Maximum Sulfur Content Research Articles

Transition to the New Green Maritime Era—Developing Hybrid Ecological Fuels Using Methanol and Biodiesel—An Experimental Procedure

The conventional utilization of fossil fuels precipitates uncontrolled carbon dioxide and sulfur oxides emissions, thereby engendering pronounced atmospheric pollution and global health ramifications. Within the maritime domain, concerted global initiatives aspire to mitigate emissions by 2050, centering on the adaptation of engines, alteration of fuel compositions, and amelioration of exhaust gas treatment protocols. This investigation pioneers experimentation with marine gas oil augmented by methanol, a practice conventionally encumbered by prohibitively expensive additives. Successful amalgamation of methanol, animal-derived biodiesel, and marine gas oil (MGO) is empirically demonstrated under meticulously controlled thermal conditions, creating a homogeneous blend with virtually zero sulfur content and reduced carbon content, featuring characteristics akin to conventional marine gas oil but with no use of expensive emulsifiers. This new blend is suitable for employment in maritime engines utilizing Delaval technology, yet with significantly lower energy requirements compared to those necessitated using conventional very low sulfur fuel oil (VLSFO) with a maximum sulfur content of 0.5% w/w.

Influence of the Nitrogen Precursor in the Development of N-Functionalities in a Mesoporous Carbon Material and Its Effect on the Li–S Cells’ Electrochemistry

Li–S batteries are positioned as a strong alternative for efficient energy storage due to their high theoretical energy density and their theoretical specific capacity (1675 mA h g−1) compared to current Li-ion batteries; however, their commercialization is affected by the rapid decay of the specific capacity as a consequence of the different species of lithium polysulfides that are generated during the charge–discharge processes. The use of nitrogen-doped mesoporous carbon materials has been shown to have the ability to confer electronic conductivity to sulfur and retain the lithium polysulfide species. However, there are not enough studies to help understand how the type of nitrogen precursor influences the development of specific nitrogen functionalities to favor the retention of lithium polysulfide species. This work seeks to determine the effect of the use of different nitrogen precursors on the structural changes of the mesoporous carbon materials prepared, and thus evaluate the electrochemical behavior of Li–S cells correlating the type of nitrogen functionality generated when the precursor is variated with the charge/discharge capacity developed during the cell operation. For this study, different carbon materials were prepared by the variation of the nitrogen source (melamine, ethylenediamine, and hexadecylamine) to obtain a N-doped mesoporous carbon with different distributions of nitrogen functionalities in its structure. The use of the primary amine ethylenediamine as a nitrogen precursor in the formation of structured carbon materials favored elemental sulfur infiltration into its pores, resulting in the maximum sulfur content within the pores and interacting with the carbonaceous matrix (78.8 wt.%). The carbon material prepared with this precursor resulted in a higher content of N-pyridinic functionality, which, combined with the high content of N-pyrrolic, resulted in the highest specific discharge capacity at 0.1 C after 100 cycles when compared to cells assembled with materials derived from the use of melamine and hexadecylamine precursors. The cell assembled with the electrode formed from ethylenediamine as a nitrogen precursor presented an initial discharge capacity of 918 mA h g−1 with a Coulombic efficiency of ~83.4% at 0.1 C after 100 cycles.

SULFATION OF BIRCH WOOD XYLAN WITH SULFAMIC ACID IN THE PRESENCE OF ACTIVATORS: EXPERIMENT AND THEORY

Xylan is a polysaccharide found in plant cell walls. It is considered to be a biodegradable polymer, which does not affect negatively the environment. Sulfated xylan derivatives exhibit valuable bioactive properties, in particular, anticoagulant and hypolipidemic. We report on the development of a new method for sulfation of birch wood xylan. Activators of the sulfation reaction with sulfamic acid have been evaluated. Numerical methods have been used to establish the optimum process parameters that ensure the maximum sulfur content in the reaction product. The incorporation of a sulfate group has been confirmed by infrared and nuclear magnetic resonance spectroscopy, and elemental analysis. The initial and sulfated xylans have been comprehensively studied by theoretical methods and the most favorable conformations of the initial xylan and its sulfate have been established.

