The subject of the present invention is a method for the manufacture of bio-methane and eco-methane by hydrogasification of bio-carbon and fossil carbon where bio-hydrogen is the gasification agent, as well as a method for the manufacture of electricity and heat.
Bio-methane is a product of hydrogasification of bio-carbon using bio-hydrogen. The product of hydrogasification of coal or lignite using bio-hydrogen is eco-methane. Bio-carbon is a product of pyrolysis of dry biomass preferably with high content of cellulose, hemicellulose and lignin. Another favourable pyrolysis product is steam and flammable gases-hereinafter referred to as the pyrolytic gas. The product of an incomplete pyrolysis of biomass at 170° C.-270° C. is semi-carbon which contains approximately 60%-65% elemental carbon C′ with chemical properties similar to those of lignite. The product of a complete pyrolysis of biomass at temperature higher than 270° C., preferably at 300° C., is bio-carbon which contains approximately 65%-80% elemental carbon C′ with chemical properties similar to those of coal or coke.
Known from the book by Jerzy Szuba, Lech Michalik, entitled: “Karbochemia”, “Silesia” publishing house, 1983, methods for hydrogasification using hydrogen obtained mostly by steam-and-oxygen based gasification of fine coke or coal.
Known from that book is the HYGAS method developed at the Institute of Gas Technology (USA). The HYGAS method is a process of high pressure hydrogasification of coal combined with gasification of fine coke, which makes it possible to obtain a high thermal value gas (substitute for natural gas). There are three tested versions of that process, differing in the method of producing hydrogen for hydrogasification. Hydrogen is obtained either by oxygen-steam coal gasification or electrothermal gasification or as a result of oxidation-reduction of iron oxides with gas obtained from gasification of fine coke (steam-iron system).
Known from that book is the Hydrane method developed by the Pittsburgh Energy Research Center (USA). The Hydrane method consists in obtaining a high thermal value gas by direct reaction of coal with hydrogen. Coal feedstock (any grade) reacts with hydrogen contained in a hot gas. The gasification process occurs at 815° C. Coal gasification occurs in a co-current, falling and thinned bed suspended in an internal reactor. Fine coke thus produced precipitates to a fluidized bed in an external reactor, to undergo further reaction with hydrogen. The internal and external reactors form a single device. Hydrogen for the process is obtained in a separate reactor by steam-oxygen gasification of a part of fine coke.
Known from the patent specification US 2011/0126458A1 is a method for the production of gaseous fuel rich in methane through a combination of hydrogasification of a coal feedstock with hydrogen and steam. Gasification is carried out on an aqueous slurry of coal using hydrogen and superheated steam in a temperature range of approximately 700° C.-1000° C. and at a pressure of approximately 132 kPa to 560 kPa. The product of such gasification is hydrogen, methane, carbon monoxide and carbon dioxide. Hydrogen is separated from this mixture in a separator and recycled back to the SHR carbon gasifier also fed with steam, and a mixture of CH4, CO and CO2 is a fuel gas rich in methane (up to 40% of CH4).
From the Chinese patent specification CN1608972A there is known a method for the production of hydrogen in a biomass gasification process using steam mixed with a CO2 acceptor in the form of a mixture of calcium oxide and magnesium oxide which exhibits catalytic properties in biomass gasification. The resulting mixture of magnesium and calcium carbonates and unreacted fine coke, separated from ash in a cyclone, is fed to a carbonates calcination reactor, where it undergoes calcination by combustion of fine coke in an air stream fed at the bottom of the carbonates calcination reactor, wherefrom a regenerated CO2 acceptor being a mixture of calcium and magnesium oxides (CaO/MgO) is recycled back to the biomass gasification reactor.
All these methane manufacturing processes feature large consumption of elemental carbon (C)—for producing two molecules of CH4 at least 5 elemental carbon atoms (C) are consumed. This limits the efficiency of the carbon hydrogasification processes. It is characterized by high CO2 emissions to atmosphere and an increased emission of solid waste to the environment.
The present invention solves the issue of application of plant-based raw materials from cultivated crops and organic waste and full utilisation of biomass having high content of cellulose, hemicellulose and lignin to produce bio-methane and bio-carbon, and, subsequently, bio-hydrogen for hydrogasification of bio-carbon to bio-methane and fossil carbon to eco-methane and high-efficiency conversion, exceeding 60%, of the chemical energy of the resulting fuel to electricity. These effects have been obtained by producing bio-carbon in a biomass pyrolysis process, forming a mixture of bio-carbon with fossil carbon, and gasification of said mixture using bio-hydrogen obtained using bio-methane, steam and a novel CO2 acceptor which is regenerated using thermal energy from a power generation unit, from pyrolytic gas combustion, and using solar energy, which leads to its accumulation.
