Sulfur Emissions Research Articles

The implications and challenges of the IMO 2020 regulation: Exploring options for compliance

AbstractThe International Maritime Organisation (IMO), as a part of its continuing efforts to regulate sulphur oxide emissions, adopted the IMO 2020 Regulation. The regulation established a new worldwide cap on the sulphur content of shipping fuel. This article critically analyses the key provisions of the IMO's latest regulation by examining the economic consequences of the regulation and its impact on the shipping industry, petroleum markets and refineries. This article highlights the challenges that State parties face in enforcing the regulation and the repercussions for non‐compliance. The key findings of this article reveal that since the enforcement of the IMO 2020 Regulation, sulphur emissions have decreased by approximately 8.5 to 8.9 million metric tons. By 2025, this reduction is expected to reach around 77% of pre‐regulation levels. Coastal settlements, particularly highly populated areas, are expected to benefit from the reduction in sulphur concentration levels.

Polyoxometalates ionic liquids based magnetic nanocomposites as an efficient heterogeneous catalysts for oxidation of thiobenzoic acid and dibenzothiophene by employing RP-HPLC-UV

Sulfur compounds need to be effectively rejected from fuel to maintain a clean environment. The removal of sulfur compounds from thiocompounds has received increased attention due to the negative environmental and industrial consequences of sulfur emissions. We examine the effectiveness of polyoxometalate (POM) ionic liquid-based nanocomposites as catalysts for the oxidative desulfurization of thiobenzoic acid and other sulfur-containing chemicals. Na-POMIL@NCP and Cr-POMIL@NCP were synthesized and thoroughly characterized using a variety of analytical techniques, including Fourier-transform infrared spectroscopy (FT-IR), UV–visible spectroscopy, powder X-ray diffraction (P-XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), fluorescence spectroscopy, and vibrating sample magnetometer (VSM). POMIL-based nanocomposites with Fe3O4@SiO2 exhibit both catalytic activity and adsorption capability. To evaluate sulfur removal efficiency and investigate the transformation paths of the thio compounds, high-performance liquid chromatography (HPLC) was performed at 33 °C using a C18 column with an acetonitrile–water mobile phase (1:1 ratio). The catalytic conversion of thiobenzoic acid and dibenzothiophene occurs at temperature, oxidant O/S ratio and catalyst concentration were investigated to determine the best catalyst for a given process. Under moderate conditions, this work proposes a cost-effective and ecologically acceptable approach for thiobenzoic acid (TB) and dibenzothiophene (DBT) production employing H2O2 as an oxidant and Na-POMIL@NCP and Cr-POMIL@NCP as heterogeneous catalysts. They are highly effective for oxidizing sulfur compounds included in diesel to lower the sulfur levels of fuel. This study provides to the development of innovative materials for ecologically friendly sulfur removal applications.

Revisiting the 10th‐Century Eldgjá Eruption: Modeling the Climatic and Environmental Impacts

AbstractThe 10th‐century Eldgjá eruption in Iceland is the largest basaltic flood lava eruption of the Common Era. However, the extent of its impacts is unclear due to limited historical records. Combining volcanology and ice‐core analyses from both recent and earlier studies, we present a gas emissions scenario for the Eldgjá eruption spanning 937 to 940 CE, co‐injecting volcanic sulfur and halogens. The combined tropospheric and stratospheric sulfur emissions are 3–8 times higher than those adopted for Eldgjá in existing paleoclimate simulations. Earth system modeling of this scenario under pre‐industrial conditions reveals a compound event with maximum northern extratropics surface cooling of C in summer‐autumn of 939 and 940 CE, prolonged Arctic sea ice growth, and large‐scale precipitation changes, concurrent with stratospheric ozone depletion and elevated pollution. These results imply that the combined climatic and environmental effects of the Eldgjá eruption may have significantly impacted human populations at the time.

