Low Sulfur Content Research Articles

PRODUCTION AND CHARACTERIZATION OF BIOBRIQUETTE FROM BIOMASS OF MANGO LEAF, SAW DUST AND RICE HUSK AS EFFICIENT ENERGY SOURCES FOR COOKING

The increasing demand for sustainable energy solutions has driven interest in alternative biomass sources for energy production. This study investigates the production and characterization of bio briquettes made from different biomass of mango leaves, sawdust, and rice huskusing limestone as binder. The objective is to evaluate the potential of these biomass materials as efficient energy sources for cooking. The bio briquettes were produced using a standard briquetting process, involving mixing, compaction, and drying. Various parameters including ultimate and proximate composition, calorific value, bulk density, hardness and durability as well as mechanical and combustion properties were analyzed to assess their performance. The results demonstrated that the bio briquettes exhibited high calorific values between 20753 to 20506 KJ/kg and high percentage of fixed carbon between 4.18 to 5.58 % which generally indicates good fuel performance.The results also indicated that the bio briquettes has low Sulphur content and high volatile matter content between 50.53 to 62.84 % an indication that they are ecofriendly and can easily burn to yield energy. The bio briquettes of mango leaves, sawdust, and rice husk not only leverages agricultural waste but also contributes to reducing dependency on non-renewable energy sources. This research underscores the potential of utilizing locally available biomass for sustainable energy solutions and offers insights into improving the efficiency of bio briquette production.

Cu Evaporation from Liquid Iron Alloy in Stream

The accumulation of copper in steel scrap is becoming an increasingly problematic issue in the steelmaking industry. Accordingly, the present study was undertaken to investigate the removal of copper from a liquid Fe–Cu alloy via tapping under vacuum. Furthermore, the impact of surface-active components sulfur and oxygen was examined. For this purpose, four Fe–0.5 wt% Cu alloys with varying oxygen and sulfur contents were melted and subsequently poured at a pressure of 100 Pa. The findings indicate that alloys with low oxygen and sulfur content exhibited enhanced copper evaporation. Additionally, the evaporation of other tramp metals, including manganese, phosphorus, and tin, was observed, and the influence of sulfur and oxygen on this process was discussed. Furthermore, the vacuum treatment conditions for copper evaporation in industrial settings were explored.

Investigating the sustainable energy generation potential of an invasive weed: Lantana camara.

Lantana camara, one of the world's top ten most invasive species, was initially cultivated for ornamental use. However, it spread uncontrollably across the fallow areas and agricultural lands, threatening approximately 44% of Indian forests. Its invasion disrupts ecosystems by suppressing nearby plant growth through allelopathy and poses toxicity risks to grazing ruminants. It significantly increases forest fire risk by adding large amounts of combustible biomass, particularly dried L. camara. Despite efforts to control it using mechanical, chemical, and biocontrol methods, the results have been largely unsatisfactory, with associated costs estimated at $18,000 per square kilometre. Considering these challenges, recent research explored the potential of L. camara as a bioenergy resource. TheL. camarabriquettes exhibit a heating value of approximately 20MJ/kg with a low sulphur (0.5%), nitrogen (1%), and ash content (2%), making them suitable for decentralised energy production. Furthermore, bioethanol production fromL. camarahydrolysate has shown promising results, yielding 0.33g/g withPichia stipitisand0.47g/g with Saccharomyces cerevisiae, which is comparable to other lignocellulosic feedstocks. Additionally, the gasification of L. camara using a downdraft gasifier produced syngas with a lower heating value (LHV) of 6.4MJ/Nm3. These findings demonstrate that using L. camara for bioenergy production presents a dual solution, addressing the growing demand for renewable energy and managing invasive species. This review aims to critically evaluate the potential and challenges associated with the different energy production pathways for L. camara, highlighting its role in sustainable energy generation.

Impact of Sulfur Deficiency and Excess on the Growth and Development of Soybean Seedlings.

