Sulfur Removal Efficiency Research Articles

Roles of chlorine and sulphate in MSWIFA in GGBFS binder: Hydration, mechanical properties and stabilization considerations

In this study, municipal solid waste incineration fly ash (MSWIFA) was first washed (pretreatment) with pure water with liquid to solid (L/S) ratio of 2, 3, 6, 10, to understand the removal efficiency of chlorine and sulphate, as well as its consequent ability as alkaline activator for granulated blast furnace slag (GGBFS). Washed MSWIFA was blended with GGBFS at a fixed ratio of 3:7 to examine their impact on mechanical properties, reaction mechanism, microstructure and leaching behavior. The results showed that chlorine in MSWIFA (>70%) can be washed out easily, while the removal of sulphate was largely depended on the L/S. GGBFS can be better activated by a low L/S (e.g. 2) washed-MSWIFA with attaining the compressive strength of 45.2MPa at 28 days. The higher chlorine and sulphate contents retained in the washed-MSWIFA, the higher the total heat release in the activated GGBFS system. Calcium silicate hydrate (C–S–H), ettringite (AFt) and Friedel’s salt were the main hydration products of the activated binders. The rapid formation of AFt was mainly responsible for the 1-day strength development. Large amounts of Friedel’s salts were formed from 1 day to 3 days associated to the inhibition of sulphate, and the presence of C–S–H played the key role in long-term strength development. The leaching test of heavy metals and soluble ions also demonstrated that washed MSWIFA activated GGBFS binders were harmless to the environment.

Effective removal of hydrogen sulfide using Mn-based recovered oxides from recycled batteries

The use of clean and environmentally friendly renewable energy as well as the minimization of waste disposal are fundamental aspects to be considered nowadays in a circular economy approach. In this way, the development of efficient systems for sulfur removal in biomass and waste gasification is of key relevance and the use of recycled materials will provide an opportunity to combine the reduction of waste‘s production and the application of circular economy principles.Sorbents from waste powder of recycled batteries have been prepared at laboratory scale. Subsequently, their potential application to syngas cleaning is evaluated specifically for H2S removal. Lab-scale tests at 400°C, 10 bar and space velocity of 3500 h−1 were carried out using first a simplified gas mixture of 0.9% H2S in N2 and then a more complex one consisting of 20% H2, 40% CO and 0.45% H2S/N2 to investigate the effect of reducing components, CO and H2 co-existing with H2S in any syngas. Sorbent utilization values as high as 80% (w/w, %) were obtained when tested under realistic syngas composition. XRF, XRD, XPS, TEM and textural characterization results of fresh and sulfided samples showed that those materials with higher Mn contents showed higher H2S removal capacity although the Mn/Zn ratio demonstrated to play a crucial role in their selectivity to form sulfides. Additionally, plausible mechanisms for H2S removal are discussed where the influence of composition, structure and morphology of the recovered binary metal oxides on sulfur removal efficiency is analysed.

Process intensification of liquid hydrocarbon fuel desulfurization using catalytic-oxidative-adsorptive method

In the present study, different metals included Ni and Cu were separately loaded on the mixed matrix of Al2O3-TiO2 to be used in catalytic-oxidative-adsorptive desulfurization of liquid hydrocarbon model fuel. The prepared catalysts were characterized by X-ray diffraction (XRD), N2 adsorption–desorption and field emission scanning electron microscopy (FE-SEM). The effects of different important parameters on catalytic-adsorptive desulfurization in the presence of hydrogen peroxide including sulfur/catalyst ratio (mg g−1) in the range of 4–12, oxidant/sulfur molar ratio (mol mol−1) of 4–10, temperature in the range of 30 °C–70 °C, and reaction time of 30–90 min. for the model fuel of n-decane with 800 ppm dibenzothiophene were investigated. Response surface methodology was used to design of experiments and explore the synergistic effects of investigated parameters. The results showed that Ni/Al2O3-TiO2 has higher sulfur removal efficiency than Cu/Al2O3-TiO2. Maximum efficiency (83.9%) was achieved when Ni/Al2O3-TiO2 was used at the conditions included sulfur to catalyst ratio = 4 mg g−1, oxidant to sulfur molar ratio = 10 mol mol−1, temperature = 70 °C, and the reaction time = 90 min. It was found that the efficiency of desulfurization for catalysts was increased with decreasing of the sulfur to catalyst ratio and increased when oxidant to sulfur molar ratio, temperature and reaction time increased.

