The Soave-Redllch-Kwong equation of state has been modified to apply to water-hydrocarbon phase equilibria in all the regions of the phase diagram. The difficulties in predicting the data in the hydrocarbon-rich and water-rich liquid regions simultaneously have been overcome by the use of an unsymmetric mixing rule. A concentrationdependent term is introduced in the water-hydrocarbon interaction to represent the structural effects in the hydrophobic interactions. The correlation so obtained is applicable over a wide range of temperatures and gives better results than any other generalized correlations available In the literature.

Nonequilibrium molecular dynamics simulations are used to study vibrational energy relaxation (VER) in liquid nitromethane after excitation of the C−H stretching vibrations. The simulated liquid consists of a mixture of excited and unexcited molecules, where the unexcited molecules were used to monitor excitation of the bath upon vibrational relaxation of the excited molecules. A previously developed projection method (Raff, L. M. J. Chem. Phys. 1988, 89, 5680) was employed to monitor the normal-mode kinetic energies of vibrations in both excited and unexcited molecules as functions of time. Overall, the results are in qualitative agreement with experimental measurements of VER in liquid nitromethane after mid-IR excitation in the C−H stretching region (Deak, J. C., Iwaki, L. K., Dlott, D. D. J. Phys. Chem. A 1999, 103, 971). The simulation results indicate that the excited C−H stretching vibrations deposit energy predominantly into the remaining vibrations in the molecules. These vibrations relax at different rates, resulting in a multistage vibrational cooling process for nitromethane, in agreement with experimental results. The excitation of vibrations of the surrounding unexcited molecules occurs through indirect rather than direct intermolecular vibrational energy transfer processes, also in agreement with experiment.

The effects of H 2 /CO ratio in syngas from a biomass gasifier, the type of a Fischer-Tropsch (FT) catalyst, addition of a reformer in a recycle mode, efficiency of CO 2 removal, and co-feeding of biomass and natural gas on the overall thermal efficiency and costs for the production of FT liquid fuels from the biomass-derived syngas were analyzed using an Aspen Plus ®-based process model. The overall thermal efficiency for biomass-fed processes was in a range of 41.3-45.5%. A

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