Filtration Equipment for Extraction & Post-Processing

How to Select Filtration Equipment for Extraction & Post-Processing

Selecting the right system starts with the material and the required separation result. Capacity alone is not enough. The following steps help define suitable filtration stages, filter media, equipment size and system connections.

Define the Separation Target

Start by defining what must be removed or recovered. Different targets require different filtration equipment, filter media and operating conditions.

Also define the required result:

• Coarse solid-liquid separation
• Liquid clarification
• Fine filtration
• Final polishing
• Concentration
• Molecular-weight fractionation
• Crystal or precipitate recovery

Standard particle filters do not automatically provide sterile filtration. Microbial control requires a defined retention target and suitable validation.

Decide Whether to Keep the Filtrate or Filter Cake

Before selecting filtration equipment, confirm which part of the material must be recovered. The valuable product may be the filtered liquid, the retained solids or both.

Keep the Filtrate

The filtrate is the liquid that passes through the filter media. In winterization filtration, the valuable cannabinoid extract normally remains in the liquid. The precipitated waxes and lipids are removed.

When the filtrate is valuable, the system should support complete drainage, low product hold-up and practical transfer to the receiving tank. 

Keep the Filter Cake

The filter cake contains the solids retained on the filter media. In crystallization, the cake may contain the valuable crystals.

When the filter cake is valuable, review:

• Cake formation and thickness
• Crystal damage
• Cake washing
• Residual liquid or solvent
• Cake discharge
• Transfer to the drying equipment

Recover Both Phases

Some processes require both the filtrate and the filter cake. The two products may need separate receiving systems. The discharge and cleaning procedures should prevent cross-contamination.

The required product determines the filter media, cake-handling method, drainage design and product-recovery arrangement.

Review the Feed Properties

The same filtration equipment can provide very different flow rates with different materials. Review the actual feed conditions before selecting the filter type and size.

Material Composition

Identify the material, extract type and current process stage. Define the particles, waxes, processing media, precipitates or crystals that must be removed.

Solvent

Confirm whether the feed contains ethanol, water, oil, hydrocarbons or another solvent. The solvent affects contact materials, seals, filter media and safety requirements.

Temperature

Temperature affects viscosity and filtration speed. It can also affect wax precipitation and product stability.

Winterized extracts may need insulated piping or jacketed equipment. This helps keep the material cold during filtration.

Viscosity

High-viscosity liquids pass through filter media more slowly. Heating may reduce viscosity in some processes. The material and solvent must tolerate the selected temperature.

Solids Loading

A high-solids feed can block a fine filter quickly. It may require coarse separation, more filtration area or equipment designed for cake formation.

Particle Size and Distribution

Large particles are usually easier to remove. Fine, soft or compressible particles can enter the filter media and cause rapid blockage.

Provide a particle-size range when possible. One average particle size may not describe the complete feed.

Waxiness or Stickiness

Waxy or sticky solids may form a dense cake. This can reduce permeability and filtration speed.

Product Sensitivity

Some products are sensitive to heat, oxygen, light or shear. They may require low-temperature processing, closed transfer or a gentler pump.

If exact information is unavailable, provide photographs, samples or previous test results. Pilot testing may be required when filtration behavior is uncertain.

Confirm Batch or Continuous Operation

The operating mode affects the structure, controls and capacity of filtration equipment. It also affects labor, cleaning and product changeover.

Batch filtration is often more practical for winterization, crystal recovery and changing products. Continuous separation is useful when the feed is stable and daily throughput is high.

The final choice should also consider operator availability, cleaning frequency and the production rates of upstream and downstream equipment.

Compare Filtration Equipment Types

This section compares the main filtration equipment by selection logic. This comparison helps you match the equipment type with your material, separation target and operating conditions. 

The best system may combine several technologies. For example, a bag filter can remove coarse solids before a cartridge or lenticular filter performs final clarification.

Configure the Filtration Stages

Do not always try to reach the final filtration grade in one step. Multi-stage filtration equipment separates coarse and fine particles through different filters.

A typical process is:

Coarse Filtration → Clarification → Fine Filtration → Final Polishing

The stages can be combined in a multi-stage filtration system on one skid or operated as separate batch steps. 

A well-designed multi-stage process can:

• Reduce rapid clogging
• Maintain a more stable flow
• Extend fine-filter service life
• Reduce consumable use
• Protect downstream equipment
• Improve final liquid clarity

Not every process needs all four stages. Low-solids liquids may only require clarification and polishing.

Select Filter Media, Grade and Consumables

Selecting filtration equipment also requires suitable filter media. Micron rating is only one part of the decision.

The finest filter is not always the best option. An unnecessarily fine grade may reduce flow and increase operating cost without improving the required product result.

Evaluate Actual Filtration Capacity

Do not select filtration equipment from a nominal flow rate alone. Nominal flow is often measured with clean water or another low-viscosity liquid. Real extracts and slurries may flow much more slowly.

Actual capacity depends on several connected factors:

• Feed viscosity and temperature
• Solids loading
• Particle size and structure
• Filtration area
• Filter media permeability
• Operating pressure or vacuum
• Filter cake formation
• Cleaning frequency
• Media replacement time
• Effective operating hours

Viscosity and Temperature

Cold or viscous liquids pass through filter media more slowly. Winterized extracts may require more filtration area because the liquid must remain cold.

