scholarly journals Oxidative Extractive Desulfurization System for Fuel Oil Using Acidic Eutectic-Based Ionic Liquid

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1050
Author(s):  
Sarrthesvaarni Rajasuriyan ◽  
Hayyiratul Fatimah Mohd Zaid ◽  
Mohd Faridzuan Majid ◽  
Raihan Mahirah Ramli ◽  
Khairulazhar Jumbri ◽  
...  

The biggest challenge faced in oil refineries is the removal of sulfur compounds in fuel oil. The sulfur compounds which are found in fuel oil such as gasoline and diesel, react with oxygen in the atmosphere to produce sulfur oxide (SOx) gases when combusted. These sulfur compounds produced from the reaction with oxygen in the atmosphere may result in various health problems and environmental effects. Hydrodesulfurization (HDS) is the conventional process used to remove sulfur compounds from fuel oil. However, the high operating conditions required for this process and its inefficiency in removing the organosulfur compounds turn to be the major drawbacks of this system. Researchers have also studied several alternatives to remove sulfur from fuel oil. The use of ionic liquids (ILs) has also drawn the interest of researchers to incorporate them in the desulfurization process. The environmental effects resulting from the use of these ILs can be eliminated using eutectic-based ionic liquids (EILs), which are known as greener solvents. In this research, a combination of extractive desulfurization (EDS) and oxidative desulfurization (ODS) using a photocatalyst and EIL was studied. The photocatalyst used is a pre-reported catalyst, Cu-Fe/TiO2 and the EIL were synthesized by mixing choline chloride (ChCl) with organic acids. The acids used for the EILs were propionic acid (PA) and p-toluenesulfonic acid (TSA). The EILs synthesized were characterized using thermogravimetry analyser (TGA) differential scanning calorimetry (DSC) analysis to determine the physical properties of the EILs. Based on the TGA analysis, ChCl (1): PA (3) obtained the highest thermal stability whereas, as for the DSC analysis, all synthesized EILs have a lower melting point than its pure component. Further evaluation on the best EIL for the desulfurization process was carried out in a photo-reactor under UV light in the presence of Cu-Fe/TiO2 photocatalyst and hydrogen peroxide (H2O2). Once the oxidation and extraction process were completed, the oil phase of the mixture was analyzed using high performance liquid chromatography (HPLC) to measure the sulfur removal efficiency. In terms of the desulfurization efficiency, the EIL of ChCl (1): TSA (2) showed a removal efficiency of about 99.07%.

2020 ◽  
Vol 1002 ◽  
pp. 423-434 ◽  
Author(s):  
Muayad A. Shihab ◽  
Amer Talal Nawaf ◽  
Shaho A. Mohamedali ◽  
Mazin N. Alsalmaney

This work was focused on the removal of sulfur compounds via adsorption process from heavy naphtha using alkali agents-activated carbon nanotubes (ACNTs). Commercial CNTs were activated using three alkali agents (KOH, NaOH, and CaCl2) to amend their surfaces for application in the petroleum industry. The characterization of the physicochemical properties of as-received CNTs and CNTs/alkali agents was performed using a scanning electron microscope (SEM), N2 adsorption/desorption isotherm, and Fourier transform infrared spectroscopy (FTIR). The effects of three operating conditions including adsorbent dosage (1-3 g), agitation speed (330-1500 rpm), and contact time (30-70 min) on the removal efficiency of sulfur compounds at constant pressure and temperature were investigated. Studying of the removal efficiency at different operating conditions was adopted to effectively evaluate the surface modifications of adsorbents on the present process. The specific surface areas of the CNTs were found to be increased upon treatment with alkali agents especially KOH and NaOH. SEM images demonstrated the formation of many defects on the CNTs surface due to the strong etching effect of both alkali agents KOH and NaOH. FTIR spectra showed different relative intensities around band 3440 cm-1 for CNTs/KOH and CNTs/NaOH which was potentially attributed to the presence of hydroxyl functional groups. The sulfur removal experiments from heavy naphtha (initially had a sulfur concentration of 350 ppm) showed that the largest sulfur removal efficiency and adsorption capacity were 69.6% and 6.6 mg/g adsorbent respectively and obtained with CNTs/KOH which presented a superior adsorption efficiency over others. The highest sulfur removal efficiency was gained at adsorbent dosage=3 g, agitation speed=1500 rpm, and contact time=70 min. The study of adsorption kinetics demonstrated that the adsorption of organosulfur compounds from heavy naphtha obeyed the pseudo-second order kinetics