Sulfate and metal removal from acid mine drainage using sugarcane vinasse as electron donor: Performance and microbial community of the down-flow structured-bed bioreactor

The down flow structured bed bioreactor (DFSBR) was applied to treat synthetic acid mine drainage (AMD) to reduce sulfate, increase the pH and precipitate metals in solutions (Co, Cu, Fe, Mn, Ni and Zn) using vinasse as an electron donor for sulfate-reducing bacteria (SRB). DFSBR achieved sulfate removal efficiencies between 55 and 91%, removal of Co and Ni were obtained with efficiencies greater than 80%, while Fe, Zn, Cu and Mn were removed with average efficiencies of 70, 80, 73 and 60%, respectively. Sulfate reduction increased pH from moderately acidic to 6.7–7.5. Modelling data confirmed the experimental results and metal sulfide precipitation was the mainly responsible for metal removal. The main genera responsible for sulfate and metal reduction were Geobacter and Desulfovibrio while fermenters were Parabacteroides and Sulfurovum. Moreover, in syntrophism with SRB, they played an important role in the efficiency of metal and sulfate removal.

Sustainable ecological engineering systems for the treatment of domestic wastewater using emerging, floating and submerged macrophytes

Water scarcity is perceived as a global systemic risk since there is an inexorable rise in water demand. An ecological engineering system mimics a natural ecosystem by balancing the trophic conditions for effective treatment of wastewater in a sequential manner. The present study was designed using emergent, floating and submerged macrophytic plants in a systematic approach. The study was evaluated with several components such as plants (water hyacinth, water lettuce and water thymes), aeration (supply of oxygen), and physical adsorption (activated carbon). Domestic wastewater collected from the local effluent treatment plant was treated individually and by combining all the components. Diverse experimental setups viz., lake sediment (control reactor), aeration, activated carbon blocks, water hyacinth, water lettuce, and water thymes were individually studied. Further the above components were combined, such as lake sediment + aeration + activated carbon blocks with plants like water hyacinth, water lettuce, and water thymes. The study inferred along with phytoremediation, and the external factors enhanced the treatment performances. Water hyacinth documented enhanced chemical oxygen demand removal efficiency of 85.71%, followed by water lettuce (80%), and water thymes (77.14%) along with the plants, both aeration, and activated carbon had stimulated the wastewater treatment. The highest removal efficiency of nitrate (70.23%), phosphate (63.64%), and sulphate (61.16%) were observed in water hyacinth due to its thick roots, and fibrous tissues reported effective treatment. The study hypothesized that these processes could be an effective strategy to restore the lakes and regulate the environmental flow. The study infers that an ecological engineering system symbiotically enables to self-organize the ecosystem within the boundary.

Comparing hydrate-based method with freezing/thawing method for chromium hydroxide sulfate removal close to the melting point of ice

