Abstract:
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. NOx 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.
摘要:
硫排放控制区(SECA),由国际海事组织(IMO)授权,调节燃料硫含量(FSC),以减轻沿海地区航运排放对环境和健康的影响。目前,FSC在SECAs内限制为0.1%(w/w),在SECAs外限制为0.5%(w/w),使用湿式硫磺洗涤器的船舶除外。这些洗涤器使使用高含硫重质燃料油(HFO)等非合规燃料的船舶能够进入SECA。然而,虽然通过洗涤器减少硫是有效的,它们捕获其他潜在有害气体的效率仍然不确定。此外,新兴的合规燃料,如高芳族燃料或低硫混合物缺乏特征,可能会带来风险。三年多,我们评估了试验船用发动机在25%和75%负荷下的排放,操纵和巡航的代表,分别。首先,表征五种不同的合规和不合规燃料的排放(船用瓦斯油MGO,加氢处理植物油HVO,high,低硫和超低硫HFOs),我们计算了排放因子(EF)。然后,使用合规和不合规的HFO测量湿式洗涤器气相捕获效率。NOxEF因燃料而异(5200-19700毫克/千瓦时),有限的洗涤器减少。CO(EF750-13700mg/kWh)和碳氢化合物(HC;EF122-1851mg/kWh)也显示出不足的减排量。与MGO和HVO相比,HFOs的致癌苯在25%负荷下明显更高,而HFOs的致癌苯则高出约一个数量级,没有观察到的洗涤器减少。相比之下,羰基如致癌甲醛和乙醛,作为臭氧前体,由于它们的极性和水溶性而被有效地洗涤。检查了所有燃料的臭氧形成潜力(OFP)。观察到燃料和发动机负载之间的显着EF差异,与湿式洗涤器提供有限的或没有减少的气体排放。我们建议加强海洋部门的法规和减排,以减轻对人类健康和环境有害的气态污染物。