Author(s):  
Waqas Ahmad

This chapter describes the occurrence of organosulfur compounds in petroleum, their detrimental effects and various techniques for removal of these compounds. The sole commercial desulfurization process i.e. HDS is broadly discussed in terms of reaction conditions, different types of catalysts used, reactor design and mechanistic pathways in the process. The shortcomings of HDS and needs for developing new desulfurization techniques is also described. Various newly developed research techniques for desulfurization are also discussed with their technical backgrounds, commercial overview, advantages and shortcomings in the light of literature reports. These techniques include, Adsorptive desulfurization, Bio-desulfurization, Precipitative desulfurization, and Oxidative desulfurization with its sub types like ODS using H2O2- Polyoxometalates (POM), ODS with Ionic liquids, Photo-oxidative desulphurization and Ultrasound Assisted ODS.


Author(s):  
Jie Zhao ◽  
Rui Wang

: The removal of sulfur compounds from fuel oil has been a major concern of the fuel industry. Hydrodesulfurization (HDS) is the most common desulfurization method currently used in oil refineries. However, HDS requires high temperature and high pressure conditions, consumption of hydrogen, and the removal effect of thiophene sulfides is not ideal. In view of defects of HDS, non-hydrodesulfurization technologies have been developed. Oxidative desulfurization (ODS) is regarded as the most potential desulfurization technology to replace HDS in industrial because of mild operating conditions and high desulfurization efficiency. However, most ODS reactions are performed in heterogeneous systems, the common problem is that the oxidant and sulfur-containing compounds cannot contact effectively. Phase Transfer Catalysts (PTCs) are a class of catalysts that can assist in the transfer of reactants, thereby increasing mass transfer and accelerating the reaction rate of the heterogeneous ODS system. In this review, we divide PTCs applied to ODS into quaternary ammonium salts PTCs, ILs PTCs, polymers PTCs, supported PTCs and reaction-controlled PTCs, and will systematically introduce and summarize the research progress of PTCs used in ODS system. It is pointed out that reaction-controlled PTCs have a broad prospect in ODS system. In addition, the synthesis and recovery of PTCs will be briefly described.


2021 ◽  
Vol 15 (3) ◽  
pp. 414-422
Author(s):  
Serhiy Pyshyev ◽  
◽  
Bohdan Korchak ◽  
Denis Miroshnichenko ◽  
Bemgba Bevan Nyakuma ◽  
...  

In the article the chemistry of the noncatalytic oxidative desulfurization process of distillate oil fractions is analyzed. The study involves the characteristics of high-sulfur straight-run diesel fraction of narrow composition (593–623 K) before and after oxidation by air at 453–493 K and a pressure of 3.0 MPa. The composition of sulfur compounds in the raw material fraction was determined. It is shown that straight-run fractions of raw materials may also contain sulfoxides, which are products of oxidation of organosulfur compounds and are formed during storage of petroleum products. On the basis of IR spectroscopic studies of raw materials, oxidized products and model mixtures, the transformation depth of fr. 593–623 K sulfur compounds, which are distributed in the form of sulfones and sulfoxides in solid and liquid oxidation products, and partially remain in the purified fuel, was analyzed in the above-mentioned process.


2019 ◽  
Vol 70 (5) ◽  
pp. 1507-1512
Author(s):  
Baker M. Abod ◽  
Ramy Mohamed Jebir Al-Alawy ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).


2014 ◽  
Vol 703 ◽  
pp. 171-174
Author(s):  
Bing Wang ◽  
Yi Xiao ◽  
Shou Hui Tong ◽  
Lan Fang ◽  
Da Hai You ◽  
...  

Improved step-feed de-nitrification progress combined with biological fluidized bed was introduced in this study. The progress had good performance and capacity of de-nitrification and organic matter. The experiment result showed that the de-nitrification efficiency of the improved biological fluidized bed with step-feed process was higher than the fluidized bed A/O process under the same water quality and the operating conditions. When the influent proportion of each segment was equal, the system showed good nitrogen removal efficiency with the change of influent C/N ratio, HRT and sludge return ratio. The removal rate of TN reached up to 88.2%. It showed that the simultaneous nitrification and de-nitrification phenomenon happened in the aerobic zone. The nitrogen removal mechanism was also studied.