In this work, both freezing/thawing method and hydrate-based method for chromium hydroxide sulfate removal with the temperature closing to melting point of ice have been conducted and compared in consideration of stirring speed, freezing time (or hydration-time), temperature, and chromium hydroxide sulfate concentration. The results suggested that chromium hydroxide sulfate removal efficiency of 93.9% was optimal with 85.6% of yield of melted water for freezing/thawing method. However, optimal chromium hydroxide sulfate removal efficiency and yield of melted water was 71.2% and 53.4% for hydrate-based method respectively. The optimal temperature for chromium hydroxide sulfate removal was different between the freezing/thawing method and the hydrate-based method. The optimal stirring speed freezing time, temperature, and chromium hydroxide sulfate concentration for freezing/thawing method were 800 r/min, 3 h, 271.6 K, and 100 ppm, respectively. However, the optimal stirring speed, hydration time, temperature, and chromium hydroxide sulfate concentration for hydrate-based method were 400 r/min, 1 h, 271.1 K, and 100 ppm, respectively. The results also suggested that the freezing/thawing method seems to be more effective than the hydrate-based method at 5.50 MPa for chromium hydroxide sulfate removal at the same temperature in this work. Therefore, the freezing/thawing method should be the first choice to remove chromium hydroxide sulfate at the temperature ranged from 269.2 K to 271.2 K when the concentration of chromium hydroxide sulfate was less than 800 ppm.

Synthesis of t‐B.PWFe/NiO nanocomposite as an efficient and heterogeneous green nanocatalyst for catalytic oxidative‐extractive desulfurization of gasoline

AbstractThis study aimed to improve the efficiency of sulfur removal from real and model liquid fuel, which is still a challenge. The heterogeneous nanocatalyst was synthesized successfully by supporting ([n‐C4H9]4N)4H[PW11FeO39] (t‐B.PWFe), on nickel oxide (NiO) as a new nanocomposite (t‐B.PWFe/NiO) via sol–gel method. The catalytic activity of the nanocomposite was evaluated for oxidative–extractive desulfurization (OEDS) of model fuel and real gasoline using CH3COOH/H2O2 as an oxidant. The synthesized nanocatalyst was characterized by means of X‐ray diffraction, scanning electron microscopy, Fourier transform infrared, ultraviolet–visible spectroscopy (UV–Vis), and cyclic voltammetry. From UV–Vis, the bandgap energy is found. After OEDS treatments, the obtained results were specified that mercaptans and total sulfur content of real gasoline lowered with about 97% yield. Mechanisms, kinetic studies, and the effect of various operational parameters were evaluated, such as temperature and time on the oxidation reaction. The unique performance of the t‐B.PWFe/NiO proved the extreme capability of this system for sulfur removal to achieve purified and clean gasoline.

Wastewater and Bioventing Treatment Systems for Acid Mine Drainage–Contaminated Soil

ABSTRACT Acid mine drainage (AMD) has continued to be a major threat leading to the destruction of the ecosystem and contamination of soil and waterbodies. The high sulfate concentration of AMD lowers the soil pH, making the soil more acidic and less productive which contributes to a reduction in the availability of arable land for agricultural purposes. Biological treatment has offered a cost-effective and eco-friendly approach through the introduction of organic substrates, aeration, or genetically modified microorganism to stimulate the contaminated environment and enhance sulfate reduction as opposed to previously used physicochemical methods which were criticized due to their inefficient and non-ecofriendly nature. This study focused on the evaluation of biological treatment through the application of wastewater (biostimulation) and air-injection (bioventing) for sulfate removal from AMD-contaminated soils. AMD-contaminated soil was amended with brewery (BWW) and municipal wastewater (MWW) at varying loading ratios to investigate the possible synergy while atmospheric air was supplied to bioventing treatments only. All treatments were conducted at mesophilic conditions for 28 days. The inability to improve sulfate removal rate through air-injection can be attributed to biosulfidogenesis preference for anoxic as against (high) oxic conditions for optimum performance. The BST and BVT treatment resulted in 34–53% and 27–42% sulfate removal efficiency, respectively. This study showed the efficacy of wastewater biostimulations and bioventing as a promising approach for sulfate and heavy metal removal from AMD-contaminated soils. The techniques have the potentials as vital tools for the mitigation of pollution aftermath in affected communities.