Effect of Potassium and Sulphur on Nutrient Uptake and Economics of Coriander (Coriandrum sativum L.)

A field experiment was conducted during rabi 2021-22 at Agronomy Instructional Farm, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, Gujarat on loamy sand soil to study the response of coriander (Coriandrum sativum L.) to potassium and sulphur. The experiment was laid out in factorial randomized block design (FRBD) consisted three level each of potassium (0, 20 and 40 kg/ha) and sulphur (0, 15 and 30 kg/ha) and replicated four times. Application of 40 kg K2O/ha gave significantly higher potassium content and uptake in seed and straw. However, different levels of potassium on sulphur content in seed and straw of coriander was not significant. The maximum sulphur content and uptake in seed and straw was recorded with application of 30 kg S/ha but sulphur application do not influence on potassium content in seed and straw. Application of 40 kg K2O /ha and to 30 kg S/ha gave significantly higher gross and net realizations as well as BCR. While, application of 20 kg K2O /ha and 15 kg S/ha resulted in the higher ICBR.

PROTON-CONDUCTING MEMBRANES BASED ON MODIFIED POLYVINYLIDENE CHLORIDE

Polyvinylidene chloride was obtained by radical polymerization of vinylidene chloride and its sulfonation was carried out. When concentrated sulfuric acid is used as a sulfonating agent, the sulfonation process proceeds in the direction of dehydrochlorination of the vinylidene chloride units, and as a result, an insoluble black reaction product is formed. Therefore, sodium sulfite was chosen as the sulphurizing agent. The optimal conditions for the reaction of polyvinylidene chloride with sodium sulfite were found, while the maximum sulfur content in the modified polyvinylidene chloride, according to elemental analysis, was 3.2%. In the IR spectrum of the modified polyvinylidene chloride, the stretching vibrations of the C-Cl bond in the region of 660 cm-1 are preserved, but absorption bands appear characteristic of the sulfogroup (1250 and 1130 cm-1) and dehydrochlorinated units of polyvinylidene chloride (1630–1670 cm-1). This means that the reaction of polyvinylidene chloride with sodium sulfite is accompanied by dehydrochlorination of vinylidene chloride units. The temperature of the start of decomposition of polyvinylidene chloride containing sulfonic acid groups, according to thermogravimetric analysis, is 250 °С, which is 30 °С higher than for the original polymer. The theoretical total ion-exchange capacity of the modified polyvinylidene chloride, calculated from the sulfur content, is consistent with the experimental values and is 1.0 meq/g and is close to the similar value for the Nafion membrane. Based on polyvinylidene chloride containing sulfonic acid groups and polyvinyl alcohol, a membrane was obtained and the dependence of proton conductivity on temperature was studied. As the temperature rises from 30 °C to 80 °C, a monotonic increase in proton conductivity is observed from 6.7·10-3 S/cm to 1.8·10-2 S/cm with an activation energy of 17±1 KJ/mol. The mechanical properties of the membrane have been studied. For citation: Badanov S.V., Urumov A.V., Shaglaeva N.S. Proton-conducting membranes based on modified polyvinylidene chloride. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 3. P. 85-92. DOI: 10.6060/ivkkt.20236603.6734.

MCM-41 supported S-alkyl/aryl-substituted 2-mercaptobenzothiazolium-based ionic liquids: synthesis, characterization, and application in the fuel desulfurization

