A method for separating gaseous carbon dioxide from air is proposed by cyclic adsorption/desorption using a sorbent. The method includes the following sequential and in this sequence repeating steps: (a) contacting air with the sorbent to allow gaseous carbon dioxide to adsorb on the sorbent under ambient atmospheric pressure and temperature conditions; (b) isolating the sorbent from the flow-through; (c) inducing an increase of the temperature of the sorbent; (d) extracting the desorbed gaseous carbon dioxide from the unit and separating gaseous carbon dioxide from steam/water; and (e) bringing the sorbent to ambient atmospheric temperature and pressure conditions. The sorbent is a water retaining and/or porous support which before use in the cyclic process has been impregnated or wetted with a solution of a secondary amine compound and the sorbent is loaded by said secondary amine compound by at least 5% by weight.

A method for preparing a ceramic composition while simultaneously reducing the quantity of carbon dioxide from municipal solid waste that would discharge into environment includes decomposing the municipal solid waste to generate a carbon dioxide-water vapor mixture, providing a matrix, the matrix containing a reactant; and contacting the carbon dioxide-water vapor mixture with the matrix to promote a reaction between the carbon dioxide of the carbon dioxide-water vapor mixture and the reactant of the matrix. The reaction forms a product, thereby producing the ceramic composition.

An apparatus and process are provided for electricity production and high-efficiency trapping of carbon dioxide, using carbon dioxide within combustion exhaust gas and converging technologies associated with a carbon dioxide absorption tower and a generating device using ions which uses a difference in concentration of salinity between seawater and freshwater. It is expected that enhanced electrical energy production efficiency, an effect of reducing costs for the operation of a carbon dioxide trapping process, and electricity production from carbon dioxide, which is a greenhouse gas, can be simultaneously achieved by increasing the difference in concentration using an absorbent for absorbing carbon dioxide.

Gas separation modules and methods for use including an integrated adsorbent and membrane. In certain refining applications, it is paramount to obtain high purity product gases. Adsorbent beds are effective at removing certain contaminants, such as CO.sub.2, from gas streams containing product and contaminant constituents to form a product-rich stream. The integrated membrane permits a further separation of products from any unadsorbed contaminant to produce a high purity product, such as hydrogen, stream. The gas separation modules described herein include stacked, radial, and spiral arrangements. Each modules includes a configuration of feed and cross-flow channels for the collection of contaminant gases and/or high purity product gases.

Processes and equipment for purification of a sour hydrocarbon mixture or a gas mixture including hydrocarbons and sour gas, at least including the steps of directing the gas mixture to contact an absorbent liquid having affinity for sour gas, providing a purified off-gas mixture, directing the purified off-gas mixture to contact a liquid hydrocarbon mixture, providing an enriched liquid hydrocarbon mixture, with the associated benefit of such a process having a high recovery of hydrocarbons from the gas mixture to the enriched liquid hydrocarbon mixture, while being efficient in removing hydrogen sulfide from the gas mixture. The gas mixture to be purified may either be a natural gas, a fuel gas or an intermediate gas stream, e.g. from naphtha, kerosene, diesel or condensate hydrotreatment or hydrocracking, and it may also include further constituents, typically hydrogen.

A process is disclosed for reversibly absorbing carbon dioxide to an alkali metal or earth alkaline absorbent. For absorption the absorbent is contacted with a first gas composition. For desorption the absorbent is contacted with a second gas composition. The moisture contents of the first and second gas compositions are controlled so that during the absorption step the absorbent is converted to a bicarbonate, and during the desorption step the absorbent is converted to a carbonate hydrate. Compared to prior art processes the process of the invention requires less energy input. The process of the invention is particularly suitable for producing a carbon dioxide enriched gas for accelerating plant growth in a greenhouse.

The present invention discloses a method for aluminum-enhanced dealkalization of red mud and separation and recovery of aluminum and iron. The method includes: dissolving red mud in water, introducing excessive SO.sub.2, introducing O.sub.2 for aeration, and refluxing part of alkaline leachate after filtering; when pH of a red mud mixture decreases to below 3, washing and filtering the red mud mixture, adding NaOH to acidic leachate to adjust its pH to a strongly alkaline level, aging and filtering the leachate, treating filter residue to recover Fe.sub.2O.sub.3, and refluxing part of alkaline leachate after filtering to the red mud mixture; and adjusting pH of the remaining alkaline leachate after filtering to a weakly acidic level, and conducting filtering to recover aluminum.

Nitrogen oxides formed in combustion engines are recycled such that the nitrogen oxides can be utilized for producing liquid or solid chemicals. The nitrogen oxides are recycled by a method including an adsorber material adsorbing nitrogen oxides from an exhaust-gas stream of the combustion engine, removing the adsorber material laden with nitrogen oxides, desorbing the adsorbed nitrogen oxides from the adsorber material, and converting the nitrogen oxides desorbed from the adsorber material into liquid or solid nitrogen-containing compounds.

An air treatment unit may include an air inlet to receive a flow of input air for treatment and a reaction reservoir configured to hold an aqueous air treatment solution. The air treatment unit may also include an air dispersing element flow connected with the air inlet, wherein the air dispersing element is configured to convert at least a portion of the flow of input air into a plurality of microbubbles for introduction into the aqueous air treatment solution, such that an amount of one or more target gas species contained within the plurality of microbubbles is reduced through reaction with the aqueous air treatment solution. The unit may include an air outlet configured to output treated air from the reaction reservoir.

The present disclosure provides a method for purifying trifluoroiodomethane. The method includes providing a process stream comprising trifluoroiodomethane, organic impurities, and acid impurities; reacting the process stream with a basic aqueous solution, the basic aqueous solution comprising water and at least one base selected from the group of an alkali metal carbonate and an alkali metal hydroxide; and separating at least some of the organic impurities from the process stream.