PGE/REWE 2015

Sessions Speakers Exhibitors Products Press Releases Show Specials Floor Plan

SCR Systems for HRSG Boilers to Achieve Low NOx Values Specified by International Regulators (Room G102-G103, Auditorium Centre, First Floor)

The paper will present a comparison of different combined cycle power plants all over the world equipped with SCR systems showing the individual design constraints. Out of that in Scandinavia we have a 400MW combined cycle with one of the lowest guaranteed emission limits with a NH3 and NOx outlet of 2 ppm each. Beside the complex design of the ammonia injection system, the side required explosion proof design due to its refinery standards and an anti seismic design. Additionally there are two 400 MW gas turbines installed in Vienna (AT) equipped with SCR systems to reduce NOx to 10 ppm with a NH3 slip of 13 ppm. Challenging is there the high NO2 / NO ratio across the load conditions. Additional challenge will be the switch from preu NH3 to aqueous ammonia as reagent. The paper will follow with the plant El-Segundo in California (US) where 2 units with SCR systems regulate the NOx emissions down to 2 ppm. The boiler load increase from 0% up to 100% in less than 15 min. A special feed forward NOx control ensures to follow fast load changes. Another 5 SCR Systems were delivered to SHELL's Pearl GTL Plant in Qatar to reduce the NOx outlet to 26.8 ppm and the NH3 slip to 3 ppm in a very rough environment like high dust environment and partly poor reagent quality. Finally the Taiyanggong gas fired power plant is a clean energy project to supply clean energy and heat starting during the period of the Beijing Olympic Games 2008 as one of the first HRSG plants equipped with SCR in China with a NOx outlet of 4 ppm.