Environmental Performance of the Shipping Industry: A Case Study of MARPOL Violations

Focusing on key areas such as sulfur emissions under MARPOL Annex VI, oil discharge violations, and other pollution infractions, the research explores trends in non-compliance, the geographical distribution of violations, and the effectiveness of regulatory enforcement. The results reveal a significant increase in sulfur violations following the introduction of stricter global fuel sulfur limits in 2020, with older vessels and ships registered under flags of convenience being the primary offenders. The analysis shows that regions with robust port state control (PSC) regimes, such as Northern Europe and North America, have lower rates of non-compliance, while areas with weaker enforcement, including Southeast Asia and Africa, exhibit higher violation rates. Regression analysis further indicates that stricter penalties and more frequent inspections correlate with improved compliance. Qualitative insights from case studies underscore cost pressures, technological challenges in retrofitting older ships, and flag state weaknesses as major drivers of non-compliance. To address these issues, the study recommends strengthening global enforcement, harmonizing penalties across jurisdictions, and incentivizing investments in pollution control technologies. The findings suggest that the International Maritime Organization (IMO) could play a critical role in coordinating these efforts, ensuring consistent regulatory standards and enforcement. The study concludes that achieving full compliance with MARPOL regulations is essential for reducing the environmental impact of the shipping industry and aligning it with global sustainability goals.

Warming effects of reduced sulfur emissions from shipping

Abstract. The regulation introduced in 2020 that limits the sulfur content in shipping fuel has reduced sulfur emissions over global open oceans by about 80 %. This is expected to have reduced aerosols that both reflect solar radiation directly and affect cloud properties, with the latter also changing the solar radiation balance. Here we investigate the impacts of this regulation on aerosols and climate in the HadGEM3-GC3.1-LL climate model. The global aerosol effective radiative forcing caused by reduced shipping emissions is estimated to be 0.13 W m−2, which is equivalent to an additional ∼50 % to the net positive forcing resulting from the reduction in all anthropogenic aerosols from the late-20th century to the pre-2020 era. Ensembles of global coupled simulations from 2020–2049 predict a global mean warming of 0.04 K averaged over this period. Our simulations are not clear on whether the global impact is yet to emerge or has already emerged because the present-day impact is masked by variability. Nevertheless, the impact of shipping emission reductions either will have already committed us to warming above the 1.5 K Paris target or will represent an important contribution that may help explain part of the rapid jump in global temperatures over the last 12 months. Consistent with previous aerosol perturbation simulations, the warming is greatest in the Arctic, reaching a mean of 0.15 K Arctic-wide and 0.3 K in the Atlantic sector of the Arctic (which represents a greater than 10 % increase in the total anthropogenic warming since pre-industrial times).

Multi-model effective radiative forcing of the 2020 sulfur cap for shipping

Abstract. New regulations of sulfur emissions from shipping were introduced in 2020, reducing emissions of SO2 from international shipping by ∼ 80 %. As SO2 is an aerosol precursor, this drop in emissions over the ocean will weaken the total aerosol effective radiative forcing (ERF) that has historically masked an uncertain fraction of the warming due to the increased concentration of greenhouse gases in the atmosphere. Here, we use four global climate models and a chemical transport model to calculate the ERF resulting from an 80 % reduction in SO2 emissions from international shipping relative to 2019 emission estimates. The individual model means range from 0.06 to 0.09 W m−2, corresponding to the ERF resulting from the increase in CO2 concentration over the last 2 to 3 years. The full uncertainty in the ERF due to the new regulation is not quantified but will very likely be high considering the contribution of uncertainties in shipping SO2 emissions, the sulfur cycle, the modelling of cloud adjustments and the impact of interannual variability on the method for calculating radiative forcing.

Evaluation and Analysis of the Energy Potential of Grapevine Peduncles of PIWI Group Varieties

This paper presents an analysis of the energy potential of grape stalk biomass from PIWI varieties, namely ‘Seyval Blanc’, ‘Muscaris’, ‘Hibernal’, and ‘Regent’, during the combustion process. Biometric, technical, and elemental analyses of the grape stalk biomass were conducted. We evaluated the mass, length, and width of the stalks and their contribution to the total cluster mass. The higher and lower heating values, moisture content, volatile compounds, ash, fixed carbon content, and elemental composition were analysed. Emissions of carbon monoxide, nitrogen oxides, carbon dioxide, sulphur, and particulates were also measured. A significant influence of the cultivar on the assessed biometric and technical parameters was found. ‘Muscaris’ exhibited the highest calorific value (HHV 16.44 MJ·kg−1) and the lowest ash content (9.99%). The highest carbon content (45.51%) was recorded for ‘Seyval Blanc’, and the highest hydrogen content (6.74%) for ‘Muscaris’. Nitrogen oxide emissions were the lowest for ‘Seyval Blanc’, making it more environmentally friendly. The biomass of grape stalks from PIWI varieties, particularly ‘Muscaris’ and ‘Seyval Blanc’, shows high energy potential and can be effectively utilised as a renewable energy source. Our results could be summarised as ‘sustainable energy production and reduced greenhouse gas emissions from grape stalks’.

