Boiling Point Research Articles

Data Reconciliation Among PIONA, GC-FIMS, and SimDis Measurements for Petroleum Fractions

PIONA (paraffin, isoparaffin, olefin, naphthene, aromatic) is a widely used characterization method for petroleum fractions boiling below 200°C, while a gas chromatography-field ionization mass spectrometry (GC-FIMS)characterization method developed at the National Centre for Upgrading Technology (NCUT) provides a reliable hydrocarbon type distribution by carbon number (#C) for middle distillates boiling between 200°C–360°C. This article proposes an integrated approach to combine the results from both PIONA and GC-FIMS measurements, resulting in detailed hydrocarbon-type distribution between the initial and end boiling points of the middle distillate. Furthermore, summing up the mass in each boiling point (BP)interval (e.g., 10°C) generates an equivalent simulated distillation (SimDis) curve that needs to be reconciled with the SimDis measured by the ASTM D2887 method. This article also discusses a simple data reconciliation approach that allowed us to use the three separate pieces of information (PIONA, GC-FIMS, and SimDis) as an internally consistent basis for the derivation of molecular representation of materials characterized in such a way.

Measurement of Total Acid Number (TAN) and TAN Boiling Point Distribution in Petroleum Products by Electrospray Ionization Mass Spectrometry

We report a new method for rapid measurement of total acid number (TAN) and TAN boiling point (BP) distribution for petroleum crude and products. The technology is based on negative ion electrospray ionization mass spectrometry (ESI-MS) for selective ionization of petroleum acid and quantification of acid structures and molecular weight distributions. A chip-based nanoelectrospray system enables microscale (<200 mg) and higher throughput (20 samples/h) measurement. Naphthenic acid structures were assigned based on nominal masses of a set of predefined acid structures. Stearic acid is used as an internal standard to calibrate ESI-MS response factors for quantification purposes. With the use of structure-property correlations, boiling point distributions of TAN values can be calculated from the composition. The rapid measurement of TAN BP distributions by ESI is demonstrated for a series of high-TAN crudes and distillation cuts. TAN values determined by the technique agree well with those by the titration method. The distributed properties compare favorably with those measured by distillation and measurement of TAN of corresponding cuts.

高沸点有機溶媒用気化器内の流動挙動に関する可視化観察

高沸点有機溶媒用気化器内の流動挙動に関する可視化観察

Prediction of the Heat of Vaporization from the Heat of Vaporization at Normal Boiling Point

A generalized enthalpy-temperature correlation for a group of liquid compounds has been developed to represent the data for a wide range of temperatures. Detailed analysis shows that the proposed correlation fits the experimental measurements of enthalpy of liquid with the calculated values with an overall absolute error of 3.7% for 79 data points.

Mathematical Modeling of Thermal Conversion of Athabasca Bitumen. Part I: Reaction Pathways and Experimental Method

Abstract Modeling of a thermal cracking process involves establishing a set of kinetic reactions that transform the feed into products. In a typical feed, there exist a large number of real components. Thus, an exact feed composition is not known. The most common method to overcome this difficulty is to define pseudo-components based on physical properties such as boiling point or molecular weight. In this work, we propose a set of model thermal cracking reactions based on nuclear magnetic resonance (NMR) data. NMR carbon type analysis improves the characterization of the feed and products by providing the contents of different carbon species (carbon bonds). This additional information enables a more descriptive and fundamental set of reactions to be developed for the model. The reactions chosen describe the types of carbon bonds that break and form in the feedstock under visbreaking conditions. The set of reactions is the centre of the pseudo-component model. Introduction Visbreaking is a thermal cracking process that has existed for many decades. It is a relatively mild process used primarily to reduce the viscosity of the heavy ends of crude oil feedstocks that results in low conversion of heavy-end material. For example, typically there is &amp;lt; 30 wt% conversion of residue with boiling points (BP) &amp;gt; 524 °C to lower-boiling components. Visbreaking is widely used in Europe and Asia due to the properties of available feedstocks and demand for heavier products such as fuel oil. In Alberta, an increasing proportion of the oil produced is extra heavy (i.e. Athabasca bitumen). Consequently, higher severity processes such as coking and residue hydrocracking are needed to convert 60 wt% or more of the residue to lighter products suitable for transportation fuels. However, there has been some interest in visbreaking as a field upgrading process to reduce the need for diluents to meet pipeline specifications for bitumen and heavy oil transportation. Despite visbreaking being a relatively simple process, modeling of the thermal cracking reactions that result in product formation poses many challenges. The greatest difficulty is to find a suitable method to describe the feedstock and product molecules. For the lightest components of crude oils (i.e. naphtha, BP &amp;lt;204 °C), there are over a thousand molecular species that can be identified and quantified. However, for fractions with boiling points &amp;gt; 204 °C, virtually every molecule is different. Thus, the challenge is to lump the molecules into a manageable number of groups, yet be able to retain enough chemical sensitivity so as to be able to develop fundamental correlations. The most common method to characterize a feedstock is to define pseudo-component lumps based on physical properties like molecular weight or boiling point. However, as these properties provide no specific information of the relative chemical reactivity of the lumps, the kinetic parameters determined are empirical and need to be adjusted for each different feedstock. Recently, nuclear magnetic resonance (NMR) spectroscopy has been used for structural analyses of petroleum fractions. Ali et al.(1) used NMR data to estimate average molecular structures of Kuwaiti vacuum gas oil.

