| Patent application number | Description | Published |
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| 20080302107 | METHOD OF AND POWER PLANT FOR GENERATING POWER BY OXYFUEL COMBUSTION - A method of and a power plant for generating power by combusting carbonaceous fuel with substantially pure oxygen, and a method of modifying a process of generating power by combusting carbonaceous fuel from combusting the fuel with air to combusting the fuel with substantially pure oxygen. The methods include feeding substantially pure oxygen into a furnace for combusting fuel with the oxygen to produce exhaust gas including mainly carbon dioxide and water, recovering low-grade heat from the exhaust gas by using multiple exhaust gas coolers arranged in a downstream portion of the exhaust gas channel, wherein a first portion of the recovered low-grade heat is used for preheating feedwater; pressurizing a first portion of the exhaust gas in multiple exhaust gas compressors so as to produce liquid carbon dioxide, recycling a second portion of the exhaust gas to the furnace via an exhaust gas recycling channel, using a first portion of steam extracted from a steam turbine system to preheat feedwater, wherein the first portion of the recovered low-grade heat is more than 50% of the total amount of recovered low-grade heat, or larger than the first portion of the recovered low-grade heat in the air-fired process, allowing minimizing of the first portion of the extracted steam, and the expanding of a second portion of the extracted steam in at least one auxiliary steam turbine for driving at least one compressor or at least one pump of the power plant. | 12-11-2008 |
| 20090020405 | METHOD OF AND A PLANT FOR COMBUSTING CARBONACEOUS FUEL BY USING A SOLID OXYGEN CARRIER - A method of and a plant for combusting carbonaceous fuel, the method including the steps of introducing particulate oxygen selective sorbent, such as a perovskite type material, into an adsorption reactor of the combustion plant to form a first particle bed in the adsorption reactor, fluidizing the first particle bed by an oxygen-containing first fluidizing gas to adsorb oxygen from the fluidizing gas to the sorbent, conveying oxygen-rich sorbent from the adsorption reactor to a combustion reactor of the combustion plant to form a second particle bed in the combustion reactor, fluidizing the second particle bed by an oxygen-deficient second fluidizing gas to desorb oxygen from the sorbent, so as to produce free oxygen gas, and introducing carbonaceous fuel into the combustion reactor to oxidize the fuel with the free oxygen gas. | 01-22-2009 |
| 20090158978 | METHOD OF CONTROLLING A PROCESS OF GENERATING POWER BY OXYFUEL COMBUSTION - A method of controlling a process of generating power in a power plant with a boiler by combusting carbonaceous fuel with substantially pure oxygen. At full load conditions, the method includes introducing a first carbonaceous fuel feed stream into a furnace, introducing a first substantially pure oxygen feed stream into the furnace for combusting the first carbonaceous fuel feed stream with the oxygen, and recirculating a portion of the exhaust gas discharged from the furnace at a first recirculation flow rate to the furnace, to form, together with the first substantially pure oxygen feed stream, a first inlet gas stream having a predetermined average oxygen content, thereby discharging exhaust gas from the furnace at a first discharge flow rate. In second load conditions, corresponding to at most 90% load, the method includes introducing a second carbonaceous fuel feed stream into the furnace, introducing a second substantially pure oxygen feed stream into the furnace for combusting the second carbonaceous fuel feed stream with the oxygen, and recirculating a portion of the exhaust gas discharged from the furnace at a second recirculation flow rate to the furnace, to form, together with the second substantially pure oxygen feed stream, a second inlet gas stream, so as to discharge exhaust gas from the furnace at a second discharge flow rate, and controlling the second recirculation flow rate to be from the first recirculation flow rate to a value providing the second discharge flow rate to be substantially as high as the first discharge flow rate. | 06-25-2009 |
