved following displacement of reaction zones of coal shafts of the gas-discharge wells. Also the reaction of steam conversion of carbon monoxide is initiated in the ground chemical complex. Gas composition is monitored. Water vapour or surface water are injected in amount that provides for reduction and stabilisation of carbon monoxide concentration in discharged gas up to 3-5 percent. Steam conversion of carbon monoxide in the ground chemical complex is carried out before its stable minimum is demonstrated, by selection of appropriate optimal types of catalyst and thermobaric conditions, and after completion of steam conversion of carbon monoxide in the ground chemical complex the carbon dioxide is caught and recycled, and remaining hydrogen is transferred to a consumer.
 Underground coal gasification technique / 2441980
FIELD: underground coal gasification. SUBSTANCE: invention belongs to the mining engineering and may be used for the underground coal gasification (UCG). The technique lies in drilling of development wells of the underground gas generator, implementation of a technological UCG process and minimization of the environmental impact on the massif mass. The direction of the drilled well is oriented at its lower bench, while vertical water wells and initial spots of directionally drilled well are located beyond the active displacement zone. The distance between the blasting and pressure relief well shall be greater than the roof fragmentation step. Ignition of the coal formation is carried out in the vertical well, what is followed by a monitoring of its connectivity with the cross sectional horizontal and boundary pressure relief wells. The monitoring of coal formation outgasing is carried out between every pair of blasting and pressure relief well; such outgasing is equaled along the underground gas generator. Gasification plot is preliminary dried to the level of 20-25 m over the inflammation horizon and keep up pressure in the underground gas generator, which should be lower, than the underground water pressure. Upon the cessation of the underground gas generator exploitation the blasting wells are injected with nitrogen for a final fire face extinguishment. EFFECT: optimum implementation of UCG technique within the whole cycle. 15 cl, 2 dwg  Method to prepare power gas of underground gasification of stone and brown coals / 2439313
Method includes primary cooling of gas in a well of an underground gasification rig using supply of sprayed water into a wall or a recuperative boiler, in which cooled gas and cooling water are separated with a wall, forced gas suction from the well, its cleaning and burning to produce heat and power energy. Primary gas cooling is carried out to the temperature of not less than 600°C. At the same time gas cleaning from dust is carried out by dry method at one, two or three stages, combining a cyclone device, a cyclone device of battery type, an electric filter or a cassette filter from gauze nets. Gas supply for burning is carried out at the temperature that is higher than temperature of stone coal resin condensation, i.e. not below 400°C.
 Utilisation method of worn-out automobile tyres at development of coal beds by underground gasification method / 2435954
Method involves preparation of gas generator for gasification by drilling a network of wells: vertical ones for blast air supply, formation ones for gas removal; in addition, between blast air and gas-removing wells there drilled are formation wells through which wastes are supplied to combustion source, combustion face is moved along the rise and spread of coal bed by supplying the blast air to blast air wells and gas removal through gas-removing wells. At that, as utilisation wastes there used is rubber of pre-crushed automobile tyres, which is supplied to combustion source when necessary through the dosing devices installed in formation wells.
 Procedure for underground gasification of coal / 2424429
Procedure for underground gasification of coal includes arrangement of chambers along bed of coal. The chambers are connected with surface at their mouths and are interconnected at their ends. Further, the procedure consists in sealing mouths, in installation of devices for blowing and gas withdrawal and in successive burning coal massifs. Also, one pair of chambers is drilled differently directed at angle one to another from one mouth and are connected with the next pair of chambers at their end. Mouths of chambers and beat of bed on surface are isolated with a continuous sealing wall.
 Procedure for gasification of hydrocarbons for production of hydrogen and synthesis gas / 2423608
Procedure for gasification of hydrocarbons consists in forming underground gas generator in hydrocarbon deposit bed and in supply of water and electric power in gas generator. Also, water is electrolysed at pressure within the range from 0.1 to 23±2 MPa and temperature within the range from 600 to 1750°C and the following products of gasification are withdrawn from the gas generator: hydrogen, oxides of carbon, methane and solid particles of carbon.
 Procedure for gasification of hydrocarbons for production of electric power and carbonic nano materials / 2415262
Procedure for gasification of hydrocarbons consists in forming underground gas generator in hydrocarbon deposit bed and in supply of water and electric power in gas generator. Also, water is electrolysed at pressure within the range from 0.1 to 23±2 MPa and temperature within the range from 600 to 1750°C; products of gasification are withdrawn from the gas generator. Products of gasification are transmitted through a gas jet mill and an electric filter and are used for production of electric power by means of fuel elements and a power unit with a gas-steam cycle; while solid carbon containing components are used for production of carbonic nano materials.
