A method for sequestering carbon dioxide includes providing a starting material having calcium ions, sulfate and/or sulfite ions, and alkali metal ions with a molar ratio ? Alk:? SO3>2.00, reacting the starting material with carbon dioxide at a pressure in the range from ambient up to 3.5 bar overpressure and/or a temperature in the range from 10 to 145? C. to obtain a carbonated product comprising calcium carbonate and alkali sulfate. The obtained product is used as a set regulator or accelerator for cement and/or as a minor or main cement component.

The present disclosure generally relates to thermally conductive hydrogels. In particular, the present disclosure relates to thermally conductive hydrogels comprising one or more acidic gas absorbents, which can be used to capture one or more acidic gases from gaseous streams or atmospheres. The present disclosure also relates to processes, methods, systems, uses and apparatuses comprising the thermally conductive hydrogels for capturing acidic gases from a gaseous stream or atmosphere.

The invention relates to a method and plant for producing cement clinker, comprising the steps of: burning raw materials to form cement clinker in a furnace, preheating the raw materials with flue gases of the furnace, and dehumidifying and cooling flue gases of the furnace by means of a condensation heat exchanger.

Techniques for drift elimination in a liquid-gas contactor system include configuring a pre-fabricated mechanical frame coupled to a drift eliminator material to produce a framed drift eliminator assembly with substantially no air gaps between the drift eliminator material and the pre-fabricated mechanical frame, and coupling the framed drift eliminator assembly to the liquid-gas contactor system.

Methods of preparing a porous robust support to host an ultra-thin enzyme-assisted membrane, and a new membrane system that can be used for gas filtration purposes to remove/separate carbon dioxide or other gases from a gas mixture such as those from power production or enhanced oil recovery or fuel production or air and recycle/collect/utilize carbon dioxide are disclosed herein. A method may include protecting the surface with a blocking material and polishing the protected surface, coating a thin layer of silica nanospheres onto the polished surface, coating a silica sol-gel and surfactant solution onto the nanospheres, and then removing the surfactant and blocking material to generate a well-defined porous structure with nanochannels.

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.

Disclosed is an absorbing liquid for separating and capturing carbon dioxide from a carbon dioxide-containing gas, the absorbing liquid containing: at least one alkanolamine represented by formula (1)

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wherein R.sup.1 represents hydrogen or C.sub.1-4 alkyl, R.sup.2 and R.sup.3 are identical or different and each represent hydrogen or C.sub.1-3 alkyl, R.sup.1, R.sup.2, and R.sup.3 are not all hydrogen, and n is 1 or 2; a low-molecular-weight diol compound and/or glycerin; and water.

Denitrifying bypass exhaust gases in a cement clinker producing plant. The plant comprises a rotary kiln connected to a calciner for the deacidification of raw material or to a rotary kiln riser shaft via a rotary kiln inlet chamber, and the bypass exhaust gas being drawn off in the region of the rotary kiln inlet chamber. The method comprises: cooling the bypass gas to between 260 C and 400 C in a cooling device, injecting an ammonia-, urea-, and/or ammonium-containing substance into the cooled bypass gas, introducing the cooled and mixed bypass gas into a ceramic filter system to filter out any halide and sulfate of the alkali metals and alkaline-earth metals precipitated during cooling the gas, and any nitrogen not reacted by the injected substances is chemically selectively reduced over a catalytic converter which is located in or directly downstream of the ceramic filter system.

Methods for the heat treatment of a material flow and the cleaning of resulting exhaust gases are disclosed. The material flow may be preheated in a preheating zone, burned in a sintering zone, and cooled in a cooling zone. Exhaust gases of the sintering zone may flow through a preheater and be used for preheating the material flow. The exhaust gases leaving the preheater may be cooled at least partially in a comminuting device in interconnected operation or at least partially in a cooling device in direct operation. Exhaust gases may then be at least partly dedusted in a dust filter. A temperature of the dedusted exhaust gas may then be raised before the exhaust gas is cleaned of pollutants in at least one catalyst. A temperature at which the exhaust gases flow through the catalyst in direct operation may be higher, at least in phases, than a temperature at which the exhaust gases flow through the catalyst in interconnected operation.

A process and system for separating CO.sub.2 from a flue gas stream is disclosed. The process involves (a) contacting a flue gas stream containing water vapor and CO.sub.2 with an ionic absorbent under absorption conditions to absorb at least a portion of the CO.sub.2 from the flue gas stream and form a CO.sub.2-absorbent complex; wherein the ionic absorbent comprises a cation and an anion comprising an amine moiety; and (b) recovering a gaseous product having a reduced CO.sub.2 content.