Densities and Viscosities for the Ternary Mixture of <i>n</i>‑Undecane (1) + Methyl Decanoate (2) + <i>n</i>‑Butanol (3) and Corresponding Binaries from <i>T</i> = 293.15 to 333.15 K and at Atmospheric Pressure

It has been proved that the general performance of aviation fuels can be improved with the addition of biofuels. To understand the fundamental physical properties of the blends, n-undecane, methyl decanoate, and n-butanol were chosen as model compounds to construct a mixed system. Densities (ρ) and viscosities (η) of the ternary system n-undecane + methyl decanoate + n-butanol and its corresponding binary systems n-undecane + methyl decanoate, n-undecane + n-butanol, and methyl decanoate + n-butanol were measured at different temperatures T = (293.15–333.15 K) and atmospheric pressure p = 0.1 MPa. The excess molar volumes (VmE) and the viscosity deviations (Δη) of the binary systems and the ternary system were correlated to the Redlich–Kister equation and four semi-empirical equations, respectively. The VmE values of the ternary system and binary systems are all positive over the entire concentration range at each experimental temperature, while their Δη values are all negative. The experimental results can provide reliable data for the compatibility of biofuels and fossil fuels

Densities and Viscosities for the Ternary Mixtures of <i>n</i>‑Undecane (1) + Butylcyclohexane (2) + 1‑Pentanol (3) and Corresponding Binaries at <i>T</i> = (293.15 to 333.15) K

The actual composition is known to be highly responsible for the physical and chemical properties of a fuel. To understand the foundational physical properties of an aviation kerosene substitute mixture for hypersonic aircraft, n-undecane, butylcyclohexane, and 1-pentanol were used to construct a ternary system. The values of density (ρ) and viscosity (η) for the ternary system and three corresponding binaries were measured at temperatures T = (293.15 to 333.15) K and pressure p = 0.1 MPa. The Redlich–Kister equation was used to fit the excess molar volumes (VmE) and viscosity deviations (Δη) of the binary systems, while those of the ternary system were correlated with four semi-empirical formulas (Cibulka, Singh, Redlich–Kister, and Nagata–Tamura equations). The experimental results show that the VmE values of the three binary mixtures have a positive relationship with the mole fraction of nonpolar components, while Δη values have a negative relationship. The non-ideal behavior of mixtures is discussed from the perspective of molecular interactions and structural effects. This work provides data support and guidance for fuel compatibility research

All-Silicon Zeolite Supported Pt Nanoparticles for Green On-Board Inert Gas Generation System

Green On-board Inert Gas Generation System (GOBIGGS) is regarded as one of the most promising routes for fuel tank inerting, whose operation efficiency can be remarkably promoted by an excellent catalyst. In the present work, three kinds of all-silicon zeolite-supported Pt nanoparticles, Pt/Si-Beta, Pt/Si-ZSM-5, Pt/SBA-15 were prepared and characterized. The activities of these catalysts for flameless combustion of fuel samples were investigated on a self-designed apparatus. The results show that among these tested catalysts, Pt/Si-Beta has the best catalytic activity, which can catalyze the complete combustion of methylcyclohexane and aviation kerosene RP-3 at 166°C and 241°C, respectively. The superb activity of Pt/Si-Beta can be ascribed to its striking hydrocarbon adsorption capacity. It can also be found that the 1.0 wt% loading amount of Pt is appropriate to meet the actual demand of the GOBIGGS system, considering catalytic effects and costs. Moreover, Pt/Si-Beta tends to exhibit superior activity and stability even in different humidity and space velocity environments for a long time. It can maintain a conversion rate of around 98% even after 30 h of continuous using. All of these show that Pt/Si-Beta has the potential to be applied to the GOBIGGS system.</p

Density and Viscosity Measurements on the Ternary System of <i>exo</i>-Tetrahydrodicyclopentadiene (1) + <i>n</i>‑Decane (2) + Iso-Butanol (3) and Corresponding Binary Systems

exo-Tetrahydrodicyclopentadiene can serve as both the propellant and coolant in hypersonic vehicles. However, its applications are restricted by the poor properties of ignition and combustion to some extent. Fuel additives such as appropriate alcohols have the ability to overcome these deficits. Research on thermophysical properties of the mixtures composed of exo-tetrahydrodicyclopentadiene and fuel additives can provide important information for the research of fuel additives. In this work, densities and viscosities of the ternary system of exo-tetrahydrodicyclopentadiene (1) + n-decane (2) + iso-butanol (3) and three corresponding binary systems have been measured over the whole composition range in the temperature range from 293.15 to 333.15 K with an interval of 5 K and at pressure p = 0.1 MPa. The values of excess molar volumes (VmE) and viscosity deviations (Δη) of three binary systems and the ternary system were calculated and then fitted to the Redlich–Kister equation and four semi-empirical equations, respectively. The variations of VmE and Δη were explained from the viewpoints of intermolecular forces and structural effects. Furthermore, the Jouyban–Acree model was used to correlate the values of densities (ρ) and viscosities (η) of the studied mixtures with high accuracy

