Liquid materials mainly refer to fats and oils, food, and article liquids(CO2 Essential Oil Extraction). The CO2 extraction process is divided into two process forms: countercurrent CO2 extraction(supercritical CO2 fractionation) and forward CO2 extraction.
Countercurrent CO2 extraction
Forward CO2 extraction
That is to say, the contact between CO2 fluid and liquid material is not the contact in the countercurrent state, but the cocurrent contact in the state of moving in the same direction.
The forward CO2 extraction process is more suitable for the extraction of food or pharmaceutical liquid materials. When the liquid material and the CO2 fluid are in parallel contact, they have high enzyme purification ability, disinfection ability and deodorization ability, and after fully contacting each other, they reach the upper part of the extraction tank together, where they are separated into two phases from each outlet discharge.
- The liquid material is sent out of the product tank through the product channel as a sterilized product with purified enzymes. In the CO2 extraction vessel, the discharge port of the CO2 fluid is arranged on the wall above the liquid material level.
- A pipe connects the discharge port to the recirculation tank, which forms a recovery channel for recirculating the supercritical fluid containing volatile components.
- The pressure control valve is set on the supercritical CO2 fluid recovery channel. When the CO2 fluid is recovered into the recirculation tank, the pressure is reduced and the CO2 is converted from the supercritical state to a gaseous or liquid state. The pressure control valve includes a A heater that compensates for adiabatic cooling.
- Another heater is placed in the recycle tank to oxidize the supercritical fluid for CO2 recycle.
Here, the undesired volatile components can be separated from CO2 and discharged, or they can not change their state, controlled by proper control of pressure regulating valve and heater.
Extraction vessel structure for forward CO2 extraction
An injection port with a filter is provided at the bottom of the CO2 extraction container, and a liquid level gauge is provided in the CO2 extraction container, which measures the position of the liquid level in the container and controls the constant liquid level of the input system.
An outlet is provided at the upper part of the CO2 extraction container, which is lower than the liquid level of the fluid material. There is an inlet for liquid material at the bottom of the container.
After the material enters from the bottom, when the liquid level is close to the upper surface, it is discharged from the outlet of the upper part. There is an outlet for discharging CO2 fluid on the top of the CO2 extraction container, and the CO2 fluid is recycled and recovered. Read More: CO2 Extraction Vessels: 4 Basics, 6 Special Requirements, 7 Important Parts, 4 Key Design Requirements
Design Calculation of Supercritical CO2 Extraction Equipment for Liquid Material
The design and calculation of liquid material supercritical CO2 fluid extraction device can also be divided into two parts
- One part is to determine the amount of extraction agent based on the phase equilibrium relationship and economic balance according to the requirements of raw material composition and product purity, and then perform the required mass transfer when the mass transfer coefficient or the height of the mass transfer unit or the height of the equal plate is known. The calculation of the number of units or equilibrium stages or tower height, that is, the calculation of the separation degree of the extraction process;
- The other part is the calculation of the mass transfer rate, that is, the calculation of the mass transfer coefficient, the height of the mass transfer unit or the height of the equal plate, and the size of the relevant tower, that is, the calculation of the equipment for the extraction process.
Industrial CO2 Extraction Machine Standard Parameter Table