Advanced Plant Extraction and Filtration Techniques at Parand company

Parand Company performs various plant extraction processes with different equipment, which are mentioned below:

Plant Extraction:

1. Extraction To extract the essence from raw plant materials, a system is needed where the raw material and the solvent are in contact for a certain period. For this purpose, an extractor is used. Percolation and maceration are types of extractors.

• Percolation The percolation system of Parand consists of 4 percolators, and its operation is as follows:
  1. Loading
  2. Preparing the solvent
  3. Soaking and circulating
  4. Unloading

  The feed is poured into the percolators. The solvent is pumped into the exchanger, heated according to the product recipe, and directed towards the product in the percolator. After a specified soaking time and number of circulations, the extract is removed from the percolator.

• Maceration This process is also known as soaking. It is also called balanced extraction, which is a physical process where the components of the plant or desired materials are transferred into a liquid solvent in the form of a liquid. This unit includes a coil-tank extractor connected to a condenser, two tanks for collecting the condensates from the condenser, a vacuum pump, and a heat exchanger for cooling and heating the jacket. The feed enters the coil-tank and, if needed, is cut before entering. Then, the solvent (water and alcohol) is added to the tank. The feed and solvent in the tank are extracted and then pumped out of the tank.

Each of these extractors is used depending on the type of raw material and the specific characteristics of the products.

2. Filtration After the extraction stage, centrifuges, plate filters, microfilters, and ultrafilters are used for clarifying food extracts, medicinal extracts, and concentrates to a maximum turbidity of less than 10 NTU. The types of filtration are as follows:

• Centrifuge Filter
• Plate Filter
• Micro Filter
• Ultra-Filter

A centrifugal filter uses centrifugal force and pressure to separate coarse and heavy particles from light particles. Other filters, utilizing membranes made from various materials such as PVDF, PES, PSU, etc., minimize the turbidity of the extracts. In all these devices, the product is introduced into the system under pressure and operates at adjustable temperatures, with pore sizes varying depending on the type of filter (500 nm – 2 kDa). The types of filtration available at Parand Company include:

• Alfalaval Filter
• Vacuum Filter
• Nutsche Filter
• Ultra-Filter
• Bucher Filter Press
• Russel Filter
• Novo Filter
• Sartorius
• Press Plate

3. Concentration After the extraction process, the extracts are concentrated to separate organic solvents and increase their shelf life. In other words, the solvent used for extracting the active ingredient from the plant during the initial extraction process is removed at this stage to reach a specific concentration. Essentially, the fluid is converted from the liquid phase to the gas phase by applying heat. This is an evaporation process used to concentrate liquid extracts. The equipment used in this section includes Centritherm, Thin Film, and Falling Film.

• Centritherm One of the concentration devices is Centritherm. In this device, the extracted essence is concentrated under a temperature of 45-55°C and a vacuum of 150-200 mbar. The process is such that the device is set to a specific temperature and pressure. A set of conical plates is indirectly heated by steam to the set temperature. With the spray nozzles, the extract is spread over the conical surfaces and concentrated, producing concentrated extract and condensed water.
• Thin-Film Another concentration device is the Thin Film. Thin Film refers to the thermal separation of products in a thin, highly turbulent liquid film created mechanically. Upon entering the Thin Film, the product contacts the rotor: it is evenly distributed around by a distribution ring, then lifted by the first rotor blades, and immediately formed into a film (0.5 – 3.5 mm). The heat transfer surface in front of each rotor blade creates an arcuate wave in the fluid. The fluid in the gap between the heat transfer surface and the rotor blade tip is highly turbulent, leading to intense heat and mass transfer rates. This turbulence produces high heat transfer coefficients, even with very viscous products. Due to the intense mixing action in the arcuate wave, overheating of temperature-sensitive products is prevented, and fouling on the heat transfer surface can be reduced or eliminated.

• Falling Film The extract flow is distributed at the top of tubes heated by indirect steam, passing as a thin layer (film) along the inner walls of the tubes. The tubes are heated from the outside, causing the liquid film to boil and evaporate. The concentrated mixture of extract and solvent vapors are separated downstream. This process is repeated several times until the specified concentration is achieved. The downward flow of the liquid film prevents deposition inside the tubes.

4. Pasteurization To eliminate pathogens in the product, extend shelf life, and preserve the organoleptic properties (taste, smell, color, and texture) of the product, the pasteurization process is carried out. The pasteurization device consists of two heat exchangers, one for heating and the other for cooling. After heating, the product enters the holding phase and then proceeds to the cooling phase. Initially, before the product enters the pasteurization circuit, the circuit is sterilized to eliminate microorganisms and internal contaminants. After the sterilization phase, due to the excessive heat of the circuits and tubes, the cooling exchanger is activated to lower the temperature to the standard level, making the device ready to receive the product. In this stage, the main heating and cooling circuits are activated, continuously performing the heating and cooling process, which is the pasteurization process. After selecting the production mode, the circulation operation stops, and the incoming product continuously enters the system, undergoes pasteurization, and is transferred to the desired output.
5. Drying Parand Company is equipped with various drying devices such as Vacuum Drying, Spray Drying, Drum Drying, and Fluidized Bed Dryer to dry products.

• Vacuum Drying Vacuum dryers are used to dry fruit concentrates and concentrated medicinal plant extracts containing temperature-sensitive active ingredients. In this device, the boiling point is reduced under the influence of vacuum, requiring less energy for the drying process. Due to the use of vacuum, the evaporation and drying speed of the products in these devices is high. The feature of this device is that a thin layer of concentrated extract is spread on the belts, allowing for better and faster evaporation.
• Spray Drying Spray drying is a method for quickly drying extracts into dry powder using hot gas. The spray dryer operates by separating the dry extract material as a solid and the solvent as vapor from the liquid stream. The incoming extract is sprayed into a hot vapor stream and evaporated using a nozzle. Solid materials are formed by the evaporation of liquid from the droplets. The spray dryer nozzles are designed to produce controlled and consistent droplet sizes to ensure uniform drying of the solids.
• Drum Drying Drum dryers consist of a precisely measured rotating drum with an internal heat flow. The heat flow causes the drum’s surface to become hot. The rotating drum surface is where the thick liquid product is applied and then scraped off by a very sensitive blade after drying. Drum dryers are one of the best options for continuously drying various liquid products, especially thick and viscous liquids. This device can also be used for drying pasty products and even two-phase products with thick and viscous liquids along with solid fibers or textures. The high precision and quality of drying are key features of the device, producing a completely uniform and consistent product.