42540 results about "Flue gas" patented technology

In a method for generating energy in an energy generating installation (10) having a gas turbine (12), in a first step, an oxygen-containing gas is compressed in a compressor (13, 14) of the gas turbine (12), in a second step the compressed gas is supplied, with the addition of fuel, for combustion in a combustion chamber (15), in a third step the hot flue gas from the combustion chamber (15) is expanded in a turbine (16) of the gas turbine (12) so as to perform work, and, in a fourth step, a branched-off part stream of the expanded flue gas is recirculated into a part of the gas turbine (12) lying upstream of the combustion chamber (15) and is compressed. A reduction in the CO₂ emission, along with minimal losses of efficiency, is achieved in that carbon dioxide (CO₂) is separated from the circulating gas in a CO₂ separator (19), and in that measures are taken to compensate for the efficiency losses in the gas turbine cyclic process which are associated with the CO₂ separation.

Certain embodiments and aspects of the present invention relate to photobioreactor apparatus (100) designed to contain a liquid medium (108) comprising at least one species of photosynthetic organism therein, and to methods of using the photobioreactor apparatus (100) as part of a gas-treatment process and system able to at least partially remove certain undesirable pollutants from a gas stream (608). In certain embodiments, the disclosed photobioreactor apparatus (100 can be utilized as part of an integrated combustion method and system, wherein photosynthetic organisms utilized within the photobioreactor (100) at least partially remove certain pollutant compounds contained within combustion gases, e.g. CO₂ and/or NO_X, and are subsequently harvested from the photobioreactor (100), processed, and utilized as a fuel source for a combustion device (e.g. an electric power plant generator and/or incinerator).

Certain embodiments and aspects of the present invention relate to photobioreactor apparatus designed to contain a liquid medium comprising at least one species of photosynthetic organisms therein, and to methods of using the photobioreactor apparatus as part of a production process for forming an organic molecule-containing product, such as a polymeric material and/or fuel-grade oil (e.g. biodiesel), from biomass produced in the photobioreactor apparatus. In certain embodiments, the disclosed organic molecule/polymer production systems and methods, photobioreactor apparatus, methods of using such apparatus, and/or gas treatment systems and methods provided herein can be utilized as part of an integrated combustion and polymer and/or fuel-grade oil (e.g. biodiesel) production method and system, wherein photosynthetic organisms utilized within the photobioreactor are used to at least partially remove certain pollutant compounds contained within combustion gases, e.g. CO₂ and/or NO_x, and are subsequently harvested from the photobioreactor, processed, and utilized as a source for generating polymers and/or organic molecule-containing products (e.g. fuel-grade oil (e.g. biodiesel)) and/or as a fuel source for a combustion device (e.g. an electric power plant generator and/or incinerator).

A method of generating energy in a power plant (30) having a gas turbine (29), includes a first step a gas containing air (1) is compressed in a first compressor (2) of the gas turbine (29), a second step the compressed gas (3, 3a, 3b; 5; 7a, 7b) is fed to a combustion process with the addition of fuel (8) in a combustor (23), a third step the hot flue gas (9) from the combustor (23) is expanded in an expander or a turbine (10), driving a generator (18), of the gas turbine (29) while performing work, and a fourth step a partial flow of the expanded flue gas (11) is recirculated to the inlet of the first compressor (2) and admixed with the gas containing air (1). Carbon dioxide (CO₂) is separated from the compressed gas (3, 3a, 3b; 5; 7a, 7b) in a CO₂ separator (6) before the third step. In such a method, the overall size and energy costs are reduced by virtue of the fact that, to permit increased CO₂ concentrations in the CO₂ separator (6), not more than about 70% of the carbon dioxide contained in the compressed gas (3, 3a, 3b; 5, 5a, 5b; 7a, 7b) is removed from the compressed gas (3, 3a, 3b; 5, 5a, 5b; 7a, 7b).

A method and apparatus for synthesizing ethanol using synthetic routes via synthesis gas are disclosed. A method and apparatus for gasifying biomass, such as biomass, in a steam gasifier that employs a fluidized bed and heating using hot flue gases from the combustion of synthesis gas is described. Methods and apparatus for converting synthesis gas into ethanol are also disclosed, using stepwise catalytic reactions to convert the carbon monoxide and hydrogen into ethanol using catalysts including iridium acetate.

An adsorbent composition for removing mercury from a flue gas stream, and a method of its use. The composition is a powdered activated carbon having at least one of a halogen-containing component and an alkaline component dispersed thereon. A flow agent can be composited with the material to maintain flowability in situ.

