High-temperature simulated distillation GC analysis of petroleum resids and their products from catalytic upgrading over Co–Mo/Al2O3 catalyst

Two petroleum resids and their products from catalytic upgrading were characterized by high-temperature simulated distillation using gas chromatography (HT-SimDis GC) with a capillary column. The atmospheric equivalent boiling points (AEBP) determined by the HT-SimDis GC method in this work reached an end point of 847°C (1557°F). This method successfully analyzed the AEBP distribution of an atmospheric resid and a vacuum resid as well as their products from catalytic hydroprocessing. The analysis of the AEBP distribution vs. reaction temperature revealed that catalytic upgrading not only produced lighter fractions but also created desirable changes in the remaining >540°C fractions. For the runs over a sulfided Co–Mo/Al₂O₃ catalyst, the yields of products with BP range of 540–700°C remained almost constant when the reaction temperature was within 350–400°C but decreased monotonically with further increasing reaction temperature up to 450°C. At 450°C, the 450–540°C fraction was also converted. The extent of catalytic hydrodesulfurization over Co–Mo/Al₂O₃ catalyst increased with temperature from 350 to 450°C.     

Mercury-mercurous propionate electrode: standard potentials at different temperatures and related thermodynamic quantities

The standard molal potentials E°_m of the Hg/Hg₂(OPr)₂, OPr⁻ electrode at 15°, 20°, 25°, 30° and 35° C have been determined. The E°_m values obtained are 0.5114, 0.5072, 0.5031, 0.4988 and 0.4942 V respectively, which can be fitted to the equation Edg_m/V = 0.5031 −8.56 × 10⁻⁴ (itt/°C − 25)−3.0588 × 10⁻⁶ (t/ °C -25)². The changes in standard free energy, entropy and enthalpy for the cell reaction have been calculated.     

Two Ferroeletric Mechanisms Confirmed in Ba5Ti2O7Cl4

The anticipated existence of two mechanisms of ferroelectricity in Ba₅Ti₂O₇Cl₄ is now confirmed by studying the variation of spontaneous polarization with temperature by hysteresis loop method, by observing the changes in domain structure, and by using thermoanalytical methods. It is found that at around 80°C the spontaneous polarization begins to fall off rapidly, and this fall continues upto 125°C after which the change in Ps is negligibly small. Also, 79°domains associated with Ti⁴⁺ ion begin to disappear at 80°C while 180° and 90° domains associated with Cl^1- ion persist beyond 200°C. Differential thermal analysis (DTA) and differential scanning calorimetry (DSC) data showed ionic changes at 80°C and 125°C. The dc conductivity measurements showed, however, no phase change in this temperature range. From the observed domain structure variation and Ps variation it is inferred that the ionic changes given by DTA and DSC relate to Ti⁴⁺ ion only. It is deduced that at 80°C there is change in Ti⁴⁺ displacement from [110] direction to [100] direction, while at 125°C the Ti⁴⁺ ion loses its off-center position resulting in the loss of ferroelectric mechanism associated with Ti⁴⁺ ion. Since 90° and 180° domain associated with Cl^1- ion continue to persist beyond 125°C, it is obvious that this ferroelectric mechanism continues to exist even as the other ferroelectric mechanism disappears at 125°C.     

Visbreaking of heavy petroleum oil catalyzed by SO/ZrO solid super-acid doped with Ni or Sn

SO₄^2-/ZrO₂ solid super-acid catalysts (SZ) doped with Ni²⁺ or Sn²⁺ (Ni²⁺/SZ, Sn²⁺/SZ) were prepared for catalytic visbreaking of heavy petroleum oil from Shengli oil field. The visbreaking reactions were carried out at 240°C and 3–4 MPa for 24 h using a heavy petroleum oil to catalyst mass ratio of 100 : 0.05. The effect of water content on viscosity of heavy petroleum oil was also investigated. Both catalysts can promote thermolysis of heavy petroleum oil and the viscosity was reduced from 0.319 Pa·s to 0.135 Pa·s for Ni²⁺/SZ and 0.163 Pa·s for (Sn²⁺/SZ) with visbreaking rates of 57.7% and 48.9%, respectively. After visbreaking, the saturated hydrocarbon content increased while aromatics, resin, asphaltene, sulfur and nitrogen content decreased. The presence of water was disadvantageous to visbreaking of heavy petroleum oil.     

