Study on the basic nitrogen compounds from coal-derived oil

The distillation range analysis and elemental analysis of fractioned direct liquefied oil were conducted. Each fraction of liquefied oil contains some nitrogen compounds. Using the acid extraction method and gas chromatography/mass spectrometry （GC-MS）, the basic nitrogen compounds have been separated and identified. Compared with the nitrogen content of the liquefied oil before and after separation, the basic nitrogen compounds account for more than half of all nitrogen compounds. The basic nitrogen compounds in the light liquefied oil are easily separated, and contain more types of basic nitrogen compounds. The results also show that there are many basic nitrogen compounds in liquefied oil, such as pyrrole, aniline, pyridine, quinoline and so on. However, there are fewer other types of basic nitrogen compounds.

Effect of Nitrogen Compounds on the Oxidation Stability of Saturate Fractions

A custom built dynamic oxygen uptake tester was used to study theinfluence of nitrogen compounds on the oxidation characteristics ofthe saturate fractions from mineral base oils. Experimental resultsindicate that nitrogen compounds, especially quinoline and indole,take part in the oxidation of saturates. It is also found that indoleis more active than quinoline. The latter can be oxidized partly intoketoimine, and the former is more rapidly oxidized into acylamide.The oxidation products, ketoimine or acylamide, could inhibit theoxidation of the saturates by decomposing hydroperoxide.

Fluid Catalytic Cracking Feed Hydrotreatment and its Impact on Distribution of Sulfur and Nitrogen Compounds in FCC Diesel

The sulfides and nitrogen compounds in FCC diesel were analyzed by gas chromatography equipped with a pulsed flame photometric detector(GC-PFPD) and gas chromatography coupled with nitrogen chemiluminescence detection(GC-NCD). And the variation of sulfides and nitrogen compounds in FCC diesel produced from gas oil feed hydrotreated at different temperatures was investigated. The test results showed that two main types of sulfur compounds, i.e. benzothiophenes(BTs) and dibenzothiophenes(DBTs) were found in diesel. Nitrogen compounds are mainly composed of non-basic nitrogen compounds, and indoles and carbazoles account for about 98% of the total nitrogen contents. The sulfides in FCC diesel obtained from hydrotreated feed are mainly BTs with a small amount of 4-MDBT and 4,6-DMDBT. With the increase in FCC feed hydrotreating temperature, indoles content in FCC diesel increases, while carbazoles content decreases.

Research on the direction of secondary migration of oil by making use of nitrogen compounds as tracers in the No. 6 area of the Melut Basin

This paper discussed the direction of secondary migration of oil in the No. 6 area of the Melut Basin by making use of nitrogen compounds as secondary oil migration tracers. From the results, we have found that the occurrence and compositional characteristics of isomeric-nitrogen compounds in crude oil precisely manifest the fractionation effect of oil migration: with increasing secondary migration distance, the absolute concentrations tend to decrease, and the ratio of nitrogen-shielded isomers to nitrogen-exposed isomers tends to increase. It is considered that the main direction of oil migration in the No. 6 area of the Melut Basin is from north to south.

Compositional Characterization of Nitrogen Compounds in Changqing Crude Oil and Its Heavy Distillates

The nitrogen-containing compounds in Changqing crude oil, its atmospheric residue(AR), and vacuum reside(VR) were characterized by negative and positive ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The heteroatom compounds(N_1, N_2, N_1O_1, O_1, and O_2 class species) could be identified by the negative ESI analysis, while the positive mode could only detect the N_1, N_2, and N_1O_1 class species. Among them, the N_1 class species were found to be predominant in crude oil, as confirmed by either negative or positive ESI analyses,which were similar in composition to AR and VR. These compounds with higher abundance were characterized by double bond equivalent(DBE) values and carbon numbers. The composition of these compounds in crude oil and its AR as well as VR was correlated with their different boiling range, DBE values and carbon numbers. The negative ESI analysis showed that the abundant N_1 class species in crude oil and AR were centered at a DBE value of 12, and these species were likely benzocarbazoles, while the N_1 class species with the DBE value ranging from 13 to 16 having more complicated molecular structures were dominant in VR. And the positive ESI analysis gave the information of the abundant N_1 class species in crude oil, AR, and VR having the DBE values in the range of 10, 9―11, and 10―16, respectively, which were likely the compounds with the core of quinoline and benzoquinoline. The analysis confirmed that the distillation process in refinery preferentially removed the low DBE value and low molecular N-class species and brought them into the light and medium distillates, while those N-class species having a high molecular condensation in the molecules with large carbon number remained in the residual oil and could continually affect the downstream oil refining process.

