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A novel encapsulated deep eutectic solvent (DES) was introduced for biodiesel production via a two-step process. The DES was encapsulated in medical capsules and were used to reduce the free fatty acid (FFA) content of acidic crude palm oil (ACPO) to the minimum acceptable level (

The feasibility of artificial intelligence (AI) as a predictive model for thorough efficacy analysis on environmental pollution applied on mangrove forests are discussed. Mangrove forests are among the most productive and biological diverse ecosystems on the planet. However, due to environmental pollution and climate change, mangrove forests are in serious decline. Despite crucial issues pertaining mangrove forests, the law enforcement on the ecosystem is still dubious due to the lack of evidence and data that could provide accurate analysis and prediction. The main highlight of this review elaborates on pollutant markers in soil, water, and air, by correlating these three aspects to the sustainability of mangrove ecosystem. The research gap identified from this review suggests the application of an integrated environmental prediction system for practical environmental insights. A predictive model for environmental decision-making could be developed by integrating meteorological, climatological, hydrological, atmospheric, and heavy metal concentration to understand the interaction between each factor for an efficient solution of pollutant reduction scheme involving mangrove ecosystems.

Separation of styrene from ethylbenzene is challenging because of their close boiling points and similar chemical characteristics. In this study, we utilized three ammonium-based deep eutectic solvents (DESs) with glycols as hydrogen bond donors to separate styrene from ethylbenzene via liquid-liquid extraction at room temperature and atmospheric pressure, with styrene concentration in the feed mixture ranging from (10 to 80) wt%. Consistency of the experimental data was ascertained by Othmer-Tobias and Hand correlations, and the NRTL binary interaction parameters were also validated for thermodynamic consistency. Distribution ratios of styrene were found to be comparable to that obtained using ionic liquids, although the selectivity values were much lower. The ternary liquid-liquid equilibria for the systems {ethylbenzene (1) + styrene (2) + DES (3)} were correlated with the NRTL model and predicted using the COSMO-RS approach. The average RMSD from the experimental data for NRTL correlation is 1.41% and for COSMO-RS prediction is 4.74%.

Climate engineering solutions with emphasis on CO2 removal remain a global open challenge to balancing atmospheric CO2 equilibrium levels. As a result, warnings of impending climate disasters are growing every day in urgency. Beyond ordinary CO2 removal through natural CO2 sinks such as oceans and forest vegetation, direct CO2 conversion into valuable intermediaries is necessary. Here, a direct electrosynthesis of the peroxydicarbonate anion (C2O62–) was investigated by the reaction of CO2 with the superoxide ion (O2·–), electrochemically generated from O2 reduction in bis(trifluoromethylsulfonyl)imide [TFSI–] anion derived ionic liquid (IL) media. This is the first time that the IL media were employed successfully for CO2 conversion into C2O62–. Moreover, the charge transfer coefficient for the O2·– generation process in the ILs was less than 0.5, indicating that the process was irreversible. Voltammetry experiments coupled with global electrophilicity index analysis revealed that, when CO2/O2 was contac...

Deep eutectic solvents (DESs) are green solvents developed as an alternative to conventional organic solvents and ionic liquids to extract nitrogen compounds from fuel oil. DESs based on p-toluenesulfonic acid (PTSA) are a new solvent class still under investigation for extraction/separation. This study investigated a new DES formed from a combination of tetrabutylphosphonium bromide (TBPBr) and PTSA at a 1:1 molar ratio. Two sets of ternary liquid&ndash, liquid equilibrium experiments were performed with different feed concentrations of nitrogen compounds ranging up to 20 mol% in gasoline and diesel model fuel oils. More than 99% of quinoline was extracted from heptane and pentadecane using the DES, leaving the minutest amount of the contaminant. Selectivity was up to 11,000 for the heptane system and up to 24,000 for the pentadecane system at room temperature. The raffinate phase&rsquo, s proton nuclear magnetic resonance (1H-NMR) spectroscopy and GC analysis identified a significantly small amount of quinoline. The selectivity toward quinoline was significantly high at low solute concentrations. The root-mean-square deviation between experimental data and the non-random two-liquid (NRTL) model was 1.12% and 0.31% with heptane and pentadecane, respectively. The results showed that the TBPBr/PTSADES is considerably efficient in eliminating nitrogen compounds from fuel oil.