MASS TRANSFER AND DIFFUSION COEFFICIENT DETERMINATION IN THE WET AND DRY SALTING OF MEAT

Dehydrated salted meat is widely used in Brazil as a very important source of animal protein. The main objective of this kind of processing is water removal. initially by osmotic pressure changes and then by drying, resulting in a product with intermediate moisture levels.

In this work, mass transfer and salt diffusion in pieces of meat submitted to wet and dry salting were studied. Slabs of beef m. trapezius with an infinite plate geometry were salted in a NaCl saturated solution or in a dry salt bed, at two temperatures (10 and 20°C) and different time exposures (120 min and 96 hours). Equilibration studies were extended up to six days.

It was observed that water loss increased with salt uptake, for increasing periods of times. At 20°C the moisture loss was higher than it was at 10°C in both salting processes. On the other hand, the kinetics of salt uptake and moisture loss were of greater importance in the process of dry salting than in that of wet salting.

The salt diffusion coefficient for wet salting was 0.26 × 10^-10m²/s at20°C and 0.25 × 10^-10 m²/s at 10°C and for the dry salting the values were 19.37 × 10^-10 m²/s at 20°C and 17.21 × 10^-10 m²/s at 10°C.     

Synthesis of fluorine-containing polyphosphates: low-temperature solution polycondensation of bisphenol AF and aryl phosphorodichloridates

This paper describes the synthesis of aromatic polyphosphates from the reaction of various aryl phosphorodichloridates with bisphenol AF in a chlorinated hydrocarbon solvent under low-temperature conditions. The polyphosphates obtained were characterized by IR,¹³3C- and ³¹P-NMR spectra, elemental analysis, inherent viscosity, TGA, DSC, X-ray diffraction, LOI, contact angle and molar mass measurement. All the polyphosphates obtained had high yields and the inherent viscosities were in the range 0.25–0.31 dl g⁻¹. The weight average molar masses ( ) were in the range 0.96 × 10⁴−1.33 × 10⁴ with relatively narrow molar mass distributions ( ). All the polymers, except polymer C, are stable up to 250°C, exhibited 10% loss of mass at 417–463°C, and had 20–30% residual mass at 700°C in nitrogen. The X-ray diffraction patterns revealed that all the polyphosphates are semicrystalline and polymer E, containing a flexible ether linkage, has a relatively large degree of crystallinity. The fluorine-containing polyphosphates have glass-transition temperatures between 81–108°C and polymer C, having a NO₂ group in the side chain phenyl ring, has the highest T_g value. The polyphosphates obtained from bisphenol AF showed better thermal stabilities and higher LOI values than those obtained from bisphenol A. The polyphosphates have good flame retardancy, as indicated by high limiting oxygen index values in the range of 47–60. The water contact angles (θ_w) of all polyphosphates are in the range of 76–109°. The contact angles of polymers A and B are larger than other polyphosphates which contain more oxygen content or bromine atoms (polymers C, D and E).     

Lattice coordination number in polystyrene solutions

Intrinsic viscosities of five polystyrene samples of molar masses ca. 10⁵–10⁶ have been measured at 34.5°C in cyclohexane (θ-solvent), 1,2,3,4-tetrahydronaphthalene (good solvent) and in binary mixtures of these two liquids. Experimental values of ⁵−³ (where is the expansion factor) were compared with values calculated on the basis of two theories which assume the lattice coordination number Z to be infinite and finite respectively. Z=∞ greatly overestimates ⁵−³, whilst good accord is obtained if Z=3 or 4 according to molar mass and solvent power.     

Thermoelectric characterization of NaxMx/2Ti1−x/2O2 (M=Co, Ni and Fe) polycrystalline materials

Layered -titanate materials, Na_xM_x/2Ti_1−x/2O₂ (M=Co, Ni and Fe, x=0.2–0.4), were synthesized by flux reactions, and electrical properties of polycrystalline products were measured at 300–800 °C. After sintering at 1250 °C in Ar, all products show n-type thermoelectric behavior. The values of both d.c. conductivity and Seebeck coefficient of polycrystalline Na_0.4Ni_0.2Ti_0.8O₂ were ca. 7×10³ S/m and ca. −193 μV/K around 700 °C, respectively. The measured thermal conductivity of layered -titanate materials has lower value than conductive oxide materials. It was ca. 1.5 Wm⁻¹ K⁻¹ at 800 °C. The estimated thermoelectric figure-of-merit, Z, of Na_0.4Ni_0.2Ti_0.8O₂ and Na_0.4Co_0.2Ti_0.8O₂ was about 1.9×10⁻⁴ and 1.2×10⁻⁴ K⁻¹ around 700 °C, respectively.     