The method for the manufacture of bio-methane and eco-methane as well as electricity and thermal energy using a process of pyrolysing biomass to biocarbon mixed with comminuted and, possibly, appropriately prepared fossil carbon and using a process of hydrogasification of the carbon mixture to raw gas, its desulphurisation and separation into hydrogen and methane using a process of producing hydrogen in a reaction of methane with steam and with a CO2 acceptor and regeneration of the acceptor and with the use of MCFC fuel cells and a gas-steam power and heat plant to produce electricity and heat, is characterized in that a comminuted dry plant-based material or a waste-based raw material is subjected, individually or in specified sets, to a pyrolysis process, either in the temperature range of approximately 170° C.-270° C. at normal pressure to produce semi-carbon and a pyrolytic gas or in the temperature range of approximately 270° C.-300° C. to produce bio-carbon and a pyrolytic gas or in the temperature range higher than 300° C., with a part of the pyrolytic gas directed to carry out pyrolysis of biomass in a biomass pyrolysis apparatus, and the other part of pyrolytic gas is directed to pre-heat the regenerating stream of CO2 in the preheater. The resulting semi-carbon, containing around 60%-65% of elemental carbon, is mixed preferably with comminuted lignite, while bio-carbon containing approximately 65%-80% of elemental carbon is mixed with comminuted coal in a ratio of elemental carbon C′ from bio-carbon to elemental carbon C from fossil carbon preferably being C′:C=1:1. This mixture is fed to a first low-pressure or high-pressure hydrogasification reactor where a process of complete hydrogasification is carried out using bio-hydrogen to produce raw gas and ash, or a process of incomplete hydrogasification to produce raw gas and fine coke. The fine coke is partly discharged to a fine coke storage facility and partly fed to pre-heat the CO2 regenerating stream in the preheater and burned. The raw gas obtained is fed to a process of separating vapours and gases, where it is dried and subjected to desulphurisation, and then separated into hydrogen, residual gases, and a methane mixture consisting of pure bio-methane and eco-methane. A part of the methane, after cooling down in a heat exchanger, is directed to supply a power generation unit, from which heat is fed to a heat exchanger to heat a regenerating CO2 stream and to a heat exchanger in the waste heat boiler that produces process steam and power steam, and the other part of the cooled down methane is fed either to a compressor or to a condenser or introduced to a gas distribution pipeline. Hot bio-methane at a temperature approximately 800° C. is fed to a third bio-hydrogen generation reactor where, in a reaction of bio-methane with hot steam supplied from the waste heat boiler and with the use of a CO2 acceptor bio-hydrogen is produced which, after cooling down, is directed to the process of hydrogasification of a carbon mixture in the first reactor, while spent CO2 acceptor in the form of a mixture of carbonates of magnesium and calcium is directed to a second reactor for calcination using hot regenerating CO2 stream. The regenerated CO2 acceptor in the form of magnesium oxide and calcium oxide is fed to the third reactor, and the CO2 stream at a temperature of approximately 400° C. leaving the second reactor is supplied in a first part to the heat exchanger in the waste heat boiler where it is cooled down. After cooling, it is directed either to a known CO2 sequestration process, or to compression and solidification of CO2 to form dry ice, or discharged to the atmosphere. The other part, as the regenerating CO2 stream, is heated to a temperature of about 700° C. needed for the calcination of magnesium carbonate, or to a temperature of about 1000-1100° C. needed for the calcination of a mixture of magnesium and calcium carbonates, and also in a preheater supplied periodically with a hot heat carrier heated in a solar collector to a temperature of 1100-1200° C., and the regenerating CO2 stream so heated is fed to a second reactor.
A comminuted dry mixture of semi-carbon with lignite or bio-carbon with coal, after removing the air from it by using CO2, is supplied from a carbon mixture preparation unit to the first low pressure reactor. In the first reactor, there occurs the process of hydrogasification of the carbon mixture, first in the internal chamber in a suspended bed falling in co-current with a gas introduced at the top of the internal chamber, said gas containing approximately 50% of H2 and 50% of CH4 at a temperature about 815° C. at normal pressure. The raw gas obtained in this process is passed from the first reactor into a separator of vapours and gases, where it is cleaned from dust and admixed gases and, in particular, is subjected to desulphurisation, after which it is separated into a pure methane mixture consisting of bio-methane and eco-methane, and into pure hydrogen recycled back to the bio-hydrogen stream. A partly reacted carbon mixture is fed to an external chamber in the first reactor, where it is made to completely react with hydrogen to produce ash and hydrogen-and-methane gas, or to partially react to form fine coke and hydrogen-and-methane gas. The ash is discharged to storage and the fine coke is fed either to combustion or to a storage facility, while the hydrogen-and-methane gas is top-fed to the inner chamber of the reactor.
