trogen species. Although we cannot definitively separate the contributions of the PACN and soot to the yield of gtiseous nitrogen, the data suggest that, in the PAC conversion regime of our measurements, the net effect of the conversion of the nitrogen in PAC is the production of gaseous nitrogen species, most probably HCN.

The cycloaddition reaction between isoamylene and α-methylstyrene yields indane compounds 1,1,2,3,3,-pentamethylindane and 3-ethyl-1,1,3-trimethylindane, which are intermediate cyclic products used in the synthesis of musk fragrances. This exothermic reaction is usually carried out industrially in large semibatch reactors. The microreactor, with enhanced heat and mass transfer characteristics, was used for the reaction with aqueous sulfuric acid as catalyst. The dependence of reactant conversion, product yield, and average reaction rates on catalyst concentration, temperature, velocity, residence time, and the molar ratio of the reactants in the feed was investigated. A similar study was also performed in the semibatch reactor to compare its performance with that of the microreactor. Higher product yields were obtained in the microreactor, and the average reaction rates in the microreactor were 3 orders of magnitude greater than those obtained in the semibatch reactor.

The cycloaddition reaction between isoamylene and ?-methylstyrene yields indane compounds 1,1,2,3,3,-pentamethylindane and 3-ethyl-1,1,3-trimethylindane, which are intermediate cyclic products used in the synthesis of musk fragrances. This exothermic reaction is conventionally carried out industrially in large semibatch reactors, which have high heat and mass transfer resistances, are difficult to optimize, and scale-up. Aqueous sulfuric acid is conventionally used as the catalyst for the cycloaddition reaction, but solid catalysts offer many advantages over the corrosive aqueous sulfuric acid catalyst including the elimination of expensive separation and purification steps, and the need to use corrosion resistant materials of construction. A microreactor, which has enhanced heat and mass transfer characteristics, high surface to volume ratio, and improved fluid mixing, was used for the reaction using an acidic solid catalyst, Filtrol-24. A parametric study to obtain the dependence of product yield, reactant conversion and space-time yield on process variables such as catalyst particle size, residence time, velocity, temperature, pressure and the molar ratio of the reactants in the feed, was conducted. Through this study the optimum reaction conditions were obtained. The cycloaddition reaction was also performed in the semi-batch reactor using Filtrol-24 catalyst in order to compare its performance to that of the microreactor. Higher product yields were obtained in the microreactor compared to the semi-batch reactor, and the space-time yield in the microreactor was 4.8 times larger than that obtained in * The financial and technical support from International Flavors and Fragrances, Inc.; and Graduate Tuition support from the Stevens Institute of Technology are gratefully acknowledged. The authors wish to thank all the members of NJCMCS at Stevens who provided valuable help during different stages of this project.Brought to you by | Gazi Universitesi Kutuphane ve Dokumanta Authenticated Download Date | 2/5/15 4:47 PM the semi-batch reactor at optimum reaction conditions in both reactors.

The hydrophilic/ hydrophobic nature of coals may be understood by considering the free energy changes associated with wetting. This approach has its basis in fundamental thermodynamics, and it explains the hydrophilic and hydrophobic nature of coal particles on the basis of molecular-level interactions. This includes surface characteristics like the increase in hydrophilicity due to oxidation and the variation of hydrophobicity with coal rank, which are well established in the literature. The free energy changes involved with the wetting of three coals with three hydrocarbon oils were measured. From these measurements, the contributions of each coal and each oil to the free energy change could be distinctly quantified. The fact that hydrophobic/hydrophilic interactions are driven by entropic effects makes the free energy measurements particularly useful in the study of such interactions. With a combination of FTIR spectroscopy and wet chemical techniques, the role of hydrogen bonding in such interactions were investigated. The factors affecting the surface free energy and methods for their assessment are discussed.