Reduction Of Sulfur Content Research Articles

Potential impacts of marine fuel regulations on an Arctic stratocumulus case and its radiative response

Abstract. Increased surface warming over the Arctic triggered by increased greenhouse gas concentrations and feedback processes in the climate system has been causing a steady decline in sea-ice extent and thickness. With the retreating sea ice, shipping activity will likely increase in the future, driven by economic activity and the potential for realizing time and fuel savings from using shorter trade routes. Moreover, over the last decade, the global shipping sector has been subject to regulatory changes that affect the physicochemical properties of exhaust particles. International regulations aiming to reduce SOx and particulate matter (PM) emissions mandate ships to burn fuels with reduced sulfur content or, alternatively, use wet scrubbing as an exhaust aftertreatment when using fuels with sulfur contents exceeding regulatory limits. Compliance measures affect the physicochemical properties of exhaust particles and their cloud condensation nucleus (CCN) activity in different ways, with the potential to have both direct and indirect impacts on atmospheric processes such as the formation and lifetime of clouds. Given the relatively pristine Arctic environment, ship exhaust particle emissions could cause a large perturbation to natural baseline Arctic aerosol concentrations. Low-level stratiform mixed-phase clouds cover large areas of the Arctic region and play an important role in the regional energy budget. Results from laboratory marine engine measurements, which investigated the impact of fuel sulfur content (FSC) reduction and wet scrubbing on exhaust particle properties, motivate the use of large-eddy simulations to further investigate how such particles may influence the micro- and macrophysical properties of a stratiform mixed-phase cloud case observed during the Arctic Summer Cloud Ocean Study campaign. Simulations with diagnostic ice crystal number concentrations revealed that enhancement of ship exhaust particles predominantly affected the liquid-phase properties of the cloud and led to decreased liquid surface precipitation, increased cloud albedo, and increased longwave surface warming. The magnitude of the impact strongly depended on ship exhaust particle concentration, hygroscopicity, and size, where the effect of particle size dominated the impact of hygroscopicity. While low-FSC exhaust particles were mostly observed to affect cloud properties at exhaust particle concentrations of 1000 cm−3, exhaust wet scrubbing already led to significant changes at concentrations of 100 cm−3. Additional simulations with the cloud ice water path increased from ≈ 5.5 to ≈ 9.3 g m−2 show more-muted responses to ship exhaust perturbations but revealed that exhaust perturbations may even lead to a slight radiative cooling effect depending on the microphysical state of the cloud. The regional impact of shipping activity on Arctic cloud properties may, therefore, strongly depend on ship fuel type, whether ships utilize wet scrubbers, and ambient thermodynamic conditions that determine prevailing cloud properties.

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.

Novel adsorption-based upgradation of end-of-life polypropylene pyrolysis oil using carbonised rice husk

Plastic waste management is a global issue, with end-of-life polypropylene (EoL PP) having significant contribution. Polypropylene degradation forms undesirable compounds in pyrolysis oil, reducing its quality and limiting its fuel usability. Pyrolysis offers a promising solution for converting plastic waste into valuable fuels; however, the presence of degraded materials necessitates an effective upgrading process to enhance the fuel quality. This study introduces an innovative ex-situ adsorption-based upgradation technique using carbonised rice husk (CRH), an abundantly available, sustainable and cost-effective biomass residue, to significantly improve the quality of pyrolysis oil derived from EoL PP. The upgradation process reduced sulphur content in polypropylene pyrolysis oil from 0.19 % to 0.02 %. The cetane index, a key fuel quality metric, rose from 43.83 to 55.25, enhancing combustion properties. Proton nuclear magnetic resonance showed an increase in paraffin content from 53.15 vol% to 60.81 vol%, improving energy content and combustion efficiency. Olefins and aromatics decreased, improving fuel stability and reducing emissions. GCxGC TOF-MS analysis revealed a decrease in oxygenates and an increase in diesel-range hydrocarbons, improving fuel quality and stability. This comprehensive study highlights the dual benefits of CRH in enhancing fuel quality and supporting circular economy practices, making a significant contribution to the development of sustainable fuel alternatives in the waste-to-energy conversion sector.