Evidence of Oil Sources and Migration in Triassic-Jurassic Reservoirs in the South Tianhuan Depression of the Ordos Basin, China Based on Analysis of Biomarkers and Nitrogen-Bearing Compounds

The Ordos Basin is an important intracontinental sedimentary basin in western China for its abundant Mesozoic crude oil resources. The southern part of the Tianhuan Depression is located in the southwestern marginal area of this Basin, in which the Jurassic and Triassic Chang-3 are the main oil-bearing strata. Currently, no consensus has been reached regarding oil source and oil migration in the area, and an assessment of oil accumulation patterns is thus challenging. In this paper, the oil source, migration direction, charging site and migration pathways are investigated through analysis of pyrrolic nitrogen compounds and hydrocarbon biomarkers. Oil source correlations show that the oils trapped in the Jurassic and Chang-3 reservoirs were derived from the Triassic Chang-7 source rocks. The Jurassic and Chang-3 crude oils both underwent distinct vertical migration from deep to shallow strata, indicating that the oils generated by Chang-7 source rocks may have migrated upward to the shallower Chang-3 and Jurassic strata under abnormally high pressures, to accumulate along the sand bodies of the ancient rivers and the unconformity surface. The charging direction of the Jurassic and Chang-3 crude oils is primarily derived from Mubo, Chenhao, and Shangliyuan, which are located northeast of the southern Tianhuan Depression, with oils moving toward the west, southwest, and south. The results show that an integration of biomarker and nitrogen-bearing compound analyses can provide useful information about oil source, migration, and accumulation.

Premature thermal decomposition behavior of 3,4-dinitrofurazanfuroxan with certain types of nitrogen-rich compounds

3,4-Dinitrofurazanfuroxan(DNTF),as a high-energy-density material,features good thermal stability and wide applications.This study aimed to elucidate the thermal decomposition mechanism of DNTF combined with nitrogen-rich compounds containing N-H.The thermal stabilities of DNTF and its hybrid systems were investigated using differential thermal analysis/thermogravimetry(TG),vacuum stability test,and accelerating rate calorimetry under isothermal,non-isothermal,and adiabatic conditions,respectively.Results showed that the thermal stability and thermal safety of DNTF significantly decreased after combining with nitrogen-rich compounds containing N-H.Calculation results showed that the activation energy of the DNTF hybrid systems was significantly lower than that of DNTF.The TGIR was used to monitor the generation of fugitive gases during the thermal decomposition of the DNTF/5-aminotetrazole(5-ATZ)hybrid.Moreover,the nitrogen-rich molecules containing N-H interacted extensively with DNTF,and this interaction accelerated the thermal degradation of DNTF.

Migration Fractionation of Neutral Nitrogen Compounds of Crude Oils from Tabei Oilfield in the Tarim Basin, China

The absolute amounts and relative distributions of neutral nitrogen compounds in the Tabei oilfield (e.g. blocks Ln1-Ln11) showed remarkable migration fractionation in the vertical direction. From Ordovician reservoirs (O) to oil legs T-Ⅲ and T-Ⅰ of Triassic reservoirs in blocks LN1-LN11, the concentrations of + decreased from {1.59}μg/g, {0.49}μg/g to {0.17}μg/g (oil). The ratios of various alkylcarbazole isomers, such as 1,8-dimethylcarbazole/nitrogen-partially shielded isomers and 1,8-dimethylcarbazole/nitrogen-exposed isomers, were adopted as the indicators of petroleum migration. The ratios increased from {0.13}, {0.20} to {0.67} and from {0.42}, {0.87} to {3.30}, corresponding to those of Ordovician oil leg and oil legs T-Ⅲ and T-Ⅰ. In going from the south to the north of the Tabei oilfield, the absolute concentrations of neutral nitrogen compounds decreased drastically, and the nitrogen-shielded isomers were enriched relative to nitrogen-exposed isomers and nitrogen-partially shielded isomers. Crude oils in the Tabei oilfield migrated laterally from the Jilake structure to the Sangtamu fault uplift and Lunnan fault uplift, and crude oils in the same fault uplift migrated and remigrated vertically from Ordovician reservoirs, to oil legs T-Ⅲ to T-Ⅰ of Triassic reservoirs.