Sulfur is a critical element for plant growth and development, serving as a component of amino acids (cysteine and methionine), iron-sulfur clusters, proteins, glutathione, coenzymes, and auxin precursors. Deficiency or low concentrations of sulfur in the soil can lead to significant growth retardation in plants. The objective of our study was to examine the effects of sulfur (S) deficiency and excess on morphological symptoms, sulfur and nitrogen (N) metabolism, as well as antioxidant activity in soybean. We found that S starvation decreased the fine root length, biomass, and activity, and the chlorophyll content was reduced, while excess sulfur promotes lateral root growth. In contrast to sulfur excess, sulfur deficiency inhibits N and S metabolism levels in both subsurface and above-ground parts, and induced the expression of some sulfur transporters (SULTRs). In this study, we created soybean hairy root lines overexpressing the SULTR gene (GmSULTR2;1a) to observe metabolic changes following sulfur deficiency treatment. The results showed that GmSULTR2;1a saved the sulfur-deficient phenotype, and the antioxidant enzyme activity was much higher than that of the wildtype in the absence of sulfur. Our study revealed the important role of sulfur element in soybean growth and development and the regulation of sulfur deficiency by GmSULTR2;1a.

Case Study: Understanding H2S Occurrence: Bakken Production Using Sulfur Isotopes

_ Souring—or H2S generation—in the Bakken petroleum system (BPS) production is becoming problematic for oil producers and pipeline operators because of the sporadic occurrence and associated economic and HSE impacts. Paradoxically, crude oil produced from the tight Middle Bakken (MB) and underlying Three Forks (TF) reservoirs of the BPS has historically been light (40 °API to 50 °API) with low sulfur content (<0.2 wt.%), typically exhibiting nonexistent to low (<10 parts per million) H2S concentrations. Additionally, neither the MB nor the TF reservoirs have public records indicating the presence of H2S during drillstem tests (DST). However, based on previous work performed by the University of North Dakota Energy & Environmental Research Center (EERC), the frequency of H2S occurrence in BPS wells has increased from 2010 to 2023. Even though the observed H2S increases correlate with larger, multistage well stimulation and completion practices in the BPS, the unclear geographical and temporal trends make the exact mechanisms responsible for souring an open research question. At least five known mechanisms can potentially lead to H2S occurrence in the oil production stream of BPS wells, including: 1. Thermochemical sulfate reduction (TSR) 2. Bacterial sulfate reduction (BSR) 3. Source rock generation 4. Migration from deeper or shallower H2S reservoirs 5. Geochemical mechanisms related to reservoir stimulation work (Table 1). Understanding the mechanisms of H2S generation might reduce the risk of souring in new wells and enable more effective mitigation and management strategies in the wells already producing H2S. Samples Used in the Study This study is focused on oil and gas operations in the North Dakota portion of the Williston Basin and the H2S occurrences in the BPS, which includes two main oil-producing reservoirs: the MB and the TF. In the simplified stratigraphic sequence, the BPS comprises three distinctive lithofacies. From deepest to shallowest, those lithofacies are the Lower Bakken Shale (LBS), the MB reservoir, and the Upper Bakken Shale (UBS). Underlying the BPS is the TF, the upper part of which is the oil-rich TF reservoir, considered part of the BPS. The UBS and LBS are the source rocks for the oil in MB and TF reservoirs and consist of black, organic-rich, siliciclastic mudstones (i.e., shale). Directly overlying the BPS is the Madison Group, a carbonate-dominated Mississippian section that is subdivided into three formations—the Lodgepole (LP), Mission Canyon (MC), and Charles. The Birdbear Formation lies beneath the TF and on top of the Duperow Formation. Both the Duperow and Birdbear Formations produce oil and are dominated by carbonate deposits of shallow marine limestone and dolostones. A sampling program was developed to investigate areas of the BPS with varying levels of souring in the production stream and multiple organic-rich formations representing potential source rocks, including the UBS, LBS, LP, and MC. The samples were collected from locations and formations with different lithologies and maturity levels. Over 70 sour wells were identified for H2S sampling in western North Dakota.

