A thermodynamically consistent model was developed for representing vapor-liquid equilibria in the acid gas (H2S, COJ-alkanolamine-water system. The model accounts for chemical equilibria in a rigorous manner. Activity coefficients are represented, with the Electrolyte-NRTL equation treating both long-range ion-ion interactions and local interactions between all true liquid-phase species. Both water and alkanolamine are treated as solvents. Adjustable parameters of the Electrolyte-NRTL equation, representing short-range binary interactions, were fitted on binary and Previous ModelsBecause of the difficulty in representing activity coefficients in concentrated electrolyte solutions, early VLE models for weak electrolyte models adopted empirical approaches that did not account for physical interactions. Van Krevelen et al. (1949) proposed a method for representing H2S, COz, and NH3 equilibrium partial pressures over aqueous solutions. In equations governing chemical equilibria, they used "apparent" equilibrium constants related to component concentrations rather than activities. In effect, they set, activity coefficients of all species to unity. Apparent equilibrium constants were fitted on experimental data to functions of ionic strength. Dankwerts and McNeil (1967) used this method to calculate vapor-and liquid-phase compositions in amine-C02-H20 systems.Kent and Eisenberg (1976) used a similar approach to represent H2S and COP equilibrium partial pressures over aqueous solutions of MEA and DEA. They also employed

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The liquefaction of pure -cellulose with hydrogen-donor solvents such as tetralln and 2-propanol was studied In a batch autoclave system under both inert and hydrogen atmospheres. Reaction conditions Involved temperatures between 270 and 400 °C, residence times between 0 and 60 min, and hydrogen pressures between 0 and 500 psi. The use of homogeneous and heterogeneous hydrogenolysis catalysts was also Investigated. Under these conditions, up to 100% of the initial cellulose feed was converted, resulting in oil yields greater than 50%. The oxygen content of the product oil was significantly lower than that of the cellulose feed (less than 25 wt % in most cases), and it generally decreased with increasing reaction temperature. Low and Intermediate temperatures (<360 °C) favored oil production, while higher temperatures Induced severe hydrocracking of the product oil to gases.