Towards sustainable energy selection for ships in response to maritime regulation

Ship owners and operators are continuously seeking financially viable ways to comply with the Sulphur emission limits set out by the IMO, which calls for a reduction of sulphur content in ship fuel to less than 0.5 % in 2020. The prudent decision in managing required energy sources by shipowners/operators will lead to an efficient ship operating decision, subsequently resulting in long-term financial return. The study aims to identify the factors influencing ship owners and operators to select the energy types in operating their vessels. Furthermore, the research explores the most desired energy sources to address the IMO Sulphur Cap Regulations 2020. One operation research method, namely the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE), and one econometrics tool, namely the conditional logit model, have been used to explore the research objectives. The PROMETHEE analysis suggests that clean fuel (VLSFO) is the best alternative to respond IMO 2020, followed by scrubber installation. The conditional logit analysis suggests almost the same, indicating clean fuel as the only alternative for responding to regulation. The decision is driven by the vessel's age negatively and the size of the vessel positively. The study will enormously impact the ship’s energy procurement practices in Bangladesh.

Sulfur Speciation in Li-S Batteries Determined by Operando Laboratory X-ray Emission Spectroscopy.

In this work, operando sulfur X-ray emission measurements on a Li-S battery cathode were performed using a laboratory setup as an alternative to more common synchrotron radiation based absorption studies. Photoexcitation by an X-ray tube was used. Valence-to-core Kβ X-ray emission spectra were recorded with a wavelength dispersive crystal spectrometer in von Hamos geometry, providing excellent energy resolution and good detection efficiency. The setup was used to record ex situ S Kβ emission spectra from S cathodes from the Li-S battery and also under operando conditions. Average S oxidation state within the battery cathode during battery cycling was determined from the shape of the Kβ emission spectra. A more detailed S species characterization was performed by fitting a linear combination of previously measured laboratory synthesized standards to the measured spectra. Relative amounts of different S species in the cathode were determined during the cycling of the Li-S battery. The main advantage of X-ray emission spectroscopy is that it can be performed on concentrated samples with S loading comparable to a real battery. The approach shows great promise for routine laboratory analysis of electrochemical processes in Li-S batteries and other sulfur-based systems under operando conditions.

How the establishment of carbon emission trading system affects ship emission reduction strategies designed for sulfur emission control area

As the backbone of the international seaborne trade, the pollution and emission from shipping are highly concerned by governments and international organizations as well. The International Maritime Organization has designated five emission control areas (ECAs) to limit sulfur oxides emissions of ships. Meanwhile, the European Union has included the shipping industry in the EU Emission Trading System since 2024 to control their carbon emissions. The strategies like switching fuel, installing scrubber or detour, are commonly used to comply with the ECA regulation, but they may increase carbon emissions and possibly incur extra carbon trading cost. In this case, the shipping company should investigate the influence of marine emission trading system (METS) on emission reduction strategies used under ECA regulation. Therefore, this paper focuses on this problem and formulates it as a mixed-integer nonlinear programming model. Several numerical experiments are conducted to show the applicability of the proposed model. The results show that ship's detour behavior is inevitable under the ECA regulation, which incurs more carbon emissions. When METS regulation is not considered, the optimal emission reduction strategy is installing scrubber. In contrast, when METS regulation is considered, the optimal choice may be installing scrubber or fuel switching depending on different sailing route, which indicates the effect of METS on ship emission reduction strategy. Moreover, the fleet deployment and sailing speed of scrubber installation strategy are affected by METS regulation, while the strategies of fuel switching and using LNG-powered ship are almost unaffected. This indicates that installing scrubber is more easily affected by emission control policies.