Optimizing in-situ upgrading of heavy crude oil via catalytic aquathermolysis using a novel graphene oxide-copper zinc ferrite nanocomposite as a catalyst

Unconventional resources, such as heavy oil, are increasingly being explored and exploited due to the declining availability of conventional petroleum resources. Heavy crude oil poses challenges in production, transportation, and refining, due to its high viscosity, low API gravity, and elevated sulfur and metal content. Improving the quality of heavy oil can be achieved through the application of steam injection, which lowers the oil’s viscosity and enhances its flow. However, steam injection alone falls short of meeting the growing demand for higher-quality petroleum products. Catalytic upgrading is therefore being investigated as a viable solution to improve heavy oil quality. This study experimentally investigates the application of two novel catalysts, namely copper-substituted zinc ferrite (ZCFO) synthesized via the sol–gel combustion method and a graphene oxide-based nanocomposite (GO-ZCFO) with different ratios, for catalyzing aquathermolysis reactions in the steam injection process, with the aim of enhancing the in-situ upgrading of heavy oil. These catalysts underwent characterization using X-ray powder diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Transmission Electron Microscopy (TEM). Their catalytic performance was assessed utilizing a high-pressure/high-temperature reactor (300 ml), with a comprehensive analysis of the changes in the physical and chemical properties of the heavy oil before and after upgrading. This analysis included measurements of sulfur content, SARA fractions, viscosity, API gravity, and Gas Chromatography (GC) of saturated hydrocarbons and evolved gases. All upgrading experiments, including both catalytic and non-catalytic aquathermolysis processes, were conducted under a reaction time of 6 h, a reaction temperature of 320 °C, and high pressure (86–112 bar). The results indicated that the introduction of the proposed catalysts as additives into the upgrading system resulted in a significant reduction in sulfur content. This, in turn, led to a decrease in resin and asphaltene content, an increase in the content of saturated hydrocarbon, particularly low-molecular-weight alkanes, and ultimately, a reduction in viscosity along with higher API gravity of the crude oil. GO-ZCFO with a weight ratio (50:50) exhibited the best catalytic performance. The heavy crude oil, upgraded with this 50:50 ratio, exhibited significant enhancements, including a 29.26% reduction in sulfur content, a 21.27% decrease in resin content, a 37.60% decrease in asphaltene content, a 46.92% increase in saturated hydrocarbon content, a 66.48% reduction in viscosity, and a 25.49% increase in API gravity. In comparison, the oil upgraded through non-catalytic aquathermolysis showed only marginal improvements, with slight reductions in sulfur content by 5.41%, resin content by 3.60%, asphaltene content by 11.36%, viscosity by 17.89%, and inconsiderable increases in saturated hydrocarbon content by 9.9% and API gravity by 3.02%. The GO-ZCFO, with its high catalytic activity, stands as a promising catalyst that contributes to improving the in-situ upgrading and thermal conversion of heavy crude oil.

Desulfurization of pyrolytic oils from waste tire pyrolysis in a fluidized bed reactor with boron nitride adsorbents

The study focused on producing hexagonal boron nitride (hBN) as an adsorbent which provides high efficiency in desulfurization processes. The synthesized hBN is used for sulfur removal from liquid fuel derived from end-of-life tires (ELTs). Characterization of hBN was performed using FTIR, XRD, TGA, and SEM-EDS analyses. Liquid fuel was produced in a fluidized bed reactor at 550 °C under a nitrogen gas flow. Post-desulfurization, the fuel's density, water content, and calorific value increased, while sulfur content and flash point decreased, with sulfur content showing a significant reduction of 79.23 %. The desulfurized fuel (PS-A) exhibited better combustion characteristics and closely resembled diesel fuel performance, though it slightly reduced engine effective efficiency by 1.06 % compared to diesel. Both PS-A and pre-desulfurized fuel (PS-B) significantly reduced soot emissions by 23.28 % and 20.81 %, respectively, compared to diesel. Additionally, CO emissions were lower for PS-A and PS-B, with reductions of 4.35 % and 2.00 %, respectively. However, CO2 emissions increased by 1.60 % for PS-A and 0.86 % for PS-B, attributed to higher fuel consumption. Overall, hBN effectively reduced sulfur content and improved several fuel properties of pyrolytic liquids. The study highlights the environmental and economic benefits of enhancing ELT-derived liquid fuels and suggests potential applications in real systems, serving as a foundation for new technologies and projects.

