Desulfurization Effect Research Articles

Cyclodextrin-assisted high selectivity of imprinted adsorbents loaded on polyoxometalate@UiO-66 for H2S removal at ambient temperature

The efficient removal of H2S is necessary for clean production and energy safety. However, industrial gases are usually accompanied by CO2 significantly affecting desulfurization effects. Hence, novel imprinted adsorbents (PMo12@UiO-66@H2S-MIP-CDs) were synthesized through surface imprinting technology using cyclodextrins (CDs) as molecular scaffolds and UiO-66 modified by phosphomolybdic acid (PMo12@UiO-66) as a support. Wherein, PMo12@UiO-66@H2S-MIP-β-CD was determined as the optimal adsorbent since β-CD with low solubility is prone to keep its inherent cavity to promote dispersion of imprinted polymers and enrich internal pore channels. H2S capacity of PMo12@UiO-66@H2S-MIP-β-CD (31.67 mg/g) was about 2.4 and 1.7 times that of PMo12@UiO-66 and PMo12@UiO-66@H2S-MIPs, respectively, revealing the remarkable contribution of β-CD as a molecular scaffold to improve desulfurization. The results showed that PMo12@UiO-66@H2S-MIP-β-CD can maintain stable desulfurization efficiency regardless of the presence of CO2 or moisture, and O2 can strengthen the redox reaction between H2S and PMo12 accompanied by the increased reduction degree of Mo6+ in PMo12. After five adsorption-regeneration cycles, PMo12@UiO-66@H2S-MIP-β-CD still exhibited ideal removal efficiency. The excellent desulfurization performance is mainly ascribed to the selective adsorption role of H2S-MIP-β-CD and oxidative removal ability of PMo12. This work provides a valuable reference for the directional design of high-capacity functional adsorbents for room-temperature desulfurization.

Molecular transformation of heavy oil during slurry phase hydrocracking process: influences of operational conditions

The influences of reaction temperature, duration, pressure, and catalyst concentration on the molecular transformation of residual slurry phase hydrocracking process were investigated. The molecular composition of the heteroatom compounds in the residue feedstock and its upgrading products were characterized using high-resolution Orbitrap mass spectrometry coupled with multiple ionization methods. The simultaneous promotion of cracking and hydrogenation reactions was observed with increasing of the reaction temperature and time. Specifically, there was a significant increase in the cracking degree of alkyl side chain, while the removal of low-condensation sulfur compounds such as sulfides and benzothiophenes was enhanced. In particular, the cracking reactions were more significantly facilitated by high temperatures, while an appropriately extended reaction time can result in the complete elimination of the aforementioned sulfur compounds with a lower degree of condensation. Under conditions of low hydrogen pressure and catalyst concentration, the products still exhibit a high relative abundance of easily convertible compounds such as sulfoxides, indicating a significant deficiency in the effectiveness of hydrogenation. The hydrogen pressure exhibits an optimal value, beyond which further increments have no effect on the composition and performance of the liquid product but can increase the yield of the liquid product. At significantly high catalyst concentration, the effect of desulfurization and deoxidation slightly diminishes, while the aromatic saturation of highly condensed compounds was notably enhanced. This hydrogenation saturation effect cannot be attained through manipulation of other operational parameters, thereby potentially benefiting subsequent product processing and utilization. This present study demonstrates a profound comprehension of the molecular-level residue slurry phase hydrocracking process, offering not only specific guide for process design and optimization but also valuable fundamental data for constructing reaction models at the molecular level.