Air pollution under formal institutions: The role of distrust environment

Formal trust is an important formal institution that may significantly impact the environment. This study uses regional distrust environment as a reverse proxy variable for formal trust and studies the impact of formal trust on corporate sulfur dioxide emissions. This study finds that the environment of distrust significantly increases the sulfur dioxide emission levels of enterprises, which means that formal trust affects the environmental management strategies of enterprises. This study also finds that some other formal institutional factors, which include marketization, the development of intermediate organizations, the legal system environment, and GDP levels, have moderating effects on the impact of distrust environment on corporate sulfur dioxide emissions. In addition, climatic conditions including temperature, humidity, and precedence, as well as the location of the enterprise, have certain moderation effects. Mechanism analysis indicates that distrust environment affects corporate sulfur dioxide emissions through the increase in coal sulfur content in enterprise production, the decrease in exhaust gas processing capacity, the reduction in financing capacity, and the decline in social and environmental responsibilities. Finally, this study finds through further analysis that the local government appears to have noticed this negative impact, and the regions with a distrust environment tend to increase their environmental regulation intensity.

Research on Hybrid Heating System in Cold Oilfield Regions

Efficient and clean treatment of wastewater and energy recovery and utilization are important links to realize low-carbon development of oilfields. Therefore, this paper innovatively proposes a multi-energy complementary co-production heating system which fully and efficiently utilizes solar energy resources, oilfield waste heat resources, and biomass resources. At the same time, a typical dormitory building in the oil region was selected as the research object, the system equipment selection was calculated according to the relevant design specifications. On this basis, the simulation system model is established, and the evaluation index and operation control strategy suitable for the system are proposed. The energy utilization rate of the system and the economic, energy-saving, and environmental benefits of the system are simulated. The results show that, under the simulated conditions of two typical days and a heating season, the main heat load of the system is borne by the sewage source heat pump, the energy efficiency is relatively low in the cold period, and the energy-saving characteristics are not obvious. With the increase in heating temperature and anaerobic reactor volume, the energy consumption of the system also increases, and the energy efficiency ratio of each subsystem and the comprehensive energy efficiency ratio of the system gradually decrease. In addition, although the initial investment in cogeneration heating systems is high, the operating costs and environmental benefits are huge. Under the condition of maintaining 35 °C, the anaerobic reactor in the system can reduce carbon emissions by 12.15 t per year, reduce sulfur dioxide emissions by 98.4 kg, reduce dust emissions by 49.2 kg, and treat up to 2700 t of sewage per year, which has broad application prospects.

Increased Asian Sulfate Aerosol Emissions Remarkably Enhance Sahel Summer Precipitation

AbstractObservational evidence shows that Sahel summer precipitation has experienced a considerable increase since the 1980s, coinciding with significant diverging trends of increased sulfate emissions in Asia and decreased emissions in Europe (dipole pattern of aerosols between Asia and Europe). The decrease in European sulfate aerosols has substantial effects on the Sahel summer precipitation increase, but the corresponding effect of increased Asian sulfate is unknown. Multi‐model simulations in the Precipitation Driver and Response Model Intercomparison Project (PDRMIP) show, compared to decreased European aerosols, that increased Asian aerosols similarly enhance the Sahel summer precipitation but with different large‐scale atmospheric circulation changes. Further analysis of the Sixth Coupled Model Intercomparison Project (CMIP6) simulations under historical attribution and various emission scenarios reinforces the results about the climate impacts of anthropogenic aerosols and suggests that in future scenarios with strong international cooperation and rapid climate mitigations (SSP2‐45), the Sahel drought will be intensified likely due to the decline in Asian aerosol emissions. Our results suggest that Asian anthropogenic aerosols are likely a non‐negligible driver of the recent recovery in Sahel precipitation amounts.

