DNX® GT series – Raising performance
The DNX® GT-series is Haldor Topsoe’s recently developed line of catalysts tailored for gas turbine service. The GT-series comprises a range of GT catalysts for SCR NOx reduction and GTC catalysts for CO oxidation.
Topsoe’s DNX® GT-series offers:
- lower pressure drop
- improved activity
- enhanced operation in all temperature ranges
- fast emission compliance
To enhance power production by minimizing the pressure drop and the required space for catalyst in the heat recovery steam generator (HRSG), Topsoe has developed a dedicated series of gas-turbine catalysts for SCR and for CO oxidation.
The GT catalysts feature an enhanced SCR activity which has been achieved through reformulating and changing the monolith structure of the original DNX®catalyst. Thereby an increased speciﬁc surface area and a higher catalyst wall utilization have been achieved which together with a larger open area provide an attractive combination of increased activity and lower pressure drop.
CO oxidation catalysts
The GTC catalysts beneﬁt from a dual functionality which make the catalysts active in CO- and VOC oxidation as well as in the SCR reaction. The GTC catalysts share the features of the well proven DNX® catalyst and are available as a high-temperature version that can be positioned upstream the ammonia injection grid (AIG) and a version optimized for positioning downstream the SCR catalyst where the dual functionality leads to reduced SCR catalyst volume and in turn even lower pressure drop.
The 20% boost in volume activity for the GT catalysts yield a corresponding reduction in required catalyst volume. Together with a 10% lower speciﬁc pressure drop, the GT catalysts offer a saving in overall pressure loss across the SCR catalyst in the order of 30% compared to the previous DNX® versions.
The dual function of the GTC catalysts makes it possible to locate the CO-oxidation catalyst downstream of the SCR in the HRSG. The SCR can then be designed with excess ammonia slip which is subsequently eliminated across the GTC catalyst with the remaining part of the NOx in the ﬂue gas. This combined GT-GTC solution offers more than 40% reduction in SCR catalyst volume and more than 25% reduction in total pressure drop.
The low volume of high-void catalysts has a low thermal mass that offers unlimited heating rate and consequently a minimum time until emission compliance.
180 - 500°C
356 - 932°F