This invention is related to so-called combined cycle co-generation installations, and it addresses present concerns of the industry. Among these, combustion stability, corrosion (due to large water content in the flue gases), large heat transfer areas, and the like. In some embodiments, an additional heat exchanger is added to heat combustion air with a portion of the exhaust gases resulting from an engine, preferably a gas turbine. As a result, the efficiency of the cycle will improve, the oxidant will be enriched by above 50% oxygen, the combustion process will be enhanced, and the dimensions of the boiler may be reduced. It is considered that the combustion air will require between 10% and 80% of the total flue gas volume, more preferably between 20% and 40%. This is the portion of the flue gases sent through the heat exchanger. A control system designed to optimize the flow of the different streams is also presented. Other inventive embodiments forego heat exchanges in lieu of precise control of two flows of exhaust gas, with preferred addition of additional oxidant to the boiler bumers.

Various methods for decreasing the amount of nitrogen oxides released to the atmosphere as a component of combustion gas mixtures are provided. The methods specifically provide for the removal of nitric oxide and nitrogen dioxide (NOx) from gas mixtures emitted from stationary combustion systems. In particular, methods for improving efficiency of nitrogen oxide reduction from combustion systems include injecting metal-containing compounds into the main combustion zone and/or the reburning zone of a combustion system. The metal containing compounds react with active combustion species, and these reactions change radical concentrations and significantly improve NOx conversion to molecular nitrogen. The metal-containing additives can be injected with the main fuel, in the main combustion zone, with secondary or reburning fuel addition, or at several locations in the main combustion zone and reburning zone. Optionally, nitrogenous reducing agents and/or overfire air can be injected downstream to further increase NOx reduction.

A method and installation are disclosed which can, for example, provide for reliable, low-Nox-emission operation of a gas turbine installation with hydrogen-rich fuel gas. An exemplary gas turbine installation includes an arrangement for flue gas recirculation into a compressor inlet and for fuel gas dilution. Oxygen content in combustion air can be reduced by recirculation of recooled flue gas, and the fuel gas can be diluted with compressed flue gas. The oxygen reduction in the combustion air can lead to minimum residual oxygen in the flue gas which can be used for fuel gas dilution. As a result of the flue gas recirculation, water content in the combustion air can be increased by feedback of the water which results as a combustion product. The oxygen reduction, increased water content, and fuel dilution can reduce the flame velocity of hydrogen-rich fuel gases and enable a robust, reliable and low-emission combustion.

A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

Bromine-containing compounds, added to the coal, or to the boiler combustion furnace, are used to enhance the oxidation of mercury, thereby enhancing the overall removal of mercury in downstream pollution control devices. The method is applicable to utility power plants equipped with wet FGD systems, as well as those plants equipped with spray dryer absorber FGD systems.

A new method for the removal of environmental compounds from gaseous streams, in particular, flue gas streams. The new method involves first oxidizing some or all of the acid anhydrides contained in the gas stream such as sulfur dioxide (SO₂) and nitric oxide (NO) and nitrous oxide (N₂O) to sulfur trioxide (SO₃) and nitrogen dioxide (NO₂). The gas stream is subsequently treated with aqua ammonia or ammonium hydroxide which captures the compounds via chemical absorption through acid-base or neutralization reactions. The products of the reactions can be collected as slurries, dewatered, and dried for use as fertilizers, or once the slurries have been dewatered, used directly as fertilizers. The ammonium hydroxide can be regenerated and recycled for use via thermal decomposition of ammonium bicarbonate, one of the products formed. There are alternative embodiments which entail stoichiometric scrubbing of nitrogen oxides and sulfur oxides with subsequent separate scrubbing of carbon dioxide.

Power plants and process for lowering CO₂ emissions generally includes extracting a portion of the recirculated CO₂-rich flue gas mid-way through the compression pathway of a gas turbine and removing the CO₂ in a separation unit. The remaining portion of the CO₂ rich flue gas (i.e., the portion of the recirculated flue gas that was not fed to the separation unit) is mixed with fresh air coming from an additional compressor-expander and then fed back to the compression pathway. As a result, flue gas recirculation increases the CO₂ concentration within the working fluid, leading to an additional increase in CO₂ partial pressure. As the concentration and partial pressure of CO₂ is increased, a lower energy penalty is observed to remove the CO₂. Moreover, a reduced volume is fed to the CO₂ separation unit during operation. Consequently, the size of the separation equipment can be reduced as well as the energy required for the separation process.

Ultra cleaning of combustion gas to near zero concentration of residual contaminants followed by the capture of CO₂ is provided. The high removal efficiency of residual contaminants is accomplished by direct contact cooling and scrubbing of the gas with cold water. The temperature of the combustion gas is reduced to 0-20 degrees Celsius to achieve maximum condensation and gas cleaning effect. The CO₂ is captured from the cooled and clean flue gas in a CO₂ absorber (134) utilizing an ammoniated solution or slurry in the NH₃—CO₂H₂O system. The absorber operates at 0-20 degrees Celsius. Regeneration is accomplished by elevating the pressure and temperature of the CO₂-rich solution from the absorber. The CO₂ vapor pressure is high and a pressurized CO₂ stream, with low concentration of NH₃ and water vapor is generated. The high pressure CO₂ stream is cooled and washed to recover the ammonia and moisture from the gas.