In the first high pressure reactor, the carbon mixture after combining with mineral oil is fed in the form of a suspension, using a spray nozzle, to the topmost section of the reactor, called the evaporation section, at a pressure of about 6.8 MPa. At the temperature prevailing there, approximately 315° C., the oil evaporates and its vapours are discharged together with a hot raw gas leaving the middle section, called the first stage of hydrogasification, to the vapour and gas separator. The separated mineral oil, then liquefied in a condenser, is recycled to the carbon suspension in oil preparation unit, and purified raw gas, especially after desulphurisation, is separated into a methane mixture and pure hydrogen combined with bio-hydrogen. Dry carbon and bio-carbon particles at a temperature of about 300° C. are directed to the central section, subjected to fluidization in a stream of biohydrogen-containing gas leaving the reactor bottom section called the second stage of carbon hydrogasfication, and in the central section, at a temperature elevated to approximately 650° C. and at a pressure of 6.0 MPa degassing and partial hydrogasification of carbon particles takes place. Partly reacted carbon mixture is subjected to complete hydrogasification in a fluidal bed in the bottom reactor section at a temperature of 750-950° C. using bio-hydrogen fed to that section.
As the CO2 acceptor that participates in the bio-hydrogen manufacturing process magnesium oxide is used, or, preferably, a mixture of magnesium oxide with calcium oxide at a preferable ratio MgO:CaO=1:3 molar quantities of the substance needed for the reaction to produce bio-hydrogen with amount of heat around 155 kJ/mol-165 kJ/mol of CH4 at more than 100° C. during continuous operation of the third reactor, depending, however, on the amount of heat brought into the reactor by these reactants; thus, this proportion is adjustable in the range of 1:10 to 10:1.
For the process of thermal decomposition of carbonates involving solar power, CO2 acceptor and contributing energy to the bio-hydrogen generation reaction, it is preferred to use calcium oxide, whose energy of CO2 uptake, 178.8 kJ/mol, contributed to the bio-hydrogen manufacturing process is about 45% of the energy of burning one mole of elemental carbon.
In the second shaft reactor, in a bed of carbonates of magnesium and calcium fluidised by a hot stream of CO2 at about 1100° C., in the bottom zone of the reactor thermal decomposition of calcium carbonate is carried out in the temperature range around 1000° C.-800° C., and in the upper zone of the reactor thermal decomposition of magnesium carbonate is carried out in the range of approximately 800° C.-400° C., producing oxides of magnesium and calcium and carbon dioxide.
The power generation unit consumes eco-methane which is supplied to the gas turbine and a fuel cell, and the heat from the fuel cell, at a temperature of approximately 650° C., is directed to a heat exchanger to heat the regenerating CO2 stream, and flue gas exiting the fuel cell, at a temperature of approximately 400° C., is supplied to a heat exchanger in the waste heat boiler.
Flue gases from the last stage of the gas turbine, at a temperature preferably about 700° C., are supplied to the heat exchanger to heat the regenerating CO2 stream, and the flue gas exiting the outlet at a temperature of 400° C.-600° C. is fed to a heat exchanger in the waste heat boiler, wherefrom power steam at about 585° C. is fed to the steam turbine of a steam turbine unit.
The waste heat boiler receives heat from the energy production unit through the approx. 400° C.-600° C. flue gases, heat from the approx. 400° C. CO2 stream leaving the second magnesium and/or calcium carbonates calcination reactor, heat from the approx. 500° C. stream of hot bio-hydrogen and from the approx. 800° C. stream of hot eco-methane produced in the first carbon hydrogasification reactor.
The regenerating CO2 stream receives heat from a heat carrier heated up to approx. 1100-1200° C. by solar energy.
The heat carrier heated by solar energy is a gas which is inert with respect to the materials used in the solar concentrators unit, preferably carbon dioxide or nitrogen or argon, or a gas with high specific heat, preferably helium, or a vapour which is inert with respect to those materials, preferably water vapour or a liquid with a high boiling point.
Bio-methane, steam and CO2 acceptor as the reactants producing bio-hydrogen in the presence of a Ni/Al2O3 nickel catalyst in the range 500° C.-900° C. and at a pressure of 1.5 MPa-4.5 MPa in the first part of the third reactor in the reactor tubes are additionally heated by hot CO2 stream having temperature of about 800° C.-1000° C.—especially during the start-up of the third reactor.