Deep eutectic solvents (DESs) are green solvents developed as an alternative to conventional organic solvents and ionic liquids to extract nitrogen compounds from fuel oil. DESs based on p-toluenesulfonic acid (PTSA) are a new solvent class still under investigation for extraction/separation. This study investigated a new DES formed from a combination of tetrabutylphosphonium bromide (TBPBr) and PTSA at a 1:1 molar ratio. Two sets of ternary liquid–liquid equilibrium experiments were performed with different feed concentrations of nitrogen compounds ranging up to 20 mol% in gasoline and diesel model fuel oils. More than 99% of quinoline was extracted from heptane and pentadecane using the DES, leaving the minutest amount of the contaminant. Selectivity was up to 11,000 for the heptane system and up to 24,000 for the pentadecane system at room temperature. The raffinate phase’s proton nuclear magnetic resonance (1H-NMR) spectroscopy and GC analysis identified a significantly small amount of quinoline. The selectivity toward quinoline was significantly high at low solute concentrations. The root-mean-square deviation between experimental data and the non-random two-liquid (NRTL) model was 1.12% and 0.31% with heptane and pentadecane, respectively. The results showed that the TBPBr/PTSADES is considerably efficient in eliminating nitrogen compounds from fuel oil.

Removal of nitrogen compounds is an essential process in the fuel processing industry. In this work, the extraction performance of 1-ethyl-3-methylimidazolium methanesulfonate ([Emim][MeSO3]) ionic liquid in removing pyrrole, indoline, pyridine and quinoline from cyclohexane is investigated. The ternary liquid-liquid equilibria for four systems containing [Emim][MeSO3] + pyrrole/indoline/pyridine/quinoline + cyclohexane were predicted using COSMO-RS and validated experimentally at 298.15 K under atmospheric pressure, with feed concentrations of nitrogen compounds ranging from 5 to 50 wt%. Othmer-Tobias and Hand correlations confirmed the consistency of the experimental data. The tie-lines obtained experimentally and predicted with COSMO-RS were in good agreement. Additionally, the non-random two-liquid (NRTL) model was successfully employed to correlate the experimental tie-lines. The effects of basicity of nitrogen compounds toward extraction efficiency were also investigated. The selectivity and distribution ratio results demonstrated the suitability of [Emim][MeSO3] as an extraction solvent for removing nitrogen compounds from fuel. Finally, the multicomponent extraction confirmed the performance of [Emim][MeSO3] for extractive denitrogenation. In all ternary systems investigated in this work, the concentration of cyclohexane in the extract phase was very small and the presence of the IL in the raffinate phase was negligible indicating minimum cross contamination between the extract and raffinate phases.

In this study, the COSMO-RS approach was used to qualitatively and quantitatively screen five choline chloride-based deep eutectic solvents (DESs) to separate the azeotropic binary formed between benzene and either methanol or ethanol. The activity coefficient at infinite dilution was calculated to evaluate the capacity, selectivity, and performance index of each DES. The interactions between the different species were also analyzed by interpreting the σ-profile and σ-potential of each component. Then, three DESs were selected for experimental validation. They were prepared by combining choline chloride with ethylene glycol, levulinic acid, and 1,2-propanediol. The best performance in terms of distribution ratio and selectivity was achieved with choline chloride/ethylene glycol DES with 1:4 molar ratio. The experimental tie-lines were successfully correlated using the NRTL model. Regardless of the system investigated, no DES was found in the raffinate phase, implying minimal cross-contamination. Finally, ...

Derived from inherent safety concept, inherent health is a new approach that aims to unearth proactive, fundamental, and permanent solutions that could eliminate or significantly reduce health risks at source, thus avoiding adding extensive end-of-pipe protections. To date, however, limited attention has been given to using this new approach to prevent Sick Building Syndrome (SBS), and an assessment tool for quantifying the "sickness" at planning stage is yet to be established. To this end, this work investigated the feasibility of addressing SBS via Inherent Health Oriented Design (IHOD) and developed SBS Contributory Indices (SBSCI) for quantifying the sickness severity. Firstly, the contributory indices were extracted from a well-practiced checklist of SBS determinants. Then, the indices were reconciled using Analytic Hierarchy Process (AHP) and equation-based Bayesian Networks (BN), and finally, the newly developed metric (i.e., SBSCI) was exemplified by a case study. The results show that the sickness level decreased by approximately 82% after IHOD modifications, implying that the modified architectural design can be less sick (inherently healthier) than the baseline design. This work presents a nexus study between the implications of "inherent" solutions and healthy buildings. This cross-cutting study would offer a new perspective on the early inspection and prevention for sick building induced health problems.