Study on combustion characteristics of crustacean biomass derived fuel coupled with in-situ capture of SO2 based on pulsed microwave radiation

Crustacean waste has great potential as fossil fuel substitution and efficient desulfurization to reduce pollutant emissions, but high moisture and poor quality restrict broad-scale utilization. This study used microwave radiation on crayfish shell to investigate the combustion characteristics and desulfurization effect in different atmospheres/pulse microwave cycle. Meanwhile, the structure evolution mechanism and molecular reaction pathways were revealed. The results show that crayfish shell derived fuel has a pleasurable combustion performance and sulfur fixation ability after microwave radiation in flue gas. The heat release of derived fuel increased by 29.9 % after five microwave cycle in flue gas, and activation energy decreased by 3.7 %. By contrast, the heat release increased by 17.4 % after five microwave cycle in inert gas, and activation energy increased by 39.3 %. Subsequently, the effect of microwave cycle times in flue gas on crayfish shell combustion and desulfurization performance was studied. The results show that the heat release of derived fuel gradually increases with microwave cycle. After seven microwave cycle, the derived fuel heat release and SO2 removal efficiency increased by 34.9 % and 44.4 %, respectively. The results establish the foundation for expanding the utilization pathway of crustacean waste and realizing the low-carbon energy transition.

Experimental Study on Combined Microwave-Magnetic Separation-Flotation Coal Desulfurization.

In order to reduce the content of sulfur and ash in coal, improve the desulfurization and deashing rates, a combined experiment method of microwave magnetic separation-flotation was proposed for raw coal. The desulfurization and deashing rates of three experiment methods, namely, single magnetic separation, microwave magnetic separation, and microwave magnetic separation-flotation, were compared. Taking the microwave magnetic separation-flotation experiment method as the main line, the effects of the microwave irradiation time, microwave power, grinding time, magnetic field intensity, plate seam width, foaming agent dosage, collector dosage, and inhibitor dosage on desulfurization and deashing were discussed, and the mechanism of microwave irradiation on magnetic separation and flotation was revealed. The results show that under the conditions of a microwave irradiation time of 60 s, a microwave power of 80% of the rated power (800 W), a grinding time of 8 min, a plate seam width (the plate seam width of a magnetic separator sorting box) of 1 mm, a magnetic field intensity of 2.32 T, a foaming agent dosage of 90 g/t, a collector dosage of 2125 g/t, and an inhibitor dosage of 1500 g/t, the desulfurization and deashing effect is the best. The desulphurization rate is 76.51%, the sulfur removal rate of pyrite is 96.50%, and the deashing rate is 61.91%. Microwaves have the characteristic of selective heating, and the thermal conductivity of organic matter in coal is greater than that of mineral. Microwave irradiation can improve the reactivity of pyrite in coal, pyrolyze pyrite into high-magnetic pyrite, improve the magnetic properties, and improve the magnetic separation effect. Therefore, microwave irradiation plays a role in promoting magnetic separation. Through microwave irradiation, the positive and negative charges in coal molecules constantly vibrate and create friction under the action of an electric field force, and the thermal action generated by this vibration and friction process affects the structural changes in oxygen-containing functional groups in coal. With the increase in the irradiation time and power, the hydrophilic functional groups of -OH and -COOH decrease and the hydrophilicity decreases. Microwave heating evaporates the water in the pores of coal samples and weakens surface hydration. At the same time, microwave irradiation destroys the structure of coal and impurity minerals, produces cracks at the junction, increases the surface area of coal to a certain extent, enhances the hydrophobicity, and then improves the effect of flotation desulfurization and deashing. Therefore, after the microwave irradiation of raw coal, the magnetic separation effect is enhanced, and the flotation desulfurization effect is also enhanced.

A green extraction method for agar with improved thermal stability and water holding capacity

The conventional agar extraction method has drawbacks such as high energy consumption, low yield, poor quality, and possible residual harmful factors, which greatly limit its application in high-end fields such as biomedicine and high-end materials. This work explored a new freezing-thawing-high-temperature coupling technique for agar extraction. It increased the yield and the strength of agar by 10.6 % and 13.7 %, respectively, as compared to direct high-temperature extraction of agar (HA). The greater molecular weight and lower sulfate content of agar obtained from freeze-thaw cycles combined with high temperature extraction (FA) may be attributed to the desulfurization effect caused by freeze-thaw cycles and the preservation of the molecular chain structure. The reduction in sulfate content decreases the steric hindrance resistance of the polysaccharide chains, enhances their interactions, and promotes the regularity and density of the agar structure, while also improving its water retention and thermal stability. In conclusion, this research can offer a theoretical basis and guidance for the eco-friendly extraction of agar with improved agar characteristics and expended its applications.