For the bio-hydrogen producing reaction in the third reactor, of carbon monoxide and water vapour with a mixture of gases flowing in from the first part to the second part of that reactor, occurring at a lower temperature range than that in the first part, either a Cu—Zn/Al2O3 catalyst is used in the range of approximately 200° C.-300° C. or an Fe/Al2O3 catalyst in a higher temperature range of 350° C.-500° C. followed by a Cu/Al2O3 catalyst in the range of approx. 200° C.-300° C.
Another subject of the present invention is a system for the manufacture of bio-methane and eco-methane as well as heat and electricity. The system for the manufacture of bio-methane and eco-methane as well as heat and electricity, consisting of a carbon hydrogasification reactor, a reactor for calcination of carbonates of magnesium and calcium, a reactor for the production of bio-hydrogen, a vapour-gas separator, an apparatus for biomass pyrolysis, a carbon mixture feed preparation unit, a waste heat boiler possibly connected to a CO2 sequestration subsystem, an energy production unit, a preheater for the regenerating CO2 stream, heat exchangers, conveyors, pumps, and pipelines for liquids, vapours and gases, is characterized in that the first carbon hydrogasification reactor having an inlet connected via a carbon mixture/carbon suspension conveyor to a carbon mixture/carbon suspension feed preparation unit that is connected to a biomass pyrolysis apparatus and a coal or lignite conveyor, and also the first reactor having an outlet for fine coke or ash and an outlet for raw gas from the first reactor has a connection to a vapour-gas separator which has an outlet for dusts, vapours and residual gases and a residual hydrogen outlet in the form of a pipeline connected to the bio-hydrogen outlet from a third reactor, said outlet being in the form of a pipeline connected to the first hydrogasification reactor. The vapour-gas separator also has an outlet for bio-methane and eco-methane in the form of a pipeline connected to the third bio-hydrogen production reactor and to an power generation unit. The flue gas outlet at the power generation unit, in the form of a pipeline, is, connected to the waste heat boiler which has a process steam outlet connected to the third bio-hydrogen production reactor and a power steam outlet connected to the steam turbine the power generation unit, and also a CO2 inlet connected to a CO2 outlet at a second carbonate calcination reactor, said reactor also having a regenerating CO2 inlet in the form of a pipeline, said inlet connected to a preheater of that stream, and a CO2 acceptor outlet connected via an acceptor conveyor to that acceptor's inlet at the third bio-hydrogen production reactor and the outlet of spent acceptor at the third reactor is connected via a spent acceptor conveyor to the second reactor for the calcination of spent CO2 acceptor in the form of calcium and magnesium carbonates.
The biomass pyrolysis apparatus has a dry biomass inlet connected to a biomass conveyor and a bio-carbon outlet connected to a bio-carbon conveyor which feeds the carbon mixture preparation unit. The pyrolytic gas outlet at the biomass pyrolysis apparatus is connected to a gas burner disposed in the biomass pyrolysis apparatus and to a gas burner disposed in the regenerating CO2 stream preheater.
The first low pressure carbon hydrogasification reactor comprises two chambers: an internal chamber for the hydrogasification of the carbon mixture and an external chamber for the hydrogasification of fine coke. It has a thermally insulated shell through which passes an inlet channel of the carbon mixture feed coming from the mixture preparation unit having a CO2 inlet connected to a CO2 pipeline, connected to a CO2 pipeline for processing, and a gas outlet. The internal chamber of the first reactor has inlets for the primary gas from the external chamber and an outlet for the raw gas, and at the bottom, an outlet for partly converted carbon mixture fed to the external chamber, which also has a hydrogen inlet.
The second reactor, shaped as a shaft furnace, has at its bottom a CO2 acceptor feeder connected via an acceptor conveyor an acceptor inlet at the third bio-hydrogen production reactor, said reactor having an outlet for spent CO2 acceptor connected via a spent acceptor conveyor to an inlet at the second magnesium and calcium carbonates calcination reactor. The second reactor is equipped with at least one regenerating CO2 stream nozzle located at the bottom and connected to the regenerating CO2 stream preheater, additionally, the second reactor has at the top a CO2 outlet connected to a CO2 inlet at the waste heat boiler.