Solids Loading and Cake Formation

High solids loading creates a filter cake more quickly. A porous cake may continue filtering well. A dense, waxy or compressible cake can cause the flow to fall rapidly.

Filtration Area and Filter Media

A larger filtration area can increase capacity and reduce the loading on each section of media. Media permeability, pore structure and dirt-holding capacity also affect flow.

Two filter media with the same micron rating may perform differently.

Pressure or Vacuum

A suitable pressure difference moves the liquid through the filter. Excessive pressure may compress the cake and reduce its permeability. It may also damage sensitive filter media or products.

Complete Batch Cycle

Capacity calculations should include more than filtration time:

• Material transfer and filling
• Filtration
• Drainage
• Cake discharge
• Filter media replacement
• Cleaning
• Preparation for the next batch

Where possible, provide previous test data. Useful information includes filter area, feed temperature, media type, batch volume, filtration time and solids collected.

Material testing gives a more reliable sizing basis than a theoretical flow rate.

Review Product Loss, Cleaning and Sanitary Requirements

Good filtration equipment should separate the target material without creating unnecessary product loss or difficult cleaning work.

Product Retained in Filter Media

Filter cloths, cartridges and depth media can retain valuable product. This loss may be important when processing concentrated or high-value extracts.

The filter media should provide the required clarity without excessive adsorption or hold-up.

Liquid Trapped in the Filter Cake

The filter cake may contain valuable liquid. Displacement, gas blowing or cake washing can recover part of this liquid when the process allows it.

The selected method must be compatible with the product and solvent.

Housing and Piping Hold-Up

Product can remain inside filter housings, valves, hoses and pipes. Shorter transfer paths, suitable pipe slopes and correctly positioned drains can reduce this loss.

The system should drain without excessive dismantling.

Filter Replacement and Cleaning

Operators need practical access to filter bags, cartridges, sheets and cloths. Heavy components may require lifting assistance.

Small systems may use manual cleaning. Larger systems may require CIP connections, spray devices or cleaning circulation.

Sanitary Design

Food, nutraceutical and natural ingredient applications may require:

• Sanitary product-contact surfaces
• Suitable internal welds
• Hygienic pipe connections
• Drainable equipment
• Reduced dead legs
• Compatible cleaning chemicals

The required sanitary standard should be confirmed before manufacturing.

Cross-Contamination

Shared equipment may retain material from the previous batch. Sensitive products may require validated cleaning procedures, dedicated filter media or separate product-contact components.

Product recovery, cleaning time and batch changeover can significantly affect the real operating cost.

Confirm Solvent, Material and Safety Requirements

Filtration equipment used with ethanol or another solvent requires a project-specific review. Confirm the solvent, operating conditions, installation area and local requirements before finalizing the system.

Wetted-Part Materials

The product-contact material must be compatible with:

• The process liquid
• The solvent
• The operating temperature
• Cleaning chemicals
• Sanitary requirements

Stainless steel is commonly used, but the required grade depends on the application.

Seal Materials

Seal materials may include PTFE, EPDM, FKM or other compounds. A seal that works with one solvent may not be suitable for another.

The operating temperature and cleaning chemicals must also be considered.

Filter Media Compatibility

The filter media must remain stable during operation. It should not swell, soften, dissolve, lose strength or release unwanted substances into the product.

Closed Material Transfer

Ethanol and other volatile solvents may require closed feed, filtration and receiving arrangements. The piping, filter housing and receiving tank should be reviewed as one transfer system.

Operating Pressure and Temperature

Confirm:

• Maximum operating pressure
• Required vacuum level
• Minimum and maximum temperatures
• Equipment design rating
• Pressure or vacuum protection
• Safe drainage and pressure release

Grounding and Bonding

Conductive equipment and transfer components may require grounding and bonding. This is especially important when flammable liquids or vapors are present.

Electrical and Area Classification

Motors, instruments, controls and electrical enclosures must suit the installation area. Requirements vary according to the solvent, ventilation, room classification and local regulations.

Local Safety Requirements

The customer should confirm applicable requirements for:

• Ventilation
• Fire protection
• Solvent storage
• Building layout
• Electrical classification
• Operator procedures
• Local inspection or certification

A standard machine should not be assumed to meet every solvent-area requirement. The final material, electrical and safety configuration must be confirmed for each project.

Integrate With Upstream and Downstream Equipment

Filtration equipment should match the complete process rather than operate as an isolated machine.

Also confirm:

• Gravity or pumped transfer
• Connection sizes and standards
• Upstream and downstream capacities
• Required batch cycle time
• Available installation space
• Electrical power
• Heating and cooling utilities
• Compressed air or inert gas
• Future capacity expansion

Correct interface confirmation can reduce on-site modifications and improve the operation of the complete line.

Information to Send Before Quotation

To recommend suitable filtration equipment and evaluate actual capacity, please provide the following material and process information. 

Send us the available information even if some values are not yet confirmed.
HiURTB will review the appropriate filtration technology, equipment capacity, filter media and system interfaces.
We will also identify any information that requires further confirmation or material testing before finalizing the configuration.