CO2 absorption with low concentration ammonia liquor

In the present work, low concentration ammonia liquor ranging from 2 to 7 wt.% was used to remove CO2 from model BFG with various packing materials. CO2 removal efficiencies were to be more than 90% with proper gas to liquid flow rate ratio. Additional column is required to concentrate ammonia gas captured from the absorber and the regenerator. With regard to the required energy for regeneration process, the distillation energy should be taken into consideration in addition to regeneration energy itself. The reboiler temperature for CO2 stripping in ammonia liquor process decreased from 96 ∘C at 2 wt.% solution to 83 ∘C at 7 wt.% solution, which is an important advantage over conventional MEA-based CO2 absorption process. The outlet gas concentrations of ammonia of the absorber and regenerator were as high as 3 vol.% implying that the installation of washing stage for ammonia capture should be considered for practical application.