The preheater of the regenerating CO2 stream is equipped with a heat exchanger, which is connected to a heat exchanger in the power generation unit, and is also equipped with a gas burner connected to the pyrolytic gas pipeline and with a pulverized fuel burner, connected to a fine coke conveyor from the first reactor and/or coal or bio-carbon conveyor. Additionally, the preheater has a heat exchanger connected to a solar collector unit through the outlet of the heat carrier to a heat exchanger placed in the focal point of each concave mirror and the inlet of that carrier. The heat exchanger in the power generation unit has at the inlet a connection to a CO2 stream pipeline, and at the outlet a connection to the heat exchanger in the preheater. The CO2 regenerating stream outlet at the heat exchanger in the preheater is connected to the inlet at the second carbonate calcination reactor—with a nozzle or a nozzle system located in the bottom of the reactor, said CO2 stream outlet also having a connection to the third reactor to heat the reactor tubes. The power and heat generation unit has an electric connection to a power grid, and a connection via a heat pipeline to a heating network.
The power generation unit, consisting of a fuel cell and a gas-steam power and heat plant, is connected to the unit's collector heat exchanger, whereas the fuel cell has a heat exchanger connected via heat pipelines to the collector heat exchanger. The outlet of the fuel cell is connected via a heat pipeline to the waste heat boiler. Flue gas outlet at the methane combustion chamber is connected to the gas turbine and the gas turbine flue gas outlet is connected to a heat exchanger located in the collector heat exchanger and, further, to the waste heat boiler. The waste heat boiler is connected to the third bio-hydrogen production reactor via a process steam pipeline and to the steam turbine of the steam turbine unit via a power steam pipeline and, additionally, a CO2 pipeline runs through the collector heat exchanger of the power generation unit, said pipeline having a heat exchanger connected to the heat exchanger in the preheater.
In addition, the waste heat boiler has an inlet for water and an inlet for CO2 from the second carbonate calcination reactor, said inlets connected through the heat exchanger in the boiler to a CO2 outlet for processing or discharging to the atmosphere and/or to a CO2 outlet for sequestration and, additionally, the waste heat boiler has an inlet for the heat carrier from the hydrogen, methane and fuel cell flue gas cooling processes.
The third bio-hydrogen production reactor has internal tubes containing a nickel catalyst supported on a ceramic substrate Ni/Al2O3 located in the first part of the third reactor, said first part connected to a hot CO2 stream heating these tubes, as well as tubes containing either a Cu—Zn/Al2O3 catalyst or an Fe/Al2O3 and Cu/Al2O3 catalyst, said tubes located in the second part of the third bio-hydrogen production reactor, whereas the third reactor has an inlet for bio-methane, an inlet for process steam and an inlet for CO2 acceptor, as well as an outlet for magnesium and calcium carbonates and an outlet for bio-hydrogen.
The power generation unit for small objects consists of either a fuel cell and/or a co-generator.
The methane pipeline that supplies methane to the power generation unit has a connection in the form of a pipeline to either a gas distribution pipeline or a methane compressor and to a CNG tank or a methane condenser and an LNG tank.
An advantage of the method of producing bio-methane and eco-methane according to the present invention is the use of bio-carbon from biomass renewable on a yearly basis to produce bio-methane and to transfer heat to the bio-hydrogen production reaction through the new CO2 acceptor in the form of magnesium and calcium oxides, said acceptor making it possible to control the heat, and the regeneration heat is available from the power generation unit, from pyrolytic gas combustion, and from solar energy, which allows for low consumption of elemental carbon C from fossil carbon and to convert it with steam to eco-methane—to produce one molecule of CH4 at most one carbon atom (C) of fossil carbon is consumed. This significantly reduces CO2 emission and carbon-related solid waste emissions into the environment. It significantly reduces the consumption of fossil carbon in the manufacture of the gaseous fuel: bio-methane or eco-methane. This fuel allows generating electricity in the power generation unit with energy efficiency exceeding 60%.
The advantage is the simultaneous hydrogasification of bio-carbon and fossil carbon in one reactor using bio-hydrogen. Hydrogasification of carbon is an exothermic process; it does not need heat to be supplied to the reaction, therefore heat exchangers in the hydrogasification reactor are not necessary. Formed in the CO2 uptake reaction, magnesium carbonate is easily calcined at about 550° C. using heat supplied from a source of electricity and heat, which greatly increases the efficiency of the system. The mixture of calcium and magnesium carbonates requires a higher calcination temperature, approx. 900° C. The appropriately higher temperature is achieved in the regenerating CO2 stream by using a gas burner and a pulverized fuel burner. The temperature of the CO2 stream, up to 1200° C., is achieved in the solar collector unit, thus creating a new method of using solar energy—it its accumulated in the regenerated CO2 acceptor, especially in the calcium-based CO2 acceptor, and then in the gaseous fuel produced, namely bio-methane and eco-methane. The efficiency of the production of electricity from solar energy is at the level of 48%. Currently, the efficiency of photovoltaic cells is approximately 15%. The pure CO2 stream obtained in the process of calcination of the spent CO2 acceptor is easy to incorporate in a CO2 sequestration process, whether under the ground or by binding CO2 to silicates to form stable products. This leads to emission-free generation of electricity using fossil carbon for this purpose.