Influence of temperature on the hydrogenation of Australian Loy-Yang brown coal. 1. Oxygen removal from coal and product distribution

A study is made of the composition of the solid, liquid and gaseous fractions produced by hydrogenation of Australian Loy-Yang brown coal at temperatures ranging from 300 to 500 °C. The high oxygen content of the coal (25.5 wt%) is not found to result in a proportionally higher hydrogen consumption when compared to previously published results for a coal with approximately half the oxygen content. Oxygen is found to be removed from the coal mainly as carbon dioxide and water, most probably by decarboxylation and dehydration reactions. At temperatures up to ≈400 °C hydrogen is consumed almost solely by transference from the solvent tetralin to the coal. By this temperature both the maximum degree of conversion and the maximum oil yield are reached. The heavy oil fraction at 400 °C is composed mainly of asphaltenes and preasphaltenes. Above 400 °C hydrogen is consumed from both solvent and gas. A major part of this appears to be involved in the stabilization of decomposition products from the tetralin. The yield of pentane-soluble material is relatively constant up to 450 °C, however, at higher temperatures conversion of asphaltenes and preasphaltenes to pentane-solubles occurs in conjunction with gasification to C₁–C₃ hydrocarbons. Despite the fact hydrogen consumption and oxygen removal both increase with rising hydrogenation temperature, the H/C atomic ratio for the three heavy oil fractions decreases over the same range.     

A correlation for predicting liquid viscosities of petroleum fractions

A correlation has been developed for estimating the liquid viscosities of petroleum fractions at 100°F and at 210°F. When used with the ASTM viscosity chart (or its analytical equivalent), the new correlation provides a method for the prediction of viscosity-temperature behavior of fractions from the Watson characterization factor and specific gravity. Essentially an extension of an API Data Book viscosity nomograph, the proposed correlation substantially improves on the accuracy and increases the range of applicability of this method. Greatest accuracy is achieved for petroleum fractions in the kerosene to heavy gas oil range, although acceptable accuracy for most engineering calculations is also obtained for lube oils and for many complex pure heavy hydrocarbons.     

Hydrothermal synthesis, characterization and structure refinement of chlorate- and perchlorate-sodalite

Chlorate- and perchlorate-sodalites were synthesized hydrothermally in the temperature range of 160°C to 500°C. IR absorption bands indicate the enclathration of NaClO₃ (624 cm⁻¹) and NaClO₄ (624 cm⁻¹ and 2050 cm⁻¹) in the sodalite cages. The thermal decomposition has been characterized by simultaneous thermal analysis (TG, DTG, DTA) and high temperature X-ray powder diffraction. The total collapse of the sodalite framework structure and the formation of nepheline could be observed at 750°C and 1100°C for chlorate-sodalite and perchlorate-sodalite, respectively.

The crystal structure has been determined for NaClO₄-sodalite showing cubic symmetry (a₀=9.071 Å, SG P 3n) and complete ordering of Si and Al in the silicate framework; the Si-O-Al angle is 146.7°. The Cl atoms of the enclathrated perchlorate are located at the central positions of the sodalite cages. For the oxygen atoms of the Cl₄⁻ anions the structure refinement led to orientationally disordered sites having a close resemblance to the well-known O(2) positions of basic sodalite Na₈[AlSiO₄]₆(OH)₂·2 H₂O.     

Electrical conductance of KI in anhydrous acetonitrile

The electrical conductivity of KI solutions in anhydrous acetonitrile has been determined at 0, 25 and 35°C in the concentration range 0·9– 600 × 10⁻⁴ mole/l. The values of Λ₀, K and a calculated from the results are, respectively: 145·9 mho/cm, 0·95 × 10 ⁻² and 1·72 Å at 0°C; 186·2 mho/cm, 8·98 × 10⁻² and 4·6 Å at 25°C; and 204·8 mho/cm, 5·17 × 10⁻² and 3·5 Å at 35°C. The phoreograms at all the three temperatures are catabatic at lower concentration, but become anabatic at 0·017, 0·022 and 0·024 respectively, at 0, 25 and 35°C.     

