Environmental Footprint of Shipping—Characteristics and Mitigation Strategies

Dear Colleagues,

Maritime shipping is the main transport mode for global trade. In recent decades,  the size and the number of maritime freights, which largely rely on the use of diesel engines, have largely expanded due to the world economy. These are very energy efficient but have non-negligible environmental impacts. While new options for marine propulsion are arising, most of the ships in operation for the next thirty years will be still based on internal combustion engines, fueled with conventional bunker oils or new fuels.

Maritime shipping a relatively small quantity of the world demand for fuels, so that its overall effects on world emissions of air pollutants might be erroneously neglected. In addition to the regional scale effects, by its nature, shipping is more prevalent in high-density areas and the effect of shipping on the population becomes appreciable in port cities and coastal areas. Additionally, the wastewater from ships that is discharged directly into the sea may play a key role in the balance of marine flora and fauna, causing the alteration of the coasts and seabed with the phenomena of eutrophication and nitrification. Ship discharge into seawater can be in the forms of waste discharge and oil and bilge water containing heavy metals and toxic hydrocarbons.

The naval architecture, the engine and plant design adhere to several engineering constraints and most of the adopted fuels are also specific to the marine application. These make ships peculiar in terms of emissions profiles and necessitate a special design of exhaust gas cleaning systems and the management of wastewater, as well as suitable environmental policies to keep the sector competitive worldwide while moving effectively towards its greening.

This Special Issue welcomes papers related to the characteristics of ships’ pollutant emissions and the control strategies for their reduction. In particular, contributions should focus on: i) the characterization of ships’ emissions and their impact on health and the environment either at the regional or global scale, ii) innovative technologies and case studies on the mitigation of ships’ emissions into air and seawater, and iii) new environmental policies (e.g., fuel quality), finance aspects, directives and their future perspectives for maritime shipping.

Characteristics of ships’ emissions and impacts on human health and the environment:

• Emissions of gas compounds (SO_x, NO_x, CO₂, hydrocarbons, etc.) and particulate matter;
• Ship emissions and climate change;
• Impact of shipping on air quality and health in port cities and coastal areas;
• Air emissions and repercussions of the seawater pollution.

Marine policies, regulation, finance and energy economics:

• Correlations between fuel quality and their environmental and toxicological footprints;
• Future strategies for decarbonization, including the use of alternative fuels or e-fuels;
• Carbon taxes;
• Current scenario of fuel supply and demand in the marine industry post-pandemic;
• The role of ports in decarbonizing the maritime industry.

Technologies to reduce air and water pollution:

• New scrubber concept including dry and wet processes and different operating modes: open, closed and hybrid scrubbers;
• Novel and better-performing reactors for catalytic reduction of NOx ship emissions;
• CO₂ capture and storage;
• Reduction in particulate matter emissions;
• Gas cleaning techniques for emerging pollutants (outside IMO Marpol VI regulations);
• Case studies and new insights into the retrofit of the existing exhaust cleaning systems on-board ships;
• Scrubber washwater systems.

Alternative fuels in the marine industry:

• Case studies on and new advances in the use of ammonia, hydrogen, methanol, LNG, LPG, and bio-fuels and also the use of so-called e-fuels;
• Feasibility and safety studies in the use of hydrogen as a future ship fuel;
• Environmental footprint of alternative fuels, economic/energy assessments, and their impact on the new installation on-board, transportation and infrastructures.

Prof. Dr. Francesco Di Natale
Dr. Domenico Flagiello
Dr. Eva Merico
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Journal of Marine Science and Engineering is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• evaluation of ships’ emission factors
• harbor air quality
• health effects of shipping
• environmental policies for maritime shipping
• ships emission control and IMO strategies
• clean fuels
• marine ECGS
• SO₂ and NOx
• removal
• diesel particles removal
• CO₂ capture and storage for marine application