|
FIELD: oil and gas industry. SUBSTANCE: invention relates to mining and can be used for underground coal gasification. The method lies in division of CO2 received in the surface chemical complex into two flows: the first flow is injected into blast injection holes of the operating underground gas generator and endothermic chemical reaction CO2+C=2CO-q is initiated in gasification zones thus enriching UCG-derived gas with combustible CO component; the second flow of CO2 is injected into depleted underground gas generator. At that quantity of CO2 injected to the operating underground gas generator is determined depending on temperature level in gasification oxidising zone and composition of the gas extracted from the neighbouring well. Bottom-ash mass of the depleted underground gas generator is saturated with lime hydrate aqueous solution [Ca(OH)2], to that end it is injected into wells of the depleted underground gas generator until concentration of this solution is stabilised which is proven by periodical solution sampling and chemical analysis of that. When concentration of lime hydrate is stabilised in analysed samples the second CO2 flow is injected into wells of the depleted gas generator for the purpose of its chemical absorption. Injection of CO2 is stopped to the depleted gas generator when its concentration in periodic samples increases up to 90%. EFFECT: technical result is obtained through complete disposal of CO2 in UCG-derived gas. 5 cl, 2 dwg
The invention relates to the field of mining, and in particular to methods of reducing emissions of carbon dioxide (CO2) in underground coal gasification (UCG). Known technology PSU, based on drilling for coal seam series blowing and suction wells designed for the gasification of coal in place of its natural occurrence, and trapping of the resulting combustible mixture component CO2in the surface chemical complex [Kreinin E.V. Underground coal gasification: fundamentals of theory and practice of innovation. - M., 2010. - s-284]. Known also technical proposals for the use of CO2for injection into oil reservoirs to increase oil recovery [White D.J., G. Burrowes, T. Davis et al. Greenhouse gas sequestration in abandoned oil reservoirs: The International energy agency Weyburn pilot project. // The journal GSA Today, 2004, vol. 14, No. 7, pp.4-10]. These solutions do not provide options for beneficial use and eventual disposal of CO2directly at PSU. Known technical solution trapping CO2is widely used in the chemical industry monoethanolamine method [Kreinin E.V., Karasevich A.M. Greenhouse effect hypothesis, the Kyoto Protocol, technical advice. - M., 2007. - SS-146], according to which from a mixture of gases absorb CO2the reaction of HO(CH2)2NH2+CO =HO(CH2)2NHCO(OH). However, the resulting monoethanolammonium thermally unstable and decomposes on reversible above reaction, so for underground gas generator this method is unsuitable. Need new reliable technology chemical binding of CO2. It is also known technical solution for the regulation of the composition of the gas CCPP by injection into an underground gas generator CO2and H2[RF Patent №2293845, 2007]. However, this solution is only partially consistent with the goal of recycling formed at PSU CO2. Need a technical solution technology PSU, different complete lack of emissions of CO2. The objective of the invention is to identify a universal solution for full utilization of CO2when PSU (operated on and spent underground gas generators). The technical result is the avoidance of emissions of CO2enterprises PSU. The problem is solved and the technical result is achieved in that in the method of disposal of CO2from gas CCGT, characterized by the generation of the combustible mixture of gases by gasification of coal in place of its natural occurrence through a series of blowing and suction holes of underground gas generator, and the capture of the said combustible mixture gas is CO 2in the surface chemical complex, dedicated in surface chemical complex CO2divided into two streams, the first of them pump in the blow well working underground gas generator, initiate in the areas of gasification endothermic chemical reaction of CO2+=2SD-173 kJ/mol and enrich the gas CCGT fuel component carbon monoxide (CO), and the second thread CO2pump in the exhaust gas generator for burial. Contributes to the achievement of a technical result that: the amount of CO2injected into the blast hole working underground gas generator set depending on the temperature in the oxidation zone of the gasification and gas composition, exhaust adjacent the borehole, thus increase the amount of injected CO2with increasing concentration Of2in the blast and reduce the inflow of groundwater into the gasification zone, and reduce it after stabilizing and increasing the concentration of CO2in the exhaust gas; - ash mass of exhaust gas generator impregnated with a special solution, predominantly aqueous solution of slaked lime [CA(Oh)2]by pumping it into the well of the waste generator to stabilize the concentration of this solution, which periodically otber the jut of his samples and subject them to chemical analysis; after the stabilization of the concentration of a special solution in the analyzed samples begin pumping in borehole exhaust gas generator CO2for its chemical sorption; - injection of CO2in the exhaust gas generator stop after increasing its concentration in periodically pumped from wells samples up to 90%. The associated analysis of the proposed solution with known shows that this method is proposed in essential features formulated for the first time and allows full utilization of CO2from gas CCGT. This indicates compliance of this decision, the criterion of "novelty". The proposed method also meets the criterion of "inventive step", as in the known solutions of the current level of technology not identified proposals for maximum utilization of CO2directly in the underground gas generator. The method is illustrated by the graphic images. Figure 1 - schematic diagram of waste underground gasifier. Figure 2 - schematic diagram of preparation of gas CCGT. On the fragment of underground gas generator (figure 1) shows a series of wells unified underground gasifier initial reaction channel gasification, presents suction 1 and blast 2 is a vazhiny, which can be inclined