Research and application of surface spray anti-corrosion technology for coiled tubing in pressurized environment

In this study, the corrosion risk of coiled tubing under high pressure, high temperature and high sulfur conditions was investigated, and the protection solution was put forward. In this paper, spray paint is used to prevent corrosion of tubing, and the effects of high temperature desulfurization and nano super absorbent spraying agent are compared. The pressure jet spraying device is designed for uniform spraying during operation to improve corrosion resistance. Determine the best spraying position and monitoring point. The results show that nano-coating agent can prevent cracking and serious corrosion, and its application effect in oil wells meets the requirements. These findings support that anti-corrosion spraying technology on coiled tubing surface can effectively prevent tubing corrosion in high temperature, high pressure and corrosive environment.

The effect of impeller height and rotation speed on the Kambala reactor desulfurization process

To improve the utilization efficiency of desulfurizer in the Kambala reactor liquid iron desulfurization process and prolong the life of the impeller, the height of the impeller and its optimal matching rotation speed are optimized. Through numerical simulation, the mixing effect of different height impellers under different rotation speeds is studied, the movement and distribution modes of desulfurizer particles are analyzed, the pumping capacity and power are calculated, and the influence of impeller height and optimal matching rotation speed on the desulfurization effect has been clarified. The numerical simulation results show that the optimization of impeller height and optimal matching rotation speed can improve the mixing effect. The height of the impeller increases, and its optimal matching rotation speed decreases. Based on the results, in existing models, it is recommended to run at 60 r/min with an impeller height of 800 mm for optimal mixing performance.

Influence of carbonate-inducing bacteria on desulfurization effect of medium and high sulfur coal gangue under spraying and preparation of desulfurized coal gangue mortar

Medium and high sulfur coal gangue (MHSCG) presents challenges for safe application on civil engineering building materials due to the high content of unstable pyrite, of which the acidic oxidation products are against alkali cementitious materials. For better utilization of MHSCG, in this research, the carbonate-inducing bacterium Sporosarcina Pasteurii with its nutrient (urea) and mineralization source (calcium) was firstly explored in MHSCG desulfurization leaching tests, revealing the mechanism of desulfurization. On this basis, the desulfurizing modification on MHSCG sand by the bacteria under different factors of OD600, urea and calcium was conducted. Moreover, the gangue sand was used to prepare the desulfurized coal gangue mortar (DCGM) and the relevant mechanical properties and influence mechanisms were discussed. The results of total sulfur and XRD analysis show that Sporosarcina Pasteurii can accelerate the desulfurization in the 7-days-spraying modification. When the optimum dosages of OD600 (0.84) and urea solution concentration (1.41 mol/L) are adopted, the total sulfur can be reduced by 33.66∼36.32 %. The total sulfur has been further reduced by 7.69 % compared with group without calcium as calcium concentration is 1.56 mol/L. The introduction of calcium can enhance the mechanical properties of MHSCG and DCGM although the desulfurization treatment has a negative impact on them. The crushing index of MHSCG sand at most decreases 10.44 % from it without calcium. When OD600 is about 0.90, urea concentration is about 1.50 mol/L and calcium concentration is about 1.49 mol/L, the 28-d compressive strength of DCGM increases to 32.01 MPa, 76.85 % higher than group without calcium, and 23.54 % higher than raw-material preparing mortar.