PREDICTION OF THE VISCOSITY OF CRUDE OIL FRACTIONS FROM A SINGLE MEASUREMENT

A generalized kinematic viscosity correlation is presented and used successfully to predict the viscosities of conventional crude oil fractions with an average absolute deviation of less than 1°. The correlation eliminates the use of physical properties and/or pseudo-critical parameters, and requires only a single viscosity measurement at 100°F and one atmosphere pressure to make a prediction     

Electrical resistivity of transition metal ion doped Mullite

The electrical resistivity of pure mullite (3Al₂O₃.2SiO₂) varies from 10¹³ ohm-cm at room temperature (r.t.) to 10⁴ ohm-cm at 1400 °C. It was observed that by doping mullite with the 3d-type transition metal ions, e.g. Mn, Fe, Cr and Ti, the resistivity of mullite could be reduced to 10¹¹ ohm-cm, i.e. 1/100 that at r.t. and 1/5 that at 1400 °C. The resistivity of doped and undoped mullite decreased by 6–5 orders at about 500–600 °C but 4–3 orders between this temperature and 1400 °C. The 3d orbital electrons, the oxidation states and the concentration of the transition metal ions as well as the sites of mullite lattice occupied by the ions were found responsible for lowering of resistivity of mullite. Evidence of the presence of Mn²⁺, Mn³⁺, Fe³⁺, Cr³⁺ and Ti⁴⁺ ions in mullite had been obtained which entered the octahedral site. The Ti⁴⁺ ion which substituted Al³⁺ ion in the octahedral site of mullite structure appeared to be the most efficient one to reduce the resistivity. This has been confirmed by the results of activation energy of resistivity/band gap energy, Eg which was the lowest for mullite doped with 1·0 wt% Ti⁴⁺ ion. At 1·0 wt% concentration level, these ions lowered the resistivity of mullite to minimum.     

Kinetics of asphaltenes conversion during hydrotreating of Maya crude

The kinetics of asphaltene conversion was studied during the hydrotreating of Maya heavy crude oil. Experimental tests were conducted in a pilot plant at the following reaction conditions: total pressure of 70–100 kg/cm², liquid hourly space-velocity (LHSV) of 0.33–1.5 h⁻¹, and reaction temperature of 380–420 °C at a constant hydrogen-to-oil ratio of 5000 ft³/bbl. A commercial NiMo/Al₂O₃ catalyst was used in all experiments. Asphaltenes were precipitated from Maya crude and from hydrotreated products in a Parr Batch Reactor at 25 kg/cm² and 60 °C with n-heptane as solvent. Asphaltene hydrocracking data were used to estimate reaction orders and activation energy using a power-law model, and the average absolute error between experimental and calculated concentrations of asphaltenes was found to be less than 5%.     

Nucleation and growth of Pd clusters in mordenite

The nucleation and growth of Pd clusters in mordenite were investigated using in situ extended X-ray absorption fine structure (EXAFS) spectroscopy and Fourier transform infrared (FTIR) spectroscopy of absorbed CO. Calcination of [Pd(NH₃)₄]²⁺-exchanged mordenite at 350°C in O₂ results in decomposition of the amine complex and formation of square-planar Pd²⁺ oxo species within the mordenite pores. Reduction of these species at 150°C in H₂ yields Pd clusters with an average nuclearity of 3. On an average two 2.22 Å Pd-O bonds are associated with each Pd₃ cluster; we infer that this interaction serves to anchor the clusters within the pores. After reduction at 150°C, the FTIR spectrum of irreversibly adsorbed CO is indicative of a mixture of Pd⁺, Pd^δ+, and Pd⁰ carbonyl species. Reduction at 350°C produces larger intrazeolitic Pd clusters (average nuclearity of 6) that exhibit only a weak interaction with the mordenite, as evidenced by their facile aggregation in the presence of CO at 30°C. Reduction at 450°C yields large 20 Å Pd clusters that we infer are located on external mordenite surfaces or locally disrupt the intracrystalline structure.     

Low-temperature prepared highly effective ferric hydroxide supported gold catalysts for carbon monoxide selective oxidation in the presence of hydrogen