Constructed wetland for improved wastewater management and increased water use efficiency in resource scarce SAT villages: a case study from Kothapally village, in India

Evaluation a field-scale of constructed wetland (CW) for the treatment of rural wastewater (WW), in resource-scarce semi-arid tropic (SAT) villages, to provide improved wastewater management and increased water use efficiency, was the main objective of this study. A CW was commissioned in Kothapally village of Telangana to treat the wastewater generated from 100 households. The CW was vegetated with Typha latifolia and Canna indica. Average COD, sulfate and inorganic nitrogen removal efficiencies observed were 65%, 60% and 67% respectively, for the study period (one year). Removal efficiency for total coliform was consistently above 80%. The treated wastewater was stored in a farm pond and was utilized for irrigation in the nearby agricultural fields (0.6 ha). This perennial source of water, helped the nearby farmers to cultivate two additional crops, chickpea during rabi and sweetcorn during summer. The assured availability of water reduced their vulnerability to dry spells during the kharif by providing means for lifesaving irrigation. The biomass harvested from the constructed wetland was used as fodder for the livestock. A net additional income of Rs.70,000 (∼US$1,000) was realized by the farmers using the treated wastewater for cultivation. Similar constructed wetland-based wastewater management system can be scaled up across water scarce semi-arid tropics. Novelty statement Field-scale performance evaluation of constructed wetland based wastewater treatment in a semi-arid tropic village is scarce in the literature. The work presented gives a feasibility assessment for this technology critical for its wide-scale application to augment rural wastewater management in resource poor villages.

Analysis of possible ways to reduce sulfur content in pig iron

One of the ways to increase the energy efficiency and intensity of blast furnace smelting, especially when using pulverized coal fuel, is to increase the hot strength of coke. In the conditions of OJSC NLMK, an oil additive was introduced into the coal charge to improve the coke quality. At the same time, sulfur content in the coke increases, and, consequently, sulfur content in the cast iron increases as well. In this regard, the task of finding ways to improve the desulfurization of cast iron in blast furnace becomes urgent. The main factors determining the desulfurization of cast iron are slag basicity, content of MgO oxide in it, temperature of the smelting products, and the slag viscosity. The purpose of this work was to compare the efficiency of sulfur removal by increasing the slag basicity and MgO content. On the basis of wellknown equations, an algorithm was developed that allows the problem to be solved. It was established that an increase in MgO content in the slag promotes desulfurization of cast iron to a greater extent than a basicity increase. In addition, an increase in MgO content by 1 % is accompanied by an increase in slag yield by 3.0 – 3.5 kg/t of cast iron. At the same time, an increase in basicity by 0.01 leads to an increase in the slag yield by 4 – 5 kg/t of pig iron. Consequently, reducing the sulfur content in pig iron by increasing the slag basicity requires less heat. In terms of the specific consumption of coke, difference in heat demand is 0.4 – 0.5 kg/t of pig iron. It is shown that with an increase in MgO content in the slag, the slag viscosity at a temperature of 1450 °C increases to a lesser extent than with an increase in basicity.

Preparation and characteristics of CuO/γ-Al2O3 nanocomposite as efficient adsorbent for adsorption of sulfur compounds from Iraqi naphtha

Herein, CuO/γ-Al 2 O 3 nanocomposite adsorbent were synthesized and characterized for adsorptive desulfurization of naphtha fraction. The γ-Al 2 O 3 nanoparticles was first, prepared by coprecipitation route and characterized by XRD, AFM, BET and SEM methods. Then, CuO was supported onto γ-Al 2 O 3 nanoparticles by impregnation method. The effects of different parameters were studied on the sulfur removal efficiency and adsorption capacity in batch and continuous modes. These parameters included contact time and adsorbent dose in batch study, while in continuous study; the breakthrough curves were generated in fixed bed adsorber. The batch adsorption study indicates that the CuO/γ-Al 2 O 3 nanoadsorbent exhibited better max adsorption capacity (78.8 mg/g) than bare γ-Al 2 O 3 (34.2 mg/g). Different adsorption kinetics models and isotherms were investigated for CuO/γ-Al 2 O 3 and γ-Al 2 O 3 nanoadsorbents. The adsorption kinetics of naphtha desulfurization were closely followed the second order kinetic model. Also, Langmuir isotherm was well represented the equilibrium adsorption of sulfur. In continuous study, breakthrough curves were generated for CuO/γ-Al 2 O 3 nanocomposite at LHSV = 2 h −1 and bed height = 7 cm. The time of breakthrough point was 320 min. Moreover, the Yoon–Nelson model fitted best for the continuous experimental data.