The subject of the present invention is illustrated in an example embodiment in the drawings in which
Bio-carbon with elemental carbon content C′ of 77% and coal having elemental carbon content of 70-80% were fed to the bio-carbon and fossil carbon hydrogasification process, keeping pre-set bio-carbon to coal ratio of C′:C=1:1. In the first bio-carbon and fossil carbon hydrogasification reactor 1 shown in
The bio-hydrogen production reaction takes place at a temperature of about 500° C. at appropriately increased pressure. Increasing the pressure to 3 MPa results in increased reaction speed, reduces the size of the third reactor 3 and increases the MgCO3 thermal decomposition temperature, thereby boosting the operation of the CO2 acceptor, and decreases reaction temperature. Heat from the heat exchangers 7c and 7d is supplied through heat pipelines, preferably the collector pipeline 7a, to the waste heat boiler 4, as well as from the hot stream of regenerating CO2 at a temperature of about 400° C. supplied to the heat exchanger in the boiler by a CO2 pipeline 10b. Most heat is supplied to the boiler by the power generation unit 5 through flue gas pipeline 7g. The waste heat boiler 4 is also supplied with make-up water from condensates and from an external source of water using a water pipeline 12. The waste heat boiler 4 produces process steam at about 400° C., which is supplied through a process steam pipeline 11a to the third bio-hydrogen production reactor 3, and power steam at a temperature of about 585° C. supplied via a power steam pipeline 11b to the power steam turbine 38 TP in the power generation unit 5.
The spent CO2 acceptor in the form of magnesium carbonate is supplied from the third bio-hydrogen production reactor 3 using the spent CO2 conveyor 14 and fed at the top of the second reactor 2, said reactor being shaft-shaped and intended for the calcination of magnesium carbonate. The regenerated CO2 acceptor in the form of magnesium oxide is fed from the bottom of the second reactor 2 via a feeder 2a and a CO2 acceptor conveyor 13 back to the third reactor 3. The calcination of magnesium carbonate occurs at a temperature of approx. 500° C.-550° C. in a falling fluidised bed inside the shaft reactor 2 using a hot stream of regenerating CO2 at a temperature around 650° C.-700° C. entering the reactor through a nozzle 2b or a battery of nozzles located at the bottom of the second reactor 2. This stream, while passing through the fluidised bed of magnesium carbonate, causes its thermal decomposition and the regenerated magnesium oxide drops down along the reactor onto a feeder 2a, and the enriched CO2 stream, cooled down at the exit of the second reactor 2 to about 400° C., enters the pipeline 10a, and then is split into two streams of CO2—the first stream of regenerating CO2 flows through pipeline 10d to heat exchanger 8 located in the power generation unit 5 where it is heated to about 650° C. by fuel cells 45 operating at a temperature of 650° C. and by a part of the blowdown exhaust flue gas at approximately 700° C. discharged from an extraction gas turbine 36 via a heat exchanger 8b and is fed to the waste heat boiler 4, and then the regenerating CO2 stream at approx. 650° C. flows through a CO2 pipeline to a regenerating CO2 heat exchanger 9 where it is heated up to approx. 700° C. by a gas burner 9b supplied with pyrolytic gas fuel fed to the burner through the pipeline 22b and the regenerating CO2 stream so heated is supplied through a CO2 pipeline 10 to the nozzle or nozzle system 2b located at the bottom of the second magnesium carbonate calcination reactor 2.