Study on water transfer characteristics and desulfurization effect during the separation of fine low rank lignite in the dry dense medium fluidized bed

Coal is an important support for the development of the national economy. Lignite has high utilization value. This paper utilizes a dry dense medium fluidized bed for separation of low rank high sulfur lignite across the size range of 6–0 mm. The study focuses on the spatial diffusion and transfer characteristics of material moisture in the fluidized bed, systematically analyzes the influence of material moisture on the bed fluidization characteristics and the bed density spatial uniform stability, explores the diffusion and separation characteristics of the material in the bed, and determines the material separation time domain. The experimental results indicate that when t = 60 s, the high concentration area of the whole bed is distributed in the center, and the low concentration area is distributed in the side wall At when t = 360 s, the high concentration area of the upper bed is distributed near the side wall, and the high concentration area of the middle and lower layers are distributed in the center of the bed. At t = 420 s, the high concentration area in the upper layer gradually disappears, and the separation of high and low-density particles is completed in the middle layer, achieving stratification. When the bed layer moisture content is 0.5 % and the air flow is 16.3 cm/s, the bed pressure drop tends to stabilize, and the bed fluidization effect is better, reaching its peak moisture content. The fluctuation in bed layer spatial density distribution is significant, especially in the central area of the upper layer (within the circular area 0 ≤ R ≤ 3 cm), where the density distribution fluctuation is most pronounced, with an average density of 1.67 g/cm3. The fluctuation amplitude of the middle bed density is relatively low, with an average density of 1.65 g/cm3. The fluctuation amplitude of the lower bed density is the smallest, with an average density of 1.53 g/cm3. When t = 0–120 s, the ash content of each layer along the bed height is close to the raw coal, which belongs to the material diffusion distribution time domain. When t = 120–240 s, the material is stratified locally, which belongs to the material initial stratification time domain. When t = 240–420 s, the high and low density particles achieve orderly stratification, which belongs to the material sorting time domain The results show that the clean coal yield was 74.68 %, sulfur content is 0.98 %, ash content is 9.96 %, gangue yield is 25.32 %, sulfur content is 18.69 %, ash content is 58.32 %, Ep is 0.65 g/cm3. The high-precision dry separation of fine grained low rank high sulfur lignite was realized.

Study on the Role of Additives in Calcination Desulfurization Process of High Sulfur Petroleum Coke

Due to the high sulfur content of high sulfur petroleum coke, sulfur-containing gas will be produced in the production process, reducing product quality and other problems, resulting in increased production costs and equipment corrosion. How to reduce the sulfur content of high sulfur petroleum coke is of great significance to improve the utilization rate of high sulfur petroleum coke and the sustainable development of related industries. In this paper, the desulfurization of high sulfur petroleum coke was carried out by using the additive-assisted high-temperature calcination method. It was found that the desulfurization effect of different kinds of desulfurization additives was different, among which MO1, MC2, MC1 desulfurization effect was better, and the desulfurization rate could reach 68%, 58%, 56%. After compounding the three desulfurizers, the desulfurization rate can be up to 75%, and then the influence of calcination temperature and time on the desulfurization rate was investigated. Finally, the physicochemical properties of petroleum coke before and after desulfurization were analyzed by X RD, FT-IR.

Microbial treatment of waste crumb rubber: Reducing energy consumption and harmful emissions during asphalt production process

The emergence of crumb rubber modified asphalt (CRMA) has promoted the recycling utilization of waste tires and the improvement of asphalt performance. However, its unsatisfactory storage stability and high construction temperature have brought about excessive energy consumption and environmental challenges. In this study, the waste crumb rubber (CR) was bio-desulfurized by the synergy between two types bacteria for 7 days and 14 days, respectively. On this basis, bio-desulfurization crumb rubber modified asphalt (BCRMA) was prepared. The desulfurization effect of CR was characterized. Thermal storage stability and environmental performance of BCRMA were mainly investigated. The results showed that bio-desulfurization increased the number of pores, surface roughness and specific surface area of CR, and decreased the content of sulfur element. Bio-desulfurization of CR improved the insufficient thermal storage stability of rubberized asphalt and reduced the risk of system segregation. Bio-desulfurization CR has been proven to be a promising environmentally friendly material that can effectively lower the release concentration and release type of harmful flue gas from CRMA. This study makes the large-scale promotion and application of CRMA possible.