Comparative evaluation of wastewater and bioventing system for the treatment of acid mine drainage contaminated soils

The increasing rate of soil pollution poses a prolific threat to the sustenance of the ecosystem. Acid mine drainage (AMD) is an environmental problem that has contributed immensely to soil pedogenesis and contamination associated with mining activities. Physical, chemical, and thermal methods of soil treatment have some rooms for improvement to meet remediation purposes. Contrary to other methods, bioremediation is a cost-effective and a sustainable biological approach that utilizes microorganisms for the remediation of a contaminated environment and does not recontaminate or further degrade the soil after application. This study aims to comparatively evaluate the application of wastewater and bioventing system for the the treatment of AMD contaminated soils. A microcosm containing 1 kg of contaminated soil was amended with wastewaters of varying (biostimulation (BSTa)) while bioventing treatment (BVTa) consists of the injection of atmospheric air through the vadose zone into bioreactors and amended with wastewater effluents. The treatment was conducted at ambient condition for 28 days. The result of the treatment recorded 28–67% and 58–70% metal (Mn, Fe, Al, Cu and Zn) removal efficiencies with 51% and 34% sulfate removal efficiencies for BSTa and BVTa treatments, respectively. However, attempts to improve the sulfate removal efficiencies through the injection of atmospheric air were not effective. This study showed that wastewater and bioventing can be effectively applied as a potential alternative for the treatment of AMD contaminated soils.

Synthesis and characterization of AFe2O4 (A: Ni, Co, Mg)-silica nanocomposites and their application for the removal of dibenzothiophene (DBT) by an adsorption process: kinetics, isotherms and experimental design.

The kinetics, equilibrium, and statistical aspects of the sulfur removal process from hydrocarbon fuels by AFe2O4–silica nanocomposites (A: Ni, Mg, and Co) have been investigated in the present study. Nanocomposites were prepared via the auto-combustion sol–gel method and then employed in the adsorptive desulfurization (ADS) process. Next, the prepared samples were characterized by different analytical methods including XRD, SEM, TEM, FT-IR, TGA, and BET. The contributions of conventional parameters including adsorbent dosage and contact time were then studied by central composite design (CCD) under response surface methodology (RSM). Based on the statistical investigations, optimum conditions for ADS were an adsorbent dosage of 7.82 g per 50 ml of the model fuel and a contact time of 32 min. The adsorption amounts reached 38.6 mg g−1 for DBT. The quadratic model was applied for the analysis of variance. Based on the experimental data, the pseudo-first-order (PFO) model could explain the adsorption kinetics of the compounds. Furthermore, the Langmuir isotherm demonstrated considerable agreement with the experimental equilibrium data. According to the results, the NiFe2O4–SiO2 nanocomposite showed the best performance compared to other compounds. The sulfur removal efficiency increased from 63 to 94% upon increasing the NiFe2O4–SiO2 dosage from 3 to 9 g per 50 ml of the model fuel.

Novel nanocomposite adsorbent for desulfurization of 4,6-dimethyldibenzothiophene from model fuel