Suppressing the nucleophilic susceptibility of ionic liquids based nanofluid is necessary for energy storage and superoxide ion (O2•−) utilization. This study reports the development of novel pseudocapacitive Fe/Ru-SiMWCNT nanofluid comprising of Fe3O4, RuO2, SiO2, and MWCNT hybridized phases. The Fe/Ru-SiMWCNT nanohybrid possessed CO2 and O2 sorption capability, as confirmed from the temperature-programmed desorption experiments. Detailed spectroscopy techniques characterize the Fe/Ru-SiMWCNT nanohybrid component's physicochemical and morphological properties. The novel ionic liquid (IL) based nanofluid index is Fe/Ru-SiMWCNT/1-(2-methoxyethyl)-1-methylpyrrolidinium tris(pentafluoroethyl) trifluorophosphate. Therefore, stable O2•− was generated therein at −0.445 V vs Ag/AgCl and recorded long-term stability for 2 days with 87.31 % efficiency. Moreover, the O2•− mediated CO2 conversion to C2O62− at −0.54 V vs Ag/AgCl with 97.90 % energy efficiency. Also, the normalized exchange current density in the nanofluid was 2.20 mA/cm2, which is higher than 1.94 mA/cm2 observed in the IL counterpart. The high normalized exchange current density is due to Fe/Ru-SiMWCNT nanohybrid phase's pseudocapacitance. Accordingly, this pseudocapacitive capability enables converting O2 and CO2 in the nanofluid with lower activation overpotential of −0.305 and −0.460 V vs Ag/AgCl, respectively. In contrast, the conversion of O2 and CO2 in the IL required higher activation overpotential of −0.826 and −1.013 V vs Ag/AgCl, respectively. The electrolysis of O2/CO2 in the nanofluid containing diethanolamine at −1.564 V vs Ag/AgCl, 60 °C and 1.0 h produced methyl 2-hydroxyethyl (methyl) carbamate as the primary product. The heteronuclear multiple bond correlation spectroscopy analysis finally elucidated the carbamate structure by two strong correlations between the protons and carbons in the vicinity of three and four bonds apart. Therefore, this study highlights the control design of electrochemically stable IL-based nanofluids robust for reactive oxygen species, energy storage and conversion.

Separation of azeotropic mixtures is a topic of great industrial interest. In this work, liquid-liquid extraction using deep eutectic solvents (DESs) is explored to separate binary azeotropic mixtures of ethanol and n-hexane, n-heptane or n-octane. Ten DESs were screened using the COSMO-RS approach by predicting the activity coefficient at infinite dilution, γ∞ of ethanol and n-alkanes in each DES. Then, three DESs were selected for experimental validation where Tetrabutylammonium bromide/Levulinic acid (TBAB/LA) with a molar ratio (1:2) gave the best extractive performance for all systems. Ternary liquid-liquid extraction experiments were conducted at room temperature with this DES. It was found that the tie-lines of all systems have positive slopes, indicating that a small amount of solvent is required to extract ethanol. Moreover, the distribution ratio and selectivity values are all greater than unity and the DES was not detected in the raffinate phase which indicate minimal cross-contamination between extract and raffinate phases. Finally, COSMO-RS predictions of the ternary tie-lines were in excellent agreement with experimental data, with an average RMSD value of 1.65%. The experimental data were also successfully correlated with NRTL model with an average RMSD value of 1.50%.

