Oxidation of nitric oxide is an important step in NOx absorption. Recent advances namely catalytic oxidation and the use of slrong oxidizing agents have been reviewed. The refinements which have been made in the kinetics of NO oxidation have been discussed. Several liquid phase absorbents have been suggested for the NO removal, particularly for the purpose of pollution abatement. Different models for NO oxidation using nitric acid have been analysed and the limitations of published information have been brought out. Absorption of tetravalent nitrogen oxide (NO2 and N2O4) has received considerable attention. The absorbents include water, nitric and sulfuric acids, sodium hydroxide, sodium sulfite and sodium chlorite. Absorption in water and nitric acid is important in the manufacture of nitric acid. The published information on the mechanism of NO2 and N2O4 absorption in water has been critically analysed. The problem of nitrous acid decomposition has been analysed on the basis of film theory. The predicti...

Absorption of NOx gases

To quickly and drastically reduce CO2 emissions and meet our ambitions of a circular future, we need to develop carbon capture and storage (CCS) and carbon capture and utilization (CCU) to deal with the CO2 that we produce. While we have many alternatives to replace fossil feedstocks for energy generation, for materials such as plastics we need carbon. The ultimate circular carbon feedstock would be CO2 . A promising route is the electrochemical reduction of CO2 to formic acid derivatives that can subsequently be converted into oxalic acid. Oxalic acid is a potential new platform chemical for material production as useful monomers such as glycolic acid can be derived from it. This work is part of the European Horizon 2020 project "Ocean" in which all these steps are developed. This Review aims to highlight new developments in oxalic acid production processes with a focus on CO2 -based routes. All available processes are critically assessed and compared on criteria including overall process efficiency and triple bottom line sustainability.

Towards Sustainable Oxalic Acid from CO2 and Biomass.

Production of oxalic acid from sugar beet molasses by formed nitrogen oxides.

The article contains sections titled:



1.	Sodium Nitrate	
1.1.	Properties	
1.2.	Occurrence	
1.3.	Production	
1.3.1.	Chile Saltpeter	
1.3.2.	Synthetic Sodium Nitrate	
1.4.	Product Forms, Storage, and Transportation	
1.5.	Uses	
1.6.	Economic Aspects	
2.	Potassium Nitrate	
2.1.	Properties	
2.2.	Occurrence	
2.3.	Production	
2.3.1.	Bacterial Production of Saltpeter	
2.3.2.	Converted Saltpeter	
2.3.3.	Potassium Nitrate from Calcium Nitrate	
2.3.4.	Potassium Nitrate from Ammonium Nitrate	
2.3.5.	Potassium Nitrate from Potassium Chloride and Nitric Acid	
2.4.	Product Forms, Storage, and Transportation	
2.5.	Uses	
2.6.	Economic Aspects	
3.	Calcium Nitrate	
3.1.	Properties	
3.2.	Occurrence	
3.3.	Production	
3.3.1.	Calcium Nitrate from Limestoneand Nitric Acid	
3.3.2.	Calcium Nitrate as a Byproduct of the Odda Process	
3.4.	Product Forms, Storage, and Transportation	
3.5.	Uses	
3.6.	Economic Aspects	
4.	Sodium Nitrite	
4.1.	Properties	
4.2.	Production	
4.3.	Product Forms, Storage, and Transportation	
4.4.	Uses	
4.5.	Economic Aspects	
5.	Potassium Nitrite	
5.1.	Properties	
5.2.	Production	
5.3.	Uses	
6.	Ammonium Nitrite	
6.1.	Properties	
6.2.	Production	
6.3.	Uses	
7.	Calcium Nitrite	
7.1.	Properties	
7.2.	Production	
7.3.	Uses	
8.	Analysis of Nitrates and Nitrites	
9.	Environmental Aspects	
10.	Toxicology and Occupational Health

S. N. Vyas

Papers

Oxidation of Sugar to Oxalic Acid and Absorption of Oxides of Nitrogen to Sodium Nitrite