Analysis on the rheological behavior, microstructure and storage stability between crumb rubber of desulfurization and depolymerization and asphalt

The compatibility of crumb rubber (CR) modified asphalt restricts its application in pavement engineering. In this study, desulfurized (DS) and depolymerized (DP) CR-modified asphalts (CRMA) were prepared, and molecular models were constructed using molecular dynamics (MD). To analyze the effect of desulfurization and depolymerization on CRMA compatibility, rheological properties, storage stability, and morphological characteristics of CRMA, DSCRMA, and DPCRMA were determined and characterized. The interaction mechanism between CR and asphalt was characterized using indicators including binding energy and diffusion coefficient. Dynamic Shear Rheometer (DSR) results showed that desulfurization and depolymerization significantly improved the high-temperature rutting resistance of CR modified asphalt. Storage stability results indicated a softening point difference of 2.1°C for DSCRMA, meeting the standard of less than 2.5°C. Scanning Electron Microscopy (SEM) revealed a decrease in the size of DSCR particles and an increase in roughness and the number of pores. Fluorescence microscopy observed better dispersion of DSCR particles in asphalt, which was consistent with SEM results. MD results indicated an increase in binding energy between DSCR and light components, while diffusion motion was constrained. The interaction capability of DPCR decreased, possibly due to uneven depolymerization accumulation. The study revealed that desulfurization significantly enhances CRMA compatibility, while the degree of CR depolymerization warrants further investigation into its effects on asphalt.

The Influence of Yttrium Content and Ceramic Crucible Materials on Desulfurization during Vacuum Induction Melting of DD5 Superalloys

In this study, the effect of adding different contents of yttrium (Y) during vacuum induction melting in Al2O3 and Y2O3 crucibles on the purification of DD5 alloys was investigated. The results show that the Y2O3 crucible exhibited great crucible stability and an excellent desulfurization effect when melting a Y-containing DD5 alloy. The S content of the alloy was reduced from 5.03 ppm to 1.36 ppm with the addition of 0.50 wt.% Y. Element Y combined with free S in the melt to form the YS phase, which was removed from the condensate shell and slag during the vacuum induction melting (VIM) process. Meanwhile, when the alloy was melted in the Y2O3 crucible with 0.50 wt.% Y addition, there was a reduction in S content from 2.77 ppm to 1.36 ppm compared to the Al2O3 crucible. Additionally, the loss of Y decreased from 0.12 wt.% to 0.05 wt.%.

Effects of different catalytic liquefaction of bio-oil on hydrothermal upgrading of heavy oil: A comprehensive analysis of composition, desulfurization and hydrogenation

Efficient utilization of biomass is one of the important ways to alleviate energy shortage. In this study, microcrystalline cellulose was used as the source of bio-oil, and Fe/HZSM-5, Ni/HZSM-5 and Mo/HZSM-5 catalysts were used to adjust the composition of bio-oil and upgrade heavy oil under hydrothermal conditions, so as to understand the influence of bio-oil generated by different catalysts on the upgrading of heavy oil. The characteristics of heavy oil before and after upgrading were analyzed by using elemental analysis, infrared spectrum and molecular weight. The composition of bio-oil was analyzed by GC/MS before, during and after entering the hydrothermal system of heavy oil. The results show that Fe-oil and Mo-oil contain more methoxy compounds and tetrahydronaphthalene, which are more conducive to the upgrading of heavy oil, and have strong desulfurization and hydrogenation effect, but have no obvious effect on nitrogen compounds.