Internal Corrosion Control Strategy of Oil Gathering and Transportation Pipeline

Abstract Internal corrosion and perforation of metal pipelines is the main reason for failure of gathering and transportation pipelines in a western oil field. The content of Cl-in the transport medium of the oilfield is between 24910-118051mg/l, the total salinity is between 65404-39363mg/l, the reduced sulfur content is between 6-36mg/l, and the number of SRBS is between 20-300 /ml, which are the main factors leading to corrosion in the pipeline. Through investigation, demonstration and field test, the internal corrosion control technology system of pipeline has been formed, which includes internal extrusion coating, internal penetration, 32MPa high pressure flexible composite pipe, polyethylene lined FRP composite pipe technology. The internal corrosion control strategy has been popularized in oil field, and the effect is good.

Parametric analysis on the sulfone adsorption of using iron impregnated bentonite

Abstract Sulfur left in liquid fuel is oxidized during combustion and released into the atmosphere, contributing to the worsening of global warming. To address this, oil refineries make use of hydrodesulfurization (HDS) to reduce sulfur content in the fuel. Alternatives to HDS are being studied due to its extreme operating conditions. An alternative for treating sulfur in fuel is oxidative desulfurization, which converts sulfur to sulfones and can be extracted using adsorption methods. This study focuses on the use of bentonite modified with Fe3+ to improve its adsorptive performance for removing dibenzothiophene sulfone (DBTO) in model oil. The prepared Fe3+-bentonite adsorbents resulted in lower removal of sulfur compared to raw bentonite. This is due to Fe3+ being a hard acid, thus lowering the affinity of bentonite in adsorbing DBTO, which is a soft base. Three parameters were varied in this study, namely adsorption time, adsorbent dosage, and temperature. Results showed that DBTO removal increased with adsorption time as the DBTO molecules occupy more adsorption sites. Increasing adsorbent dosage also increases sulfur removal as it introduces more reaction sites for DBTO removal. The DBTO and bentonite system was also found to be endothermic as desulfurization increased with the temperature rise. With the data collected in this study, it is recommended to explore the possible upscaling of adsorptive desulfurization.

Theoretical study of the oxidative desulfurization reaction in sulfur compounds present in crude oil

Oxidative desulfurization (ODS) has emerged as a highly promising and effective complementary technique to hydrodesulfurization for reducing sulfur content in fossil fuels. Notably, ODS demonstrates superior efficacy in removing challenging sulfur compounds (SCs) such as 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene. Therefore, it is imperative to unveil the molecular mechanisms underlying the ODS process and comprehend the reactivity properties of the participating species, offering insights to explain the mechanisms implicated. In this study, a thorough analysis of the reaction coordinate associated with the ODS process for a specific set of SCs was undertaken. The approach involved utilizing the Density Functional Theory and comparing the results with prior experimental observations to ensure the relevance of the findings in this study. In addition, reactivity trends were rationalized by applying temperature-dependent chemical reactivity theory. In this way, these results contribute to understanding the ODS process, which is essential to an environmentally friendly fuel production.

Production of low-sulphur tailings by hydrocycloning

Acid mine drainage (AMD) is an environmental problem in gold mines containing sulphur minerals. The potential for acid drainage in tailings facilities must be considered when studying their dry closure. Therefore, controlling the sulphur content in the final layer of tailings deposition has the potential to prevent AMD after closure. In this context, the rougher flotation tailings were hydrocycloning in a pilot plant in a gold mining company to assess the potential for generating modified tailings with low-sulphur content. A total of 10 samples were composited over one hour of pilot plant operation. The hydrocyclone overflow showed an average reduction of 36.2% in sulphur content and an average metallurgical recovery of 20.0%. The underflow had an average increase in sulphur content of 16.8% and 80.0% metallurgical recovery. These results demonstrated the possibility of generating modified tailings with reduced sulphur content through hydrocycloning.