2016 ◽  
Vol 75 (3) ◽  
pp. 619-628 ◽  
Author(s):  
Melike Isgoren ◽  
Erhan Gengec ◽  
Sevil Veli

This paper deals with finding optimum reaction conditions for wet air oxidation (WAO) of malathion aqueous solution, by Response Surface Methodology. Reaction conditions, which affect the removal efficiencies most during the non-catalytic WAO system, are: temperature (60–120 °C), applied pressure (20–40 bar), the pH value (3–7), and reaction time (0–120 min). Those were chosen as independent parameters of the model. The interactions between parameters were evaluated by Box-Behnken and the quadratic model fitted very well with the experimental data (29 runs). A higher value of R2 and adjusted R2 (>0.91) demonstrated that the model could explain the results successfully. As a result, optimum removal efficiency (97.8%) was obtained at pH 5, 20 bars of pressure, 116 °C, and 96 min. These results showed that Box–Behnken is a suitable design to optimize operating conditions and removal efficiency for non-catalytic WAO process. The EC20 value of raw wastewater was measured as 35.40% for malathion (20 mg/L). After the treatment, no toxicity was observed at the optimum reaction conditions. The results show that the WAO is an efficient treatment system for malathion degradation and has the ability of converting malathion to the non-toxic forms.


2007 ◽  
Vol 54 (6) ◽  
pp. 444-448 ◽  
Author(s):  
N. A. Zroichikov ◽  
M. G. Lyskov ◽  
V. B. Prokhorov ◽  
E. A. Morozova

1985 ◽  
Vol 107 (3) ◽  
pp. 744-757 ◽  
Author(s):  
J. Bellan ◽  
S. Elghobashi

In this review, literature relevant to the problems of deposits and corrosion in industrial/commercial furnaces and boilers is analyzed, and the facts are synthesized into a picture that addresses corrosion problems expected with the use of unconventional fuels. Corrosion is found to depend greatly on the phenomena occurring during the combustion of fuel-oil sprays introduced into the furnace. In a first step, the drops that form the spray heat up and evaporate in a way that closely resembles a batch distillation process. Eventually, ignition and combustion occur with the subsequent change of the liquid fuel drops into carbonaceous, porous, sphere-like particles called cenospheres. In a second step, these cenospheres burn and the products of this combustion step determine the majority of the deposits on metal surfaces. This observation is very important since nonvolatile, non-combustible, corrosive trace compounds existing in the initial fuel-oil drop will have a much higher concentration in the cenosphere than in the original fuel. Accordingly, it is recommended that the theoretical and experimental study of oil spray combustion, cenosphere formation, and cenosphere combustion in a cloud of cenospheres receive a very high priority. Corrosion by gases is found to be unimportant. Deposits are found to be much more corrosive when in liquid form, although corrosion by solid deposits is by no means negligible. As a result, it is suggested in the study that corrosion on highly polished metal surfaces should be studied in order to evaluate the potential of this method of inhibiting deposition and thus hindering corrosion. Recent advances in the theory of deposition from combustion gases are also outlined in this study. The literature survey shows that the main corrosion-causing fuel constituents present in unconventional fuels are sulfur, alkali, vanadium, carbon and carbon monoxide, iron, and chloride. It is found that sometimes one of these compounds might act as a catalyst in corrosive reactions initiated by another compound, and therefore great care must be taken to identify the corrosion-causing compound in the deposits on metal surfaces. It is also found that in some cases a corrosive compound will inhibit the corrosive action of another corrosive compound. It is recommended that such situations be studied further so as to investigate the possibility of an optimum concentration of two such corrosive compounds that would minimize metal wastage. The problem of performing meaningful corrosion experiments is also addressed in this report and specific recommendations are made to achieve this goal. Finally, the effects of additives and the furnace operating conditions are discussed, and potential problems with both additives and new operating conditions are mentioned. The recommendations at the end of this study present a comprehensive set of areas to be investigated in order to better understand and be able to mitigate corrosion problems associated with unconventional fuels. High-priority experimental and theoretical studies are also outlined.


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