Air Pollutant Emission Factors of Inland River Ships under Compliance

Inland river ships (IRSs) use diesel with a lower sulfur content and emit relatively low emissions, making it challenging to monitor their emissions. Sniffer monitoring equipment was installed from August 2020 to June 2022 at the Gezhou Dam of the Yangtze River and monitored emissions from 8,238 IRSs passing through the lock. We partnered with the maritime department to select 100 ships passing through the lock to extract fuel oil samples for direct fuel sulfur content (FSC) detection, which determined the actual FSC of the passing ships. The monitoring data from these 100 ships indicated that the relative error of the SO2 emission factors (EFs) and FSC results is significant at the 10-parts-per-million level. The monitoring data from the remaining 8,138 ships showed that the EFs of NO, NO2, PM2.5, and PM10 were 24.02 ± 16.92 g kg−1, 10.30 ± 18.08 g kg−1, 0.72 ± 0.60 g kg−1, and 0.92 ± 0.70 g kg−1, respectively. The NOx EFs of container ships are higher than those of other ship types, while the PM EFs for different ship types do not significantly differ. Based on these EFs, we calculated the average emission rates for different types of ships passing through locks, which is a real-time measurement method for estimating ship emissions. In addition, a comparison of ship EF measurements over the past 20 years revealed that EF values for SO2, NOx, and PM exhibited a downward trend, with the calculated results of the current study determined to be the lowest numerical level.

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.

Efficiency analysis of the application of thermal methods at the Pirallahi and Darwin bank fields

The efficiency of oil and gas field development is associated with the correct choice of appropriate measures to be implemented. This research considers the Pirallahi and Darwin Bank fields with hard-to-recover oil reserves. The Pirallahi field is located in the eastern part of the Absheron Peninsula. The initial balance reserve for the facility is 4 million tons, and the level of reserve utilization is 19%. Among the notable features, the Pirallahi deposit represents the southern fold of the PK (Pre-Kirma- ki) horizon. Across the horizon, the initial balance reserve is approximately one million tons, and the utilization rate is 17%. In other groups, the level of utilization exceeds 20%. Accordingly, the volume of initial balance reserves ranges between 8-35 million tons. Industrially important objects here are KSv (Kirmaki suite, fifth horizon), KSn (Kirmaki suite, n horizon), and PKS (Post-Kirmaki suite). To develop oil reserves, more than 1000 production wells were drilled at different stages of the development process. The southern fold consists of a brachyanticline extending from northwest to southeast. The main tectonic element of the southern fold is its thrust nature and its very complex tectonic structure. The fold is heavily watered. Therefore, to increase the efficiency of developing these fields, it is necessary to use appropriate methods of influencing the formations. To enhance the efficiency of the development process in the northern part, the in-situ combustion method was applied. The Darwin Bank field belongs to the Absheron archipelago and has a tectonic brachyanticlinal structure. The structure is complicated by numerous longitudinal and transverse faults. It is divided into six tectonic zones by several transverse and one longitudinal fault passing through the crest. Darwin Bank oils are heavy oils with low sulfur content. In addition, low paraffin and high resin content are observed in the composition of field oil. For both fields, the recovery rate of geological reserves fluctuates around 30%. The article, primarily, examines the selection of objects and the use of enhanced oil recovery methods in these fields. The in-situ combustion method was used in the northern part of the Pirallahi field and Darwin Bank.

Comparative analysis of the combustion and emission characteristics of biojet and conventional Jet A‐1 fuel: a review

AbstractConventional jet fuels derived from fossil sources contribute to greenhouse gas emissions and air pollution, leading to climate change. Recent studies have shown that biobased jet fuels from different feedstocks offer a more sustainable alternative to conventional fuels as they are derived from renewable biomass, reducing greenhouse gas emissions. The major feedstocks reviewed are jatropha curcas, camelina, karanja oil, waste cooking oil, and municipal solid waste. They offer diverse benefits for sustainable aviation fuel development. As a comparative analysis, this review examined jet fuel characteristics based on their physicochemical properties, namely energy content, viscosity, calorific value, cetane number, and freezing and flash points. The objective was to understand the influence of the properties on performance evaluation, environmental impact, and combustion characteristics. The properties of biojet fuels are compared with their fossil counterparts to validate their suitability as renewable alternatives and their benefits in terms of emissions reduction and engine performance. Biojet fuels perform better in terms of lower sulfur content, lower soot content, and a lower freezing point, their aromatic content, and their high cetane number. This study enhances the understanding of biojet fuels and their quality, and supports the development of sustainable fuel options. Overall, adherence to the American Society for Testing and Materials (ASTM) D7566‐18 standard is crucial for the acceptance and integration of biojet fuels into the aviation sector. Future research should explore feedstocks such as wood biomass, wastepaper, and agricultural residues for biojet fuels. It should also investigate the combustion and emission characteristics of biosourced aviation fuel at higher blending ratios (>50% by volume) with fossil Jet A‐1.

