A method of treating a subterranean formation by contacting the formation with the following: (a) ammonium compound; (b) an oxidizing agent selected from a perchlorate or a nitrite or combinations thereof; and (c) sulfamic acid.

A method of recovering ammonia bicarbonate from a biogas and digestate liquor uses an arrangement of equipment in an operational arrangement that requires relatively modest capital investment and that operates with simplicity to provide solid ammonia bicarbonate. In a specific form the method achieves this by upgrading of biogas to produce a rejected stream having a high mole fraction of CO.sub.2 at an elevated pressure that eliminates the need for further compression when using the CO.sub.2 for recovery of ammonia bicarbonate. The method operates can operate at a high pH produced inherently in a digestate stripper by concurrently stripping dissolved CO.sub.2 from solution to improve the simplicity of solid AB recovery.

A method of recovering ammonia bicarbonate from a biogas and digestate liquor uses an arrangement of equipment in an operational arrangement that requires relatively modest capital investment and that operates with simplicity to provide solid ammonia bicarbonate. In a specific form the method achieves this by upgrading of biogas to produce a rejected stream having a high mole fraction of CO.sub.2 at an elevated pressure that eliminates the need for further compression when using the CO.sub.2 for recovery of ammonia bicarbonate. The method operates can operate at a high pH produced inherently in a digestate stripper by concurrently stripping dissolved CO.sub.2 from solution to improve the simplicity of solid AB recovery.

Multi-stage ammonia-based decarbonization, characterized in that ammonia is used as an absorbent to absorb CO.sub.2 in a process gas in an absorber, and the absorber may include four or more stages of absorption, where a first-stage absorption, a second-stage absorption, a third-stage absorption, a fourth-stage absorption, and higher-stage absorptions may be sequentially arranged along the flow direction of the process gas; and the temperature of the process gas in the second and third-stage absorptions may be controlled not to be lower than the temperature of the process gas in the first-stage absorption, and the temperature of the process gas in the fourth and any higher-stage absorptions may be controlled to be lower than the temperature of the process gas in the first-stage absorption.

Multi-stage ammonia-based decarbonization, characterized in that ammonia is used as an absorbent to absorb CO.sub.2 in a process gas in an absorber, and the absorber may include four or more stages of absorption, where a first-stage absorption, a second-stage absorption, a third-stage absorption, a fourth-stage absorption, and higher-stage absorptions may be sequentially arranged along the flow direction of the process gas; and the temperature of the process gas in the second and third-stage absorptions may be controlled not to be lower than the temperature of the process gas in the first-stage absorption, and the temperature of the process gas in the fourth and any higher-stage absorptions may be controlled to be lower than the temperature of the process gas in the first-stage absorption.

Device and methods for producing ammonium bicarbonate in an ammonia-based decarbonization system are provided. The device may include a cooling function zone, an ammonium bicarbonate generation zone, a carbon dioxide absorption zone and an ammonia removal function zone. The cooling function zone may remove heat from the decarbonization system. The ammonium bicarbonate generation zone may generate ammonium bicarbonate. The carbon dioxide absorption zone, which may use multi-stage absorption, may absorb carbon dioxide in process gas. The ammonia removal function zone may remove ammonia in decarbonized process gas. Absorbent ammonia for carbon dioxide removal may be mainly fed to the absorption zone. As a result of the zone control of ammonium bicarbonate generation, CO.sub.2 absorption and ammonia removal, the efficiency of decarbonization and absorption may be improved, and ammonia escape may be reduced. Meanwhile, carbon dioxide in flue gas can be used for producing ammonium bicarbonate as a nitrogen fertilizer.

Device and methods for producing ammonium bicarbonate in an ammonia-based decarbonization system are provided. The device may include a cooling function zone, an ammonium bicarbonate generation zone, a carbon dioxide absorption zone and an ammonia removal function zone. The cooling function zone may remove heat from the decarbonization system. The ammonium bicarbonate generation zone may generate ammonium bicarbonate. The carbon dioxide absorption zone, which may use multi-stage absorption, may absorb carbon dioxide in process gas. The ammonia removal function zone may remove ammonia in decarbonized process gas. Absorbent ammonia for carbon dioxide removal may be mainly fed to the absorption zone. As a result of the zone control of ammonium bicarbonate generation, CO.sub.2 absorption and ammonia removal, the efficiency of decarbonization and absorption may be improved, and ammonia escape may be reduced. Meanwhile, carbon dioxide in flue gas can be used for producing ammonium bicarbonate as a nitrogen fertilizer.

Provided herein are zero carbon dioxide (CO.sub.2) emission processes and systems to carry out the processes, comprising a) calcining limestone in a cement plant in an electric kiln to form a mixture comprising calcium oxide and a first gaseous stream comprising clean carbon dioxide, wherein the clean carbon dioxide comprises no gaseous or non-gaseous components from combustion of fuel; b) treating the mixture comprising calcium oxide with a N-containing salt solution under one or more dissolution conditions to produce a first aqueous solution comprising calcium salt; and c) contacting the first aqueous solution with the first gaseous stream comprising clean carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising vaterite, aragonite, calcite, or combinations thereof.

A process and system for removing ammonia from ammonia-containing purge gas of a urea plant, the process comprising: contacting said ammonia-containing purge gas with carbon dioxide at a low temperature, reaction of ammonia to form crystals of ammonium salts in a multiphase stream, and removal of the solid ammonium salts from the multiphase stream.

A process and system for removing ammonia from ammonia-containing purge gas of a urea plant, the process comprising: contacting said ammonia-containing purge gas with carbon dioxide at a low temperature, reaction of ammonia to form crystals of ammonium salts in a multiphase stream, and removal of the solid ammonium salts from the multiphase stream.