Incumbent clinker production practices fall short of meeting carbon-emission neutral targets, pressing the need to implement waste valorization approaches in cement plants to mitigate environmental impacts. However, there is a lack of knowledge on the future environmental performance of emerging waste-to-heat and fuel upcycling in clinker manufacturing. This study examines the prospective life cycle impacts of (1) solid recovered fuel (SRF) utilization and (2) on-site marine fuel production using integrated fluidized bed pyrolysis to substitute fossil fuels in clinker production and marine transportation. Environmental impacts are projected between 2025 and 2050 by applying learning effects in the foreground life cycle inventory and shared socioeconomic pathways (SSP1, SSP2), extended with the 1.9 W m−2 representative concentration pathway (SSP2-RCP1.9), in the background system. The highest decarbonization progress (−538.9 kg CO2-eq (t clinker)−1) is achieved under the SSP2-RCP1.9 development trajectory, driven by avoidance of emissions from waste management systems and converting biogenic carbon-rich municipal solid waste resources. The predicted CO2-eq impacts are found to be lower than the point source emission from raw meal calcination in several SSP scenarios, indicating that carbon-emission neutrality is attainable in combination with retrofitted carbon capture, utilization, and storage (CCUS) technologies. The assessment highlights the potential for burden shifting to other environmental impacts, e.g., particulate matter formation (+37.0 % by 2050), pointing to the need to evaluate additional pyrolysis oil upgrading and NOX emission mitigation strategies. Overall, synergizing waste pyrolysis with clinker production is found to be favourable due to (i) improved energy requirements, (ii) reduced fossil fuel use and impacts on climate change and ecosystem quality, and (iii) high potential for technological learning-driven environmental progress.
Although the existing literature identifies a fuel levy imposed by means of a global agreement as the most efficient policy for carbon pricing in the maritime sector, scholars and policy makers have debated the possibility for regional measures to be introduced in case a global agreement cannot be achieved. This debate has highlighted several economic, legal, and political challenges that the implementation of an efficient and effective regional scheme would have to face. This article compares the relative performance of various regional measures for carbon pricing based on the following criteria: jurisdictional basis, data availability, environmental effectiveness and avoidance strategies, impact on competitiveness, differentiation for developing countries, and incentives for reaching a global agreement. The main finding is that, if carefully designed, a cargo-based measure that covers the emissions released throughout the whole voyage to the cargo destination presents various advantages compared with other regional carbon pricing schemes. These advantages have been largely ignored in the literature.
ECOPRODIGI (2017-2020) is an Interreg Baltic Sea Region flagship project, which links research organisations, enterprises, associations and business support organisations. Altogether, 21 partners jointly investigate the most critical eco-inefficiencies in maritime processes in the Baltic Sea Region as well as develop and pilot digital solutions for improving the eco-efficiency by focusing on three specific cases: 1) digital performance monitoring of vessels, 2) cargo stowage optimisation at ports and 3) process optimisation at shipyards. Furthermore, looking towards the future, the project partners, on one hand, create a digitalisation roadmap and training modules for future decision makers in the maritime industry but also reach out to policymakers to engage them in discussion regarding how they can support the digital change. This report provides an overview of the project and main findings achieved to date, describes the main eco-inefficiencies identified and presents the potential of digital technologies and new concepts for improving them. Also, as the current digital transformation relates to the way how changes are managed in organisations, this report presents the main challenges and requirements identified in the process of moving towards more digitalised business operations. Finally, the last section looks at the maritime sector from a broader perspective and provides some ideas about the most likely future developments. The main findings of the project so far indicate that major improvements in eco-efficiency can be carried out in the maritime industry. They can be summarised as follows: 1) In the first case, ‘digital performance monitoring’, the project partners estimate, for instance, that fuel consumption and emissions can potentially be reduced by 2-20% based on data and analysis from distinct ship segments, routes and their baseline situations. The reductions are possible to achieve by taking such actions as capitalising on the latest digital technologies, utilising and analysing real-time operational data and vessel performance, anticipating operating conditions and maintenance of the ship and its components, changing working methods and improving practices as well as placing a focus on the training of personnel. 2) In the second case, ‘cargo stowage optimisation’ the project partners identified a set of eco-efficiency bottlenecks in the cargo stowage processes at ports that can be subject to improvement. The use of advanced digital technologies can contribute to more efficient utilisation of vessels and terminal operations. The port stays can be reduced, and, thereby, vessels can sail more slowly and reduce fuel consumption and emissions. Moreover, when stability calculations improve due to further digitalisation of cargo unit data, the ship can be loaded more optimally and the amount of ballast water can potentially be decreased without compromising safety, which again reduces fuel consumption on the sea leg. It is estimated that fuel consumption and emissions can potentially be reduced by 2-10% per route and ship and that additional benefits can be gained on the landside due to future digital decision support tools applied for the end-to-end stowage process. In addition, improved cargo unit pick up time estimates can be provided to customers waiting for the cargo to be handled at port, whereby the service improves. 3) In the third case, ‘process optimisation at shipyards’, improved situational awareness and process management, including the use of new technologies, such as 3D and solutions for managing the complex supply chain, have potential for improving the shipyard processes aimed at increased eco-efficiency. For example, in block building phase 3D technology reduces lead-time and potentially saves hundreds of man-hours in rework due to the fact that more efficient processes and proactive actions are enabled.