Evaluating the performance effectiveness of briquettes made from coconut dreg charcoal (CDC), tea residue (TR), and cocoa pod (CP)

Abstract Environmental pollution, depletion of fossil fuels, and a significant rise in the human population are contributing to an increase in the greenhouse gas in the atmosphere. Addressing these challenges necessitates the production of clean, low-carbon emission, and sustainable bioenergy, such as briquettes, which can significantly contribute to knowledge and innovation. To assess the effectiveness of briquettes, their characteristics need to be tested using proximate analysis. In examining the characteristics of briquettes, the average moisture content of coconut dreg charcoal and tea residue (CDC+TR) measured 4.835%, contrasting with the 5.9% found in the cocoa pod (CP). The average ash content in CDC+TR was 2.351%, while CP recorded 3.2%. The average volatile matter in CDC+TR was 24.993%, while in CP, it was 31.5%. CDC+TR had an average fixed carbon of 67.815%, compared to CP of 59.5%. Furthermore, the average gross calorific value in CDC+TR was 4562.16 cal/g, whereas in CP, it was 4205.2 cal/g. In conclusion, CP briquettes could serve as an alternative energy source due to ease of production, low sulfur content, and favorable calorific value. CDC+TR, on the other hand, enhanced energy efficiency because of their lower moisture content, ash content, and volatile matter. Additionally, CDC+TR briquettes had higher fixed carbon and gross calorific values compared to CP, making them a suitable energy source.

EVALUATION OF COMPATIBLE PROCESSING ROUTES USING THERMAL TREATMENT FOR UPGRADING OF MOPA MURO AND OBAN MASSIF MANGANESE DEPOSITS

The present study deals with evaluation and compatibility of processing routes using thermal treatment for upgrade of mopa muro and oban Massif manganese ore deposits. The study samples are characterized by XRD, XRF and SEM analysis. The results of SEM analysis show the micro-cracks in the thermally treated manganese sample, Mineralogical investigation shows that in the Mopa Muro manganese ore, most of the Manganese occurs in the silicate managenese mineral as in Almandine (Fe2+)3Al2(SiO4)3, Spessartine(Mn2+)3Al2(SiO4)3, Clinochlore (Al-Fe-SiO2-OH), Geothite FeO(OH),while the Oban Massif is rich in, Pyrolusite MnO2, Clinochlore (Al-Fe-SiO2-OH ), and Spessartine(Mn2+)3Al2(SiO4)3. The mineralogy of the two deposits also revealed that there is a Free Silica (Quartz) in abundant. The low content of sulphur and phosphorus is however within the requirement of the metallurgical grade manganese ore, while 44.08% and 42.07% of manganese (Mn) obtained for Mopa Muro and Oban Massif manganese ores respectively after all analysis indicate apparent inability of the ores meet the requirement of metallurgical grade manganese with values less than 66% recommended specification using thermal treatment.

Catalytic Valorization of Organic Solid Waste: A Pilot-Scale Run of Sugarcane Bagasse

Organic solid waste treatment is crucial for enhancing environmental sustainability, promoting economic growth, and improving public health. Following our previous organic solid waste upgrading technique, a further two-step pilot-scale run, using sugarcane bagasse as the feedstock, has been successfully conducted with long-term stability. Firstly, the sugarcane bagasse was treated under mild conditions (400 °C and 1 bar of CH4), and this catalytic Methanolysis treatment resulted in a bio-oil with a yield of 60.5 wt.%. Following that, it was subjected to a catalytic Methano-Refining process (400 °C and 50 bar of CH4) to achieve high-quality renewable fuel with a liquid yield of 95.0 wt.%. Additionally, this renewable fuel can be regarded as an ideal diesel component with a high cetane number, high heating values, a low freezing point, low density and viscosity, and low oxygen, nitrogen, and sulfur contents. The successful pilot-scale catalytic upgrading of sugarcane bagasse further verified the effectiveness of this methane-assisted organic solid waste upgrading technique and confirmed the high flexibility of this innovative technology for processing a wide spectrum of agricultural and forestry residues. This study will shed light on the further valorization of organic solid waste and other carbonaceous materials.

