## 3 Results and Discussion
### Case Study B: Hybridization with GT (Gas Turbine) Fed with External Fuel
During the preheater design, it is important to control the minimum displacement of the pinch point temperature in this zone by properly selecting the exchange area or the outlet temperature of the hot fluid. This singularity can be seen in Figure 12b, where the temperature difference between the hot and cold fluids is shown with respect to the exchanged thermal power parametrized for different glycerol concentrations. Keeping in mind Figure 5, the heat capacity behavior at the lowest glycerol concentration (10 wt.%) reaches a greater maximum value at lower temperatures than at the highest concentration of glycerol (30 wt.%). The evolution of the observed fluid property allows the transition of cold fluid to supercritical phase at lower thermal power when the glycerol concentration increases. For the temperature considered at the reactor inlet (520 \({}^{\circ}\)C), the minimum pinch point temperature always occurs at the beginning of the preheater. However, when the temperature at the reactor entrance is below 520 \({}^{\circ}\)C, the minimum pinch point temperature is moved to an intermediate point of the preheater (the exchanged thermal power is approximately between 300 and 400 kW) instead of taking place at the entrance. To calculate the exhaust gas flowrate and the mechanical power produced by the GT, a fuel-air equivalence ratio of 0.319 is considered [55]. As is well known, this fuel-air equivalence ratio is applied to the whole combustion chamber from an energy balance point of view, although the combustion chamber is designed in such a way that combustion evolves at the stoichiometric fuel-air equivalence ratio. For this case, the electricity generation yield (n\({}_{\text{GCT}}\)) achieves 30% [55]. Figure 13a shows the electricity generation in the GT for the operating conditions. In the same way, to quantify the available energy in the hot effluent leaving the reactor, a cycle yield of 12% [55] is considered for the exchange of thermal power. Figure 13b exhibits the electricity generation for different operating conditions of the plant. Figure 12: (**a**) TQ curve along the preheater; (**b**) Temperature difference between the hot and cold streams in the preheater versus the exchanged thermal power for different glycerol mass concentrations. As can be seen in these figures, the results obtained show the same trends previously explained for case study A, increasing the electricity generation when the plant operates at low glycerol concentrations in the feed stream. Thus, data obtained from Figure 13 show that the plant with GT could produce total electrical power in the range from 482 to 684 kW. By evaluating the electrical efficiency as previously described in case study A (but considering electricity generated in the GT instead of the ICE), the values obtained are exposed in Table 5. These results are obtained when the reactor inlet temperature is 520 \({}^{\circ}\)C.  
As previously mentioned in case study A, syngas (mainly H2, CH4, and CO) generation can be referenced to the base scenario but moving the operating temperature range to those considered here (established by the temperature of the exhaust GT gases). Although the proposed process configurations do not allow the operation of the plant without external energy supply, there are other alternative technologies that can satisfy the demand for energy. In this way, future research directions are proposed in the next section as new case studies to be analyzed in forthcoming works.