Simultaneous Temperature and Velocity Fields Measurements near the Boiling Point

Simultaneous measurement technique for temperature and velocity fields near a heated solid body has been constructed. The measurement system consists of a 3 plate CCD color camera, a color image grabber, a lighting system, a host computer and a software for the whole quantification process. Thermo Chromic Liquid Crystals (TCLC) was used as temperature sensors. A neural network was used to get a calibration curve between the temperature and the color change of the TCLC in order to enhance the dynamic range of temperature measurement. The velocity field measurement was attained by the use of the gray level images taken for the flow field, and by introducing the cross correlation technique. The temperature and the velocity fields of the forced and the natural convective flows near the surface of a cartridge heater were measured simultaneously with the constructed measurement system.

Reply to “Comment on ‘Critical Properties, Normal Boiling Temperature, and Acentric Factor of Fifty Ionic Liquids'”

Reply to “Comment on ‘Critical Properties, Normal Boiling Temperature, and Acentric Factor of Fifty Ionic Liquids'”

Comparative study of the performance of three- and four-parameter correlation equations for the temperature dependence of the enthalpy of vaporization for pure substance refrigerants

A few commonly used correlation equations of the enthalpy of vaporization which is essential to the analysis of refrigeration cycles are reviewed. A new four-parameter correlation equation is proposed assuming that the enthalpy of vaporization could be represented by a function having a linear term to the temperature and an additional term which slowly decreases as the temperature increases. It is not a common practice to measure the enthalpy of vaporization by experiment; therefore, performance of the new correlation equation for the temperature dependence of the enthalpy of vaporization is examined using numeric data from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) tables for 22 pure substance refrigerants. The new correlation equation and other existing ones are fitted to the data optimizing the root mean squared deviation. All data points are weighted equally and NBP (normal boiling point) is used as a fixed point since the NBP is important for refrigeration applications. The new four-parameter equation yields an average absolute deviation of 0.05% for 22 refrigerants which is smaller than those of other four-parameter equations, such as Guermouche–Vergaund (0.08%), Aerebrot (0.13%), Radoz–Lyderson (0.08%), and Somayajulu four-parameter equation (0.08%). After the optimization, it is found that a specific exponent in the new equation has approximately the same value for almost every substance tested so that the original four-parameter correlation could be reduced to a three-parameter one. The new three parameter correlation yields an average absolute deviation of 0.14% for the same 22 refrigerants, which also is smaller than those of other three-parameter correlations, such as Xiang (0.18%), Majer–Svoboda–Pick (0.18%), and Somayajulu three-parameter equation (0.27%).

Boiling Temperature and Reversed Deliquescence Relative Humidity Measurements for Mineral Assemblages in the NaCl + NaNO3 + KNO3 + Ca(NO3)2 + H2O System

Boiling temperature measurements have been made at ambient pressure for saturated ternary solutions of NaCl + KNO3 + H2O, NaNO3 + KNO3 + H2O, and NaCl + Ca(NO3)2 + H2O over the full composition range, along with those of the single salt systems. Boiling temperatures were also measured for the four component NaCl + NaNO3 + KNO3 + H2O and five component NaCl + NaNO3 + KNO3 + Ca(NO3)2 + H2O mixtures, where the solute mole fraction of Ca(NO3)2, x{Ca(NO3)2}, was varied between 0 and 0.25. The maximum boiling temperature found for the NaCl + KNO3 + H2O system is ≈134.9 ∘C; for the NaNO3 + KNO3 + H2O system is ≈165.1 ∘C at x(NaNO3) ≈ 0.46 and x(KNO3) ≈ 0.54; and for the NaCl + Ca(NO3)2 + H2O system is 164.7 ± 0.6 ∘C at x{NaCl} ≈ 0.25 and x{Ca(NO3)2} ≈ 0.75. The NaCl + NaNO3 + KNO3 + Ca(NO3)2 + H2O system forms molten salts below their maximum boiling temperatures and the temperatures corresponding to the cessation of boiling (dry-out temperatures) of these liquid mixtures were determined. These dry-out temperatures range from ≈300 ∘C when x{Ca(NO3)2} = 0 to ≥ 400 ∘C when x{Ca(NO3)2} = 0.20 and 0.25. Mutual deliquescence/efflorescence relative humidity (MDRH/MERH) measurements were also made for the NaNO3 + KNO3 and NaCl + NaNO3 + KNO3 salt mixture from 120 to 180 ∘C at ambient pressure. The NaNO3 + KNO3 salt mixture has a MDRH of 26.4% at 120 ∘C and 20.0% at 150 ∘C. This salt mixture also absorbs water at 180 ∘C, which is higher than expected from the boiling temperature experiments. The NaCl + NaNO3 + KNO3 salt mixture was found to have a MDRH of 25.9% at 120 ∘C and 10.5% at 180 ∘C. The investigated mixture compositions correspond to some of the major mineral assemblages that are predicted to control brine composition due to the deliquescence of salts formed in dust deposited on waste canisters in the proposed nuclear repository at Yucca Mountain, Nevada.

