Sustainability in Maritime Sector: Waste Management Alternatives Evaluated in a Circular Carbon Economy Perspective

Abstract

Sustainability and waste management on board are key issues that need to be addressed by the maritime sector also in terms of greenhouse gas emissions (GHG). With the aim of evaluating waste management alternatives in a circular economy perspective, the study examines a combined system for the optimisation of ship waste management and assesses its possible use for energy purposes. Different systems are analysed in relation to their GHG emission reduction potential regardless of routes and ports of destination. A SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis was carried out on waste management alternatives in order to preliminary identify their potential in terms of GHG emissions reduction, cost, environmental sustainability, methodological coherence, feasibility and replicability. Following this analysis, two case studies of particular interest were identified: (1) the thermo-chemical treatment of waste oils and sludge to obtain fuel oils; (2) the installation of a waste-to-energy plant and subsequent energy recovery on board. UNFCCC (United Nations Framework Convention on Climate Change) methodologies were applied to these two case studies to calculate GHG emission reduction resulting from their implementation. The obtained results are presented with the aim of supporting sustainable waste management strategies on board in a circular carbon economy perspective.

Life Cycle Sustainability Analysis of Resource Recovery from Waste Management Systems in a Circular Economy Perspective Key Findings from This Special Issue

“…Gallo et al [33] investigated the type and amount of waste that is generated on average by a typical cruise ship, with a 5000 people hosting capacity, a 300 m length, and a 100 kt tonnage. The authors' attention fell on this research field because such a ship is like a small floating city that, depending upon logistical and management peculiarities, can generate even huge amounts of highly diversified waste [33]. In their study, the authors analysed a set of on-board waste management solutions in a CE perspective, based upon their GHG reduction potential regardless of routes and ports of destinations.…”

“…In their study, the authors analysed a set of on-board waste management solutions in a CE perspective, based upon their GHG reduction potential regardless of routes and ports of destinations. To that end, Gallo et al [33] applied the SWOT analysis to a set of waste management options for the estimation of the related issues of GHG emissions, cost, environmental sustainability, methodological coherence, feasibility and replicability, and determined the following ones to be of particular interest-the thermos-chemical treatment of properly collected waste oils and sludge for conversion into fuel oils, and the installation on board of a waste-toenergy plant with energy recovery. Then, for those two options, the authors carried out a complementary assessment of the GHG-emission reduction following their application, using the UNFCCC methodologies-the study highlighted no particularly significant reduction in that sense.…”

“…In all contributions, the authors explored several relevant aspects connected with this SI's research theme, so enriching the current state-of-the-art in the field of sustainable waste recovery systems for production of value-added commodities under a CE perspective. Some of the sectors where CE can be beneficial for enhancement of their sustainability performance were explored in this SI's paper collection: post-use plastics end-of-life [11,30]; waste heat recovery [31]; waste management [32,33]; electrics and electronics [34]; and olive oil [35].…”

“…-Midpoint Life Cycle Assessment (LCA) focussed upon a single Environmental Indicator (EI), as done by Spierling et al [30]; -Midpoint LCA of multiple EIs [11]; -Endpoint LCA of multiple EIs extended to other relevant issues [31]; -Life-cycle multicriteria analysis as a decision support tool [32]; -Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis combined with other environmental assessment methodologies [33]; -Questionnaire-based investigation [34]; -Questionnaire-based investigation combined with a SWOT analysis [35].…”

“…The waste management investigation was narrowed to the maritime sector in the study of Gallo et al [33], which is reviewed in the next section, as it reports upon findings from the combined application of SWOT analysis and the methodology developed by the United Nations Framework Convention on Climate Change (UNFCCC).…”