Thailand’s Kra Canal: economic feasibility and expert perspectives on its complexity

PurposeAsia is one of the most important economic regions of the world. The Kra Canal is considered as a potential maritime transportation node in global trade. Indeed, for centuries, a canal across the Kra isthmus in Thailand has been proposed as holding significant economic and logistical benefits through goods transfer and exchange, yet it remains unconstructed. Common tools in feasibility studies are PESTELE and SWOT analyses, which incorporate cost-benefit and value analyses. The purpose of this paper is to assess the feasibility of the Kra Canal using approaches to complement existing studies.Design/methodology/approachIn this paper, we combine quantitative and qualitative methodologies to holistically assess the feasibility of the Kra Canal. Quantitatively, we consider the economic feasibility of the canal using Net Present Value to evaluate its potential financial benefits. Qualitatively, we then present expert perspectives gathered from in-depth interviews with field experts (n = 20) to identify key aspects of complexity related to the economic, political and overall feasibility of the canal.FindingsWe discuss the possibility of the canal’s construction and describe possible future impacts the canal could have on the region geopolitically, for example, in its role in China’s One Belt One Road initiative and also in how Singapore and Tanjung Pelapas in Malaysia might react. Ultimately, we find significant complexities with the Kra Canal project, ones which anyone contemplating its construction would, we argue, be wise to consider.Originality/valueThis paper combined qualitative and quantitative methods to explore the economic, political and overall feasibility of the Kra Canal. The methodologies and findings supplement past relevant studies and help evaluate the economic, political and overall feasibility of the Kra Canal’s investment project. This is particularly timely considering its potential ability as a route given recent geopolitical events and, for example, as part of China’s Belt and Road initiative and its ability to reduce carbon and sulphur emissions.

The repercussions of enacting the IMO 2020 regulation for mitigating ship emissions in Malaysian waters

ABSTRACT The IMO 2020 regulations, introduced by the International Maritime Organization (IMO), came into effect on January 1, 2020, with the primary goal of reducing sulphur oxide emissions from ships by capping the allowable sulphur content in marine fuels at 0.50%. This measure aims to minimize the harmful environmental and health impacts of sulphur emissions, which contribute to air pollution and acid rain. However, the implementation of these regulations has posed considerable challenges for Malaysia’s maritime sector, particularly due to increased operational costs and difficulties in complying with the stringent requirements. This study critically analyses the challenges associated with the enforcement of IMO 2020 regulations in Malaysia, focusing on regulatory compliance. By conducting a comprehensive review of existing literature and integrating insights from key stakeholders and regulatory authorities, this research evaluates the current state of implementation. The findings reveal that the enforcement of IMO 2020 in Malaysia has been suboptimal, largely due to gaps in regulatory execution and industry preparedness. For Malaysia to fully align with international standards and contribute to the preservation of a sustainable maritime ecosystem, concerted efforts are essential to enhance enforcement mechanisms and ensure compliance with global emission reduction targets.

Predicting hygroscopic growth of organosulfur aerosol particles using COSMOtherm

Abstract. Organosulfur (OS) compounds are important sulfur species in atmospheric aerosol particles, due to the reduction of global inorganic sulfur emissions. Understanding the physicochemical properties, such as hygroscopicity, of OS compounds is important for predicting future aerosol–cloud–climate interactions. However, their hygroscopicity is not yet well understood due to the scarcity of authentic standards. In this work, we investigated a group of OS compounds with short carbon chains (C1–C5) and oxygen-containing functional groups in the form of sodium, potassium, or ammonium salts and their mixtures with ammonium sulfate. The hygroscopic growth factors (HGFs) of these OS compounds have been experimentally studied. Here, the HGFs were calculated from mass fraction of water that was computed using the conductor-like screening model for real solvents (COSMO-RS). A good agreement was found between the model-estimated and experimental HGFs for the studied OS compounds. This quantum-chemistry-based approach for HGF estimation will open up the possibility of investigating the hygroscopicity of other OS compounds present in the atmosphere.

Simultaneous measurement of SO2 and CO2 for sulfur content detection in marine diesel fuel using QCL absorption spectroscopy

Simultaneous measurement of CO2 and SO2 in ship exhaust gases is a common method for assessing compliance with sulfur emission standards. This study develops a new ship exhaust gas analyzer using time-division multiplexing of two quantum cascade lasers for simultaneous detection of the two gas species. A digital circuit integrated with a dual-channel waveform generator and a lock-in amplifier is developed to implement wavelength modulation spectroscopy (WMS) scheme. To enhance the measurement accuracy of SO2 with broadband absorption feature, a novel WMS approach that combines first-harmonic and normalized second-harmonic detection is introduced. A Kalman filter algorithm is employed to further refine the measurement precision. Experimental results show a 30.76% increase in detection accuracy. With a 1 s time resolution, the sensitivities of 13.4 ppb for SO2 and 9.81 ppm for CO2 are achieved. The effectiveness of the prototype for sulfur content detection is demonstrated, aiding emission management of water transport emissions.

