Demonstration of the ammonia engine exhaust gas after-treatment system

On February 23, the Korean Register (KR) successfully conducted a land-based demonstration of an aftertreatment system capable of effectively reducing exhaust gas generated from ammonia engines. KR demonstrated this technology as the lead organization of the national R&D project titled “Development of Integrated Management Technology for Greenhouse Gas Emissions from Ships,” supported by the Ministry of Oceans and Fisheries.

The system is Korea’s first microwave catalyst heating-type exhaust gas aftertreatment system in Korea designed for MW-class ammonia (NH₃) engine exhaust gas. KR carried out joint technology development with EcoPro HN and HD Korea Shipbuilding & Offshore Engineering, and the prototype demonstrated its durability and performance through long-duration operation at the KR Green Ship Equipment Test & Certification Center (KR TCC) located in Gunsan.

The project was conducted with policy support from the Ministry of Oceans and Fisheries and the Korea Institute of Marine Science & Technology Promotion (KIMST). In addition to KR, major industry–academia–research institutions, including EcoPro HN, HD Korea Shipbuilding & Offshore Engineering, HD Hyundai Marine Solution, and the Korea Institute of Industrial Technology, participated in the entire process of technology development and demonstration.

Ammonia has attracted attention as a next-generation carbon-free fuel for the shipbuilding and shipping industries because it does not emit carbon dioxide or sulfur oxides during combustion and is relatively easy to store and transport. The International Energy Agency (IEA) also projects in its Net Zero by 2050 Roadmap that ammonia could account for approximately 44% of global marine fuel demand by 2050.

However, exhaust gas from ammonia engines may contain air pollutants such as nitrogen oxides (NOx, N₂O) and unburned ammonia, making the development of effective aftertreatment technologies essential for emission reduction. These pollutants can be reduced by converting them into harmless substances through catalytic reactions, and precise control of the catalyst activation temperature is considered a key factor in the commercialization of such systems.

The newly developed system significantly improves exhaust gas purification performance by applying a microwave-based catalyst heating method, which efficiently activates the catalyst. This enables effective emission reduction under a wide range of operating conditions and allows stable operation with minimized fuel consumption even in changing navigation environments.

KIM Daeheon, Executive Vice President of KR, stated, “To commercialize ammonia-fueled ships, it is essential to secure exhaust gas aftertreatment technologies as well as fuel technologies.” He added, “Through this demonstration, we have verified the effectiveness of the jointly developed system. We will actively support the transition to carbon-free ships by expanding its application to various dual-fuel engines in the future.”