The efficacy of inherent safety interventions for shaping Friendlier Chemical Processes (FCP) has been demonstrated in simultaneously augmenting safety (S), health (H), and environmental (E) performance while operating economically. However, there is limited attention to linking inherent safety concept with HE and cost issues when modifying process design, and a hierarchical metric used for measuring the inherent friendliness is yet to be presented. To this end, this study developed a Reconciled Friendly Process Metric (RFPM) for generating FCP via Systematic Inherent Safety (SIS) modifications. Firstly, the prestigious inherent SHE and cost metrics were selected and adapted to measure friendliness features. Then, the metrics were reconciled by Analytic Hierarchy Process (AHP) and Fuzzy Comprehensive Evaluation (FCE), and finally, the RFPM was validated through biodiesel production process. The results show that the base design is estimated as under Moderate (M) condition, while the modified design is estimated as under Relatively Friendly (RF) condition, which implies that the modified design is inherently friendlier than the base design. This newly developed RFPM can be used as a tool for hierarchically indicating the friendliness of processing scenarios and making trade-offs among safety, health, environmental, and cost concerns during design stage.

Since the inception of inherent safety in the 1970s, impressive progress has been made in using it to shape Friendlier Chemical Processes (FCP) which are largely characterized by proactive and simultaneous augmentation in safety, health, environment, and economic performance. However, a comprehensive survey on its temporal accomplishments over the past four decades is yet to be presented. Especially, the methodologies, typical implementation frameworks, and selection guidelines for the numerous Inherent Safety Metrics (ISMs) remain to be further elucidated. In this context, this work investigates the development spectrum of inherent safety with a primary focus on the ISMs in chemical processes. Firstly, the basic cognition for inherent safety is encapsulated from its origin, early development, principles, implementation stages, and benefits. Subsequently, its current practice for creating FCP is highlighted via synthesizing the implementation spectrum of Inherently Safer Design (ISD), ISMs and selection guidelines, and cost metrics. Meanwhile, the prominent industrial applications in the offshore industry, nuclear industry, dust explosion prevention, and risk-based safety interventions are also presented. Finally, some findings based future research recommendations are concluded as the way forward. In general, this work presents a complete picture of the most concerning contents of inherent safety, which is expected to help researchers and practitioners majoring in chemical process safety to gain a better and faster understanding on its concept and efficacy for shaping FCP.

Of the numerous inherent safety assessment tools, a dynamic metric capable of investigating and incorporating the temporal risk evolution when conducting Inherently Safer Modifications (ISMs) is yet to be established. To this end, this work developed a Dynamic Inherent Safety Metric (DISM) and validated its functionality and viability through a case study. Firstly, the Information-Flow-based Accident-causing Model (IFAM) was adapted to construct the topology of Bayesian Networks (BN). Then, Bayesian deductive reasoning was executed to do crucial risk identification by ranking posterior probabilities. Finally, risk-based ISMs were performed to address the relatively contributing risk factors. The case study results show that the fire and explosion risk decreased by approximately a third after implementing ISMs, thus demonstrating that the modified processing scenario could be inherently safer than the original processing scenario. The newly developed inherent safety metric (i.e., DISM) can assist in temporal risk identification and assessment, and it is expected to function as a novel assessment tool for measuring and comparing the inherent safeness before and after implementing ISMs with simultaneous considerations on the time-varying risk factors.

The generation of superoxide (O2•–) in ionic liquids (ILs) has been used to destroy hazardous materials. In this study, O2•– was used for the oxidative desulfurization of benzothiophene (BT) and dibenzothiophene (DBT) in two ILs as reaction media. The O2•– was released by dissolving potassium superoxide in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [BMPyrr][TFSI] and n-methoxyethyl-n-methylmorpholinium bis(trifluoromethylsulfonyl)imide [MOEMMor][TFSI]. The highest conversion percentages for BT in [MOEMMor][TFSI] and [BMPyrr][TFSI] were 99.4 and 96.6%, respectively, and the highest conversion percentages for DBT in [MOEMMor][TFSI] and [BMPyrr][TFSI] were 98.3 and 94.3%, respectively. As the temperature was increased, the reaction of the O2•– with BT and DBT was enhanced significantly. The BT was converted easier than DBT due to the nucleophilic characteristic of the O2•– and the higher electron density of the sulfur atom in DBT than that in BT. In addition, the ILs had a clear effect o...