Strict limits on the maximum sulphur content in fuel used by ships have recently been imposed in some Emission Control Areas (ECAs). In order to comply with these regulations many ship operators will switch to more expensive low-sulphur fuel when sailing inside ECAs. Since they are concerned about minimizing their costs, it is likely that speed and routing decisions will change because of this. In this paper, we develop an optimization model to be applied by ship operators for determining sailing paths and speeds that minimize operating costs for a ship along a given sequence of ports. We perform a computational study on a number of realistic shipping routes in order to evaluate possible impacts on sailing paths and speeds, and hence fuel consumption and costs, from the ECA regulations. Moreover, the aim is to examine the implications for the society with regards to environmental effects. Comparisons of cases show that a likely effect of the regulations is that ship operators will often choose to sail longer distances to avoid sailing time within ECAs. Another effect is that they will sail at lower speeds within and higher speeds outside the ECAs in order to use less of the more expensive fuel. On some shipping routes, this might give a considerable increase in the total amount of fuel consumed and the CO2 emissions.
This paper deals with two speed optimization problems for ships that sail in and out of Emission Control Areas (ECAs) with strict limits on sulfur emissions. For ships crossing in and out of ECAs, such as deep-sea vessels, one of the common options for complying with these limits is to burn heavy fuel oil (HFO) outside the ECA and switch to low-sulfur fuel such as marine gas oil (MGO) inside the ECA. As the prices of these two fuels are generally very different, so may be the speeds that the ship will sail at outside and inside the ECA. The first optimization problem examined by the paper considers an extension of the model of Ronen (1982) in which ship speeds both inside and outside the ECA are optimized. The second problem is called the ECA refraction problem, due to its conceptual similarity with the refraction problem when light travels across two different media, and also involves optimizing the point at which the ship crosses the ECA boundary. In both cases the objective of the problem is to maximize daily profit. In addition to mathematical formulations, examples and sensitivity analyses are presented for both problems.
The literature on liner shipping includes many models on containership speed optimization, fleet deployment, fleet size and mix, network design and other problem variants and combinations. Many of these models, and in fact most models at the tactical planning level, assume a fixed revenue for the ship operator and as a result they typically minimize costs. This treatment does not capture a fundamental characteristic of shipping market behavior, that ships tend to speed up in periods of high freight rates and slow down in depressed market conditions. This paper develops a simple model for a fixed route scenario which, among other things, incorporates the influence of freight rates, along with that of fuel prices and cargo inventory costs into the overall decision process. The objective to be maximized is the line’s average daily profit. Departing from convention, the model is also able to consider flexible service frequencies, to be selected from a broader set than the standard assumption of one call per week. It is shown that this may lead to better solutions and that the cost of forcing a fixed frequency can be significant. Such cost is attributed either to additional fuel cost if the fleet is forced to sail faster to accommodate a frequency that is higher than the optimal one, or to lost income if the opposite is the case. The impact of the line’s decisions on CO2 emissions is also examined and illustrative runs of the model are made on three existing services.
The “Initial IMO Strategy” was adopted in the 72nd session of the Marine Environment Protection Committee (MEPC 72) of the International Maritime Organization (IMO) in April 2018. It has set, among other things, ambitious targets to reduce greenhouse gas (GHG) emissions from ships, and purports to express a strong political will to phase them out as soon as possible. The most ambitious of these targets is to reduce GHG emissions by 2050 at least 50% vis-à-vis 2008 levels, and there is also an intermediate target to reduce CO2 emissions per transport work by 2030 at least 40%, again vis-à-vis 2008 levels. More than three years since the adoption of the Initial IMO Strategy, this chapter takes stock at the status of shipping decarbonisation and attempts to assess prospects for the future. Obstacles towards achieving the IMO targets are identified and discussed.
The purpose of this short paper is to provide a brief and non‐encyclopedic commentary on the decisions made at IMO MEPC 76 (June 2021) and assess the prospects for the future of shipping decarbonization in the aftermath of that meeting. The recent action of the European Commission to include shipping into the EU Emissions Trading System (ETS) is also discussed.
The purpose of this paper is to assess the status and prospects of the decarbonization of maritime transport. Already more than two years have passed since the landmark decision of the International Maritime Organization (IMO) in April 2018, which entailed ambitious targets to reduce greenhouse gas (GHG) emissions from ships. The paper attempts to address the following three questions: (a) where do we stand with respect to GHG emissions from ships, (b) how is the Initial IMO Strategy progressing, and (c) what should be done to move ahead? To that effect, our methodology includes commenting on some of the key issues addressed by the recently released 4th IMO GHG study, assessing progress at the IMO since 2018, and finally identifying other issues that we consider relevant and important as regards maritime GHG emissions, such as for instance the role of the European Green Deal and how this may interact with the IMO process. Even though the approach of the paper is to a significant extent qualitative, some key quantitative and modelling aspects are considered as well. On the basis of our analysis, our main conjecture is that there is not yet light at the end of the tunnel with respect to decarbonizing maritime transport.
There have been a number of recent papers in the literature that investigate the relationship between ship speed and required power, or between ship speed and fuel consumption. Using regression analyses for selected case studies these papers show that in many cases the traditional “cube law” is not valid, and exponents lower than 3 (and in some cases lower than 2 or even below 1) are more appropriate. Perhaps more important, they use these results to derive implications on the validity (or lack thereof) of policies to reduce greenhouse gas (GHG) emissions from ships through slow steaming. This paper reviews some of these papers and shows that their results are partially based on pitfalls in the analysis which are identified. Policy implications particularly on the quest to reduce GHG emissions from ships are also discussed.