Adsorptive removal of nitrogen-containing compounds from fuel by metal-organic frameworks

The adsorptive denitrogenation from fuels over three metal-organic frameworks(MIL-96(Al),MIL-53(Al)and MIL-101(Cr))was studied by batch adsorption experiments.Four nitrogen-containing compounds(NCCs)pyridine,pyrrole,quinoline and indole were used as model NCCs in fuels to study the adsorption mechanism.The physicochemical properties of the adsorbents were characterized by XRD,N2physical adsorption,FT-IR spectrum and Hammett indicator method.The metal-organic frameworks(MOFs),especially the MIL-101(Cr)containing Lewis acid sites as well as high specific surface area,can adsorb large quantities of NCCs from fuels.In addition,the adsorptive capacity over MIL-101(Cr)will be different for NCCs with different basicity.The stronger basicity of the NCC is,the more it can be absorbed over MIL-101(Cr).Furthermore,pore size and shape also affect the adsorption capacity for a given adsorbate,which can be proved by the adsorption over MIL-53(Al)and MIL-96(Al).The pseudo-second-order kinetic model and Langmuir equation can be used to describe kinetics and thermodynamics of the adsorption process,respectively.Finally,the regeneration of the used adsorbent has been conducted successfully by just washing it with ethanol.

Simultaneous biodegradation of nitrogen-containing aromatic compounds in a sequencing batch bioreactor

Many nitrogen-containing aromatic compounds （NACs）, such as nitrobenzene （NB）, 4-nitrophenol （4-NP）, aniline （AN）, and 2,4-dinitrophenol （2,4-DNP）, are environmentally hazardous, and their removal from contaminated water is one of the main challenges facing wastewater treatment plants. In this study, synthetic wastewater containing NB, 4-NP, 2,4-DNP, and AN at concentrations ranging from 50 to 180 mg/L was fed into a sequencing batch reactor （SBR）. Analyses of the SBR system indicated that it simultaneously removed more than 99% of the NACs at loading rates of 0.36 kg NB/（m^3·d）, 0.3 kg 4-NP/（m^3·d）, 0.25 kg AN/（m^3·d）, and 0.1 kg 2,4-DNP/（m^3·d）. Bacterial groups of Bacteriodetes, Candidate division TM7, α-Proteobacteria, and β-Proteobacteria were dominant in the clone libraries of 16S rRNA genes retrieved from the microbial communities in the SBR system. ＂Cycle tests＂ designed to alter feeding and aeration parameters of the SBR system demonstrated that the resident microbial biome of the SBR system responded rapidly to changing conditions. Consumption of O2 was concomitant with the apparent mineralization of NACs. Aromatic ring-cleaving dioxygenase activities suggested that （1） AN and NB were degraded via catechol 2,3-dioxygenase; （2） 4-NP was degraded via 1,2,4-benzentriol 1,2-dioxygenase; and （3） 2,4-DNP was degraded via an unresolved pathway.

Effects of typical nitrogenous compounds on trihalomethanes formation and chlorine demand during drinking water chlorination

Glycine(Gly),cysteine(Cys),aspartic acid(Asp),leucine(Leu),lysine(Lys),and methyl amine(MA) were chosen as typical nitrogenous compounds,and the effects of them on trihalomethanes (THMs) formation and chlorine demand were performed on filtrated water. Results show that the nitrogenous compounds enhance THMs formation,and the increased levels are controlled by characteristics and the concentration of nitrogenous compounds. The increase in THMs formation follows the order of Asp(126 μg/L)>Cys(119 μg/L)>MA(106 μg/L)>Lys(97 μg/L)≈Gly(96 μg/L)>Leu(80 μg/L)(while nitrogenous compounds=1.0 mg/L,and background THMs=60 μg/L). The increase in chlorine demand is approximately proportionate to the content of nitrogenous compounds,which illustrates that the increase is mainly caused by the reaction of nitrogenous compounds with chlorine. And the increase in chlorine demand follows the order of Cys(27.8 mg/L)>Asp(22.6 mg/L)=Gly(22.6 mg/L)>Lys(21.6 mg/L)>MA(14.1 mg/L)>Leu(11.8 mg/L) (while nitrogenous compounds=1.0 mg/L,and background chorine demand=1.8 mg/L). The mechanisms of nitrogenous compounds enhancing THMs formation are summ the increase of chlorine demand raising THMs formation in reaction of NOM with chlorine,and the THMs formation in chlorination of nitrogenous compounds themselves.

