# Energy Recovery via Thermal Gasification from Waste Insulation Electrical Cables (WIEC)
## 4 Results
### System Efficiency for the Blending Ratio 80:20 for PFB/Wiec  
Regarding the theoretical parameters, it is possible to state that when LHV increases, the ER also increases, and CGE also increases. Larger ER are associated with oxidation reactions with a higher rate than thermal cracking reactions [48] and, eventually, an increase in CO2 and N2 concentrations. However, the concentrations of CO and H2 in the syngas tend to decrease. If one compares the reduction in the concentration of H2 with the increase in the ER, it is possible to notice that it does not increase due to the presence of polymeric as compared with the forest biomass. The presence of higher concentrations of volatile material in WIEC increases the amount of tar produced. Therefore, the cracking and tar adsorption reactions with high ER, maintain a high operating temperature which helps in increasing the H2 concentration [49]. In addition, with the improvement of the ER, an evolution in the concentrations of H2 and CO was noted. This was the case presented in a gasification by [PERSON] et al. [50], in which, while there was a reduction from 0.38 to 0.25 of the ER, it was observed that the percentage of H2 and CO increased to 33% and 70%, respectively. It can be noted that ER has a variation of 0.05 between tests, where the minimum ER obtained is 0.23 and the maximum ER is 0.28 for the 10 kW and 15 kW tests, respectively. During each test, another observation was that the ER tended to decrease, except for the 10 kW test, where a lower LHV of the synthesis gas led to the engine needing more fuel, and consequently more oxidizing agent entering the reactor. The studies explained the effects of ER on the gasification of polymeric residues, with air as an oxidizing agent [51]. The results showed that the lowest heating value decreased from 13.42 to 7.05 MJ/Nm\({}^{3}\) when the ER was increased from 0.21 to 0.41. A similar result was also presented by [PERSON] et al. [52], with a higher heating value reducing from 11.3 to 5.17 MJ/Nm\({}^{3}\) when the ER was increased from 0.2 to 0.45. In Table 3, the results of some experiments, for lowest or equal temperatures, showed that for a higher ER, the H2 content was higher, due to the fact that a lower temperature in the oxidation zone favored a greater capitalization of light hydrocarbons, which when entering in the reduction zone, underwent secondary cracking, producing shorter chain hydrocarbons and other products of the gas phase, such as H2. Although an increase in ER reduces the evolution of H2 and CO, the high temperatures in the bed means that there is an improvement in cracking of the alkali, consequently improving the reaction of coal formation through the water-gas shift and Boudouard reactions [52]. This fact is quite visible when compared with the results of controlled tests with vacuum pumps and tests performed with the engine, where tar production was much lower. To carry out the efficiency experiments, three electric loads were used in the generator, 5, 10, and 15 kW, with a duration of three hours for each experiment. All energy balances were considered, as shown in Table 4.  
The results in Table 4 show that the efficiency of the engine remained practically the same, regardless of the electrical load that was used, remaining between 16% and 19% throughout the tests.