The specification discloses methods and apparatus for producing carbon black from CO.sub.2 by way of a reactor having a chamber filled with a molten salt electrolyte. On application of a current through one or more cathodes and one or more anodes affixed to the reactor, dissolved CO.sub.2 within the molten salt electrolyte is converted into carbon black and oxygen gas. The carbon black is collected.

An integrated amine and redox gas treatment system is configured to treat an influent hydrocarbon containing stream. The system includes a reduction oxidation unit connected directly downstream of an amine unit. The amine unit is configured to separate the influent fluid stream into a first amine effluent stream including hydrocarbons and a second amine effluent stream including a connection pressure and comprising CO.sub.2. The reduction oxidation unit is configured to receive the second amine effluent stream from the amine unit and operate at the connection pressure while releasing a reduction oxidation effluent stream including purified CO.sub.2. The connection pressure includes a single pressure or a plurality of pressures at which both the amine unit and the reduction oxidation unit are configured to operate.

The present disclosure relates, in part, to enhanced weathering systems and/or apparatuses and methods of use thereof. In one aspect, the present disclosure provides a method of at least partially sequestering CO.sub.2 from an influent aqueous solution comprising aqueous and/or gaseous CO.sub.2. In another aspect, the present disclosure provides a method of at least partially sequestering CO.sub.2 from a gaseous CO.sub.2 source. In another aspect, the present disclosure provides systems and/or apparatuses suitable for use in the methods described herein. In another aspect, the present disclosure provides a method of optimizing the design and operation of a system for at least partial sequestration of CO.sub.2 from a water source.

The present disclosure provides systems and methods useful in capture of one more moieties (e.g., carbon dioxide) from a gas stream (i.e., direct air capture). In various embodiments, the systems and methods can utilize at least a scrubbing unit, a regeneration unit, and an electrolysis unit whereby an alkali solution can be used to strip the moiety (e.g., carbon dioxide) from the gas stream, the removed moiety can be regenerated and optionally purified for capture or other use, and a formed salt can be subjected to electrolysis to recycle the alkali solution back to the scrubber for re-use with simultaneous production of one or more further chemicals.

An apparatus for reducing mercury content of cement kiln exhaust gas 11 comprising: a mixing and heating device 19 for mixing cement kiln dusts D2, D4 included in a cement kiln combustion exhaust gas G1 into a cement raw material R2 withdrawn from a cyclone 4C (or 4B) other than the highest stage cyclone 4D and the lowest stage cyclone 4A of a preheater 4 for preheating cement raw material R1 while heating the cement kiln dusts D2, D4 through sensible heat of the cement raw material R2; a mercury recovery device 21 for recovering mercury Hg vaporized from the cement kiln dusts D2, D4 by the mixing and heating; and a feeder for feeding mercury-removed dusts D5, D6 discharged from the mixing and heating device 19 to a cyclone 4B (or 4A) positioning at a lower stage from the cyclone 4C (or 4B) from which the cement raw material R2 is withdrawn.

Methods of sequestering carbon dioxide (CO.sub.2) are provided. Aspects of the methods include contacting a CO.sub.2 containing gaseous stream with an aqueous medium under conditions sufficient to produce a bicarbonate rich product. The resultant bicarbonate rich product (or a component thereof) is then combined with a cation source under conditions sufficient to produce a solid carbonate composition and product CO.sub.2 gas, followed by injection of the product CO.sub.2 gas into a subsurface geological location to sequester CO.sub.2. Also provided are systems configured for carrying out the methods.

Methods of sequestering carbon dioxide (CO.sub.2) are provided. Aspects of the methods include contacting a CO.sub.2 containing gaseous stream with an aqueous medium under conditions sufficient to produce a bicarbonate rich product. The resultant bicarbonate rich product (or a component thereof) is then combined with a cation source under conditions sufficient to produce a solid carbonate composition and product CO.sub.2 gas, followed by injection of the product CO.sub.2 gas into a subsurface geological location to sequester CO.sub.2. Also provided are systems configured for carrying out the methods.

A device for recovering polluted air is disclosed. The device includes air collecting part, a main control part, a discharging part, and an air sending pipe. The air collecting part includes a cover body, a lower side of which is opened, and a filter member attached to an inside of the cover body. The main control part includes a pump capable of sucking and delivering gas. The discharging part including an air storage container to be installed in the sea. The air sending pipe couples between the air collecting part and the main control part and between the main control part and the discharging part to permit movement of the gas between the parts. The gas that is polluted air is sucked from the air collecting part by the pump and is delivered to the discharging part, and the gas is discharged from the air storage container into the sea.

A device for recovering polluted air is disclosed. The device includes air collecting part, a main control part, a discharging part, and an air sending pipe. The air collecting part includes a cover body, a lower side of which is opened, and a filter member attached to an inside of the cover body. The main control part includes a pump capable of sucking and delivering gas. The discharging part including an air storage container to be installed in the sea. The air sending pipe couples between the air collecting part and the main control part and between the main control part and the discharging part to permit movement of the gas between the parts. The gas that is polluted air is sucked from the air collecting part by the pump and is delivered to the discharging part, and the gas is discharged from the air storage container into the sea.

A method and system are provided to recover water and carbon dioxide from combustion emissions. The recovery includes, among other things, electrolysis and carbon dioxide capture in a suitable solvent. The recovered water and carbon dioxide are subject to reaction, such as a catalytic methanation reaction, to generate at least methane.