University of the Bundeswehr Munich, Faculty for Mechanical Engineering, Institute of Chemistry and Environmental Engineering, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany.
Joint Mass Spectrometry Center (JMSC) at Comprehensive Molecular Analytics (CMA), Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
Environ Res. 2024 Nov 1;260:119609. doi: 10.1016/j.envres.2024.119609. Epub 2024 Jul 11.
Sulphur Emission Control Areas (SECAs), mandated by the International Maritime Organization (IMO), regulate fuel sulphur content (FSC) to mitigate the environmental and health impact of shipping emissions in coastal areas. Currently, FSC is limited to 0.1% (w/w) within and 0.5% (w/w) outside SECAs, with exceptions for ships employing wet sulphur scrubbers. These scrubbers enable vessels using non-compliant fuels such as high-sulphur heavy fuel oils (HFOs) to enter SECAs. However, while sulphur reduction via scrubbers is effective, their efficiency in capturing other potentially harmful gases remains uncertain. Moreover, emerging compliant fuels like highly aromatic fuels or low-sulphur blends lack characterisation and may pose risks. Over three years, we assessed emissions from an experimental marine engine at 25% and 75% load, representative of manoeuvring and cruising, respectively. First, characterizing emissions from five different compliant and non-compliant fuels (marine gas oil MGO, hydro-treated vegetable oil HVO, high-, low- and ultra-low sulphur HFOs), we calculated emission factors (EF). Then, the wet scrubber gas-phase capture efficiency was measured using compliant and non-compliant HFOs. NO EF varied among fuels (5200-19700 mg/kWh), with limited scrubber reduction. CO (EF 750-13700 mg/kWh) and hydrocarbons (HC; EF 122-1851 mg/kWh) showed also insufficient abatement. Carcinogenic benzene was notably higher at 25% load and about an order of magnitude higher with HFOs compared to MGO and HVO, with no observed scrubber reduction. In contrast, carbonyls such as carcinogenic formaldehyde and acetaldehyde, acting as ozone precursors, were effectively scrubbed due to their polarity and water solubility. The ozone formation potential (OFP) of all fuels was examined. Significant EF differences between fuels and engine loads were observed, with the wet scrubber providing limited or no reduction of gaseous emissions. We suggest enhanced regulations and emission abatements in the marine sector to mitigate gaseous pollutants harmful to human health and the environment.
硫排放控制区（SECAs）是国际海事组织（IMO）规定的，其目的是控制燃油中的硫含量（FSC），以减轻航运排放对沿海地区的环境和健康的影响。目前，SECAs 内 FSC 限制在 0.1%（w/w）以内，SECAs 外 FSC 限制在 0.5%（w/w）以内，但使用湿式硫洗涤器的船舶除外。这些洗涤器允许使用不合规燃料（如高硫重燃料油（HFO））的船舶进入 SECAs。然而，虽然洗涤器可以有效地减少硫的排放，但它们对其他潜在有害气体的捕捉效率仍不确定。此外，像高芳烃燃料或低硫混合燃料等新兴合规燃料缺乏特性，可能存在风险。在三年的时间里，我们评估了一艘实验性船用发动机在 25%和 75%负荷下的排放情况，这分别代表了操纵和巡航。首先，我们对五种不同的合规和不合规燃料（船用柴油 MGO、加氢处理植物油 HVO、高、低和超低硫 HFO）的排放进行了特征描述，计算了排放因子（EF）。然后，使用合规和不合规的 HFO 测量了湿式洗涤器的气相捕集效率。NO 的 EF 因燃料而异（5200-19700mg/kWh），洗涤器的减少效果有限。CO（EF 750-13700mg/kWh）和碳氢化合物（HC；EF 122-1851mg/kWh）的去除效果也不充分。致癌苯在 25%负荷下明显更高，与 MGO 和 HVO 相比，HFO 的含量高出一个数量级，而且没有观察到洗涤器的减少。相比之下，由于极性和水溶性，作为臭氧前体的羰基化合物（如致癌的甲醛和乙醛）可以被有效地洗涤。所有燃料的臭氧生成潜力（OFP）都进行了研究。观察到燃料和发动机负荷之间的 EF 存在显著差异，湿式洗涤器对气态排放的减少作用有限或没有。我们建议在海洋部门加强法规和减排措施，以减轻对人类健康和环境有害的气态污染物。
