Abstract: Processes for removing contaminants in CO2 recovery processes are described. The processes incorporate water wash units and/or NO2—SO2 removal section to remove sulfur oxide compounds and heavy nitric oxide compounds such as NO2. Some processes include CO2 PSA units and CO2 fractionation columns, while others only use CO2 PSA units. The CO2 PSA concentrates CO2 along with heavy nitric oxide compounds, SO2 and NH3. Optional quench columns, guard beds, particulate polishing units, and molecular sieves can be used remove HCl, HF, SO2, SO3, NH3, hydrocarbons, mercury, and heavy metals.

Abstract: Processes have been developed for oxidizing alkyl aromatic compounds, and which reduce the amount of 4-CBA in the solid oxidation products. The process can reduce the makeup amount of ionic liquid, carboxylic acid, catalyst, bromine source, and ammonia source.

Abstract: Processes have been developed to obtain recycle ionic liquid streams which are active for oxidation of alkyl aromatic compounds, and which reduce the amount of 4-CBA in the solid oxidation products. The process can reduce the makeup amount of ionic liquid, carboxylic acid, catalyst, bromine source, and ammonia source.