Lignin pyrolysis assisted by molten salt medium: Evolution behavior of volatiles and biochar structure

This study focuses on the use of a molten salt reaction medium (NaCl-KCl-LiCl) in the lignin pyrolysis process to modify the pyrolysis volatiles and biochar structure. The effect of pyrolysis reaction temperature (300°C, 400°C, 500°C, and 600°C) and lignin/molten salt mass ratios (3:1, 1:1, 1:3 and 1:5) on the evolution behavior of volatiles and biochar structure was explored. The pyrolysis products were determined using GS-MS, CO2 adsorption-desorption analyses, SEM, elemental analysis, proximate analysis, Raman, XRD, and TG/DTG analysis. Results indicated that the introduction of molten salt can enhance the lignin depolymerization, leading to the production of phenolic precursors. Moreover, the metal cation (Na+, K+ and Li+) of molten salt can in-situ induce the modification of biochar structure with high porosity. The lower sulfur content in biochar was attributed to the immobilize function of molten salt. The evolution behaviour of volatiles and biochar structure during molten salt-assisted lignin pyrolysis was proposed. This study can serve as a benchmark for the high-value recycling of industrial lignin waste.

The Impact of Organic and Chemical Organic Fertilizers on the Efficiency of Cadmium Mobility Reduction by Potassium Hydroxide Modified Biochar

The aim of this study was to investigate the impact of organic and chemical organic fertilizers on the translocation of cadmium in crude oil-contaminated soil treated with potassium hydroxide-modified biochar (KOH-biochar). The soil sample was collected from Chonburi Province. The soil was characterized as moderately acidic sandy loam with relatively low organic matter, medium salinity, medium cation exchange capacity, and high nutrient levels. The concentration of cadmium in the soil fell within the acceptable range for agricultural use. The KOH-biochar exhibited strong alkalinity, a high carbon/nitrogen (C/N) ratio, and an oxygen/carbon (O/C) ratio. Crude oil was slightly acidic, with high organic matter content and low sulfur and cadmium concentrations. The synthetic soil created in this study composed of 5% crude oil, and 100 mg/kg of cadmium. KOH-biochar, organic and chemical organic fertilizers were applied to this synthetic soil. Subsequently, the soil was subjected to extraction with 0.005 M diethylenetriamine pentaacetate (DTPA), and a sequential extraction method was employed to determine six different forms of cadmium in the soil samples. Cadmium concentrations in the extracts were measured using a graphite furnace atomic absorption spectrophotometer. The findings revealed that fertilizers effectively slowed down the movement of cadmium. Fertilizer application led to the transformation of cadmium from unstable forms to more stable forms within the soil. Fertilizer with the highest organic matter content and pH showed the least cadmium mobility. Increased nitrogen and phosphorus content in the fertilizer resulted in slightly higher cadmium mobility within the soil. Conversely, higher potassium content in the fertilizer led to slightly reduced cadmium mobility in the soil.

Tuning electron configuration of metal sites for the diesel adsorptive desulfurization over ion-exchanged zeolite Y

In diesel adsorption desulfurization, the coordination bonding between the adsorbent and sulfur compounds is interfered by aromatic compounds in diesel. Transition metal cation exchanged zeolites Y has exhibits exceptional anti-interference performance. In this work, the influence of electron configuration on coordination bonding is explored, specifically between the adsorbent and substrate, using both experimental and DFT theoretical methods. Initially, NiY, CuY and ZnY were synthesized and evaluated for their desulfurization performance in model solution (sulfur content: 25 ppmw dibenzothiophene [DBT]) with two toluene concentrations (1 w% and 3 w%). It is found that CuY showed the highest performance with retention rate at 70.2 %. Subsequently, DFT calculations revealed the binding energy between Cu(II) and DBT was −2.71 eV, higher than Ni(II) and Zn(II), and that between Cu(II) and toluene was −1.75 eV, lower than Ni(II) and Zn(II), indicating that the highest binding energy difference was responsible for the best adsorption capability. Apart from these, wave function analysis show the electron configuration between Cu(II) and DBT had the highest binding energy difference. Finally, the impact of electron configuration on adsorption performance is further investigated by modulating the electron configuration of Ni(II) to enhance/suppress its adsorption capability. According to the findings of this study, tuning the electron configuration is an effective strategy to develop materials in adsorptive desulfurization particularly for extra low sulfur content.

