3.4. Energy consumption
An energy consumption monitoring of the different experiments was performed. Table 3 indicates the measures obtained per process. It appears clearly that 5 h reflux is the most energy-consuming technique (850 kWh/kg extract) and consequently the process with the highest carbon emissions associated (680 kg CO2/kg extract). It is mainly due to the long extraction duration (5 h). US processes applied during 30 min present the lowest values compared to MW processes and HRE: US probe resulted in an energetic consumption of 23 kWh/kg extract and 19 kg CO2/kg extract. MW treatments also show reduced values compared to HRE, with few differences between MW processes