Zero Emissions Ammonia Power Technology

The broad context behind this research topic is based on the imminent need to transition away from conventional fossil fuels in the transportation sector. Indeed, the urgency to address climate change is recognised within the UK's Climate Change Act, which stipulates a legally binding greenhouse gas (GHG) emission reduction target of at least 100% by 2050 (against the 1990 baseline.) Given that the transportation sector is the largest contributor to the UK's GHG emissions, drastic changes are required within the transportation sector for the compliance of this target. In this respect, green ammonia has attracted significant attention as a viable, carbon-free, fuel of the future, with the potential to replace conventional fossil fuels in transportation. In particular, the maritime industry has directed considerable investment towards the adoption of green ammonia as a shipping fuel.

This project addresses one of the challenges facing the transition towards a future fuel system based on green ammonia. This challenge pertains to the high nitrous oxide (NOx) emissions associated with the ammonia combustion process. Given the significant environmental and health implications associated with NOx emissions, it is imperative that these NOx emissions are controlled by implementing NOx aftertreatment devices.

The best approach to reduce NOx emissions is through catalytic reduction, which yields nitrogen and steam. Today, the most prominent technologies for NOx reduction under the O2-rich exhaust environment are: i) lean NOx trap (LNT), ii) ammonia selective catalytic reduction (SCR), which is frequently also equipped with an ammonia slip catalyst (ASC). Selective catalytic reduction of NOx has typically been performed using traditional catalytic converters. These technologies represent the current, most advanced NOx aftertreatment devices available, but are expensive, large and poorly durable. These factors, coupled with the high NOx emissions associated with the ammonia combustion process, limit the economic and technical suitability of the current NOx aftertreatment technologies to ammonia-fuelled engines.

This research topic targets the need to investigate innovative solutions to advance the development of an affordable, improved and more efficient NOx emission reduction technology, which could be implemented in an ammonia-fuelled engine. Specifically, the research project will deliver a pioneering technology for NOx emissions reduction: the Micro-structured Multifunctional Converter. Smaller, multifunctional, cheaper and more durable than the traditional catalytic converters, this technology offers enormous potential. Therefore, the overarching objective of this project is to investigate the feasibility of a novel Micro-structured Multifunctional Converter for NOx emissions reduction under typical exhaust operation conditions found in ammonia-fuelled engines.

The significance and relevance of this research topic cannot be understated. This project offers the potential to generate important contributions towards the development of NOx aftertreatment system that can economically and technically meet the requirements of an ammonia-fuelled engine. The advancement of such technologies is pivotal to the transition into a future fuel system based on zero-carbon, green ammonia, and in turn, the compliance of the UK's climate change targets.