Revealing the vital role of sulfur site on the surface of pyrite in 1O2 formation for promoting ciprofloxacin degradation via peracetic acid activation

Pyrite has been widely utilized to activate oxidants for water treatment, yet the regulation of reactive oxygen species (ROS) by sulfur sites on its surface has been overlooked. In this study, the surface sulfur sites were regulated by thermal modification of natural pyrite in the N2 atmosphere (denoted as P-X, where X represented pyrolysis temperatures ranging from 400 to 700 °C), and these modified pyrites were employed to activate peracetic acid (PAA) for ciprofloxacin (CIP) degradation. The results revealed that the degradation rate of CIP increased as the reduced sulfur content increased, with the P600/PAA system achieving the highest apparent degradation rate (kobs = 0.0999 min−1). Quenching experiments and electron paramagnetic resonance (EPR) analysis identified various ROS involved in the P-X/PAA system, with hydroxyl radical (·OH) and singlet oxygen (1O2) identified as dominant reactive species responsible for CIP degradation. The reduced sulfur sites served as the primary active sites facilitating the conversion of organic radicals (·CH3C(O)OO) into superoxide radicals (·O2−) and 1O2. Furthermore, the P600/PAA system demonstrated robust adaptability under both acidic and neutral pH conditions, efficiently degrading CIP even in the presence of complex matrices such as Cl−, NO3−, SO42−, NH4+, or humic acid (HA) in water bodies, although HCO3− was found to inhibit CIP degradation. This study significantly enhances our understanding of the interaction between reduced sulfur sites and ROS in PAA-based advanced oxidation processes (AOPs), offering a promising technology for efficient antibiotic treatment in water purification.

Carboxylic acid-based deep eutectic solvent for efficient desulfurization: Experimental and computational thermodynamics

The improvement of fuel quality requires the reduction of sulfur content. The main challenge of catalytic cracking diesel extraction desulfurization is to find low-price and good-performance extractants. Based on experimental research, this work further explores the separation mechanism of DES for thiophene (TP) and benzothiophene (BTP). First, the COSMOS-RS model was used to predict the separation performance of 10 HBAs and 10 HBDs for TP and BTP. The results showed that the low-cost carboxylic acid based DES had excellent separation performance. Secondly, the effect of experimental conditions on the separation performance of three carboxylic acid based DESs was investigated. When the molar ratio of DES to TP and BTP was 3:1, after three stage extraction, the extraction rates of TP and BTP by TEAC: PrA(1:3) were 98.06 % and 98.53 %, respectively. Finally, the structure–activity relationship was studied by using quantum chemistry and molecular dynamics simulation. It was found that EvdW plays a dominant role in the desulfurization process and does not include H-bond interactions. TEA+ was distributed parallel to the aromatic ring and has a CH···π interaction with thiophene. TP and BTP were distributed in the voids of DES and do not affect the regeneration performance of DES.

Electronic and Molecular Structures of a Series of Nickel Bis-1,1-Dithiolates.

A series of homoleptic Ni bis-1,1-dithiolates, [Ni(S2C2RR')2]2- (R=CN, R'=CN, CO2Et, CONH2, Ph, Ph-4-Cl, Ph-4-OMe, Ph-4-NO2, Ph-3-CF3, Ph-4-CF3, Ph-4-CN; R=NO2, R'=H; R=R'=CO2Et) have been synthesized from the reaction of the alkali metal salt of the ligand and nickel chloride, and isolated as tetraphenylphosphonium or tetrabutylammonium salts. The complexes were characterized by X-ray crystallography, high-resolution mass spectrometry, and infrared (IR), nuclear magnetic resonance (NMR) and electronic absorption spectroscopies. The molecular structures show a rigidly square planar Ni(II) center linking two four-membered chelate rings whose dimensions are constant across the series. The electronic effect of the ligand substituent is revealed in the 13C NMR and electronic spectra, and corroborated by density functional calculations. Electron withdrawing groups deshield the low-field CS2 resonance, and the signature charge transfer band in the visible region is red-shifted. These observables have been accurately reproduced computationally, and revealed the Ni contribution to the ground state diminishes with decreasing electron withdrawing capacity of the ligand substituent. In contrast to 1,2-dithiolates, the redox inactivity afforded by 1,1-dithiolates stems from the smaller chelate ring and substantially reduced sulfur content that is key to stabilizing the radical form.

