An alkaline aqueous ferric iron salt solution is disclosed. Generally, the alkaline aqueous ferric iron salt solution comprises ferric ions (Fe.sup.3+), potassium ions (K.sup.+), carbonate ions (CO.sub.3.sup.2−), bicarbonate ions (HCO.sub.3.sup.−), hydroxide ions (OH.sup.−), optionally nitrate ions (NO.sub.3.sup.−). Further, a molar ratio of the potassium ions to the ferric ions is generally at least 5.0. The ferric iron is complexed with carbonate, bicarbonate or both to form a water-soluble complex that is anionic in nature and highly soluble in the alkaline aqueous ferric iron salt solution at pH above 8.5, and a pH of the alkaline aqueous ferric iron salt solution is at least 8.5.

A wet scrubber at least comprises a treatment tank, a jet pipe, a gas-liquid separation component, and a spray component. The treatment tank is used to contain a cleaning solution. The jet pipe is disposed in the treatment tank, by injecting the cleaning solution to suck in an exhaust gas, and mixing the cleaning solution with the exhaust gas, and directly injecting into the cleaning solution contained in the treatment tank, thereby forming a plurality of microbubbles in the cleaning solution to dissolve the exhaust gas and capture solid particles in the exhaust gas. The gas-liquid separation component is used to filter and block water mist raised in the cleaning solution. The spray component is used to prevent the solid particles from clogging the gas-liquid separation component.

A system for removing undesirable compounds from contaminated air includes a biofilter having an alkaline material introduction system and a fuzzy-logic based controller. A contaminant, such as hydrogen sulfide, is removed from contaminated air by passing the contaminated air through the biofilter.

Disclosed is a method for fast and cost-efficient preparation of ikaite crystals. The method comprises contacting an alkaline aqueous solution, which comprises carbonate and bicarbonate ions, with a water solution, which comprises Ca.sup.2+, at a temperature not exceeding 15° C., wherein contact between the alkaline aqueous solution and the water solution takes place at a permeable or porous surface, through which either solution is fed to the other at a flow rate facilitating formation of ikaite crystals. Also disclosed is system for carrying out the ikaite preparation process. The process and system provides a cost efficient and effective means for capture and storage of carbon dioxide.

In accordance with one aspect of the presently disclosed inventive concepts, a porous ceramic structure includes a three-dimensional printed structure having predefined features, where the three-dimensional structure has a geometric shape. The average length of the features may be at least 10 microns. The three-dimensional structure includes a ceramic material having an open cell structure with a plurality of pores, where the pores form continuous channels through the ceramic material from one side of the ceramic material to an opposite side of the ceramic material.

This disclosure provides an apparatus to manipulate the crystal morphology of a powder to improve the flow of a powder from a vessel and/or flowability of a powder in order to achieve stable fluidization of the powder within a vessel.

A process for converting natural calcium carbonate into precipitated calcium carbonate, involving treating the natural calcium carbonate with a sulfate to produce a gypsum and reacting the gypsum with at least one carbonate source to produce precipitated calcium carbonate. The crystalline polymorph, particle size, and various other characteristics of the precipitated calcium carbonate are controlled by varying conditions during the reacting. Since the natural calcium carbonate is not calcined, the process relates to a low energy method of producing precipitated calcium carbonate of controlled polymorph and particle size with limestone, marble, or chalk as the calcium source.

A method for separating gaseous carbon dioxide from a gas mixture by cyclic adsorption/desorption using a sorbent material adsorbing said gaseous carbon dioxide, wherein the method comprises the following sequential and in this sequence repeating steps: (a) an adsorption step; (b) and isolating step; (c) injecting a stream of saturated or superheated steam and thereby inducing an increase in internal pressure of the reactor unit and an increase of the temperature of the sorbent from ambient atmospheric temperature to a temperature between 60 and 110° C., starting the desorption of CO2; (d) extracting at least the desorbed gaseous carbon dioxide from the unit and separating gaseous carbon dioxide from water by condensation in or downstream of the unit, while preferably still injecting; (e) bringing the sorbent material to ambient atmospheric pressure conditions and ambient atmospheric temperature conditions

Improved methods and systems are provided for the on-board removal of sulfur dioxide generated by a marine vessel. The method includes spraying an alkaline fluid into the flue gas to produce a saturated flue gas stream containing the alkaline fluid; and flowing the saturated flue gas stream containing the alkaline fluid through a venturi to cause the particulates in the flue gas to impact the alkaline fluid and react at least a portion of the sulfur dioxide with the alkaline fluid.

The present disclosure provides a system for capturing carbon from air based on bipolar membrane electrodialysis, which includes a first cation exchange membrane, a bipolar membrane and a second cation exchange membrane arranged in sequence, where a desorption chamber is arranged between the first cation exchange membrane and the bipolar membrane, and an absorption chamber is arranged between the bipolar membrane and the second cation exchange membrane; and a cathode reaction chamber is arranged on the other side of the first cation exchange membrane, and an anode reaction chamber is arranged on the other side of the second cation exchange membrane. The system improves carbon capture rate and capture purity, and can be adapted to various scenarios.