Supported ionic liquids (SILs), synthesized by immobilization of ionic liquids (ILs) onto solid support materials, have played an effective role in several applications like fuel desulfurization, organic catalysis, gas separations, biofuel synthesis, etc., in comparison to pure ILs which suffer from many drawbacks like difficult recovery, high cost, mass transfer issue owing to large viscosity, toxic nature, complications in product purifications and fixed bed reactor technology. In this study, a series of new SILs (MCM-41@[S-RBTh][Cl]; R = aryl/alkyl groups) were synthesized via immobilization of different S-alkyl/aryl-substituted 2-mercaptobenzothiazolium-based ILs onto MCM-41 silica support. Structure elucidation of SILs was achieved through SEM, EDS, SAXS, NMR, BET, and FT-IR spectroscopy. Further, the synthesized SILs and MCM-41 were investigated for the removal of sulfur-containing aromatic species from model gasoline and real gasoline. MCM-41@[S-BzBTh][Cl] (0.5 g) removed maximum sulfur content with the percentage of 57.5 % (at 35 °C), 58.7 % (at 40 °C), and 63.4 % (at 45 °C) of TS, TN, and DBT respectively, from model gasoline (5 g) of sulfur concentration of 200 ppm under shaking conditions for 140 min. The impact of the aryl group and different lengths of alkyl groups of supported benzothiazolium-based ILs on their adsorption performance was also studied.

Sulfation of Wheat Straw Soda Lignin with Sulfamic Acid over Solid Catalysts.

Soda lignin is a by-product of the soda process for producing cellulose from grassy raw materials. Since a method for the industrial processing of lignin of this type is still lacking, several research teams have been working on solving this problem. We first propose a modification of soda lignin with sulfamic acid over solid catalysts. As solid catalysts for lignin sulfation, modified carbon catalysts (with acid sites) and titanium and aluminum oxides have been used. In the elemental analysis, it is shown that the maximum sulfur content (16.5 wt%) was obtained with the Sibunit-4® catalyst oxidized at 400 °C. The incorporation of a sulfate group has been proven by the elemental analysis and Fourier-transform infrared spectroscopy. The molecular weight distribution has been examined by gel permeation chromatography. It has been demonstrated that the solid catalysts used in the sulfation process causes hydrolysis reactions and reduces the molecular weight and polydispersity index. It has been established by the thermal analysis that sulfated lignin is thermally stabile at temperatures of up to 200 °C. According to the atomic force microscopy data, the surface of the investigated film consists of particles with an average size of 50 nm. The characteristics of the initial and sulfated β-O-4 lignin model compounds have been calculated and recorded using the density functional theory.

Influence of Zinc and Vermicompost on Growth, Yield And Mineral Nutrient Accumulation in Onion (Allium Cepa L.)

Effects of zinc, vermicompost and their joint effects on growth, yield and nutrient accumulation in the leaves and bulb of onion (Allium cepa L.) were examined. The experiment was conducted in a completely randomized design (CRD) replicated thrice with twelve treatments involving different doses of Zn and vermicompost and a control treatments. Growth parameters viz. leaf height, leaf number, leaf area, leaf area index, bulb height, bulb area and fresh and dry weight of leaf, stem, bulb and root were assessed. The highest leaf height (63.87 cm), leaf number (28), leaf area (614.21 cm2), fresh weight (29.46 g) and dry weight (10.79 g) at first harvest were found in 30% vermicompost + 70% Zn application. The highest leaf height (42.33 cm), leaf number (15), leaf area (328.21 cm2), bulb height (5.67 cm), bulb equatorial diameter (5.67 cm), fresh weight (28.77 g) and dry weight (6.21 g) were found at second harvest in 30% vermicompost + 70% Zn. The maximum nitrogen, phosphorus, potassium and Sulphur content of leaf were observed in 80% vermicompost + 20% Zn application. The maximum nitrogen, phosphorus, potassium and sulphur content of bulb were observed in 60% vermicompost + 40% Zn application. The overall best growth performance and nutrient accumulation were observed in 30% vermicompost + 70% Zn application. Dhaka Univ. J. Biol. Sci. 31(1): 59-66, 2022 (January)