The health and economic impacts of exposure to marine mobile emissions from ships in Durban port, South Africa

South Africa remains an uncharted realm in terms of marine mobile emissions inventory and hence the impact of pollution from ships in coastal cities remains unknown. Such a void creates uncertainties about the extent of population exposure to pollution from ships, the health impact and economic value associated with the changes in policies for the port city of Durban.This study was aimed at estimating the health and economic impact of marine mobile emissions and the health and economic benefits associated with improvement in air quality within the port city of Durban, which is under eThekwini municipality. The population exposure to particulate matter of less than 2.5 and 10 μm (PM2.5 and PM10) and sulphur dioxide (SO2) from ships calling into Durban port were estimated using the AERMOD air dispersion model. The BenMAP modelling tool was then used to estimate the health impact and economic value of changes in emission of PM2.5, PM10 and SO2 from ships visiting Durban port. The reduction in emissions from ships was due to the reduction in the sulphur content of fuel from 3.5% to 0.5% that was implemented by the International Maritime Organisation (IMO) on the 01st of January 2020.The results showed that PM2.5 and PM10 emissions reduced by 63% in 2020 compared to 2018, whilst SO2 emissions reduced by 82% over the same period. The BenMAP results indicated that 49 premature mortalities were avoided in 2020 compared to 2018 since the IMO's forced reduction in sulphur content of fuel by 85% in 2020. These avoided cases on mortality were estimated a monetary value of R228 million using the World Bank’s 2016 estimates and R683 million using the USEPA Mean VSL estimate. Such monetary values were respectively equivalent to 0.05% and 0.2% of the eThekwini's GDP, which was estimated at R468 billion in 2016.

Desulfurization of Basra Diesel Fuel by Emulsification – Adsorption Processes

In this study, the combined emulsification–adsorption processes were employed for the desulfurization of Basra diesel fuel. A high sulfur diesel fuel of 1.4538 wt% from the Basra refinery was oxidized effectively with H2O2 and Acetic acid (AcOH) as a catalyst to reduce sulfur content to 1.0875 wt% before being emulsified. The emulsification desulfurization (EDS) process using Alkyl benzene sulfonate (ABS) as a surfactant was optimized by 20 trails according to Response Surface Methodology (RSM). A 0.83886 wt% was achieved at the following optimum conditions: Surfactant concentration 20 wt.%, temperature 57.56 ᵒC, and homogenization speed 5695 rpm. The adsorptive desulfurization (ADS) process using activated bentonite clay was carried out in a batch system. The RSM was applied to determine the effect of contact time (1-10 hr), clay mass (5- 20 gm/50ml), and temperature (30-100 ᵒC) on the sulfur removal. Results showed that the sulfur content of 0.57 wt% was achieved at the following conditions: adsorption time 7.18 hrs., temperature 53.3 ᵒC, and clay mass 15.24 gm/ 50ml. The achieved sulfur removal efficiency was 23% and 32% for EDS and ADS respectively. The diesel fuel quality was studied by GC and IREX.

