Mitigation of Ship Emissions: Overview of Recent Trends

Abstract

The urgency of reducing flue gas pollution in maritime transport makes it necessary to take a holistic view of its sustainability and environmental impacts. Among the approaches to reducing ship exhaust emissions, marinized gas scrubbers, given their ability to be retrofitted to existing ships, are a central element in the tradeoff against the use of expensive low-sulfur fuels. However, compounding this issue, the priority of reducing greenhouse gas (GHG) emissions in the coming decades poses new challenges to emissions compliance. The use of exhaust gas cleaning systems to remove SO X , NO X , and particulate matter (PM) emissions will be enhanced in the short to medium term by GHG reductions. In this study, the different types of scrubbers for seaborne operation and the potential risks associated with their secondary emissions will be critically reviewed. In addition, NO X reduction systems and recent efforts to reduce CO 2 through onboard carbon capture systems or alternative fuel combustion will also be covered.

Solids Mixing in Marinized Bubbling Fluidized Beds: Gas Distribution Study

“…The offshore oil and gas industry also uses multiphase reactors or scrubbers for on-board conversion or treatment . In particular, fluidized bed reactors are a suitable choice for commercial ship exhaust gas treatment systems due to their ability to increase gas–solid contacting . Within the realm of technical literature on fluidized beds, there are numerous suggestions put forth to improve their performance, with examples of internal modifications including the use of tapered or fountain-spouted fluidized beds. − Offshore units and mini-refineries must be robust despite the challenges posed by sea movements.…”

“…Exhaust gas cleaning systems (EGCS) are the workhorse of MARPOL Annex VI, Regulation 4, which allow ships to continue burning cheap, high-sulfur fuels . Marinized fluidized bed or packed scrubbers are the main EGCS component and can be installed on existing ships . Using EGCS to reduce SO X , NO X , and particulate matter emissions can also contribute to greenhouse gas emission reductions in the short to medium term.…”

“…Using EGCS to reduce SO X , NO X , and particulate matter emissions can also contribute to greenhouse gas emission reductions in the short to medium term. However, further action is necessary to achieve long-term emissions compliance …”

“…6 Marinized fluidized bed or packed scrubbers are the main EGCS component and can be installed on existing ships. 7 Using EGCS to reduce SO X , NO X , and particulate matter emissions can also contribute to greenhouse gas emission reductions in the short to medium term. However, further action is necessary to achieve long-term emissions compliance.…”

“…However, further action is necessary to achieve long-term emissions compliance. 7 For the past several decades, multiphase reactors have been used in offshore applications such as subsea hydrocarbon extraction. 8 The offshore oil and gas industry also uses multiphase reactors or scrubbers for on-board conversion or treatment.…”