In the present study, TiO 2 /Y-zeolite nanocomposite was successfully manufactured from TiO 2 prepared by sol–gel method and commercial HY zeolite. Then, characterized by XRD, AFM, BET, SEM and EDX analysis. The nanocomposite was introduced for ultra-deep adsorptive desulfurization of 4,6- dimethyldibenzothiophene (4,6-DMDBT) from model fuel at mild conditions of 25 °C and atmospheric pressure via batch mode experiments. The results showed that the adsorbent achieved a sulfur removal efficiency higher than 99% with an initial sulfur content in the model fuel of 280 ppm. This high performance was attributed to its large surface area and good mechanical properties. The effect of different initial sulfur content of model fuel and adsorbent amount were also investigated. The most of the sulfur compound was removed before equilibrium time 30 min. A high static saturated sulfur capacity of 11 (mg S/g adsorbent) was achieved. The adsorption equilibrium analysis was investigated and experimental data were best fitted with Langmuir isotherm. The isotherm equations corelate the data with correlation coefficients (R 2 ) values in the order of: Langmuir > Temkin > Freundlich.

Using Box-Behnken experimental design for optimization of gas oil desulfurization by electrochemical oxidation technique

Iraqi gas oil with sulfur content 9400 ppm was desulfurized electrochemically at constant current (300 mA), the process consists two steps; first step is electrochemical desulfurization by using electrochemical cell contains two graphite electrodes while the used electrolyte is NaCl to enhance electrolyte electrical conductivity, and hydrogen peroxide as an oxidant agent, second step is extraction with acetonitrile. Optimization of process parameters was done by applying response surface methodology RSM combined with Box –Behnken experimental method, in which the sulfur removal efficiency was acted as response function while the reaction temperature, NaCl concentration and time were selected as controllable (studied) variables. The sulfur removal efficiency was ranged from 55.84 % to 88.07%. The results were analyzed with Design-Expert software by fitting with second order polynomial model and the empirical model was exhibited high correlation factor (R2=0.9966) and the estimated optimization solution stated that maximum sulfur removal efficiency is 88.611% at temperature (57.656 °C), NaCl concentration (0.106 M) and, time (51.46 min.).

A novel method for fuel oil desulphurization by deep eutectic solvent extraction coupled with reduction using sodium borohydride

AbstractIn order to improve sulphur removal efficiency, deep eutectic solvent (DES) is first introduced into the fuel oil desulphurization process with sodium borohydride (NaBH4). Thereby, a novel method for fuel oil desulphurization by extraction coupled with reduction is proposed, where DES is used as stabilizer and extractant and NaBH4 is used as reducing agent. The nickel borides produced from NaBH4 and nickel salts were characterized using a particle size analyzer, surface area analyzer, and transmission electron microscopy. The results show that the nickel borides produced in DES have smaller particle sizes and a higher BET surface area than that in methanol/tetrahydrofuran (MeOH/THF). Sulphur removal efficiency using DES as medium was higher than that using MeOH/THF as medium. The effect of process parameters on the sulphur removal efficiency was investigated by orthogonal experiments. The results showed that the sulphur removal efficiency of dibenzothiophene can reach more than 96%. The desulphurization of dibenzothiophene should proceed over the cleavage of C−S bond to biphenyl and desulphurization reaction followed the pseudo‐first‐order reaction. The structures of the DESs remained unchanged after regeneration. In summary, the novel desulphurization method is feasible and promising.

Anaerobic co-digestion of landfill leachate and acid mine drainage using up-flow anaerobic sludge blanket reactor.

A laboratory-scale up-flow anaerobic sludge blanket (UASB) reactor was developed and constructed for the treatment of landfill leachate and acid mine drainage (AMD). The removal of chemical oxygen demand (COD), sulfate, and metal ions was studied. The maximum COD and sulfate removal efficiency reached 75% and 69%, respectively, during the start-up phase of the UASB. The hydraulic retention time (HRT) had a significant influence on the system. The maximum removal efficiency for COD and sulfate reached 83% and 78%, respectively, at an HRT of 20 h. The methane production process competed with the sulfate reduction process in the UASB. The fractionation of metals in the sludge was analyzed to facilitate metal recovery in a later processing stage. The most abundant sulfate-reducing bacteria was Desulfobulbus, and the methanogen archaeal community in the reactor was mainly composed of Methanobacterium.

