10. Solid-liquid extraction pilot plants

a) Soxhlet-type plant

Brand and model:In-house manufacturing.

Temperature range:0 to 180 °C.

Operating pressure:-1 to 1 bar.

Description:Stainless steel equipment with a solids extraction vessel of 30 L volume. Includes an evaporator.

The plant consists of four main parts:

A) Thermo tank with agitator (38 L capacity).
B) Condensation and storage column.
C) Reactor (30 L capacity).
D) Water traps.

b) Delignification plant

Brand and model:In-house manufacturing.

Capacity:800 L extractor.

Description:The extraction plant is made of stainless steel (DIN 1.4571), except for the pump and heat exchanger, and consists of the following parts:

A) 800 L extractor (maximum pressure 12 bar).
B) Recirculation pump (Rheinhütte, titanium, 3 kW motor).
C) Heat exchanger (Schiller, Hastelloy C4, 6 m² exchange surface).
D) 6 storage tanks (1 m³, atmospheric pressure).

c) Bark extraction plant

Brand and model:In-house manufacturing.

Capacity:4000 L extractor.

Description:The extraction plant is made of stainless steel (DIN 1.4571), except for the pump and heat exchanger, and consists of the following parts:

A) 4000 L extractor (maximum pressure 6 bar).
B) Recirculation pump (KSB, stainless steel 316, 1.5 kW motor, 12 m³ flow rate).
C) Heat exchanger (in-house manufacturing, stainless steel 304L, 7.96 m² exchange surface).
D) Pressurized storage tank (2.3 m³, maximum pressure 6 bar).

d) Continuous extraction plant

Brand and model:In-house manufacturing.

Capacity:Between 1–5 kg/h.

Description:Composed of four modules operating in series, each consisting of a vertical feed tube and an inclined reaction tube, both equipped with screws for forced material transport. The extraction liquid circulates in countercurrent. The components are:

A) Solid feed tank.
B) Solid feed tank to pressure zone.
C) 4 inclined extractors with transport screws.
D) Solid discharge system from the pressure zone.
E) Tank and pump for the circulation of the extraction liquid.