Hydrotreating of the Cut Which Has Boiling Range From Initial Boiling Point To 823K

The wide petroleum distillate, which has the boiling range from initial boiling point to 823 k, were hydroteated in trickle – bed reactor using cobalt – molybdenum alumina as a Catalyst. The reaction range temperatures was 598 – 673 k, while LHSV was 0.7 – 2 hr-1. The pressure and H2/Oil for all experiments keep constant at 3Mpa and 300 L/L respectively. The result shows that the sulphur and metals content decreased with the increasing of temperature and decreasing in LHSV. Desulphurization kinetic was studied and found that the kinetic of sulphur removal is of first – order. Activation energy was calculated and this value is 28.225 KJ / mole.

Inorganic Complexes Retain Diethyl Ether Well Above Its Boiling Point through OH2···OEt2 Hydrogen Bonding

The structures of [M(2,2‘-bpy)(SC{O}Ph)3(H2O)]·Et2O (M = La (1), Pr (2), and Sm (3); 2,2‘-bpy = 2,2‘-bipyridine) have an eight-membered hydrogen-bonded ring formed between two diethyl ether (Et2O) and two aqua ligands, and they retain Et2O above its boiling point despite the presence of channels in the lattice for Et2O to escape. The inception temperatures for the weight loss of Et2O, 82, 69, and 51 °C for 1, 2, and 3, respectively, appear to be controlled by the size of the metal ions. Et2O-free solid 1 is able to take back Et2O quantitatively.

New Molecular Descriptors based upon the Euler Equations for Chemical Graphs

The Euler equations for the chemical graphs are an extension of such equations for the polyhedra. These equations admit several potential forms of molecular descriptors that can be used in the characterizations of the properties of polycyclic aromatic hydrocarbons (PAH) in a typical Quantitative Structure Property–Activity Relationship (QSPR-QSAR). In this paper we describe the nature of these Euler relations for hydrocarbon graphs and the descriptors they admit, applying them to predict 37 boiling points (BP), 26 n-octanol/water partition coefficients (log(k ow)), and 47 retention time indexes (RI) for reversed-phase liquid chromatography analysis. Final results suggest that these new descriptors can be used to complement others in a QSPR-QSAR study.

Determination and Characterization of the Pyrolysis Products of Isoprocarb by GC MS

The pyrolysis behavior of isoprocarb (an insecticide with contact and stomach action) is investigated using pyrolysis-gas chromatography-mass spectrometry. The pyrolysis products are separated using an HP-5 column under temperature program with helium as the carrier gas. The total of 80 separated pyrolysis components at 600 degrees C, 750 degrees C, and 900 degrees C under helium atmosphere are identified using a probability-based matching search procedure, combined with the correlation of boiling point (BP) and Lee retention index (RI). Some of the BP values of the tentative components are estimated using the group contributions method because experimental values are not available. The levels of the identified components are estimated by the peak area normalization method from the chromatogram. It is found that isoprocarb decomposes more with the increase of temperature, and a large number of mono aromatics and polycyclic aromatic hydrocarbons and their derivatives are produced when the pyrolysis temperature is higher than 750 degrees C. The content of the decomposition products in the pyrolysate varies from 0.04% to 22.20%.

True Boiling Point Extended Curve of Vacuum Residue Through Molecular Distillation

Molecular distillation is a separation process that explores high vacuum, operation at reduced temperatures, and low exposition of the material at the operating temperature. The term vacuum residue (heavy petroleum fractions) refers to the bottom of the vacuum distillation, which has an atmospheric equivalent temperature (AET) above 540°C. For the assay of the properties of petroleum and petroleum products, the use of the true boiling point (TBP) distillation analysis is accepted as a common practice; however, for heavy petroleum fractions, some difficulties appear for determination of TBP of these petroleum fractions. The objective of this work is to develop a new and a more appropriated method to extend the TBP curve to use it for characterizing vacuum residue of heavy petroleum. The falling film molecular distillator was used. The results showed that it is possible to extend the TBP curve through molecular distillation process with very good precision.