Sorbents for removal of mercury and other pollutants from gas streams, such as a flue gas stream from coal-fired utility plants, and methods for their manufacture and use are disclosed. The methods include mixing sorbent substrate particles with a sulfide salt and a metal salt to form a metal sulfide on the outer surface of the sorbent particles.

Disclosed herein, without limitation, are activated carbon honeycomb catalyst beds and systems for removing mercury and other toxic metals from a process stream, i.e, from flue gas of a coal combustion system. The activated carbon honeycomb can for example remove greater than 90% mercury from flue gas with a simple design and without adding material to the flue gas. Also disclosed herein, and without limitation, are methods for manufacturing and using the disclosed honeycomb catalyst beds and systems.

There is provided a process for the capture and sequestration of carbon dioxide that would otherwise enter the atmosphere and contribute to global warming and other problems. CO₂ capture is accomplished by reacting carbon dioxide in flue gas with an alkali metal carbonate, or a metal oxide, particularly containing an alkaline earth metal or iron, to form a carbonate salt. A preferred carbonate for CO₂ capture is a dilute aqueous solution of additive-free (Na₂CO₃). Other carbonates include (K₂CO₃) or other metal ion that can produce both a carbonate and a bicarbonate salt. Examples of suitable metal oxides include several alkaline earths including CaO and MgO. The captured CO₂ is preferably sequestered using any available mineral or industrial waste that contains calcium magnesium or iron in non-carbonate forms, or iron in the Fe⁺² oxidation state.

An integrated power production system including a fossil fuel power plant for processing fossil based fuel such as coal or natural gas arranged in tandem with a carbonate fuel cell having an anode and a cathode section. The flue gas of the power plant serves exclusively as the inlet gas for the cathode section of the fuel cell. Anode exhaust gas leaving the anode section of the fuel cell is subjected to processing including sequestration of the carbon dioxide in the exhaust gas.

The present invention relates to a method to catalyze the oxidation of Hg(0) in a flue gas stream prior to standard emissions control equipment. The oxidized mercury has been found to be more condensable than Hg(0) and consequently more easily removed from the gas phase. Accordingly, mercury in its oxidized form can be trapped from a flue gas stream or the like by absorption onto a solid mass or can be more efficiently removed from flue gas streams by wet processes such as a two-stage wet FGD. The gist underlying the inventive concept of the instant invention relates to the use of a porous bed of gold-coated material that is saturated with Hg(0) to the point that the gold in the presence of HCl in the exhaust stream catalyses the oxidation of Hg(0).

A method of remediating and recovering energy from combustion products from a fossil fuel power plant having at least one fossil fuel combustion chamber, at least one compressor, at least one turbine, at least one heat exchanger and a source of oxygen. Combustion products including non-condensable gases such as oxygen and nitrogen and condensable vapors such as water vapor and acid gases such as SO_X and NO_X and CO₂ and pollutants are produced and energy is recovered during the remediation which recycles combustion products and adds oxygen to support combustion. The temperature and/or pressure of the combustion products are changed by cooling through heat exchange with thermodynamic working fluids in the power generation cycle and/or compressing and/or heating and/or expanding the combustion products to a temperature/pressure combination below the dew point of at least some of the condensable vapors to condense liquid having some acid gases dissolved and/or entrained and/or directly condense acid gas vapors from the combustion products and to entrain and/or dissolve some of the pollutants while recovering sensible and/or latent heat from the combustion products through heat exchange between the combustion products and thermodynamic working fluids and/or cooling fluids used in the power generating cycle. Then the CO₂, SO₂, and H₂O poor and oxygen enriched remediation stream is sent to an exhaust and/or an air separation unit and/or a turbine.

Impure carbon dioxide (“CO₂”) comprising a first contaminant selected from the group consisting of oxygen (“O₂”) and carbon monoxide (“CO”) is purified by separating expanded impure carbon dioxide liquid in a mass transfer separation column system. The impure carbon dioxide may be derived from, for example, flue gas from an oxyfuel combustion process or waste gas from a hydrogen (“H₂”) PSA system.

A process for sequestering carbon dioxide from the flue gas emitted from a combustion chamber is disclosed. In the process, a foam including a foaming agent and the flue gas is formed, and the foam is added to a mixture including a cementitious material (e.g., fly ash) and water to form a foamed mixture. Thereafter, the foamed mixture is allowed to set, preferably to a controlled low-strength material having a compressive strength of 1200 psi or less. The carbon dioxide in the flue gas and waste heat reacts with hydration products in the controlled low-strength material to increase strength. In this process, the carbon dioxide is sequestered. The CLSM can be crushed or pelletized to form a lightweight aggregate with properties similar to the naturally occurring mineral, pumice.