## 3 Results and Discussion
### Proximate Analysis  
Distillation stilage has a moisture content of 5.454%, slightly higher than the 5.268% moisture content of wine pomace (Table 3). The small difference can be attributed to the evaporation of water during the distillation process, which results in a relatively higher moisture content in the distillation stilage. Low moisture content is advantageous for energy recovery because it means less energy is required to evaporate the water during combustion or thermal conversion processes, making both samples suitable in this regard. The volatile matter content, which represents the portion of the biomass that vaporizes when heated and is indicative of the material's combustibility, is 58.97% for distillation stilage and 62.695% for wine pomace. Wine pomace's higher volatile matter content  
Figure 1: Oven drying curves at 30 °C.  
suggests that it may have a higher potential for energy release during combustion. Ash content, the non-combustible residue remaining after combustion, is 3.762% for distillation stillage and 6.359% for wine pomace. Lower ash content is preferable for energy recovery since it reduces the amount of residue and fouling in combustion systems. In this case, distillation stillage has a significant advantage with its lower ash content. Fixed carbon, which contributes to the char left after volatile matter is released and is an important factor for sustained combustion, is 31.813% for distillation stillage and 25.677% for wine pomace. The higher fixed carbon content in distillation stillage indicates a greater potential for sustained energy release through slower-burning carbon residues.  
When comparing these findings with the study by [43], which analyzed grape stalks and grape pomace, similar patterns emerge. Grape stalks had a moisture content of 7.20%, volatile matter of 71.6%, ash content of 5.20%, and fixed carbon of 16.0%. Grape pomace had 5.40% moisture, 70.2% volatile matter, 6.40% ash, and 18.0% fixed carbon. The distillation stillage and wine pomace from this study has lower moisture and volatile matter contents than the grape stalks and grape pomace analyzed by [43], but the fixed carbon content in this distillation stillage is significantly higher, indicating a superior potential for sustained energy release.  
The t-test results from the proximate analysis reveal that significant differences exist between the two materials in volatile matter content (\(p\)-value equal to 0.00112), ash content (\(p\)-value equal to 0.000348), and fixed carbon content (\(p\)-value equal to 0.0000418). However, there is no significant difference in moisture content (\(p\)-value equal to 0.105).  
In summary, both distillation stillage and wine pomace show promise for energy recovery. Distillation stillage has advantages with lower ash content and higher fixed carbon, suggesting more efficient combustion with less residue. Wine pomace, with higher volatile matter content, may offer a quicker and more intense initial energy release. The choice between the two would depend on the specific requirements of the energy recovery process, such as the need for rapid energy release versus sustained combustion with minimal residue.