Factors affecting percent conversion

In this paper we report on factors which affect the conversion of fuel nitrogen to TFN in laboratory jet-stirred combustors which serve to simulate the primary zone in a gas turbine. The independent variables in the experiments were fuel type (aliphatic isooctane vs. aromatic toluene), equivalence ratio (fuel-to-oxygen ratio of combustor feed divided by stoichiometric fuel-to-oxygen ratio), average gas residence time in the combustor, and method of fuel injection into the combustor (prevaporized and premixed with air vs. direct liquid spray). Combustion temperature was kept constant at about 1900K in all experiments. Pyridine, C5,H5N, was added to the fuels to provide a fuel-nitrogen concentration of one percent by weight. 

The first step in the development of an optimum design is to determine what factor is to be optimized. Typical factors would be total cost per unit of production or per unit of time, profit, amount of final product per unit of time, and percent conversion. Once the basis is determined, it is necessary to develop relationships showing how the different variables involved affect the chosen... 

The enzymatic activity strongly depends on temperature. In case of reaction using Novozyme-435 in toluene, the polymerization rate of e-CL was the fastest at 90 C (7). Since Novozyme-435 can be used below 140 C without deactivation in scCOa as described above section, the reactivity was investigated as a function of temperature below 100 °C. The initial slope of the percent monomer conversion versus time plots was used to calculate the apparent rate constant ( app)- Figure 6 shows k pp depending on reaction temperature. The reaction provided the fastest rate at 80 °C, which is almost the same as the reaction in toluene. Even for the reaction condition at 20 °C lower than critical temperature, the enzyme catalyzed the polymerization of e-CL although the reaction rate was very slow. This indicates that super critical state is not required for polymerization of e-CL catalyzed by Novozyme-435. The dielectric constants at 10 MPa take between 1.54 and 1.12 at 10 C and 80 C, respectively. This range is not so wide that the reactivity wouldn t be affected. Rather the reaction temperature would be a dominant factor to enhance the polymerization. 

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