Thermal Behavior,Sensitivity,Detonation Velocity and Pressure of a Nitrogen-Rich Compound

The nitrogen content of tetrazolo triazines is 68.9%.In this paper,tetrazolotriazines was synthetized.The TG-DSC test indicated its decomposition process in detail.The non-isothermal kinetic parameters were speculated by Kissinger and Ozawa methods.It revealed the mechanism function of thermal decomposition.The impact and friction sensitivity were tested.The detonation pressure and velocity were calculated.It has a wide range of potential applications as a kind of energetic material.

Geochemical significance of pyrrolic nitrogen compounds in various kinds of crude oils from the Tarim Basin

This is a report of the differences in abundances of pyrrolic nitrogen compounds and distribution of alkylated carbazoles among various oils from the Tarim Basin. At the same time, their geochemical significance is discussed.

Mass-Spectrometric Method of Measurement of Isotopic Content of Nitrogen in Organic Compounds

Nitrogen-15 isotope-modified compounds are widely used in medicine, pharmacology, agriculture and various fields of science and their nomenclature is gradually increasing. Their widespread use depends on the availability of inexpensive and simple isotope analysis methods. The present article is an attempt to determine the nitrogen-15 isotope content directly in organic compounds without their conversion. The general principle of possibility of determination of the isotopes of nitrogen directly in organic compounds is proposed. Based on the study of mass-spectra of Carbamide Carbonyldiamide, isocyanic acid and nitrobenzene the mass peaks are selected, by which it is possible to determine the atomic fraction of the isotopes of nitrogen. The respective formulas are proposed.

Distribution and Significance of Carbazole Compounds in Palaeozoic Oils from the Tazhong Uplift, Tarim

Carbazole compounds in crude oils from the Tazhong uplift of the Tarim basin have been fractionated and detected and successfully used to study petroleum migration and trace source rocks in the study area. Alkylcarbazoles have been found in large amounts in the oil samples analyzed and alkylbenzocarbazoles detected in a small concentration only in part of the samples, but alkyldibenzocarbazoles have not been found in oils. Based on the distribution of G1, G2 and G3 of C2-alkylcarbazoles, the ratio of C3-carbazoles to C2-carbazoles and the relative amounts of alkylcarbazoles and alkylbenzocarbazoles, one can know that the vertical oil migration in the Tazhong uplift is generally from below upward, i.e. from the Ordovician through the Silurian to the Carboniferous. Evidently, source rocks in the uplift should be lower Palaeozoic strata (Ordovician and Cambrian). This study shows that carbazoles are of great importance in the study of petroleum migration and source rocks.

The correlation between nitrogen species in coke and NO_x formation during regeneration

Nitrogen oxides （NOx） emission during the regeneration ofcoked fluid catalytic cracking （FCC） catalysts is an en- vironmental issue. In order to identify the correlations between nitrogen species in coke and different nitrogen- containing products in tail gas, three coked catalysts with multilayer structural coke molecules were prepared in a fixed bed with model compounds （o-xylene and quinoline） at first. A series of characterization methods were used to analyze coke, including elemental analysis, FT-IR, XPS, and TG-MS. XPS characterization indicates all coked catalysts present two types of nitrogen species and the type with a higher binding energy is related with the inner part nitrogen atoms interacting with acid sites. Due to the stronger adsorption ability on acid sites for basic nitrogen compounds, the multilayer structural coke has unbalanced distribution of carbon and ni- trogen atoms between the inner part and the outer edge, which strongly affects gas product formation. At the early stage of regeneration, oxidation starts from the outer edge and the product NO can be reduced to N2 in high CO concentration. At the later stage, the inner part rich in nitrogen begins to be exposed to 02. At this period, the formation of CO decreases due to lack of carbon atoms, which is not beneficial to the reduction of NO. There- fore, nitrogen species in the inner part of multilayer structural coke contributes more to NOx formation. Based on the multilayer structure model of coke molecule and its oxidation behavior, a possible strategy to control NOx emission was discussed merely from concept.

