1273results about "By chemical separation" patented technology

A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

Compositions comprising synthetic rock, e.g., aggregate, and methods of producing and using them are provided. The rock, e.g., aggregate, contains CO2 and / or other components of an industrial waste stream. The CO2 may be in the form of divalent cation carbonates, e.g., magnesium and calcium carbonates. Aspects of the invention include contacting a CO2 containing gaseous stream with a water to dissolve CO2, and placing the water under precipitation conditions sufficient to produce a carbonate containing precipitate product, e.g., a divalent cation carbonate.

A combined cycle system includes, a pre-steam-methane-reformer operating at a temperature of less than about 800 degrees Celsius to reform a mixed fuel stream to generate a first reformate stream, a water-gas-shift reactor to convert carbon monoxide in the first reformate stream to carbon dioxide and form a second reformate stream, a carbon dioxide removal unit for removing carbon dioxide from the second reformate stream and form a carbon dioxide stream and a third reformate stream; wherein less than about 50 percent of the carbon contained in the mixed fuel stream is recovered as carbon dioxide by the removal unit, a gas turbine unit for generating power and an exhaust stream, and a steam generator unit configured to receive the exhaust stream, wherein the heat of the exhaust stream is transferred to a water stream to generate the steam for the mixed fuel stream and for a steam turbine.

A method for mineral sequestration of pollutant gases resulting from the combustion of carbon-based fuels such as carbon and sulfur dioxides is provided and includes, providing a particulate magnesium-containing mineral and exposing the magnesium-containing mineral to a weak acid to dissolve magnesium from the mineral and form a magnesium-containing solution. The surface of the particulate magnesium-containing mineral is physically activated to expose and dissolve additional magnesium into the solution. Pollutant gases such as carbon dioxide are mixed with the magnesium-containing solution. When the pH of the magnesium-containing solution is increased, solid magnesium carbonate is formed.

Certain embodiments and aspects of the present invention relate to a photobioreactor including covered photobioreactor units through which a liquid medium stream and a gas stream flow. The liquid medium comprises at least one species of phototrophic organism therein. Certain methods of using the photobioreactor system as part of fuel generation system and / or a gas-treatment process or system at least partially remove certain undesirable pollutants from a gas stream. In certain embodiments, a portion of the liquid medium is diverted from a photobioreactor unit and reintroduced upstream of the diversion position. In certain embodiments, the disclosed photobioreactor system, methods of using such systems, and / or gas treatment apparatus and methods provided herein can be used as part of an integrated combustion method and system, wherein photosynthetic organisms used within the photobioreactor are harvested from the photobioreactor, processed, and used as a fuel source for a combustion system such as an electric power plant.

A reaction-based process has been developed for the selective removal of carbon dioxide (CO2) from a multicomponent gas mixture to provide a gaseous stream depleted in CO2 compared to the inlet CO2 concentration in the stream. The proposed process effects the separation of CO2 from a mixture of gases (such as flue gas / fuel gas) by its reaction with metal oxides (such as calcium oxide). The Calcium based Reaction Separation for CO2 (CaRS-CO2) process consists of contacting a CO2 laden gas with calcium oxide (CaO) in a reactor such that CaO captures the CO2 by the formation of calcium carbonate (CaCO3). Once “spent”, CaCO3 is regenerated by its calcination leading to the formation of fresh CaO sorbent and the evolution of a concentrated stream of CO2. The “regenerated” CaO is then recycled for the further capture of more CO2. This carbonation-calcination cycle forms the basis of the CaRS-CO2 process. This process also identifies the application of a mesoporous CaCO3 structure, developed by a process detailed elsewhere, that attains >90% conversion over multiple carbonation and calcination cycles. Lastly, thermal regeneration (calcination) under vacuum provided a better sorbent structure that maintained reproducible reactivity levels over multiple cycles.

A reaction-based process has been developed for the selective removal of carbon dioxide (CO2) from a multicomponent gas mixture to provide a gaseous stream depleted in CO2 compared to the inlet CO2 concentration in the stream. The proposed process effects the separation of CO2 from a mixture of gases (such as flue gas / fuel gas) by its reaction with metal oxides (such as calcium oxide). The Calcium based Reaction Separation for CO2 (CaRS—CO2) process consists of contacting a CO2 laden gas with calcium oxide (CaO) in a reactor such that CaO captures the CO2 by the formation of calcium carbonate (CaCOa). Once “spent”, CaCO3 is regenerated by its calcination leading to the formation of fresh CaO sorbent and the evolution of a concentrated stream of CO2. The “regenerated” CaO is then recycled for the further capture of more CO2. This carbonation-calcination cycle forms the basis of the CaRS—CO2 process. This process also identifies the application of a mesoporous CaCO3 structure, developed by a process detailed elsewhere, that attains >90% conversion over multiple carbonation and calcination cycles. Lastly, thermal regeneration (calcination) under vacuum provided a better sorbent structure that maintained reproducible reactivity levels over multiple cycles.

Methods for reducing and eliminating carbon dioxide from the emissions of solid fuel fired power plants, particularly coal fired power plants, and to sequester the carbon dioxide, typically by using existing equipment. In some embodiments, the methods involve pyrolyzing the solid fuel to remove volatile matter and using the volatile matter to produce hydrogen. Additionally, the methods may involve burning the solid fuel or pyrolized solid fuel at very fuel rich stoichiometric conditions. Sequestration may include the production of a carbon dioxide-containing solution and the pumping of the solution into the ground, particularly in areas high in limestone.

Carbon dioxide is separated from a feed gas, preferably derived from flue gas from an oxyfuel combustion process, in a membrane separation system to produce separated carbon dioxide gas which is fed to the oxyfuel combustion process to improve the performance of the process.

The method of simultaneously reducing carbon dioxide (CO2) emissions and sulfur dioxide (SO2) emissions produced by the combustion of carbon-containing matter in a hearth consists in injecting into the hearth a calcium-based agent, a fraction of which absorbs SO2 after decarbonization, and then, after the flue gases have been subjected to intermediate cooling, in causing them to transit via a first reactor and in putting them in contact therein with the other fraction of the absorbant that has not reacted with SO2 so as to capture CO2 from the flue gases by carbonization, then, in a separator, in extracting the solids contained in the flue gases output from the first reactor so as to subject them to heat treatment in a second reactor in order to extract CO2 therefrom by decarbonization and in order to recycle the resulting regenerated CO2 absorbant to the first reactor.