Technical paper
The Impact of Acid Gas Loading on the Heat of Absorption and VOC and BTEX Solubility in Amine Sweetening Units
In amine sweetening units, the heat of absorption and VOC and BTEX solubility have been found to vary significantly with acid gas loading as well as with temperature, amine type, and amine concentration. The heat of absorption declines by up to 20% while VOC and BTEX solubility can drop by as much as 40 to 50% with loadings up to 0.5 mol/mol for MDEA solutions. VOC and BTEX solubility are also highly dependent on temperature and amine concentration. As a result, amine sweetening units should be operated at the lowest circulation rate possible as limited by corrosion and treating requirements. For example, over circulation of 100 gpm in amine sweetening units can cost about $250,000/yr in additional reboiler fuel, can greatly increase pick up of VOC and BTEX, and lead to problems with emissions or in downstream sulfur recovery units.
In amine sweetening units, the heat of absorption and VOC and BTEX solubility have been found to vary significantly with acid gas loading as well as with temperature, amine type, and amine concentration. The heat of absorption declines by up to 20% while VOC and BTEX solubility can drop by as much as 40 to 50% with loadings up to 0.5 mol/mol for MDEA solutions. VOC and BTEX solubility are also highly dependent on temperature and amine concentration. As a result, amine sweetening units should be operated at the lowest circulation rate possible as limited by corrosion and treating requirements. For example, over circulation of 100 gpm in amine sweetening units can cost about $250,000/yr in additional reboiler fuel, can greatly increase pick up of VOC and BTEX, and lead to problems with emissions or in downstream sulfur recovery units.