Performance of an ammonia-based CO2 capture pilot facility in iron and steel industry

• Published in: International journal of greenhouse gas control Vol. 27; pp. 239 - 246
• Main Authors: Han, Kunwoo, Ahn, Chi Kyu, Lee, Man Su
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-08-2014
• Subjects: Aqueous ammonia; CO2 capture; Iron and steel industry; Waste heat utilization; Iron and steel industry; Waste heat utilization; CO2 capture; Aqueous ammonia
• ISSN: 1750-5836; 1878-0148
• DOI: 10.1016/j.ijggc.2014.05.014

•Pilot plant of aqueous ammonia-based CO2 capture has been working successfully.•The technical performance was satisfactory: CO2 removal at 90%.•The thermal energy requirement for the absorbent regeneration was 2.5GJ/t-CO2.•Waste heat at ∼150°C was recovered and used for the absorbent regeneration.•Purification and liquefaction units were integrated with the pilot facility.
In the present paper, we report experimental results from an ammonia-based carbon dioxide (CO2) capture process operation. A pilot facility of 1000Nm3/h to remove CO2 from blast furnace gas (BFG, ∼23% of CO2) has been constructed in an iron-making workplace, resulting in the CO2 production of 10t-CO2/d. Steam generated from waste heat recovery system has been successfully supplied to the CO2 removal unit for regeneration of absorbent solution and concentration of ammonia. Technical performance shows that the facility can capture CO2 at the rate of 90% with the purity of 99% in the product CO2 stream. Results of process simulations and process operation confirmed the improvement of process economics through heat integration and pressurized absorption. Thermal energy requirement for the regeneration of absorbent solution could be lowered to 2.5GJ/t-CO2. Accordingly, the ammonia slip has been reduced to the level of ∼10ppm in both columns of absorption and regeneration. From this study we found that the technology could be a competitive option for the economic reduction of CO2 emissions in large stationary point sources such as in iron and steel industry. Conclusively, we insist that the developed technology is extremely functional if there exists waste heat at low temperature.