Improved back propagation neural network method for predicting sulfur content in hot metal

Blast furnace smelting is a traditional iron-making process. Its product, hot metal, is an important raw material for the production of steel. Steelmaking efficiency can be improved and steel product quality can be stabilized by using proper hot metal. Sulfur is an important indicator reflecting the quality of hot metal, it is necessary to establish an accurate prediction model to predict the sulfur content of hot metal, to effectively guide the production process. There is a non-linear relationship among the factors influencing the desulfurization effect during the blast furnace smelting process, and the back propagation neural network (BPNN) model has a strong ability to solve nonlinear problems. However, BPNN has the disadvantages of slow convergence speed and easy to fall into local minima. To improve the prediction accuracy, an improved algorithm combining Kmeans and BPNN is proposed in this paper. The study showed that compared with the BPNN model and case-based reasoning (CBR) model, the Kmeans-BPNN model has the lowest RMSE and MAPE values, which indicates a high degree of fit and a low degree of dispersion. The Kmeans-BPNN model has the largest HR value, which indicates the highest prediction accuracy. The proposed Kmeans-BPNN prediction model achieves a hit rate of 96%, which is 4.5% higher than before the improvement. It can effectively improve the prediction accuracy of hot metal sulfur content.

Comparative investigation on the chemical pre-desulfurization process of a high sulfur coal through orthogonal experiments: a case study

ABSTRACT The effect of different chemical pre-desulfurization processes were compared to achieve the utilization of high sulfur coal efficiently and economically and its total sulfur content is 2.19%. The major influence factors were the reagent dosage, desulfurization temperature, and time. Compared with single-factor experiments, orthogonal experiments can greatly reduce the number of experiments and ensure the rationality of experimental data. The desulfurization rate of acid leach, alkali leach, oxidation, and catalytic reduction were 41.67%, 17.16%, 26.96%, and 27.45%, respectively, and the total sulfur after the pre-desulfurization process were 1.19%, 1.69%, 1.49%, and 1.48%, respectively. Range analysis and variance analysis were employed for the crucial operational parameters. In acid and alkali leaching desulfurization process, the acid/alkali concentration had the greatest influence on the desulfurization effect. In oxidation desulfurization process, the desulfurization time had the greatest influence on the desulfurization effect. In catalytic reduction desulfurization, the reducing agent dosage was the most important factor. The main factor for the results above was that the desulfurization mechanisms were different. Therefore, the research of different desulfurization mechanisms is the main direction of future work. The consequence of this paper would provide data support for the selection of the desulfurization method for high sulfur coal.

Simultaneous removal of SO2 and NOx by potassium-modified carbide slag

The treatment of solid waste carbide slag (CS) poses an urgent challenge in terms of its resolution. This study presented an efficient and cost-effective method for simultaneous desulfurization and denitrification at low temperatures using different modified potassium compounds (KOH, K2CO3, and KHCO3) as adsorbents. The experimental results revealed the significant impact of potassium modification on the performance of the CS, leading to a significant improvement in its denitrification activity while maintaining the same desulfurization effect. The denitrification rates of the modified CS demonstrated increases by 30 % (KOH), 25 % (K2CO3), and 40 % (KHCO3), respectively, compared to the unmodified CS at 200 ℃. The NO adsorption capacities were 2.48 (KOH), 2.24 (K2CO3), and 3.05 (KHCO3) times that of CS, respectively. Subsequent investigations suggested that the potassium modification process induced changes in the microstructure of CS, augmenting the abundance of oxygen vacancies, KOx, C = O, and Oads, thereby enhancing the intensity and quantity of basic sites. This reduced the activation energy of the CS during simultaneous desulfurization and denitrification. In addition, it was observed that certain byproducts formed during the desulfurization and denitrification processes, such as sulfate, sulfite, and nitrate, accumulated on the surface and within the inner pores of the adsorbents, ultimately resulting in a decline in catalytic activity. This study aims to embrace the “treat waste with waste” approach and is expected to provide guidance for the advancement of simultaneous desulfurization and denitrification technologies targeting solid waste CS.

