Extraction of Materials by Liquid Solvent Under Elevated Pressure



Developed by
Naik S N  Dr.
Center for Rural Development and Technology

Like liquids at normal pressure, liquids under elevated pressure can be used as solvents. For the separation of solute from such solvents liquefied gas is evaporated through the solvent. This process termed as Sub-critical Liquid Extraction (SLE) is simpler than the Super critical Fluid Extraction (SFE) and could be performed in one vessel only. The liquefied gas yields similar results both in terms of quality and quantity of the extract as super-critical gases used in SFE. SLE process is therefore less expensive and can be applied to many practical problems relating to leaching of plant materials, soils, polymers, etc.


A schematic diagram of the device for SLE process is given in the figure enclosed. The device broadly comprises of an autoclave (1) with in-built extraction chamber (2) channel s(4) & (5) for passage of liquid solvent , evaporation chamber (6A) and a condenser (8). The raw material (3) to be subjected for extraction procedure is taken in the extraction chamber while liquid solvent (carbon dioxide) is filled in channel (4) so that hydrostatic pressure is created for forcing the liquid solvent through the raw material. The solvent after getting loaded with the extract falls through the channel (5) into the evaporation chamber where the extract (6) gets deposited at the bottom and collected through the valve (7). Liquid solvent after evaporation passes upwards through channel (5) into the condenser (8) and collects in the channel (4) through the path (9).

Special Features:
Extraction from plant materials using liquid solvent at elevated pressure; Continuous extraction mode in a single vessel; Use of Liquid carbon dioxide more suitable for extraction of food flavors, essential oils and fragrance from plant materials; Efficient extraction; Better quality of extract.

Prospective users
Extraction of flavours, essential oils from plant materials like, Hop flower, clove, cumin, cedar wood etc

Extraction, plant material, liquid carbon dioxide, flavours

Type of Technology:

Status of IPR Protection:
Indian Patent Application with the title "An apparatus and method for continuous extraction of material by liquid under elevated pressure"

Status of Development:
A pilot plant (10 ltrs.) has been designed and operated for extraction of flavouring compounds from Hop flowers. Detailed chemical analysis of the extract established the quality of extract is very go

Major Equipment & Facilities required:
Extraction/Separation Vessel; High Pressure Compressor; Heat Exchanger; Instrumentation and Control; Laboratory equipment; Thermic Fluid Generator; Cold Storage Tanks; Packaging machinery.

Services offered by Technology Transfer:
Know how manual including quality control procedures
Design of 10 ltrss. Pilot plant
Process demonstration

For further informatiom, Please contact directly the faculty member/inventor under intimation to Managing Director, FITT, sengupta@fitt.iitd.ernet.in.