Ceramic candle filter and use of the filter in the removal of particulate matter in form of soot, ash, metals and metal compounds, together with hydrocarbons and optionally nitrogen oxides being present in process off-gas or engine exhaust gas, wherein a noble metal comprising catalyst is arranged on the permeation side of the filter and/or on the dispersion side of the filter and/or within wall of the filter, said noble metal comprising catalyst contains a noble metal in an amount of between 20 and 1000 ppm/weight of the filter.

Methods of sequestering carbon dioxide (CO.sub.2) are provided. Aspects of the methods include contacting an aqueous capture ammonia with a gaseous source of CO.sub.2 under conditions sufficient to produce an aqueous ammonium carbonate. The aqueous ammonium carbonate is then combined with a cation source under conditions sufficient to produce a solid CO.sub.2 sequestering carbonate and an aqueous ammonium salt. The aqueous capture ammonia is then regenerated from the from the aqueous ammonium salt. Also provided are systems configured for carrying out the methods.

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.

Several embodiments of the present technology are directed to the removal of one or more air pollutants using cooling and/or calcium-containing particles. In some embodiments, a method for removing air pollutants comprises flowing a gas stream having calcium-containing particles and one or more of mercury or hydrochloric acid molecules, and cooling the gas stream, thereby causing at least a portion of the calcium-containing particles to adsorb to the mercury and/or hydrochloric acid molecules in the gas stream. The method can further comprise, after cooling the gas stream, filtering the gas stream to remove at least a portion of the calcium-containing particles having adsorbed mercury and hydrochloric acid.

A method for reducing pollution in a cement kiln environment and a system for treating cement kiln exhaust gas are provided. The method includes the steps of: treating a cement kiln exhaust gas stream with a treating fluid, such as a water soluble alkaline-earth metal sulfide. In one application, the treating fluid is injected by spraying droplets into the cement kiln exhaust gas stream. A system for treating cement kiln exhaust gas includes a reagent containing a water soluble alkaline-earth metal sulfide in water, and a nozzle to spray the reagent into the cement kiln exhaust gas stream.

A method for manufacturing clinker includes sintering raw meal in a kiln to clinker, preheating the raw meal (prior to sintering the raw meal) in a preheater using a main flue gas stream from the kiln as heat source, dedusting the main flue gas downstream of the preheater at a temperature below the boiling point of mercury (thereby obtaining mercury loaded dust) and withdrawing a bypass flue gas stream from the kiln. The method is configured to efficiently remove mercury from the manufacturing process if mercury in the bypass flue gas is vaporized by injecting of at least a fraction of the mercury-loaded dust into the bypass flue gas stream. Subsequently, the bypass flue gas is dedusted and cooled down. Thereby, the mercury can be adsorbed by injecting an adsorbent (such as activated charcoal) into the bypass flue gas. With subsequent removal of the adsorbent, mercury is finally removed from the manufacturing process.

This invention is directed to methods and systems for controlling water in acid gas removal processes comprising the steps of a) treating the gas stream in an absorption zone with the NAS absorption liquid; b) direction the acid gas-loaded NAS absorption liquid to a regeneration zone; c) directing the regenerated NAS absorption liquid to step a); and d) controlling the first and second set of conditions.

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.

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.

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.