Ferric hydroxide supported Au catalysts prepared with co-precipitation method at room temperature without any heat treatment hereafter exhibited high catalytic activity and selectivity for CO oxidation in air and CO selective oxidation in the presence of H₂. With calcination temperature rising, both activity and selectivity decreased. X-ray Photoelectron Spectra (XPS) indicated that Au existed as Au⁰ and Au⁺ in the catalyst without heat treatment and even after being calcined at 200 °C, while after being calcined at 400 °C, Au existed as Au⁰ completely. X-ray Diffraction (XRD) and High Resolution Transmission Electron Microscopic (HRTEM) investigations indicated that both the supports and Au species were highly dispersed as nano or sub-nano particles even after being calcined at 200 °C, but after being calcined at 400 °C the supports transformed to crystal Fe₂O₃ with typical diameter of 30 nm and Au species aggregated to nano-particles with typical diameter of 2–4 nm. HRTEM investigations also suggested that the supports calcined at 200 °C were composed of amorphous ferric hydroxide and crystal ferric oxide. Results of computer simulation (CS) showed that O₂ was adsorbed on Au crystal cell and then were activated, which should be the key factor for the subsequent reaction. It also suggested that O₂ species were more easily adsorbed on Au⁺ than on Au⁰, indicating that higher positive charge of the Au species possessed the higher activity for CO oxidation.     

Hydrogen production from coal-alkali interaction

The interaction between Poniati-Girimint coal and alkali has been studied at temperatures from 400 °C to 700 °C and with various ratios of alkali to coal from O to 1.4, using a heating rare of 5 °C min⁻¹ or shock heating at 600 °C. With slow heating, the optimum temperature and alkali to coal ratio for maximum yield of hydrogen at atmospheric pressure were 600 °C and 1.25, respectively. Under these conditions the yields of hydrogen and methane were 505 m³ and 76 m³ per tonne of coal, respectively. In shock pyrolysis the corresponding yields were 370 m³ and 34 m³ per tonne of coal, respectively. The recovery of alkali was 87%, 13% having reacted with the mineral matter of the coal. X-ray diffraction and infrared studies of the washed residual char indicated that the mineral matter present was highly dispersed and had probably been converted into sodium and aluminosilicates.     

Effective Au-Au-Clx/Fe(OH)y catalysts containing Cl for selective CO oxidations at lower temperatures

Supported Au catalysts Au-Au⁺-Cl_x/Fe(OH)_y (x < 4, y ≤ 3) and Au-Cl_x/Fe₂O₃ prepared with co-precipitation without any washing to remove Cl⁻ and without calcining or calcined at 400 °C were studied. It was found that the presence of Cl⁻ had little impact on the activity over the unwashed and uncalcined catalysts; however, the activity for CO oxidation would be greatly reduced only after Au-Au⁺-Cl_x/Fe(OH)_y was further calcined at elevated temperatures, such as 400 °C. XPS investigation showed that Au in catalyst without calcining was composed of Au and Au⁺, while after calcined at 400 °C it reduced to Au⁰ completely. It also showed that catalysts precipitated at 70 °C could form more Au⁺ species than that precipitated at room temperatures. Results of XRD and TEM characterizations indicated that without calcining not only the Au nano-particles but also the supports were highly dispersed, while calcined at 400 °C, the Au nano-particles aggregated and the supports changed to lump sinter. Results of UV–vis observation showed that the Fe(NO₃)₃ and HAuCl₄ hydrolyzed partially to form Fe(OH)₃ and [AuCl_x(OH)_4−x]⁻ (x = 1–3), respectively, at 70 °C, and such pre-partially hydrolyzed iron and gold species and the possible interaction between them during the hydrolysis may be favorable for the formation of more active precursor and to avoid the formation of Au–Cl bonds. Results of computer simulation showed that the reaction molecular of CO or O₂ were more easily adsorbed on Au⁺ and Au⁰, but was very difficultly absorbed on Au⁻. It also indicated that when Cl⁻ was adsorbed on Au⁰, the Au atom would mostly take a negative electric charge, which would restrain the adsorption of the reaction molecular severely and restrain the subsequent reactions while when Cl⁻ was adsorbed on Au⁺ there only a little of the Au atom take negative electric charge, which resulting a little impact on the activity.     

The preparation of high-surface area, thermally-stable, metal-oxide catalysts and supports by a cellulose templating approach

A simple and convenient templating approach for the preparation of metal-oxide catalysts and supports has been studied. The method, based on the absorption of an aqueous solution of metal salts by cellulose material, followed by drying and combustion of the organic matrix, leads to the formation of high-surface area mesoporous materials with unusually high thermal stability. Examples include Ce–Zr mixed oxides (BET surface areas of 90–130 m²/g after calcination at 800°C for 2 h; 21–30 m²/g after 12 h at 1050°C) and La-stabilized alumina (BET surface areas of 275–320 m²/g after calcination at 800°C for 2 h, 88–141 m²/g after 12 h at 1050°C). The pore-size distribution, morphology, and the effect of preparation parameters on surface area are discussed.