The future high-Mach aircraft requires advanced jet fuel with high stability in rigorous thermal environments. In this work high-temperature thermal stability of two JP-8 type jet fuels, a petroleumderived JP-8P and a coal-derived JP-8C was studied by stressing in closed reactors at 450 °C under 0.7 MPa of N2 for periods ranging from 0.5 to 16 h. The extents of fuel degradation in terms of liquid depletion, gas formation, and solid deposition were always higher with JP-8P than with JP-8C.There appeared an induction period for solid formation, which was longer for JP-8C than for JP-8P. Tests with the saturates isolated chromatographically from these fuels indicated that JP-8C saturates are much more stable than the JP-8P saturates, and the higher stability of JP-8C is due to its composition. JP-8C is rich in one-to three-ring cycloalkanes and two-ring hydroaromatics, while JP-8P is composed mainly of long-chain paraffins. GC-MS provided valuable information on the relative stability and molecular transformation of hydrocarbon components in these jet fuels. Cycloalkanes were found to be more stable than long-chain paraffins with the same carbon number. The stability decreases with increasing length of main chain for the long-chain paraffins, or side chain for alkylcycloalkanes. Multisubstituted cycloalkanes are more stable than the monosubstituted ones with the same carbon number. Steric conformation of cycloalkanes also affects their reactivity; for decalin, the trans isomer was found to be more stable than the cis isomer. The higher stability of JP-8C can be attributed mainly to its higher content of cycloalkanes. Tetralins and decalins present in JP-8C also contribute to capping the thermally generated reactive radicals by hydrogen donation.

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Sulfonated sucrose-derived carbon, glucose-derived carbon, and nut shell activated carbon (NSAC) catalysts were prepared and characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). FT-IR and XPS spectra showed that −SO3H groups could be introduced into the carbon precursors after the sulfonation treatment. Higher concentration of −SO3H groups in the sulfonated sucrose-carbon and glucose-carbon most likely accounts for their higher activities compared to sulfonated NSAC. Hydrolysis of microcrystalline cellulose was examined in a common ionic liquid, 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), with the sulfonated carbon catalysts. Maximum yields of glucose (59%) and total products (80%, defined as the sum of glucose, cellobiose, and 5-hydroxymethylfurfural) could be obtained with sulfonated sucrose-carbon at 120 °C for 4 h. With a regeneration procedure, the catalyst could be reused.

This article provides an introductory overview for defining the scope, potential and limitations of carbon dioxide (CO 2 ) conversion and utilization. There are various sources of CO 2 emissions, which are dominated by combustion of liquid, solid, and gaseous fuels. The amount of CO 2 consumption for organic chemicals is relatively small compared to CO 2 emitted from fossil fuel combustion. However, CO 2 conversion and utilization should be an integral part of carbon management. Proper use of CO 2 for chemical processing can add value to the CO 2 disposal by making industrially useful carbon-based products. Studies on CO 2 conversion into carbon-based chemicals and materials are important for sustainable development. CO 2 conversion and utilization could also be positioned as a step for CO 2 recycling and resource conservation.Carbon dioxide, C0 2 , is a colorless and odorless gas. The molecule is linear with a double bond between the carbon and oxygen atoms (0=C=0). C0 2 occurs in nature and serves as source of carbon for photosynthesis of plants and crops. It is present in atmosphere with a volumetric concentration of 0.037 % (368 parts per million by volume) as of December 1999 (1). Combustion of most carbon-containing substances produces CO2. Energy utilization in modern societies today is'based on combustion of carbonaceous fuels, which are 2