High Sulfur in Primitive Arc Magmas, Its Origin and Implications

Sulfur contents in 98.5% of melt inclusions (MI) from calc-alkaline subduction basalts do not exceed 4000 ppm, whereas experimentally established limits of sulfur solubility in basaltic melts with high fO2 (characteristic of subduction zones, e.g., QFM + 2) surpass 14,000 ppm. Here we show that primitive (Mg# 62-64) subduction melts may contain high sulfur, approaching the experimental limit of sulfur solubility. Up to 11,700 ppm S was measured in olivine-hosted MI from primitive arc basalt from the 1941 eruption of the Tolbachik volcano, Kamchatka. These MI often contain magmatic sulfide globules (occasionally enriched in Cu, Ni, and platinum-group elements) and anhydrite enclosed within a brown, oxidized glass. We conclude that the ubiquitous low sulfur contents in MI may originate either from insufficient availability of sulfur in the magma generation zone or early magma degassing prior to inclusion entrapment. Our findings extend the measured range of sulfur concentrations in primitive calc-alkaline basaltic melts and demonstrate that no fundamental limit of 4000 ppm S exists for relatively oxidized subduction basalts, where the maximum sulfur content may approach the solubility limit determined by crystallization of magmatic anhydrite.

Food Xanthan Polysaccharide Sulfation Process with Sulfamic Acid.

Xanthan is an important polysaccharide with many beneficial properties. Sulfated xanthan derivatives have anticoagulant and antithrombotic activity. This work proposes a new method for the synthesis of xanthan sulfates using sulfamic acid. Various N-substituted ureas have been investigated as process activators. It was found that urea has the greatest activating ability. BBD of xanthan sulfation process with sulfamic acid in 1,4-dioxane has been carried out. It was shown that the optimal conditions for the sulfation of xanthan (13.1 wt% sulfur content) are: the amount of sulfating complex per 1 g of xanthan is 3.5 mmol, temperature 90 °C, duration 2.3 h. Sulfated xanthan with the maximum sulfur content was analyzed by physicochemical methods. Thus, in the FTIR spectrum of xanthan sulfate, in comparison with the initial xanthanum, absorption bands appear at 1247 cm−1, which corresponds to the vibrations of the sulfate group. It was shown by GPC chromatography that the starting xanthan gum has a bimodal molecular weight distribution of particles, including a high molecular weight fraction with Mw > 1000 kDa and an LMW fraction with Mw < 600 kDa. It was found that the Mw of sulfated xanthan gum has a lower value (~612 kDa) in comparison with the original xanthan gum, and a narrower molecular weight distribution and is characterized by lower PD values. It was shown by thermal analysis that the main decomposition of xanthan sulfate, in contrast to the initial xanthan, occurs in two stages. The DTG curve has two pronounced peaks, with maxima at 226 and 286 °C.

Effects of seawater scrubbing on a microplanktonic community during a summer-bloom in the Baltic Sea

The International Maritime Organization (IMO) has gradually applied stricter regulations on the maximum sulphur content permitted in marine fuels and from January 1, 2020, the global fuel sulphur limit was reduced from 3.5% to 0.5%. An attractive option for shipowners is to install exhaust gas cleaning systems, also known as scrubbers, and continue to use high sulphur fuel oil. In the scrubber, the exhausts are led through a fine spray of water, in which sulphur oxides are easily dissolved. The process results in large volumes of acidic discharge water, but while regulations are focused on sulphur oxides removal and acidification, other pollutants e.g. polycyclic aromatic hydrocarbons, metals and nitrogen oxides can be transferred from the exhausts to the washwater and discharged to the marine environment. The aim of the current study was to investigate how different treatments of scrubber discharge water (1, 3 and 10%) affect a natural Baltic Sea summer microplanktonic community. To resolve potential contribution of acidification from the total effect of the scrubber discharge water, “pH controls” were included where the pH of natural sea water was reduced to match the scrubber treatments. Biological effects (e.g. microplankton species composition, biovolume and primary productivity) and chemical parameters (e.g. pH and alkalinity) were monitored and analysed during 14 days of exposure. Significant effects were observed in the 3% scrubber treatment, with more than 20% increase in total biovolume of microplankton compared to the control group, and an even greater effect in the 10% scrubber treatment. Group-specific impacts were recorded where diatoms, flagellates incertae sedis, chlorophytes and ciliates increased in biovolume with increasing concentrations of scrubber water while no effect was recorded for cyanobacteria. In contrast, these effects was not observed in the “pH controls”, a suggestion that other parameters/stressors in the scrubber water were responsible for the observed effects.