This work investigates the use of deep eutectic solvents (DESs) to extract sulfur-based compounds from n-heptane as model diesel compounds. Four DESs were prepared by combining tetrabutylammonium bromide or methyltriphenylphosphonium bromide with ethylene glycol, triethylene glycol, or sulfolane. All DESs showed good ability to extract thiophene with the best extraction efficiency (35%) being observed for the sulfolane-based DES. The extraction efficiency can be further enhanced to reach 98% when five extraction cycles are performed. Moreover, the DESs were easily regenerated using rotary evaporation. In addition,1H NMR analysis is used to elucidate the extraction mechanism. Finally, the COSMO-RS model was used to predict the ternary tie lines for the studied systems and the NRTL model allowed, correlating the experimental data with an average root-mean-square deviation of

Recently, we published the results of screening the performance of 94 deep eutectic solvents (DESs) by COSMO-RS for potential use in the extractive denitrogenation of diesel. In this work and based on our previous predictions, tetrabutylammonium bromide + ethylene glycol and tetrabutylphosphonium bromide + ethylene glycol DESs at molar ratio 1:2 were explored experimentally for the removal of pyrrole, pyridine, indoline and quinoline from a model diesel compound, n-hexadecane. Ternary (liquid + liquid) equilibrium experiments were conducted at room temperature with nitrogen concentrations in the feed ranging from (5 to 50) wt%. 1H NMR spectroscopy was used for compositional analysis of the extract and raffinate phases. No amount of the solvent in the raffinate phases was detected; indicating minimal cross contamination. Also, it was found that all systems exhibit Type I phase behavior with positive slopes which indicate that small amount of solvents is required to remove the nitrogen compounds. Moreover, the distribution ratio and selectivity values are all greater than unity with higher values reported for non-basic nitrogen compounds. COSMO-RS predictions of the ternary tie lines were in good agreement with experimental data with average RMSD value of 2.51%. The experimental data were also well correlated with NRTL model with average RMSD value of 0.60%.

The accomplishments of inherent safety in the field of loss prevention thus far are impressive due to its scientific philosophy: reducing risks at source rather than adding engineered and procedural protections. Generally, the implementation of inherent safety can be done through a cohesive set of fourteen principles elucidated by Kletz and Amyotte. This work, guided by the fourteen principles, presents a systematic review on the implementation methodologies of inherent safety. Firstly, PRISMA procedure was adopted to select eligible literatures according to inclusive and exclusive criteria. After obtaining the selected literatures, the preference, level of application, and gaps in using these principles were critically analyzed. Of the fourteen principles, intensification, substitution, attenuation, simplification, limitation of effects, and avoidance of knock-on effects are preferable to implementing inherent safety in chemical process. Although the remaining principles are also potentially useful, they are not commonly used due to their costs and complexities of implementation. Overall, this work presents a complete spectrum to look across the implementation methodologies of inherent safety and concludes with some holistic and inclusive approaches as future research recommendations.

As a proactive safeguard, inherent safety has been regarded as the top hierarchy for loss prevention and risk management due to its salient features in eliminating or significantly reducing risks at source rather than mitigating them by add-on protections. Simultaneously, various assessment tools have been developed for ranking and selecting inherently safer designs or modifications. However, there still lacks a metric that can systematically incorporate various hazardous factors, which may hinder most industries from utilizing it to a full extent. To address this limitation, this work developed a Systematic Inherent Safety Metric (SISM) for measuring the inherently safer modifications. Firstly, the conceptual framework of SIS was proposed based on 5M1E (man, machine, material, method, measurement, and environment). Subsequently, analytic hierarchy process and fuzzy comprehensive evaluation were adapted to conduct risk identification and assessment. Finally, taking chlorine liquefaction process as a case study, the applicability and efficacy of SIS were validated based on PDCA (plan-do-check-action) cycle. The results show that the SISM value has improved from the relatively dangerous (RD) to the relatively safe (RS) after implementing SIS, thus demonstrating that the revised design is inherently safer than the base design.