Sulfur oxidation of ferrate synthesized from sludge in the aspect of desulfurization: A parametric study

Abstract The emission of sulfur in the atmosphere poses a significant threat to human health and the environment. To address this issue, stringent regulations have been implemented to limit the sulfur content in diesel, and novel desulfurization technologies are being developed. One notable technology is oxidative desulfurization (ODS), which employs oxidants to transform sulfur compounds into their corresponding sulfones, which are relatively easier to recover. The application of high-shear mixing in ODS has been studied to increase sulfur-to-sulfone conversion by creating smaller droplets and reducing mass transfer resistance. This research investigates the application of potassium ferrate derived from drinking water treatment sludge (DWTS), in the mixing-assisted oxidative desulfurization (MAOD) of a dibenzothiophene (DBT) model fuel. Potassium ferrate was synthesized using the wet oxidation method. The study evaluated the effects of ferrate concentration (400 to 600 ppm), agitation speed (4,400 to 10,800 rpm), and temperature (40 to 60 °C) on the efficiency of DBT conversion. The results revealed that 493.2 ppm DBT conversion was achieved at 550 ppm Fe(VI) concentration, 7,600 rpm agitation speed, and 50 °C temperature. Notably, increasing Fe(VI) concentration, agitation speed, and temperature had significant effects on sulfur reduction. This study demonstrates the potential of using potassium ferrate derived from DWTS in MAOD for effective desulfurization and discusses insights into the effects of operating conditions to enhance desulfurization efficiency. Ultimately, the study contributes to the development of environmentally friendly and cost-effective desulfurization technologies.

Evaluating eco-economic benefits of anchoring and drifting under government sulfur emission policies

Driven by global sulphur strategy, reducing sulfur emissions from the global shipping industry is of great significance for achieving sustainable development goals related to addressing climate change. This study explores the impact of government sulfur emission policies on the choice of mooring modes, include anchoring and drifting, for shipping lines. In this study, a bi-level programming model is constructed and linearized to minimize the total vessel emissions in emission control areas during the planning horizon and the total cost of each type of vessel. The leader of this model is the department that issues regulations and decides on the anchorage to regulate whether marine gas oil must be used. The followers are the shipping lines that execute transportation tasks and choose whether a vessel will anchor or drift. In addition, many numerical experiments and sensitivity analysis are conducted, and data and theoretical support for relevant decision-making are provided.

Rapid cycling and emission of volatile sulfur compounds in the eastern Indian Ocean: Impact of runoff inputs and implications for balancing atmospheric carbonyl sulfide budget

Volatile sulfur compounds, such as dimethyl sulfide (DMS), carbonyl sulfide (OCS), and carbon disulfide (CS2), significantly influence atmospheric chemistry and climate change. Despite the oceans being an important source of these sulfides, the limited understanding of their biogeochemical cycles in seawater introduces considerable uncertainties in quantifying their oceanic emissions and assessing atmospheric OCS budgets. To address this issue, we conducted a comprehensive field survey in the tropical eastern Indian Ocean (EIO) to examine the spatial distributions, source-sink dynamics, and sea-air exchange fluxes of marine DMS, OCS, and CS2. Our study indicates that nutrients, organic matter, and freshwater input from terrestrial runoff significantly affect most of the source-sink processes of these sulfides in the Bay of Bengal and even the tropical EIO. The resulting sulfide accumulation in seawater combined with high wind speeds establishes the tropical EIO as a considerable direct and indirect atmospheric OCS source. These insights underscore the potentially critical role of marine environments influenced by runoff in contributing to the atmospheric OCS budget. However, by integrating these results with previous field surveys, we believe that actual OCS emissions from tropical oceans exceed some bottom-up box-model simulations, yet fall significantly below those predicted by top-down models, still insufficient to bridge the atmospheric OCS source gap. Our detailed examination of source-sink dynamics offers deeper insights into the marine sulfur cycle and has potential implications for refining future box-models, thus mitigating uncertainties in estimating marine sulfur emissions.