Comparing emissions of polyaromatic hydrocarbons and metals from marine fuels and scrubbers

• Presenting emission factors to the marine environment from the use of scrubbers. • Scrubber discharge water is enriched with metals and polyaromatic hydrocarbons (PAHs). • Heavy fuel oil combustion with scrubbers increase the relative environmental load. • Scrubbers introduce new contamination sources of chromium to the marine environment. In January 2020, new global regulations were implemented to limit the maximum sulphur content in marine fuels. As an alternative to switch to compliant fuels, the regulations allow for installations of exhaust gas cleaning systems, e.g. scrubbers, that enables a continued use of less expensive heavy fuel oils (HFOs). Characterization of scrubber discharge water shows that the acidified water also becomes enriched with contaminants, and large quantities of metals and polyaromatic hydrocarbons (PAHs) are thus being discharged directly to the marine environment. When emissions of contaminants to the atmosphere and the marine environment are evaluated simultaneously, the results show that HFO, with scrubbers installed, generates higher emission factors of both metals and PAHs compared to MGO. This highlights the importance of including both the marine and the atmospheric perspective when comparing environmental loads and impact of contaminants from shipping.

Marine fuels after 2020 III

On 1st January 2020, a drastic change came into force to reduce the maximum permitted sulphur content of marine fuels from 3.5 % wt. to 0.5% wt. for the deep sea and oceans. This change had an impact not only on the shipping industry, but also on the entire refining sector, be it oil marketers, refineries, traders and manufacturers of fuels and end-user additives. In 2017 and 2018, the situation regarding marine fuels and the impending IMO 2020 changes was mapped out in the articles "Marine Fuels Post-2020" and "Marine Fuels Post-2020 II" published in Paliva journal. These publications are directly followed by the present article, which summarises the current data (as of early 2021) and experience from the past year, the first year of implementation of IMO 2020. The article describes how vessel operators have coped with this drastic reduction of the maximum sulphur content of marine fuels, as well as the economic consequences of this change.

Science and Technology Progress on the Desulfurization Process of Crude Oil

Currently, crude oil still remains an irreplaceable energy source for chemical industrial processes, transportation systems, electricity, and other human activities. However, crude oil contains sulfur elements as the major impurities in the form of aliphatic and aromatic organosulfur compounds. During the combustion of fuel, these organosulfur compounds are converted to harmful SOx gases; thus, many countries strictly limit the maximum sulfur content in the fuels. To fulfill the government regulation, refineries are trying to decrease the maximum sulfur content in crude oil through several desulfurization technologies, such as hydrodesulfurization, adsorption, oxidative‐desulfurization, alkylation, and biodesulfurization. Each desulfurization technology has its own advantages and disadvantages. In this review article, we aimed to briefly summarize the progress in the developing science and technology of each desulfurization process of crude oil. Several fields in the desulfurization process are still facing challenges to create better designs and development for a safer future of the world.

Characterization of possible alternative materials for the production of marine fuels

Maritime transport is a significant contributor to the environmental pollution. For this reason, the maximum sulfur content in liquid marine fuels has been drastically reduced since January 1st 2020 for deep sea areas. This reduction can be solved by diluting the conventional high sulfur fuels with suitable low sulfur components. However, mixing two or more components with each other carries a potential risk of incompatibility or instability of the final product, especially in the case of longer storage and subsequent transportation to the end consumers. For the above reasons, this work deals with the mapping of alternative raw materials that could be used to produce very low sulfur fuel oils (VLSFO) with a sulfur level up to 0.5 wt%. A total of 5 raw materials (1 conventional fuel oil – HSFO and 4 alternative raw materials) were characterized. The individual raw materials were compared to each other with regard to the quality properties required for marine fuels according to the ISO 8217. Subsequently, the suitability of these raw materials for further mixing was outlined in order to meet the required quality parameters for marine fuel mixing.