Geochemistry of Middle Jurassic Coals from the Dananhu Mine, Xinjiang: Emphasis on Sediment Source and Control Factors of Critical Metals

In recent years, coal-type critical metal deposits have become a research hotspot in coal geology. As a major coal-accumulating basin in the Xinjiang area, the Turpan-Hami Basin contains abundant coal resources and has the potential to become a large coal-type critical metal deposit. However, previous studies on the enrichment characteristics of critical metal elements in coal are few and need further research. Based on SEM-EDS, XRF, and ICP-MS experiments, this study investigates the coal petrology, mineralogy, and geochemistry of the No. 22 coal of the Xishanyao Formation from the Dananhu Coal Mine, Xinjiang, to identify the sediment source, depositional environment, and controlling factors of the critical metal elements of the No. 22 coal. The results showed that the Dananhu coals are characterized by a low ash yield, low total sulfur content, high volatile yield, and high inertinite proportions. Quartz, kaolinite, and illite are the main minerals in the coal. Compared with the world’s low-rank coals, Ni, Co, Mo, and Ta are slightly enriched, Li, Rb, Cs, Ba, Tl, Bi, and Ge are depleted, and the concentrations of other trace elements are comparable to the average values of the world’s low-rank coals. The REY of the Dannanhu coals exhibited high fractionation, with its enrichment patterns characterized by the H-type and M-H-type. Although most of the critical metals are not enriched in the Dannanhu coals, the Ga, Zr (Hf), and Nb (Ta) concentrations in the coal ash of the Dannanhu coals have reached the economic cut-off grade and have the potential to be a substitute for rare metal resources. The terrigenous detrital sources of the Dannanhu coals mainly come from the Paleozoic dacite, andesite, and a small amount of granite from the Harik Mountain and Eastern Bogda Mountain in the Turpan-Hami Basin. The Dannanhu coals are generally in a dry and hot depositional environment, with high salinity and weak reduction-oxidation. The low source input and weak reduction-oxidation environment have resulted in low concentrations of critical metal of the No. 22 coal from the Dananhu Coal Mine.

Thermoelectric performance of n-type Bi2S3-alloyed Bi2Te2.7Se0.3

The effect of isovalent sulfur substitution on the thermoelectric properties of n-type Bi2Te2.7Se0.3 alloy has been studied systematically. At low sulfur concentrations, where the samples are single phase, changes in defect chemistry and density of states impacted significantly electrical resistivity and thermopower. Isovalent sulfur substitution enhanced thermopower and reduced thermal conductivity for both single and multiphase samples. This reduction in thermal conductivity was particularly noticeable in samples containing Bi2S3-based secondary phase, reaching a low thermal conductivity of ∼0.3 W m−1 K−1 at 525 K. A maximum figure of merit, zT, of 0.55 was achieved for the sample with the highest sulfur content, demonstrating the potential of this approach to optimise the thermoelectric performance of Bi2Te3-based materials.

Production of biodiesel from non-edible waste palm oil and sterculia foetida using microwave irradiation