Supercritical Water as a Reaction Medium for Nitrogen-Containing Heterocycles

Supercritical water has been focused on as an environmentally attractive reaction media, in which organic materials can be decomposed into smaller molecules. The reaction behavior of pyrrole as a simple model compound of nonbasic nitrogen compounds found in petroleum residua was studied in supercritical water with a batch type reactor. The reaction was carried out at temperatures of 698-748 K and at various pressures under an argon atmosphere. The chemical species in the aqueous products were identified by GCMS （gas chromatography mass spectrometry） and quantified using GC-FID （gas chromatography flame ionization detector）. The effect of temperature and reaction time on the conversion process of pyrrole is presented. Under supercritical water conditions, pyrrole underwent successful decomposition in water into its derived compounds. The conversion of pyrrole could approach 81.12 wt% at 723 K and 40 MPa within 240 min of reaction time. The decomposition process was accelerated with the existence of water at the same temperature. Ultimate analysis of solid products was also conducted using a CHN analyzer. The process investigated in this study may form the basis for an efficient method of nitrogen compound decomposition in future.

BaSi_(2)O_(2)N_(2):Eu^(2+),Mn^(2+)荧光粉的制备及对Eu^(2+)晶体学格位的讨论

文章采用两步固相法制备了BaSi_(2)O_(2)N_(2):Eu^(2+),Mn^(2+)荧光粉,利用荧光光谱仪(PL)、扫描隧道显微镜(SEM)和X射线衍射仪(XRD)对所制备样品的荧光性能、颗粒表面形貌和晶体结构进行研究。其光谱呈现Eu^(2+)的d-f跃迁的宽谱带特性,发射光谱峰值为490 nm,激发光谱覆盖了370~470 nm,与蓝光和近紫外光LED芯片的激发波长相匹配。Mn^(2+)的掺杂并未改变BaSi_(2)O_(2)N_(2):Eu^(2+)的发光谱形和晶体结构,但是增强了Eu^(2+)的发光强度,当Mn^(2+)的掺杂浓度为0.02 mol时,其发光强度提高了46%;所制备荧光粉表面形貌呈无规则状。通过UITERT经验公式讨论了Eu^(2+)在BaSi_(2)O_(2)N_(2):Eu^(2+)中的晶体学格位,所计算的理论值489 nm与实验观测值490 nm相近。

Ionic Liquid Assisted Extraction of Nitrogen and Sulphur-Containing Air Pollutants from Model Oil and Regeneration of the Spent Ionic Liquid

Removal of air pollutants, such as nitrogen and sulphur containing compounds from a model oil (dodecane) was studied. An ionic liquid (1-ethyl-3-methylimidazolium chloride [C2mim] [Cl]) was used as an extractant. Liquid-liquid extraction by using 1-ethyl-3-methylimidazolium chloride [C2mim] [Cl] was found to be a very promising method for the removal of N- and S-compounds. This was evaluated by using a model oil (dodecane) with indole as a neutral nitrogen compound and pyridine as a basic nitrogen compound. Dibenzothiophene (DBT) was used as a sulphur compound. An extraction capacity of up to 90 wt% was achieved for the model oil containing pyridine, while only 76 wt% of indole in the oil was extracted. The extraction capacity of a model sulphur compound DBT was found to be up to 99 wt%. Regeneration of the spent ionic liquid was carried out with toluene back-extraction. A 1:1 toluene-to-IL wt ratio was performed at room temperature. It was observed that, for the spent ionic liquid containing DBT as a model compound more than 85 wt% (corresponding 3852 mg/kg) could be removed from the oil. After the second regeneration cycle, 86 wt% of the DBT was recovered from the ionic liquid to toluene. In the case of indole as the nitrogen containing species, more than 99 wt%, (corresponding to 2993 mg/kg) of the original indole was transferred from the model oil to the ionic liquid. After the first-regeneration cycle of the spent ionic liquid, 54 wt% of the indole–in-IL was transferred to toluene. Thus, both extractions of nitrogen and sulphur model compounds were successfully carried out from model oil and the back-extraction of these compounds from the ionic liquids to toluene demonstrated the proved the concept of the regeneration point of view.