Removal of CO2 from flue gas with ammonia solution in a packed tower

Hsin Ta Hsueh, Chi Liang Hsiao, Hsin Chu

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


Ammonia was used for the major absorbent while sodium hydroxide was used as a reference in either a bubble column (semi-batch reaction) or a packed tower (continuous reaction) to absorb CO2 in this study. In the bubble column, bubbling time as a function of temperature, pH, and dissolved inorganic carbon concentration in the solution was measured to see the characteristics of the reaction and the capacity of ammonia with regard to CO2 absorption. Its CO2 removal efficiency (RE) and/or absorbent utilization (AU) in the packed tower were quantified as a function of packing type, concentration/pH of absorbent, concentration of simulated flue gas (CO2, O2, SO2, NO), gas flow rate, and liquid/gas ratio. Additionally, an empirical formula obtained, via the analysis of a multiple regression, was used to relate CO2 RE and the major operation parameters. In the bubble column, the capacity of ammonia on CO2 absorption is 1.4 kg CO2 kg−1 NH3 in an exothermic reaction. In the packed tower, the optimum number of packing layers is 21 layers in an orderly arrangement with a reaction length of 220 mm. In addition, the optimum CO2 RE and AU are 93 and 19%, respectively, at a given condition. After a multiple regression, the empirical formula indicates four major parameters responsible for CO2 removal, namely ammonia concentration, CO2 concentration, gas flow rate, and initial pH of ammonia solution. The results of this work are feasible for practical application with regard to CO2 absorption with ammonia in a packed tower.

Original languageEnglish
Pages (from-to)1-7
Number of pages7
JournalSustainable Environment Research
Issue number1
Publication statusPublished - 2010

All Science Journal Classification (ASJC) codes

  • Environmental Engineering
  • Renewable Energy, Sustainability and the Environment
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution


Dive into the research topics of 'Removal of CO2 from flue gas with ammonia solution in a packed tower'. Together they form a unique fingerprint.

Cite this