Abstract The environmental damage stemming from traditional diesel begins during crude oil extraction and persists throughout its usage. The burning of fossil fuels has further deteriorate the environmental effect and added to global warming by emitting harmful substances. Moreover, the reduction of finite fossil fuel reserves due to widespread extraction has made the adoption of renewable resources essential. Given these considerations, biodiesel emerges as a highly promising alternative to conventional diesel due to its environmentally beneficial nature, renewable source, and economic feasibility. In this study, biodiesel was prepared by a microwave reactor in the presence of potassium methoxide using blended waste palm oil and sterculia foetida. The effects of raw materials characteristics on transesterification products were studied. The studied process parameters were methanol/oil ratio, microwave temperature, catalyst concentration, reaction time, and stirring speed. The optimal yield with 98.5% FAME content was obtained at a methanol/oil ratio of 60 vol. %, microwave temperature of 120 °C, catalyst concentration of 0.3 wt.%, and 3 min reaction time, and stirring speed of 500 rpm. The potassium methoxide was used to catalyse the transesterification process. The physicochemical properties and the fatty acid methyl ester composition were discussed thoroughly. The flash point of biodiesel, at 157.5°C, exceeds that of diesel fuel by more than two times. The cetane index is 59.5 which is higher than diesel (49.6). The biodiesel’s fuel properties conformed to the requirements of both ASTM D6751 and EN 14214. High biodiesel conversion and low sulphur content show that waste palm oil and sterculia foetida are sustainable and economical feedstocks that produce clean fuel to aid the feasibility of the energy transition of the global energy sector. In addition, the selection of synthesis approaches can be further explored for potential catalysts to ensure eco-green biodiesel’s sustainability with minimised.

Synergistic restriction of polysulfides enabled by cobalt@carbon spheres embedded CNTs: A facile approach for constructing sulfur cathodes with high sulfur content

Despite the bright fortune of lithium-sulfur (Li-S) batteries as one of the next-generation energy storage systems owing to the ultrahigh theoretical energy density and earth-abundance of sulfur, crucial challenges including polysulfide shuttling and low sulfur content of sulfur cathodes need to be overcome before the commercial survival of sulfur cathodes. Herein, cobalt/carbon spheres embedded CNTs (Co-C-CNTs) are rationally designed as multifunctional hosts to synergistically address the drawbacks of sulfur cathodes. The host is synthesized by a facile pyrolysis using Co(OH)2 template and followed with the controllable etching process. The hierarchical porous structure owning high pore volume and surface area can buffer the volume change, physically confine polysulfides, and provide conductive networks. Besides, partially remained metallic cobalt nanoparticles are favorable for chemical adsorption and conversion of polysulfides, as validated by density functional theory simulations. With the combination of above merits, the S@Co-C-CNTs cathodes with a high sulfur content of 80 wt% present a superior initial capacity (1568 mAh g−1 at 0.1C) with ultrahigh 93.6% active material utilization, and excellent rate performance (649 mAh g−1 at 2C), providing feasible strategies for the optimization of cathodes in metal-sulfur batteries.

Hydroprocessing of Gasoline on Modified Alumina Catalysts

The hydroprocessing of gasoline on modified alumina catalysts makes it possible to obtain high-octane products. The implementation and development of the process have largely become possible due to the development of modified alumina catalysts that do not contain noble metals and exhibit special catalytic properties. This article discusses topical issues of petrochemistry, namely the creation of catalysts with improved characteristics for the production of high-octane gasoline with low sulfur content. New catalytic systems based on alumina and other carriers modified with transition metals, lanthanum and phosphorus were synthesized. By physico-chemical methods of analysis TPD of ammonia, TEM and XRD, we studied the acid–base and structural characteristics of the developed catalysts. The activity of the developed catalysts in the studied process of hydrotreating gasoline fractions depends on the structure and condition of the active centers. The process of hydrotreating straight-run gasoline in the presence of synthesized catalysts was carried out on a laboratory flow unit. It was shown that, during the hydrotreating of straight-run gasoline on the NiO-MoO3-La-P-HZSM-HY-Al2O3 catalyst, the octane number in the final product increased to 88.6, and the sulfur content decreased from 0.0088 to 0.001%. It was found that the minimum sulfur content in the gasoline hydrotreating product of 0.0005% was achieved on the catalyst CoO-WO3-La-P-HZSM-HY-Al2O3, which is significantly lower than for other studied catalytic systems. The obtained results of the sulfur content in the hydrotreating products fully comply with the Euro-5 standard. Thus, the efficiency of hydrotreating the gasoline fractions studied in this work was mainly determined by the nature of the carriers and modifiers used for the synthesis of catalysts and the technological parameters of the process. The synthesized catalysts showed high activity and selectivity, resulting in high-octane gasoline with a low sulfur content that meets international quality standards.