When necessary, the heat exchanger 7c through which a hot stream of eco-methane flows at a temperature of approximately 800° C., gets connected via a heat pipeline to the CO2 regenerating stream heater 9 and further to the waste heat boiler 4. The second stream of excess CO2 at a temperature of approximately 400° C. flows through the CO2 pipeline 10b to the heat exchanger 4a in the waste heat boiler heat 4 and, cooled down in the boiler, is discharged by CO2 pipeline 10f for utilisation. The cooled eco-methane stream flows through the pipeline 20d to the power generation unit 5, said unit having a connection to a power grid 6, where it feeds the fuel cell 45 and a gas-steam power and heat plant. Hot flue gases from the fuel cell flow in pipelines 7e through the collector pipeline 7f to the waste heat boiler 4. The fuel cell also comprises a heat exchanger 8a connected to a heat exchanger in the collector heat exchanger 8 of the power generation unit 5. It also has a connection through an inverter to the power network 6. The cooled eco-methane stream also flows through the pipeline 20e into a combustion chamber 34 of a gas turbine unit that consists of a first gas turbine 36 connected via a shaft to a first generator 36a and to an air compressor 35, said first generator 36a having a connection to the power grid 6. The air compressor 35 delivers air to the combustion chamber 34 through a pipeline 42. The hot and compressed flue gases at a temperature of approx. 1200° C. leave the chamber 34 and flow to the first gas turbine 36 where they expand and partially cool down to a temperature of approximately 700° C. in the last stage of the turbine and the flue gases flow through the blowout flue gas pipeline 43 to the heat exchanger 8b located in the collector heat exchanger 8 and further are sent to the waste heat boiler 4. The expanded flue gases leaving the first turbine 36 are sent through a flue gas pipeline 7g directly to the waste heat boiler 4. The waste heat boiler 4 produces process steam at about 400° C., said steam being sent through steam pipeline 1a to the third reactor 3, and power steam at 585° C. sent through steam pipeline 11b to a second steam turbine 38 coupled through a shaft to a second generator 38a, said generator having a connection to the power grid 6. The steam turbine 38 is connected by a cooled down steam pipeline to a condensing unit 39, from which the resulting condensate flows through a condensate pipeline 40 to a condensate pump 41 and are pumped to the waste heat boiler 4.
Bio-carbon with elemental carbon content C′ of 77% was fed using bio-hydrogen to the bio-carbon hydrogasification process. In the first bio-carbon hydrogasification reactor shown in
The operation of the waste heat boiler 4 producing only process steam at a temperature of approximately 400° C. delivered through process steam pipeline 11a to the third bio-hydrogen production reactor 3, and partly through pipeline 11b for heating purposes, is carried out as described in Example I. The calcination of the spent CO2 acceptor in the form of magnesium carbonate in the second reactor 2, using a hot stream of regenerating CO2 supplied through CO2 pipeline 10d to the heat exchanger 8 located in the fuel cell 45, where it is heated up to a temperature of about 600° C., and then fed to the heater 9 that heats this stream, where it is heated up by the gas burner 9b supplied with pyrolytic gas and partly with bio-methane to approximately 700° C., and then recycled via CO2 pipeline 10 to the second MgCO3 calcination reactor 2, is carried out as described in Example I.
The bio-methane stream, cooled down in the heat exchanger 7c, flows to the power generation unit 5 where it feeds the fuel cell 45. Hot flue gases from the fuel cell flow through pipelines 7e and further through collector pipeline 7f to the waste heat boiler 4 where they pass heat, and then are discharged to the atmosphere. The fuel cell also comprises a heat exchanger 8a, shown in
It also has a connection through an inverter to the power grid 6.
Semi-carbon with elemental carbon content C′ of approx. 60% and lignite with elemental carbon content C of approx. 60% were fed to the bio-carbon and fossil carbon hydrogasification process, keeping the pre-set, preferred bio-carbon to coal ratio of C′:C=1:1. In the first bio-carbon and fossil carbon hydrogasification reactor 1 shown in
Cooled down eco-methane is sent via pipeline 20d to the power generation unit 5 being a gas-steam power and heat plant to combustion chamber 34 of the first gas turbine 36 in that unit. The process of generating electricity and heat has been shown in Example I.
In another embodiment of the invention, the preheater 9 of the regenerating CO2 stream is connected to a solar collector system as shown in
As shown in
The power generation unit 5 has an electric connection 6 to a power grid, and a connection, via heat pipeline 7b to a municipal heat pipeline, as well as a connection via hot flue gas pipeline 7g to the waste heat boiler 4; additionally, the waste heat boiler 4 has a connection via water pipeline 12 to an external source of water.