or oblique-horizontal respectively for horizontal and inclined coal seams. Blast 2 and exhaust 1 wells initially intersect the transverse inclined-horizontal well 3, with which is connected a vertical borehole 4. Final stage the final (final) gasification presents the final line 5 Vyazovaya coal seam, limiting waste space (the volume of the reaction channel is proved) 6. Reaction channel is proved (used) space (the volume of the reaction channel is proved) 6 filled with ash, slag, hit the roof and underground waters. The method is as follows. Gas CCGT plants in terrestrial chemical complex (figure 2) consistently trained to use: cooling, cleaning, conversion of CO (CO+H2O=CO2+H2), the trapping of H2S and, finally, the capture of CO2. The remaining combustible components (CO+H2+CH4) are sent to the consumer. Subject to review of the proposed technical solution is the utilization (use) CO2selected in the final stage of terrestrial chemical complex (figure 2). The amount CO2divided into two streams. The first one pump with blown in well 2 (figure 1). In the area of response do the article with a hot coal surface is initiated by the endothermic reaction of the Boudoir: CO 2+=2SD-173 kJ/mol. The gas mixture is enriched fuel component (CO), and this increases its heat of combustion, and hence the energy efficiency of the process of PSU. The amount of injection in blast wells CO2depends on the temperature in the gasification zone. The higher the concentration of oxygen in the blast (from 21% in air blast to 95-98% in the oxygen blowing) and less than the gravitational flow of water in the area of coal gasification, the greater may be the amount of CO2injected into the blast hole. This performance monitoring supply CO2in the area of coal gasification carried out on the composition of the gas controlled by the adjacent suction hole 1 (Fig 1). After the beginning of the growing concentration of CO2in the exhaust gas reduces the amount of CO2injected into the blast borehole 2. The second (remaining) part of the CO2allocated land complex (figure 2), pump in the adjacent exhaust gas generator. Operating company PSU, as a rule, there are several underground gas generators, and the number of generators has completed its work and is located in the auxiliary operations (neutralization groundwater conservation wells and others). Reaction channel is proved space exhaust gas generator is filled with ash, slag and abrasive the camping breed immediate roof (item 6 in figure 1). Ash mass is 40-60% of the volume of the reaction channel is proved and is characterized by high porosity and developed internal surface. Because of this reaction channel is proved space waste underground gas generator can be used for the disposal of gaseous substances, including CO2. For the disposal of CO2in a reaction channel is proved space waste generators in wells pump water solution of calcium hydroxide (slaked lime) CA(Oh)2. Calcium hydroxide fills the reaction channel is proved space and a highly developed pore ash mass. By sampling and chemical analysis to establish the completeness of the filling volume of the reaction channel is proved underground gas generator slaked lime, as evidenced by the cessation of growth of its concentration in the samples solution. Then start pumping in the exhaust underground gasifier CO2. The reaction of the chemical sorption: CA(Oh)2+CO2=Caso3↓+H2O+113 kJ/mol. Calcium carbonate (caso3) precipitates and securely binds a CO2. Heat several heats the array, but given more fluid mass and the surrounding rocks, the temperature increased slightly. Injection of CO2in the exhaust gas generator stop after appearing in the OTB is selected from the wells and analyzed samples the concentration of CO 2about 80-90%. The latter indicates near complete consumption of CA(Oh)2and the termination of the chemical binding of the CO2to caso3. The proposed method of disposal of CO2it is planned to implement for experienced underground gas generator is designed in Kuzbass. This will be the first experience in creating efficient technologies in energy without greenhouse gas emissions (CO2). 1. The method of disposal of carbon dioxide (CO2from gas, underground coal gasification, which consists in generating a combustible mixture of gases by gasification of coal in place of its natural occurrence through a series of blowing and suction holes of underground gas generator, and the capture of the said combustible mixture of gases CO2in the surface chemical complex, wherein the selected surface chemical complex CO2divided into two streams, the first of them pump in the blow well working underground gas generator, initiate in the areas of gasification endothermic chemical reaction of CO2+=2SD-173 kJ/mol and enrich the gas from underground coal gasification fuel component carbon monoxide (CO), and the second thread CO2pump in the exhaust gas generator for burial. 2. The method of disposal of carbon dioxide (CO2) according to claim 1, characterized in that the amount of CO2injected into the blast hole working underground gas generator set depending on the temperature in the oxidation zone of the gasification and gas composition, exhaust adjacent the borehole, thus increase the amount of injected CO2with increasing concentration Of2in the blast and reduce the inflow of groundwater into the gasification zone, and reduce it after stabilizing and increasing the concentration of CO2in the exhaust gas. 3. The method of disposal of carbon dioxide (CO2) according to claim 1, characterized in that the ash mass of exhaust gas generator is impregnated with an aqueous solution of slaked lime [CA(Oh)2]by pumping it into the well of the waste generator to stabilize the concentration of this solution, which periodically take it to trial and subject them to chemical analysis. 4. The method of disposal of carbon dioxide (CO2) according to claim 3, characterized in that after the stabilization of the concentration of CA(Oh)2in the analyzed samples begin pumping in borehole exhaust gas generator CO2for its chemical sorption. 5. The method of disposal of carbon dioxide (CO2) according to any one of claims 1, 3, 4, characterized in that the injection of CO2in the exhaust gas generator stop after against the behaviour of its concentration in periodically pumped from wells samples up to 90%.
|