Characterization of possible alternative materials for the production of marine fuels

Maritime transport is a significant contributor to the environmental pollution. For this reason, the maximum sulfur content in liquid marine fuels has been drastically reduced since January 1st 2020 for deep sea areas. This reduction can be solved by diluting the conventional high sulfur fuels with suitable low sulfur components. However, mixing two or more components with each other carries a potential risk of incompatibility or instability of the final product, especially in the case of longer storage and subsequent transportation to the end consumers. For the above reasons, this work deals with the mapping of alternative raw materials that could be used to produce very low sulfur fuel oils (VLSFO) with a sulfur level up to 0.5 wt%. A total of 5 raw materials (1 conventional fuel oil – HSFO and 4 alternative raw materials) were characterized. The individual raw materials were compared to each other with regard to the quality properties required for marine fuels according to the ISO 8217. Subsequently, the suitability of these raw materials for further mixing was outlined in order to meet the required quality parameters for marine fuel mixing.

Synthesis of Asphaltene-Based Strongly Acidic Sulfonated Cation Exchangers and Determination of Their Catalytic Properties in the 2,2-Dimethyl-1,3-Dioxolane Synthesis Reaction

Results of a study of the reaction products of asphaltene sulfonation with sulfuric acid in various temperature and time ranges have been described. The maximum sulfur content in sulfonated cation exchangers at an asphaltene sulfonation temperature of 100 and 120°С and a reaction time of 2 h has been determined. The maximum static exchange capacity of 4.3 meq/g has been found for the products of sulfonation with a sulfuric acid–oleum mixture. The asphaltene-based strongly acidic sulfocationite has been tested in the 2,2-dimethyl-1,3-dioxolane synthesis reaction.

Environmentally friendly guar gum sulfation with a sulfamic acid-urea mixture

The guar gum was sulfated for the first time with a deep eutectic solvent, a sulfamic acid / urea mixture at a ratio of (1:1). The optimal conditions of the process are shown to ensure the production of guar gum sulfate with a maximum sulfur content (16.1% wt.). The introduction of a sulfate group into a guar gum molecule is proved by elemental analysis. A mathematical model of the process of sulfation of guar gum is calculated. It is shown that the resulting model has high predictive properties. The developed method is environmentally safer due to the fact that it eliminates the use of toxic solvents.

Detailed Chemical Characterization of Bunker Fuels by High-Resolution Time-of-Flight Mass Spectrometry Hyphenated to GC × GC and Thermal Analysis

On January 1, 2020, new International Maritime Organization (IMO) legislation will reduce the maximum sulfur content for marine fuels outside of sulfur emission control areas (SECA) from now 3.50% ...

Is It Possible To Develop Complex S-Se Graded Band Gap Profiles in Kesterite-Based Solar Cells?

This work presents the development of a novel chalcogenization process for the fabrication of Cu2ZnSn(S,Se)4 (CZTSSe or kesterite)-based solar cells that enable the generation of sharp graded anionic compositional profiles with high S content at the top and low S content at the bottom. This is achieved through the optimization of the annealing parameters including the study of several sulfur sources with different predicted reactivities (elemental S, thiourea, SnS, and SeS2). As a result, depending on the sulfur source employed, devices with superficially localized maximum sulfur content between 50 and 20% within the charge depletion zone and between 10 and 30% toward the bulk material are obtained. This complex graded structure is confirmed and characterized by combining multiwavelength depth-resolved Raman spectroscopy measurements together with in-depth Auger electron spectroscopy and X-ray fluorescence. In addition, the devices fabricated with such graded band gap absorbers are shown to be fully functional with conversion efficiencies around 9% and with improved VOC deficit values that correlate with the presence of a gradient. These results represent one step forward toward anionic band gap grading in kesterite solar cells.