1-Ethyl-3-methylimidazolium ethyl sulfate ([EMIM][EtSO4]), 1-ethyl-3-methylpyridinium ethyl sulfate ([EMPY][EtSO4]) and 1-ethyl-3-methylimidazolium methanesulfonate ([EMIM][MeSO3]) ionic liquids were investigated to remove pyrrole, indoline, pyridine and quinoline nitrogen compounds from n-hexadecane. Twelve sets of ternary liquid–liquid equilibrium experiments were conducted at room temperature and atmospheric pressure with feed concentrations of nitrogen compounds ranging between 5 and 50 wt%. The ternary phase diagrams for all systems show positive slope, indicating that small amount of solvent is sufficient to remove the nitrogen compounds. Based on the values of distribution coefficient and selectivity, all three ionic liquids are potential solvents for removal of nitrogen compounds, but more effective in removing 5-membered compounds (pyrrole, indoline) than 6-membered compounds (pyridine and quinoline). COSMO-RS predictions of the ternary tie-lines were in good agreement with experimental results (RMSD

Ternary liquid-liquid equilibria for four systems containing ionic liquids {1-ethyl-3-methylimidazolium ethylsulphate ([EMIM][EtSO4]) and 1-ethyl-3-methylpyridinium ethylsulphate ([EMPY][EtSO4])}(1)+pyrrole/pyridine(2)+isododecane (3) have been determined at 298.15 K. The solute distribution coefficient and selectivity were calculated from experimental LLE data. All systems showed high distribution coefficient and selectivity values at the entire range of pyrrole or pyridine in feed. The consistency of experimental data was ascertained by applying the Othmer-Tobias and hand equations. Furthermore, the experimental LLE data have been compared and correlated using COSMO-RS, NRTL and UNIQUAC models. The influence of aromatic structure without inside ring of cation has a significant role on denitrification process at 298.15 K.

(Liquid + liquid) extraction of ethylbenzene from n-octane by using tetrabutylammonium bromide-based deep eutectic solvents (DESs) containing pyridine, ethylene glycol, or a mixture of both complexing agents was investigated at 25 °C and atmospheric pressure. The performance of each DES was determined from the distribution ratio and selectivity values calculated using experimental (liquid + liquid) equilibrium data of the ternary systems ethylbenzene + n-octane + DESs. The DES with only ethylene glycol had a high selectivity but a low distribution ratio, whereas the DES with only pyridine had a high distribution ratio but a low selectivity. For the other DESs, adding pyridine increased the distribution ratio, and increasing the molar ratio of ethylene glycol increased the selectivity. Generally, whenever the selectivity increased, the distribution ratio decreased, and vice versa. The nonrandom two-liquid model was used to correlate the experimental data, and the average root mean square deviation (RMSD) between correlated and experimental tie lines was 1.4%. Moreover, the Conductor-like Screening Model for Real Solvents was successfully used to predict the ternary tie lines for the studied systems with an average RMSD of 3.7%.

The predictive Soave–Redlich–Kwong (PSRK) model was applied to predict CO 2 solubility in imidazolium-based ionic liquids containing bis(trifluoromethylsulfonyl)imide [Tf 2 N], tetrafluoroborate [BF 4 ], and hexafluorophosphate [PF 6 ] anions. The UNIFAC PSRK matrix was extended to include these new groups. Binary interaction parameters were obtained by regressing experimental vapor–liquid equilibrium data available in the literature. Experimental data were subjected to a consistency test, and only consistent data were considered during the regression. The model predictions showed satisfactory agreement with the experimental data at pressures up to 5 MPa, with an overall root mean square deviation (RMSD) of 0.31. The prediction ability of the model was tested for ionic liquids containing long alkyl chains, exhibiting an overall RMSD of 0.40. The results indicated that the PSRK model provides a reasonable prediction of CO 2 solubility in ionic liquids at pressures not in the vicinity of the critical pressures of CO 2 and ionic liquids.

A total of 94 deep eutectic solvents (DESs) based on different combinations of salt cation, anion, hydrogen-bond donor (HBD) and salt:HBD molar ratio are screened via the conductor-like screening model for real solvents for potential use in the extractive denitrification of diesel. Five nonbasic and six basic nitrogen compounds were included in this study. The activity coefficient at infinite dilution, γ∞, of each nitrogen compound in the DESs was predicted; and the values are used to screen the DESs on the basis of selectivity, capacity, and performance index at infinite dilution (S∞, C∞, and PI). The extraction of nitrogen compounds using DES is driven by hydrogen-bonding interaction. It was found that nonbasic compounds report higher S∞ and C∞ than basic compounds. Ammonium-based DESs give higher S∞ but phosphonium-based DESs report higher C∞. DESs combined with Cl– anion give higher S∞, but those with Br– anion report higher C∞. DESs with alcohol- and amide-based HBDs give higher S∞ but HBDs with carb...