Densities and Viscosities for the Ternary System of Decalin + Methylcyclohexane + Cyclopentanol and Corresponding Binaries at <i>T</i> = 293.15 to 343.15 K

Densities (ρ) and viscosities (η) for the ternary system of decalin (1) + methylcyclohexane (2) + cyclopentanol (3) and three corresponding binary systems have been measured over the whole composition range at 11 temperature points from 293.15 K to 343.15 K under atmospheric pressure (0.1 MPa). The excess molar volumes (VmE) and viscosity deviations (Δη) of binary systems have been calculated and further fitted with the Redlich–Kister equation, while corresponding physical data of the ternary system have been correlated via the Clibuka, Singh, Nagata-Tamura, and Redlich–Kister equations. The VmE values are negative for the binary system of decalin (1) + methylcyclohexane (2) with a minimum when the moles of the two components are similar. For the system of decalin (1) + cyclopentanol (2), the VmE values are always positive with a maximun at about x1 = 0.6. At the same time, a sigmoid curve can be observed for the system of methylcyclohexane (1) + cyclopentanol (2). The minimum and maximum appear around x1 = 0.2 and x1 = 0.9, respectively. The Δη values of the three binary systems are all negative and the absolute values decrease with increase in temperature. For the ternary system, the VmE values are partially negative and the Δη values are negative over the entire concentration range. The nonideal behaviors of the mixtures are discussed in the perspective of intermolecular interaction and structural effect

Strategically Designed Hyperbranched Polyglycerol as an Efficient Integrated Additive for Hydrocarbon Fuels

In this study, palmitoyl and hindered phenolic hyperbranched polyglycerol (CBHPG), with hyperbranched polyglycerol (HPG) as the structural core and hindered phenol or alkyl chain as the decorated shell, has been strategically designed and synthesized as an efficient integrated additive to enhance the energy efficiency and inhibit the oxidation coking of hydrocarbon fuels. The superior thermal stability and solubility of CBHPG were confirmed by thermal gravimetric analysis and dynamic light scattering. In the presence of CBHPG with high antioxidant activity, the oxidation induction time of n-undecane increased more than 2-fold at 170 °C. In deposition tests, the amphiphilic macromolecule CBHPG showed excellent performance with 58% oxidation coking inhibition rate of Chinese Jet Fuel (RP-3). The Jet Fuel Thermal Oxidation Stability test at 355 °C also exhibited that CBHPG could greatly reduce the deposit of RP-3 by decreasing the deposit rating from >4 to <1. In cracking experiments, the addition of 0.1 wt % CBHPG with sufficient polymerization could increase the conversion of n-undecane by 17.6%, with the corresponding heat sink by 6.1% at 675 °C. The above results indicated that CBHPG could efficiently enhance the performance of hydrocarbon fuels due to multipurposes in antioxidation, coking inhibition, and cracking promotion. CBHPG with a strategically designed structure as an integrated additive shows great promise in improving the energy efficiency and safety in future advanced aircraft

Densities and Viscosities of the Ternary Mixtures of Decalin (1) + <i>n</i>‑Hexadecane (2) + 1‑Butanol (3) and Corresponding Binary Systems

Active cooling by endothermic hydrocarbon fuels (EHFs) is considered as a practical approach to deal with the thermal management problem of hypersonic aircrafts. As a typical component of EHFs, decalin is usually thermally stable while it is apt to coke and has poor combustion performance. n-Hexadecane, a normal alkane with a relatively high H/C ratio, can effectively improve the combustion performance of EHFs, and 1-butanol has remarkable anti-coking properties. As a fundamental work for fuel design, decalin, n-hexadecane, and 1-butanol were selected as model compounds to construct a surrogate fuel system, which was used to investigate the effects of composition and condition on its thermophysical properties. Densities (ρ) and viscosities (η) of the ternary system of decalin (1) + n-hexadecane (2) + 1-butanol (3) and corresponding binary systems were measured at temperatures T = (293.15 to 333.15) K and pressure p = 0.1 MPa. The excess molar volumes (VmE) and the viscosity deviations (Δη) of the mixtures were calculated and fitted to several semi-empirical equations. The tendencies of VmE and Δη with composition and temperature were discussed from intermolecular force and molecular size, respectively