Characterization of crude petroleum by NIR

Petroleum is a product whose composition (quality) varies due to its natural origin and to transport and storage conditions. In Brazil in particular, crude petroleum comes from a variety of very different oil fields that produce predominantly heavy petroleum. This work proposes a methodology for the estimation of the SimDis (Simulated Distillation) properties of crude petroleum based on NIR (Near Infrared) spectroscopy. SimDis analysis, which takes about three hours to perform, is rapid relative to TBP (True Boiling Point) determination. In the proposed methodology, a NIR transmission probe is used and no desalting or thermal conditioning is applied to the samples before measurement. In order to build the correlations, forty petroleum samples with API grades ranging from 31.1 to 36.4 were employed. The NIR spectral data were correlated with the SimDis curves (weight percent vaporized at a given temperature) and the salt content of the petroleum by neural network techniques. The resulting network reproduced quite accurately the SimDis curves, showing the technical feasibility of the proposed methodology.

Simple generalized vapour pressure- and boiling point correlation for refrigerants

A simple generalized vapour pressure equation has been developed to correlate vapour pressures of refrigerants. The proposed vapour pressure equation has one or three adjustable parameters depending on the required accuracy. In the first case the adjustable parameter has been correlated with the reduced triple point temperature. Thus, the proposed vapour pressure equation requires only the fluid-dependent critical and triple point parameters and enables the accurate description of the entire temperature range of pure refrigerants from the triple to the critical point. Another advantage of the proposed correlation is its possibility of being inversed; this way the Boiling point can be calculated from vapour pressures through a single equation. Finally, a predictive method for the triple point pressure is suggested.

Estimation of the Enthalpy of Vaporization and the Entropy of Vaporization for Pure Organic Compounds at 298.15 K and at Normal Boiling Temperature by a Group Contribution Method

A new group contribution method for estimating the enthalpy of vaporization at 298.15 K (ΔHV(298.15 K)) and at the normal boiling temperature (ΔHV(Tb)), as well as the entropy of vaporization at the normal boiling temperature (ΔSV(Tb)), of pure organic compounds has been developed. Large databases of critically assessed data have been used for group contribution calculations: data for 831 compounds have been used for estimations at 298.15 K, and data for 589 compounds have been used for estimations at the normal boiling temperature. Values obtained by the method developed here have been compared with estimations by the Ducros, Chickos, and Ma and Zhao group contribution methods and by empirical equations by Vetere. A statistical analysis of the regressed data has been also performed, indicating the confidence of the regressed parameters and other related information. The average relative errors (ARE) for the new method are as follows: for ΔHV(298.15 K), 2.2%; for ΔHV(Tb), 2.6%; and for ΔSV(Tb), 1.8%. Th...

Study of Thermal Behavior of Vitamin D3 by Pyrolysis ‐ GC ‐ MS in Combination with Boiling Point ‐ Retention Time Correlation

The thermal behavior of vitamin D3 was studied based on pyrolysis-GC-MS technique. It was pyrolyzed at 600 degrees C, 750 degrees C, 900 degrees C, respectively. The pyrolysis product were separated With an HP-5 column and identified by the NIST mass spectral search program in combination with the correlation of boiling point and retention time (BP-RT). There are totally 50 components, including mono aromatics and polycyclic aromatic hydrocarbons (PAHs), were determined. It is shown that the contents of the PAHs are increasing with the increasing of the pyrolysis temperature. The contents of the determined components vary from 0.04% to 37.08%.

On the Critical Temperature, Normal Boiling Point, and Vapor Pressure of Ionic Liquids

One-stage, reduced-pressure distillations at moderate temperature of 1-decyl- and 1-dodecyl-3-methylimidazolium bistriflilamide ([Ntf(2)](-)) ionic liquids (ILs) have been performed. These liquid-vapor equilibria can be understood in light of predictions for normal boiling points of ILs. The predictions are based on experimental surface tension and density data, which are used to estimate the critical points of several ILs and their corresponding normal boiling temperatures. In contrast to the situation found for relatively unstable ILs at high-temperature such as those containing [BF(4)](-) or [PF(6)](-) anions, [Ntf(2)](-)-based ILs constitute a promising class in which reliable, accurate vapor pressure measurements can in principle be performed. This property is paramount for assisting in the development and testing of accurate molecular models.

The Use of IR Spectra for Estimating the Boiling Points and Molecular Weights of Monohydric Aliphatic Alcohols

The use of transformed IR spectra as descriptors of molecular structure in estimating the boiling points and molecular weights of alcohols was studied. No additional data on molecular structure are required for the estimation.