A process and a chemical production unit for producing crystalline ammonium chloride in the presence of a crystallization additive are provided, wherein the process comprises the steps a) reacting NH.sub.3 and HCl by feeding NH.sub.3 and HCl to an aqueous solution of ammonium chloride; b) crystallizing ammonium chloride from the aqueous ammonium solution obtained in step a), and c) separating the crystalline ammonium chloride, wherein energy required in step b) is generated in step a). The crystalline ammonium chloride, obtainable by said process, is suitable as a flavoring agent, as an animal feed additive, as an additive for a cosmetic composition or as an additive for a pharmaceutical composition.

A system for recovering ammonia from an endothermic reaction in a subsurface formation may comprise a subsurface formation; a wellbore fluidly connected to the subsurface formation; a tubing string positioned within the wellbore, wherein the wellbore and an exterior of the tubing string together define a wellbore annulus; a wellhead comprising one or more injection lines and one or more return lines fluidly connected to the wellbore; one or more fluid injection pumps configured to supply an endothermic fluid composition to the subsurface formation through the one or more injection lines and the tubing string, the endothermic fluid composition operable to form ammonia when reacted; and one or more ammonia retention vessels fluidly connected to the return lines for receiving the ammonia through the wellbore annulus.

A carbon capture system is used to remove carbon dioxide from flue gas emissions. The system consists of a first scrubbing column, a carbonating tower, and a separation system. In the first scrubbing column, nitrates and sulfates are removed from the flue gas, producing a purified flue gas and a bottoms product containing the sulfates and nitrates. The purified flue gas is then transferred to a carbonating tower, where it is contacted with a solution (such as brine, ammonia, or a weak base) to remove carbon dioxide, producing a lean brine solution. The lean brine solution is then filtered to recover sodium bicarbonate or soda ash.

The present invention relates to a freeze desalination method where carbon dioxide, in the form of dry ice, is injected into saltwater. The carbon dioxide sublimes, which cause ice to form around the carbon dioxide bubble. The ice bubble floats to the top of the saltwater, and it can then be skimmed off the top and melted. This water has a low concentration of salt. It then can go through further desalination methods, such as reverse osmosis, to further purify the water. The embodiments described herein are not limiting and this can be accomplished by methods not described fully herein. Particularly, the present invention provides a direct freeze desalination (DFD) method wherein solid carbon dioxide pellets are injected into saline water, forming buoyant ice balls that are separated, washed, and melted. The process uniquely integrates CO.sub.2 recycling, energy-saving compression, and optional mineral recovery to produce potable water with lower energy consumption compared to conventional methods

A system for recovering ammonia from an endothermic reaction in a subsurface formation may comprise a subsurface formation; a wellbore fluidly connected to the subsurface formation; a tubing string positioned within the wellbore, wherein the wellbore and an exterior of the tubing string together define a wellbore annulus; a wellhead comprising one or more injection lines and one or more return lines fluidly connected to the wellbore; one or more fluid injection pumps configured to supply an endothermic fluid composition to the subsurface formation through the one or more injection lines and the tubing string, the endothermic fluid composition operable to form ammonia when reacted; and one or more ammonia retention vessels fluidly connected to the return lines for receiving the ammonia through the wellbore annulus.