Requirement to produce Ultra Low Sulphur Diesel is becoming more stringent with the target of zero emission. The presence of nitrogen compound in crude oil is undesirable because it inhibits the efficiency of desulphurisation process besides being environmentally hazardous when found in transportation fuels. Extractive denitrification with ionic liquids (ILs) as solvents has been found to be applicable for denitrification but more insights are required to explain the interaction between ILs and nitrogen compounds. In this study, the interaction between pyrrole as model nitrogen compound with 18 ILs built from 6 cations and 3 anions is investigated by means of quantum chemical calculation. Geometry optimisation was done for individual molecules of pyrrole, cations and anions, as well as complexes of ILs, pyrrole–cation, pyrrole–anion, pyrrole–IL at Hartree–Fock level and 6-31G* basis set. NBO analysis was performed from the optimised geometry for each molecule and complex. The interaction between pyrrole and ILs is investigated via HOMO and LUMO energy values and gaps, global scalar properties, interaction energies and partial charges. It was found that [EPY][EtSO4] is the most favourable IL for the removal of pyrrole.

Ab initio method was applied to investigate the interaction between six heterocyclic nitrogen compounds with 18 ionic liquids. Important quantum chemical descriptors like orbital energy values, orbital energy gap, and global scalar properties including hardness, softness, electronegativity, and electrophilicity index were calculated for each individual species, ionic liquid complexes, and complexes of ionic liquid with heterocyclic nitrogen compounds. The effect of interaction energy and partial charge transfer were also investigated for the ion pair and their complexes. COSMO-RS model is used for qualitative screening of the ionic liquids via σ-profile and σ-potential. Comparison between experimental and COSMO-RS predicted ternary tie-lines were done to validate computational method; good agreement was achieved with average RMSD less than 5%. From the results, ILs based on aromatic ring cations combined with either [EtSO4] or [Ac] anion are recommended as solvent for extractive denitrification of liquid ...

The removal of aromatic nitrogen compound from diesel oil is important to produce cleaner fuel and reduce the environmental impact. Therefore, denitrification of diesel oil is carried out by liquid-liquid extraction at ambient and moderate condition. The aim of this work is to study liquid-liquid extraction (LLE) for the mixture of ionic liquids (ILs); 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO4]) and 1-ethyl-3-methylpyridinium ethylsulfate ([EMPy][EtSO4], nitrogen compounds; pyrrole (PYR) and model diesel compound; isododecane (ISOD). The selectivity and solute distribution ratio values were calculated, four ternary diagrams were generated and denitrification efficiency was determined to evaluate the effectiveness of the extraction. The Conductor-like Screening Model for Real Solvents (COSMO-RS) model was used to predict the composition of the ternary systems. The experimental values and COSMO-RS prediction were then compared to determine the root-mean-square deviation (RMSD) for each system. The slope of tie lines is positive for all ternary system and the average RMSD is 2.825 %. The prediction gave RMSD of 1.12 % for [EMIM][EtSO4](1) + Pyrrole(2) + Isodecane(3) system; 2.51 % for [EMPy][EtSO4](1) + Pyrrole(2) + Isodecane(3) system.

Separation of aromatics from aliphatics is a challenging process because of the close range of their boiling points and the formation of several combinations of azeotropes. Until now, no feasible separation process is available for aromatic concentrations below 20 wt%. In this work, we have investigated the possibility of using a selected deep eutectic solvent (DES) for the liquid–liquid extraction of benzene, toluene, ethylbenzene and m-xylene (BTEX) aromatics. The DES used in this work was synthesized by combining tetrabutylammonium salt and sulfolane. Equilibrium data for the ternary system consisting of BTEX aromatics, n-octane and DES were measured at 25 °C and atmospheric pressure. The results showed that the used DESs have comparable distribution ratios and selectivities to those of commercial solvents. In all tested systems, sulfolane was not present in the hydrocarbon layer. It was also found that the selectivity decreases with decreasing polarity of the aromatic compound. The Non-Random Two Liquid (NRTL) model was successfully used to correlate the experimental tie-lines and to calculate the phase compositions of the ternary systems. In addition, the performance of COSMO-RS to predict the ternary tie-lines for the studied systems was evaluated and the σ-profiles were used to explain the interaction between the DES and the aromatic compounds.