3D printing of hierarchically porous lightweight activated carbon/alumina monolithic adsorbent for adsorptive desulfurization of hydrogenated diesel

Hierarchically porous materials have shown extensive applications in the domain of adsorbing environmental contaminants. Herein, a novel approach utilizing a 3D printing-freeze-drying strategy was presented to successfully design a hierarchically porous lightweight three-dimensional activated carbon/alumina (3D-AC/Al2O3) monolithic adsorbent for adsorptive desulfurization of hydrogenated diesel. 3D-AC/Al2O3 monolithic adsorbents can exhibit superior adsorptive desulfurization performance at room temperature, as well as good cycling performance, thermal and mechanical stability. With incorporating designed 3D-printed liquid redistributor to enhance mass transfer within fixed bed, 3D-AC/Al2O3 can achieve 96.6 % sulfur removal with the sulfur adsorption capacity of 10.13 mg-S/g-Ads for feed oil of high initial sulfur content. Benefited from the hierarchical porous structure to form micron-millimeter scale adsorption micro-channel, feed oil can enter the interior of the monolithic adsorbents and fully contact with the adsorptive active sites to enhance the mass transfer. Furthermore, through the design of the “adsorption-elution” reaction process, it becomes possible to accomplish both the removal of sulfides from feed oil through adsorption and the recovery of value-added sulfides that adsorbed onto the adsorbents. This simultaneous achievement highlights the practical potential for application in this context. Notably, the integrated 3D-AC/Al2O3 adsorbent exhibited promising desulfurization effects for application of real hydrogenated diesel.

Investigation into the Enhancement of Gas-Liquid Mass Transfer of Absorption of H2S by MDEA with Carbon Quantum Dots.

Although the addition of fine particles can enhance mass transfer, the stability of suspension is still a challenge. Responding to this, this study introduced carbon quantum dots (CQDs) with good hydrophilicity into a desulfurizer. N-doped carbon quantum dots (N-CQDs) were prepared by the hydrothermal method and characterized by TEM, FT-IR, and XPS. The stability and rheological properties of MDEA-based CQD solutions with different concentrations were studied. CQD solutions with low concentrations showed good stability, and the viscosity of CQD solutions was positively correlated with concentration and inversely correlated with temperature. The desulfurization experiment showed that the desulfurization effect and mass transfer enhancement of MDEA-based CQD solutions were coinfluenced by the viscosity and concentration of the solution; 0.01 vol % CQD solution had the best desulfurization effect, and the mass transfer coefficient was 0.66 mol/(m3h kPa), which increased by 26.61% compared to the base solution.

Efficient immobilization of acids into activated carbon for high durability and continuous desulfurization of diesel fuel

AbstractFuel contaminants are the most critical issues in human health, cars' engines life and performance, and refinery equipment, and have an ultimate consecutive economic negative impact over time. Nowadays, sulfur is considered as one of the most dangerous contaminants in fuel, and different approaches have been carried out for desulfurization processing. In this study, new modified activated carbon (AC) for adsorptive diesel fuel desulfurization is carried out. To increase the robustness and effectiveness of a continuous adsorptive desulfurization (ADS) process, the study provides a new surface modification technique of the AC. Real diesel fuel (RDF, sulfur content 7510 ppm) and model diesel fuel (MDF, dibenzothiophene content 637 ppm) were used in a series of ADS tests carried out in a fixed‐bed adsorption column under atmospheric pressure and temperature. To achieve zero emissions of diesel fuel, the process parameters were optimized using the experimental findings. The AC and modified AC were tested via Brunauer–Emmett–Teller and Fourier Transform Infrared to evaluate the effect of the modification process on adsorbent characterization. The liquid hourly space velocity of the feedstock, the height of the absorber bed, and the kind of AC were the optimization parameters. In these circumstances, the ADS procedure was examined to address the impact of the feedstock flow rate on the effectiveness of ADS. The sulfur removal efficiency was 85.3% for RDF and 94% for MDF at 9 cm bed height, 8 h−1 LSHV, and 10 g bed weight, respectively. This is the first time that AC has been used to examine the stability of continuous ADS and to examine how acid immobilization affects sulfur removal. The investigation showed that the modified AC had a high rate of stability and was effective in the continuous ADS process. The spent modified AC was regenerated via a solvent extractive regeneration process to evaluate the durability of the ACs. The results proved that the regeneration performance of various solvents for modified activated carbon 1 decreases as follows: iso‐octane > ethanol > methanol > acetonitrile.