РОЗРОБКА РОЗРАХУНКОВИХ МОДЕЛЕЙ ПИТОМИХ ВИТРАТ МАГНІЮ ТА ВМІСТУ СІРКИ В ЧАВУНІ ПРИ ДЛЯ УПРАВЛІННЯ ПРОЦЕСОМ ІНЖЕКЦІЙНОЇ ДЕСУЛЬФУРАЦІЇ ЧАВУНУ

Built and put into operation experimental industrial and industrial installations and cast iron desulfurization departments ensured a reduction of sulfur content in cast iron to 0.005-0.010% in industrial conditions. The purpose of the work is to reliably predict the calculation of the necessary consumption of magnesium from various conditions - the initial sulfur content, the mass of cast iron and the given final sulfur content to ensure the reduction of desulfurization costs. In addition, it is important to predict the current content of sulfur in cast iron depending on the consumption of magnesium in order to increase the reliability of the achieved content of sulfur in molten iron. The developments carried out to assess the regularities of the processes of out-of-furnace desulfurization of cast iron by monoinjection of granular magnesium made it possible to obtain calculation models for the assessment of existing and newly built capacities for desulfurization of cast iron in ladles of different sizes (40-350 t) at different initial sulfur contents in cast iron (0.02-0.07 %) and requirements for the final content of sulfur in cast iron (≤0.002-0.015%). Calculation models are presented.

Synthesis and functionalization of carbon nanospheres from asphaltene fraction for crude oil upgrading and viscosity reduction

Nanoparticles provide a promising, cost-effective eco-friendly solution to the challenges posed by heavy-oil reservoirs, significantly enhancing oil recovery rates by reducing viscosity without requiring extensive thermal inputs. In this study, carbon nanospheres (CNSs) and functionalized-CNSs nanofluids were prepared by incorporating surfactants (T80 or BMIMCl). These nanofluids were evaluated for their efficacy in upgrading crude oil, particularly focusing on viscosity-reduction. Rheological tests were conducted across varying shear rates (60–300 s−1) and concentrations (0.02–3 wt.%) to comprehensively assess the impact of these additives on the crude oil’s proprieties. The results showed a notable enhancement in crude oil viscosity reduction, with the following order observed: CNS-TiO2 < CNS-TiO2/DMIMCl < CNS-TiO2/T80, yielding reduction rates of 95%, 95.83%, and 97.08%, respectively, at an optimal dosage of 2.75 wt.% and a shear rate of 300 s−1. The surface functionalization of CNS particles and their crystallinity are the main mechanisms driving the reduction in oil viscosity. Moreover, the properties of the crude oil were investigated upon the utilization of CNS-TiO2/T80 nanofluid. It was found that this nanofluid led to a substantial reduction in sulfur content by 78.32% and a significant decrease in the percentage of heavier molecules, ranging from C12 to C35 and up to C36, with 47.76% and 97.98%, respectively.

Synergistic interaction between scrap tyre and plastics for the production of sulphur-free, light oil from fast co-pyrolysis

Fast co-pyrolysis offers a sustainable solution for upcycling polymer waste, including scrap tyre and plastics. Previous studies primarily focused on slow heating rates, neglecting synergistic mechanisms and sulphur transformation in co-pyrolysis with tyre. This research explored fast co-pyrolysis of scrap tyre with polypropylene (PP), low-density polyethylene (LDPE), and polystyrene (PS) to understand synergistic effects and sulphur transformation mechanisms. A pronounced synergy was observed between scrap tyre and plastics, with the nature of the synergy being plastic-type dependent. Remarkably, blending 75 wt% PS or LDPE with tyre effectively eliminated sulphur-bearing compounds in the liquid product. This reduction in sulphur content can substantially mitigate the release of hazardous materials into the environment, emphasizing the environmental significance of co-pyrolysis. The synergy between PP or LDPE and tyre amplified the production of lighter hydrocarbons, while PS's interaction led to the creation of monocyclic aromatics. These findings offer insights into the intricate chemistry of scrap tyre and plastic interactions and highlight the potential of co-pyrolysis in waste management. By converting potential pollutants into valuable products, this method can significantly reduce the release of hazardous materials into the environment.