The second reactor 2 for the calcination of magnesium carbonate or a mixture of magnesium and calcium carbonates is preferably built in the shape of a shaft furnace; it consists of a thermally insulated shell having at its top an inlet for spent CO2 acceptor, connected via spent CO2 acceptor conveyor 14 to the spent acceptor outlet at the third bio-hydrogen production reactor 3, and having at the bottom an outlet for regenerated CO2 acceptor in the form of magnesium oxide or a mixture of magnesium and calcium oxides, said outlet connected to a CO2 acceptor feeder 2a and further, via acceptor conveyor 13, to the CO2 acceptor inlet at the third reactor 3. The second reactor 2 has at its bottom a CO2 nozzle system 2b that feeds hot regenerating CO2 stream at a temperature of approx. 650° C.-700° C. in case of thermal decomposition of MgCO3 in the fluidised bed or approx. 1000° C.-1100° C. in the case of thermal decomposition of a mixture of carbonates MgCO3 and CaCO3 in the fluidised bed, and at the top it has a CO2 outlet connected to CO2 pipeline 10a splitting into two branches: into a branch 10b of the CO2 pipeline connected to heat exchanger 4a located in the waste heat boiler 4 and, on leaving the waste heat boiler, splitting into CO2 pipeline 10c leading to the CO2 sequestration sub-system and pipeline 10f, and into a branch 10d of the regenerating CO2 stream pipeline connected to the collector heat exchanger 8 located in the power generation unit 5 and further connected to the heat exchanger 9a in the regenerating CO2 stream preheater 9 and further, through a CO2 pipeline 10 it is connected to a nozzle system 2b. The regenerating CO2 stream preheater 9 additionally has a gas burner 9b connected to pyrolytic gas pipeline 22b, a pulverised coal burner 27a with a fine coke/coal pulveriser mill connected to ground fine coke conveyor 28a and to coal/bio-coal conveyor 27, whereas the ground coke conveyor 28a has a connection to the fine coke conveyor 28 which also has a connection to fine coke conveyor 28b discharging to a storage facility. The CO2 preheater 9 also has an outlet for ash, connected to waste conveyor 29, and also has a heat exchanger 30 connected to the solar collector unit. The waste heat boiler 4 has a collective heat inlet 7a connected to a heat exchanger 7d for bio-hydrogen and a heat exchanger 7c for eco-methane. It also has an inlet for condensate and make-up water, connected to water pipeline 12, and an outlet for power steam connected via steam pipeline 11b to a steam turbine in the power generation unit 5, and a process steam outlet connected via steam pipeline 11a to the third reactor 3. The hot CO2 stream pipeline 10 has a connection in the form of C02 pipeline 10e to the third reactor 3.
The third bio-hydrogen production reactor 3 is built inside with tubes 3a with catalyst inside them, has a bio-hydrogen outlet connected through hot bio-hydrogen pipeline 18a to heat exchanger 7d and to pipeline 19 for recycled hydrogen from the vapour-gas separator. The heat exchanger 7d is connected via a pipeline to the waste heat boiler 4, and also, via cooled down bio-hydrogen pipeline 18b, to the first carbon hydrogasification reactor. The hot bio-methane inlet at the third reactor 3 is connected through bio-methane pipeline 20a to methane mixture pipeline 20 coming from the vapour-gas separator 15, which is also connected to eco-methane pipeline 20b connected to heat exchanger 7c and further connected through pipeline 20c and pipeline 20d to the power generation unit 5. That unit also has a connection 6 to a power grid.
The fuel cell 45 is connected to an air pipeline 44, and the pipelines 7e for flue gases exiting the fuel cell 45 are connected through collector pipeline 7f to a heat exchanger in the waste heat boiler 4. The heat exchanger 8a located in the fuel cell 45 is connected to the collector heat exchanger 8 through pipeline 10d with regenerating CO2 stream preheater. The electricity outlet at the fuel cell 45 is connected by an inverter to a power grid 6.
The combustion chamber 34 is connected at the inlet, by air pipeline 37, to an air compressor 35 coupled via shaft with the first gas turbine 36 and a start-up engine 35a, and at its exit the combustion chamber 34 is connected by hot flue gas pipeline 42 to the first gas turbine 36 coupled via shaft with the first generator 36a connected to the power grid 6, whereas the exit of the discharge flue gases from the turbine is connected by flue gas pipeline 43 to the heat exchanger 8b located in the collector heat exchanger 8 of the power generation unit 5 and further connected to the waste heat boiler 4, and the outlet of the expanded flue gas from the first turbine 36 is connected via flue gas pipeline 7g to the waste heat boiler 4 which has a discharge outlet 43a for cooled down flue gas and an inlet of the collector heat pipeline 7a. In addition, the waste heat boiler 4 has a hot CO2 stream inlet through CO2 pipeline 10b and an outlet of that pipeline branching out into CO2 pipeline 10c connected to the CO2 sequestration sub-system and CO2 pipeline 10f connected to CO2 pipeline 10g.
The waste heat boiler 4 also has a process steam outlet connected via steam pipeline 11a to the third bio-hydrogen production reactor, as well as a power steam discharge outlet connected through steam pipeline 11b to the second steam turbine 38, and the outlet at the second turbine 38 is connected to a condenser 39 which, in turn, via condensate pipeline 40 through condensate pump 41, is connected to the waste heat boiler 4. The waste heat boiler 4 also has a connection to an external water source through water pipeline 12.
Number | Date | Country | Kind |
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P.411560 | Mar 2015 | PL | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2016/051373 | 3/10/2016 | WO | 00 |