A mixed salt composition adapted for use as a sorbent for carbon dioxide removal from a gaseous stream is provided, the composition being in solid form and including magnesium oxide, an alkali metal carbonate, and an alkali metal nitrate, wherein the composition has a molar excess of magnesium characterized by a Mg:X atomic ratio of at least about 3:1, wherein X is the alkali metal. A process for preparing the mixed salt is also provided, the process including mixing a magnesium salt with a solution comprising alkali metal ions, carbonate ions, and nitrate ions to form a slurry or colloid including a solid mixed salt including magnesium carbonate; separating the solid mixed salt from the slurry or colloid to form a wet cake; drying the wet cake to form a dry cake including the solid mixed salt; and calcining the dry cake to form a mixed salt sorbent.

A system for reducing ore includes a hydrogen supply unit configured to supply hydrogen, a furnace configured to reduce the ore using the supplied hydrogen, and a hydrogen recovery unit configured to recover hydrogen from an exhaust gas that is exhausted from the furnace.

A compound of the general formula (I) ##STR00001##
in which R.sub.1, R.sub.2 and R.sub.3 are independently selected from C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; each R.sub.4 is independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; each R.sub.5 is independently selected from hydrogen, C.sub.1-4-alkyl and C.sub.1-4-hydroxyalkyl; m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is an integer from 0 to 10. A preferred compound of the formula (I) is 2-(2-tert-butylaminoethoxy)ethylamine. Absorbents comprising a compound of the formula (I) have rapid absorption of carbon dioxide from fluid streams and are also suitable for processes for the simultaneous removal of H.sub.2S and CO.sub.2, where given H.sub.2S limits have to be observed but complete removal of CO.sub.2 is not required.

The present invention aims to provide a gas-selective permeable membrane that has gas permeability and gas selectivity capable of highly separating a target gas from other gases, is less likely to be influenced by the temperature condition employed, and is excellent in strength and handleability. The invention uses at least one or more polymerizable compounds to provide a gas-selective permeable film that contains a polymer having an optically uniaxial or multiaxial molecular alignment and to provide a laminate including a gas-permeable substrate and the permeable membrane laminated thereon.

A gas separation membrane including a gas separation layer contains a crosslinked polyimide compound. In the gas separation membrane, and a gas separation module, a gas separator, and a gas separation method obtained by using the gas separation membrane, the crosslinked polyimide compound has a specific structural portion. A composition for forming a gas separation layer suitable for forming a gas separation layer of the gas separation membrane; a method of producing a gas separation membrane obtained by using this composition; a polyimide compound suitable as a raw material of a gas separation layer of the gas separation membrane; and a diamine monomer suitable for synthesis of this polyimide compound are provided.

Provided are a composition, a device, a filter, a method and the like, which convert toxic carbon monoxide and/or carbon dioxide in waste gas to formic acid without by-products at room temperature and at room pressure by using carbon monoxide dehydrogenase and formic acid dehydrogenase. The composition, the device, the filter, the method and the like enable the removal of carbon monoxide which is emitted in a great amount from industries such as petrochemical and steel industry and tobacco combustion, household cooking appliances, and various boiler combustion, through a cigarette filter, an air purifier, a household cooking appliance suction filter, a gas boiler, etc. Accordingly, the production method can be variously applied.

This invention discloses a calcination process to produce high purity CO.sub.2 from solids containing CaCO.sub.3 which operates cyclically and continuously on the solids, arranged in a packed or a moving bed, and wherein each cycle comprises a first step where the combustion at atmospheric pressure of a fuel in the bed of solids containing CaCO.sub.3 heats them up to 800-900? C. and a second step wherein a vacuum pressure between 0.05 and 0.5 atm is applied to extract pure CO.sub.2 from the solids containing CaCO.sub.3 while cooling them by 30-200? C. Said combustion can be carried out directly with air, oxygen enriched air or O.sub.2/CO.sub.2 mixtures when the process is applied to the calcination of a continuous flow of limestone in a moving bed shaft kiln. The process is also applied to calcine CaCO.sub.3 formed in reversible calcium looping processes comprising a carbonation reaction step to form CaCO.sub.3 from CaO.

The present invention relates to a method for manufacturing a carbon membrane supported on a ceramic support. The present invention also relates to a carbon membrane prepared from hydroquinone on a ceramic tubular support and to the use of such a membrane. The present invention is focused on the preparation of carbon membranes from hydroquinone oligomer as a thermosetting precursor for gas separation. In an example chemical post treatment of membranes is used for increasing the H.sub.2/CO.sub.2, H.sub.2/N.sub.2 and CO.sub.2/N.sub.2 selectivities.

An organic carbonate synthesis catalyst for electrochemically synthesizing an organic carbonate from carbon monoxide, comprises: an active particle containing a metal element; and a porous carbon supporting the active particle.

The invention describes a process for producing sulfuric acid by catalytic oxidation of SO.sub.2 to SO.sub.3 and subsequent absorption of the SO.sub.3 in sulfuric acid, wherein the SO.sub.3 is introduced into a first absorption stage (primary absorber) and at least partly absorbed there in concentrated sulfuric acid, wherein the SO.sub.3 not absorbed in the first absorption stage is supplied to a second absorption stage (secondary absorber) for the further absorption in concentrated sulfuric acid, and wherein the sulfuric acid is cooled after passing through the two absorption stages. The cooling of the sulfuric acid is effected in at least two heat exchangers connected in parallel, wherein one of the at least two heat exchangers is operated as partial evaporator and is cooled with boiler feed water/steam and the other one is cooled with cooling water and operated as pure acid cooler.