Marine Fuel Regulations and Engine Emissions: Impacts on Physicochemical Properties, Cloud Activity and Emission Factors

AbstractMarine regulations aim to reduce sulfur and nitrogen exhaust emissions from maritime shipping. Here, two compliance pathways for reducing sulfur dioxide emissions, fuel sulfur content reduction and exhaust wet scrubbing, are studied for their effects on physicochemical properties and cloud forming abilities of engine exhaust particles. A test‐bed diesel engine was utilized to study fresh exhaust emissions from combustion of non‐compliant, high sulfur content fuel with (WS) and without (HiS) the usage of a wet scrubber as well as a regulatory compliant, low sulfur content fuel (LoS). Particle number emissions are decreased by ≈99% when switching to LoS due to absence of 20–30 nm sulfate rich particles. While number emissions for WS are also decreased, a shift in the sulfate mode toward larger sizes was found to increase particle mass emission factors by at least 31%. Changes in the mixing state induced by the compliance measures are reflected in the hygroscopicity of the exhaust particles. Fuel sulfur reduction decreased cloud condensation nuclei emissions by at least 97% due to emissions of primarily hydrophobic soot particles. Wet scrubbing increased those emissions, mainly driven by changes in particle size distributions. Our results indicate that both compliance alternatives have no obvious impact on the ice forming abilities of 200 nm exhaust particles. These detailed results are relevant for atmospheric processes and might be useful input parameters for cloud‐resolving models to investigate ship aerosol‐cloud interactions and to quantify the impact of shipping on radiative budgets from local to global scales.

Coal quality enhancement by using bio extracts of carissa carandas fruits in combination with Hydro Fluoric acid

ABSTRACT This paper addresses the imperative need for environmentally sustainable beneficiation technologies tailored for low-rank coals, constituting about 50% of global coal deposits. The focus is on recent advancements in bio-beneficiation methods for sub-bituminous coals in thermal power stations, employing ”bio extract of Carissa carandas fruits” with lower concentrations of Hydrofluoric acid. The objective is to enhance coal quality by reducing ash content and adjusting mineral composition to mitigate clinker formation during combustion. The research investigates simultaneous coal treatment with bio extract and low-concentration Hydrofluoric acid. While traditional beneficiation techniques, such as physical, chemical, and physicochemical methods, have been extensively used, a research gap is identified in green methods utilizing biomaterial extracts to remove/reduce metal oxides from coal and the need to regulate the silica-to-alumina ratio in coal composition, for resolving the issue of clinker formation. The investigation demonstrates the bio extract’s efficacy in leaching alumina, iron oxide, and alkali/alkaline earth metal oxides from coal, significantly reducing ash content. Consequently, there is a remarkable increase in coal’s gross calorific value post bio-beneficiation, accompanied by a significant reduction in sulfur content in addition to the decrease in tendency of clinker formation of coal during combustion. This study is a significant contribution to the field of environmentally friendly coal beneficiation and to reduce the tendency of clinker formation during combustion.

Desulfurisasi Batubara Dengan Metode Leaching Menggunakan Naoh Dan HCL Di PT. Anugerah Krida Utama, Kutai Kartanegara, Kalimantan Timur

The utilization of coal as a fossil fuel causes several ecological problems, as for the consequences of the coal combustion process, namely pollution and emissions. Combustion of high sulfur coal produces sulfur dioxide gas (SO2). This sulfur dioxide (SO2) will become H2SO4 (sulfuric acid) which can directly or indirectly disrupt human life, such as causing acid rain, causing tightness in the respiratory tract and causing corrosion and shortening the life of factory equipment. To reduce SO2 gas, a reduction in sulfur content is carried out before combustion which is called desulfurization. This research was conducted using the leaching method with variations in leaching agent and solution concentration. Leaching agents used in this study are NaOH and HCl. The coal to be desulfurized is coal from PT Anugerah Krida Utama with an initial total sulfur content of 4,05% adb. 10 grams of coal with a size of 0,212 mm was leached with 250 ml of chemical solution using a hot plate stirrer at 80˚C and 250 rpm for 1 hour. The results showed that the optimum condition for leaching agent NaOH occurred at a concentration of 8 M showing the initial total sulfur content of 4,05% adb decreased to 1,69% adb with a maximum percentage decrease of 58,27% and at leaching agent HCl the optimum condition occurred at a concentration of 1 M showing the initial total sulfur content of 4,05% adb decreased to 2,91% adb with a maximum percentage decrease of 28,14%.