Clariant has scored a major breakthrough in industrial emissions control, with its EnviCat NSCR catalyst outperforming guaranteed emissions reduction targets at the nitric acid production facility of JSC Rustavi Azot in Georgia.

The honeycomb catalyst achieved an impressive 98.97% reduction in nitrogen oxides (NOx) and 97.8% reduction in nitrous oxide (N2O), comfortably exceeding the guaranteed reduction target of 95% for both pollutants.

The results are particularly significant because they were achieved with minimal modifications to the plant's existing reactor infrastructure, delivering substantial cost savings compared with conventional bulk catalyst alternatives.

The project was implemented in partnership with Alvigo, Clariant's engineering partner, with partial financial support from NACAG (Nitric Acid Climate Action Group), part of GIZ (Deutsche Gesellschaft für Internationale Zusammenarbeit).

Nora Schiefenhoevel, Vice President and Head of  said, "As the chemical industry works to reduce its environmental footprint, we are committed to ensuring that best-in-class emissions control technology is within reach for producers across all plant configurations. 

"The results at Rustavi Azot demonstrate that high performance and economic viability are fully compatible. Together with our partner Alvigo, we are proud to be contributing to the decarbonization of nitric acid production in Georgia and beyond."

Gocha Kartelishvili, Chief Engineer at JSC Rustavi Azot, stated, "Our requirements were straightforward: reduce emissions, preserve our existing unit, and keep costs manageable. The EnviCat NSCR catalyst delivered on every aspect and went further than anticipated. The results speak for themselves, and we are proud that this project in Georgia demonstrates what responsible, practical emissions control looks like in action."

Founded in 1956 and part of the Indorama Group since 2023, JSC Rustavi Azot operates a nitric acid production unit that had been running continuously for decades. Its last reactor revamp took place approximately 15 years ago.

The facility was relying on an ageing, high-palladium-loading alumina bulk NSCR catalyst to remove NOx, raising concerns about its ability to meet increasingly stringent emissions requirements.

A complete unit revamp or replacement of conventional granulated bulk catalysts would have involved significant expenditure. The plant therefore needed a solution that could deliver regulatory compliance without the financial burden of major infrastructure upgrades. 

The combination of Alvigo's flexible process engineering and Clariant's EnviCat NSCR technology emerged as the most effective and economically viable option. 

The catalyst's honeycomb design gives it a significant cost advantage over conventional bulk catalysts while allowing it to be configured to fit existing reactor infrastructure. This eliminates the need for capital-intensive modifications and makes it particularly attractive for ageing industrial facilities seeking to improve emissions performance. 

EnviCat NSCR uses methane as a reducing agent to convert up to 95% of NOx and N2O into harmless nitrogen and water. 

Designed to operate at tail-gas temperatures above 400°C, the catalyst combines high temperature stability with a large surface area, low pressure drop and extended operating life. 

The performance at Rustavi Azot further reinforces the technology's established track record of long-term reliability across its reference installations. 

The project highlights how advanced catalytic technology can help industrial producers achieve stringent environmental targets without undertaking expensive plant overhauls, offering a potentially compelling route to cleaner and more economically viable nitric acid production.