Sustainable MArine pollutant Reduction Technology
Shipping of large quantities of cargo requires substantial energy, generating an estimated 1.06 billion tons of CO2 emissions annually – about 2.89% of global CO2 emissions and 15-20% of global NOx and SOx emissions [V1]. Most current ships are powered by diesel engines, which emit greenhouse and/or harmful gases such as CO2, CO, NOx, volatile organic compounds (VOCs), SOx and particulate matter (e.g. soot) [V2]. In 2018, the International Maritime Organization (IMO) implemented a strategy to reduce greenhouse gas emissions from international shipping, targeting a 40% reduction in CO2-emissions by 2030 and a 50% cut in total greenhouse gas emissions by 2050 (compared to 2008 levels). This has pressured the shipping industry to innovate to meet these targets. While alternative energy carriers (e.g. methanol, H2 and NH3) are being explored [V3], they are not yet widely deployable [V4], and concerns remain regarding their environmental impact, supply chain, and sustainability [V5]. Moreover, diesel-powered ships built from 2019 onward, with expected lifespans of ~30 years, risk non-compliance with 2050 targets.
Therefore, the focus lies on adopting transition technologies to improve combustion efficiency, operational efficiency and introducing advanced exhaust-treatment systems to mitigate harmful gas emissions. In 2018, greenhouse gas emissions from international shipping had already decreased by 22%, partly due to energy-saving measures like “slow steaming” and engine power limitation - measures that lower fuel use and emissions [V3]. However, operating at lower power creates a new challenge as it alters exhaust gas properties, composition and temperature and can increase average NOx emissions despite the lower fuel consumption and CO2 emissions [V4, V13]. This necessitates the development of innovative exhaust gas treatments, tailored to the altered exhaust conditions when energy saving measures are used. Moreover, dual-fuel systems – such as addition of green methanol – are also changing exhaust characteristics, further necessitating the development of innovative adapted exhaust gas treatment systems.
Therefore, the SMART project goal is to adapt the exhaust gas treatment systems to both the CO2 limiting measures such as variable load and slow steaming engine operation and/or dual fuel systems, thereby further reducing the global footprint and greenhouse gas emissions of international shipping towards the 2050 goal.
To tackle these challenges, SMART takes an integrated approach to maximize emission reductions by:
1) Implementing operational measures and dual-fuel systems at the engine level, while
2) developing innovative, improved exhaust gas treatment catalysts adapted to the altered exhaust gas properties, compositions and temperatures of these sustainable engine operation and dual-fuel systems.
The SMART project therefore puts forth four key research objectives:
1) Establish a benchmark matrix measuring the exhaust gas properties, compositions and temperatures as a function of engine load (10-100%) and dual-fuel (diesel- methanol) operation to create a database of exhaust properties, compositions and temperatures related to emission reduction at the level of the engine (WP1).
2) Innovative catalyst shaping technologies and their benefits beyond current state-of-the-art will be validated with the purpose to decrease pressure drop and noise levels, accommodate pressure and thermal gradients when varying loads, while enhancing catalyst performance and stability and reducing required catalyst volumes. To design the most optimal geometries (shapes), a combination of modelling and experimental validation will be followed (WP2).
3) Develop innovative platinum group metal (PGM)-free Cu-based catalysts with lower light-off temperatures compared to the state-of-the art, able to oxidize CO and hydrocarbons and directly reduce NOx (direct deNOx), avoiding the need for reductants (such as ammonia or urea), and adjusted to the variable load, slow steaming and dual-fuel configurations. To achieve this, bi- or multimetallic catalyst compositions will be used together with synthetic approaches that allow highly dispersed metal species and strong metal support interaction. Iterative design is guided by results and input from the advisory board (AB) (WP3).
4) Evaluate these innovative and shaped marine engine adapted catalysts on a real marine engine laboratory set-up, evaluating real-time catalyst performance on a marine engine operated at varying engine load and with dual-fuel systems, with the aim to reduce marine emissions beyond the current 22% (WP4).