| 20090260585 | Oxyfuel Combusting Boiler System and a Method of Generating Power By Using the Boiler System - Carbonaceous fuel is combusted with an oxidant gas in a furnace of a boiler system to generate power. Oxidant gas is fed into the furnace for combusting the fuel to produce exhaust gas, the exhaust gas is discharged from the furnace via an exhaust gas channel, a stream of feedwater is conveyed from a final economizer arranged in the exhaust gas channel to evaporating and superheating heat exchange surfaces arranged in the furnace and in the exhaust gas channel for converting the feedwater to superheated steam, the superheated steam is converted in a high-pressure steam turbine for generating power, a first portion of steam is extracted from the high-pressure steam turbine for preheating the feedwater, a second portion of steam is conveyed from the high-pressure steam turbine to reheating heat exchange surfaces arranged in the exhaust gas channel for generating reheated steam, and the reheated steam is expanded in an intermediate pressure steam turbine for generating power. The oxidant gas can be a mixture of substantially pure oxygen and recycled exhaust gas, and the ratio of the first and second portions of steam can be controlled to obtain a desired flue gas temperature in the exhaust gas channel downstream of the final economizer. | 10-22-2009 |
| 20100077947 | METHOD OF COMBUSTING SULFUR-CONTAINING FUEL - A method of combusting sulfur-containing fuel in a circulating fluidized bed boiler includes the steps of (a) feeding sulfur-containing fuel into a furnace of the circulating fluidized bed boiler, (b) combusting the fuel with oxidant gas consisting essentially of pure oxygen and circulated exhaust gas, so as to form exhaust gas having carbon dioxide and water as its main components, and (c) feeding calcium carbonate containing material into the furnace so as to capture sulfur dioxide into calcium sulfate in the furnace. The temperature in the furnace is maintained above 870° C. | 04-01-2010 |
| 20110094228 | Method of Increasing the Performance of a Carbonaceous Fuel Combusting Boiler System - A method of increasing the power of a carbonaceous fuel combusting boiler system includes the steps of (a) feeding carbonaceous fuel into a furnace of the boiler system, (b) feeding oxidant gas into the furnace for combusting fuel to produce exhaust gas, (c) discharging the exhaust gas from the furnace via an exhaust gas channel, (d) conveying a stream of feedwater from a boiler economizer arranged in the exhaust gas channel to evaporating and superheating heat exchange surfaces arranged in the furnace and in the exhaust gas channel for converting the feedwater to superheated steam, (e) expanding the superheated steam in a high-pressure steam turbine for generating power, (f) extracting steam from the high-pressure steam turbine at a decreased rate for preheating the feedwater, (g) conveying steam from the high-pressure steam turbine at an increased rate to a reheater arranged in the exhaust gas channel for generating reheated steam, (h) expanding the reheated steam in an intermediate pressure steam turbine for generating power, and (i) conveying the exhaust gas in the exhaust gas channel from the reheater through a boiler economizer to a gas heater. The heat exchange surface area of at least one of the reheater and the boiler economizer is increased and/or a high pressure economizer is added downstream of the boiler economizer and upstream of the gas heater. | 04-28-2011 |
| 20110139046 | Emissionless Oxyfuel Combustion Process and a Combustion System Using Such a Process - A method of combusting carbonaceous fuel in a combustion system. The combustion system includes a source of oxygen and a furnace. The method includes the steps of (a) feeding fuel and combustion gas including oxygen and recycling gas into the furnace for combusting the fuel with the oxygen and producing exhaust gas that includes CO | 06-16-2011 |
| 20110265697 | Circulating Fluidized Bed Combustor and a Method of Operating a Circulating Fluidized Bed Combustor - A circulating fluidized bed combustor arrangement includes (a) a circulating fluidized bed reactor in which (i) a combustion chamber combusts a fuel material in a suspension of solid particles of a circulating fluidized bed, (ii) a first cyclone separator arrangement receives a mixture of gases and solid particles from the combustion chamber for separating a first fraction of the solid particles from the exhaust gases, and (iii) a solid particle return system connected to the first cyclone separator returns separated solid particles to the combustion chamber, (b) a heat transfer section including a water/steam heat exchanger section arranged after the first cyclone separator arrangement in the exhaust gas flow path, (c) a heat recovery device provided in connection with the combustion chamber, the first cyclone separator arrangement and the heat transfer section being arranged for recovering heat resulting from the combustion process in the combustion chamber, (d) a selective catalytic reduction system arranged in the exhaust gas flow path, after the heat transfer section, for removing NOx from the exhaust gas, (e) a device for injecting NOx reducing agent into the exhaust gases upstream of the selective catalytic reduction system, and (f) a second cyclone separator arrangement provided downstream of the first cyclone separator arrangement and upstream of the heat transfer section, in which a second fraction of the solid particles is separated form the exhaust gases. | 11-03-2011 |
