Extraction Of Nitrogen Compounds Research Articles

Extraction of Nitrogen Compounds from Tobacco Waste via Thermal Treatment

Alkaloids, typical nitrogen compounds, were found to be abundant in tobacco waste. The recovery of alkaloids from tobacco waste for biological pesticides could reduce the use of traditional chemical pesticides and avoid the pollution of farmland by the leaching of alkaloids from tobacco waste. Considering the fact that alkaloids can easily volatilize, thermal treatment is expected to be a potential technology to achieve the release and recovery of alkaloids from tobacco waste. For better understanding of conversion behavior of nitrogen-containing compounds in tobacco waste during thermal treatment, purge/trap-GC/MS (gas chromatography mass spectrometry), PY-GC/MS (pyrolysis-gas chromatography mass spectrometry), and fixed-bed/ATD-GC/MS (auto-thermal desorption gas chromatography mass spectrometry) were adopted to detect the ingredients and concentration of nitrogen-containing compounds in tobacco waste and/or volatiles. The results of purge/trap-GC/MS showed that nitrogen-containing compounds in tobacco waste could be effectively evaporated at 180 °C in the forms of N-benzyl-N-ethyl-P-isopropyl benzamide, 2-Amino-4-methylphenol, or N-butyl-tert-butylamine. Specifically, N-benzyl-N-ethyl-P-isopropyl benzamide was the main nitrogenous compound in the volatiles of tobacco wastes accordingly. (S)-3-(1-Methyl-2-pyrrolidinyl) pyridine was dominant in N-compounds in pyrolysis condition according to the results of Py-GC/MS. In air atmosphere, with the heating temperature increasing, the concentration of main (S)-3-(1-Methyl-2-pyrrolidinyl) pyridine was firstly increased and then decreased. Besides, the interactions between the released volatiles could be accelerated at a high temperature. Accordingly, these findings suggested that pyrolysis under proper conditions could effectively promote the extraction of alkaloids from tobacco waste.

Extraction of nitrogen compounds from model fuel using 1-ethyl-3-methylimidazolium methanesulfonate

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.

Low-waste ion exchange technology of extraction of nitrogen compounds from water

The processes of sorption of nitrates on a low­base anionite Dowex Marathone from acidic and neutral solutions were researched. It is shown that the application of the anionite in the main form provides effective extraction of nitrates from acidic solutions in the presence of chlorides and sulfates at high values of exchanging dynamic capacity of anionite by nitrates. The use of solutions of ammonia for the regeneration of anionite provides a complete restoration of the capacity of anionite with non­significant remnants of ammonia. Exhausted solutions after the regeneration and neutralization contain mostly ammonium nitrate, therefore they are suitable for the production of liquid fertilizers. It was found that the extraction of the hardness ions from water on the cationites in acidic form increases the exchanging capacity of cationites on ammonium ions. During the process of water treatment it is advisable to use a two­stage cationization while applying sub­acid cationite in acidic form during the first stage and highly­acid cationite also in acidic form. This scheme is reasonable during the water purification with high hydro­carbonate alkalinity. In other case the application of a sub­acid cationite is not effective. It is shown that the cationite in the ammonium form is advisable to regenerate by the solutions of nitric acid, which provides the recycling of exhausted regenerative solutions with obtaining liquid fertilizers. The conceptual technological scheme of a low­waste technology of water purification from nitrogen compounds was designed, based on a two­stage cationization of water on the cationites in acidic form and extraction of anions on the low­base anionite in the main form, which provides an effective extraction of nitrogen compounds from the water.

Extraction of nitrogen compounds from diesel fuel using imidazolium- and pyridinium-based ionic liquids: Experiments, COSMO-RS prediction and NRTL correlation

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 50wt%. 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<5%). The experimental data were also correlated using the NRTL model with excellent agreement (RMSD<1%).

Evaluating the Performance of Deep Eutectic Solvents for Use in Extractive Denitrification of Liquid Fuels by the Conductor-like Screening Model for Real Solvents

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...

Novel simple method for quantitation of nitrogen compounds in middle distillates using solid phase extraction and comprehensive two-dimensional gas chromatography

Nitrogen speciation in crude oil and its fractions has become an important issue due to the undesirable effects of nitrogen compounds during important petroleum refining processes. In this work, a comprehensive two-dimensional gas chromatography method with a nitrogen chemiluminescence detector (GC×GC-NCD) was used for the speciation and quantification of nitrogen compounds in middle distillates. The developed method is based on an extraction of nitrogen compounds from the hydrocarbon matrix followed by their fractionation using solid phase extraction (SPE). Two fractions were collected thus minimizing misidentifications; the first one contained anilines, indoles and carbazoles and the second one contained pyridines, quinolines and acridines. An excellent agreement for total nitrogen content was found between the results obtained with the present method and those from the American Society for Testing Materials (ASTM) method. Good recoveries, repeatability and low detection limits (LOD), in a range from 10 to 20μgL−1, were also achieved.

Removal of Nitrogen Compounds before Deep Hydrotreatment of Synthetic Crude Oils

Synthetic crude oils (SCOs) derived from oil shale, coal, and oil sands contain relatively large amounts of heteroatoms such as nitrogen and sulfur, and severe hydrorefining conditions are necessary to convert SCOs into substitute transport fuels. In this study, extraction of nitrogen compounds from SCOs by complex formation with CuCl2.2H2O was carried out and the denitrogenated oils were hydrotreated to explore the effect of nitrogen pre-removal on hydrodenitrogenation (HDN) and hydrodesulfurization (HDS). Light gas oil fractions derived from shale oil, coal-derived liquid, and pyrolysis product of Athabasca bitumen were used as feedstocks. Hydrotreatment tests were carried out using a batch-type autoclave and commercial NiMo/Al2O3 catalyst at 350°C for 2-4 h under H2 initial pressure of 5 MPa. The results showed that basic and heterocyclic nitrogen compounds could be separated efficiently from SCO by complex formation. The pre-removal of nitrogen compounds greatly enhanced the HDN reaction rates and greatly reduced the residual nitrogen content. The recovery of CuCl2.2H2O was also possible by simply washing CH2Cl2 solution containing the complex with water. The proposed method is another option for the conversion of SCO to a high quality feedstock suitable for production of clean diesel fuels.

98/03608 Solvent extraction of nitrogen compounds from catalytically-cracked diesel oil by metal ion complexation

98/03608 Solvent extraction of nitrogen compounds from catalytically-cracked diesel oil by metal ion complexation

96/00305 Solvent extraction of nitrogen compounds from coal tar fraction

96/00305 Solvent extraction of nitrogen compounds from coal tar fraction