Carbamazepine biodegradation and volatile fatty acids production by selectively enriched sulfate‐reducing bacteria and fermentative acidogenic bacteria

AbstractBACKGROUNDThe micropollutant carbamazepine (CBZ) is persistent and resistant to conventional wastewater treatment. This study investigated the role of fermentative acidogenic bacteria (FAB) and sulfate‐reducing bacteria (SRB) for CBZ biodegradation and volatile fatty acid (VFA) production.RESULTSThe experimental results demonstrated that CBZ biodegradation, total organic carbon and sulfate removal efficiency reached 46%, 36% and 98%, respectively, after 144 h of operation with VFA production of acetic acid (20.72 mmol L−1), propionic acid (3.67 mmol L−1) and butyric acid (4.90 mmol L−1). However, the acetate fraction decreased from 78% to 70% with a decrease in chemical oxygen demand/sulfate (COD:SO42−) ratios from 1.06 to 0.35, respectively, suggesting that acetate was partially oxidized by SRB under substrate/COD limiting conditions. The biodegradation performance of SRB + FAB was also compared with that of a mixed microbial community (MMC).CONCLUSIONSUpon increasing the initial CBZ concentration from 42.3 to 169.2 μmol L−1, SRB + FAB exhibited much higher CBZ biodegradation (33%) than MMC (12%). Microbial community analyses confirmed the enrichment of VFA‐producing species including phylum Firmicutes (2.4% to 36.8%) and class Clostridia (1.3% to 29.6%). Moreover, aromatic and nitroaromatic compound‐degrading bacteria such as Escherichia and Desulfovibrio were also enriched. This signifies the applicability of SRB + FAB to pharmaceutical pollutant biodegradation in the environment. © 2020 Society of Chemical Industry (SCI)

The application of combined lignite cleaning processes, bacterial leaching and flotation, for reducing higher ash and sulfur contents

ABSTRACT In this study, biological and physicochemical processes were combined to decrease the ash and sulfur contents of finely ground coal. Firstly, biodesulphurization experiments of lignites with high ash and sulfur contents were carried out with air-supply fiberglass bioreactor using Acidithiobacillus ferrooxidans. At the end of the 12-hour bacterial desulfurization experiments; ash content, sulfur content, calorific value, sulfur emission value, recovery of calorific value, and combustible recovery values were 33.88%, 3.97%, 3982 kcal/kg, 0.24% 91.22%, and 89.74%, respectively. Afterward, in the second stage experiments, flotation method was used to beneficiation Can/Canakkale lignites by physicochemical methods. In flotation experiments, the effects of collector (Fuel oil; 0–900 g/t) and frother (MIBC; 0–300 g/t) dosages on flotation were investigated. Optimum collector and frother dosages were determined as 750 g/t and 250 g/t in flotation experiments, respectively. In flotation experiments under optimum conditions ash content, sulfur content, calorific value, sulfur emission value, recovery of calorific value and combustible recovery values were 16.38%, 0.75%, 5166 kcal/kg, 0.03% 98.60%, and 96.11%, respectively. As a result of all experiments, ash and sulfur removal efficiencies were carried out 65.12% and 86.93% in Can/Canakkale lignites, respectively.

Enhanced oxidative desulfurization of model fuel: A comprehensive experimental study

In this study desulfurization has been surveyed with particular attention to the effect of temperature, Fe+2/H2O2 molar ratio, residence time, fluid viscosity and agitation speed. Demonstration of factors' effects approved via ANVOVA by Taguchi experimental design and printed a vital effect of temperature and oil volume fraction as the most two considerable parameters with contribution percent of 92.5% and 87.5%, respectively. The aforementioned approach led to reduction of sulfur content of understudy fuel from 650 to 800 ppm to 185.7 ppm during 45 min of oxidative reaction. The sulfur removal efficiency predicted by the software was 86.47% and the value from the experiment was 89.39% while it was arranged based on the severity index for more accuracy of results. As a result removal efficiency with Fenton reactions as a strong economic process under a pseudo-first order kinetics model was approved.