Fig 1.
Overview of the 19 experimental conditions employed in this study.
Fig 2.
Schematic figure of basic extraction pilot-scale installation.
Reprinted from Machado et al. [16] under a CC BY license, with permission from Carlos Machado, original copyright 2023.
Fig 3.
Diagram with instrumentation, chilled water, channeling control, and image processing system.
Reprinted from Machado et al. [17] under a CC BY license, with permission from Carlos Machado, original copyright 2023.
Fig 4.
Process flowchart with embedded technology.
Fig 5.
Control architecture: Sensors, image processing system and programmable logic controller (PLC) at plant floor level and remotely installed SCADA (plant floor or control room).
Reprinted from Machado et al. [18] under a CC BY license, with permission from Carlos Machado, original copyright 2023.
Fig 6.
Thermocouple installation: Inserted directly into the raw material mass.
Fig 7.
Process temperature (channeling detection) of Experiment 11.
(A) TT1 and TT2. (B) TT3 and TT4. (C) TT5 and TT.
Fig 8.
Channeling correction apparat: Thin stainless-steel paddles reaccommodate the herb in order to attenuate or minimize the effects of channeling.
Fig 9.
Channeling control flowchart: Temperature differences are the input; control system answers with a step-motor action.
Fig 10.
The routine of endpoint determination: After the maximum slope period, the economical endpoint is determined during the asymptotic phase.
(A) Routine for the economical extraction time with image processing system. (B) Sketch of the extracted volume versus time graph.
Fig 11.
Image of the extraction endpoint.
Experiment 17. (B) Experiment 18. (C) Experiment 19. Reprinted from Machado et al. [18] under a CC BY license, with permission from Carlos Machado, original copyright 2023.
Table 1.
Average extracted volume per experimental mode.
Fig 12.
Yield data (mL/kg) of the EO extraction process according to the 19 experimental batches performed.
Fig 13.
Citral content determined by chromatography for the 19 experimental batches performed.