Background
A pharmaceutical manufacturer required an effective filtration solution for folic acid processing. The primary objective was to recover a complete and stable filter cake while maintaining efficient filtration performance during laboratory-scale testing.
The customer also needed to evaluate suitable filter sheets for future scale-up production and downstream material recovery.
Filtration Challenges
During the folic acid filtration process, the production team encountered several issues:
- High solid content in the slurry
- Difficulty forming a stable filter cake
- Increasing filtration pressure during operation
- Need for efficient recovery of valuable solids
- Requirement for stable flow rate and clear filtrate
To address these challenges, a filtration trial was conducted using Great Wall Filtration depth filter sheets and a vertical filtration system.
Filtration Trial Setup
Equipment
- Vertical filter system
- Filtration area: 0.008 m²
Filter Media
- Great Wall BIO-PH20 filter sheets
- Filtration rating: 0.5–0.8 μm
Operating Conditions
- Ambient temperature
- System cleaned with 5% NaOH and 5% HCl solution before operation
- Filter sheets pre-rinsed with purified water prior to filtration
Filtration Procedure
- The folic acid slurry was thoroughly mixed before filtration.
- The selected filter sheets were installed in the vertical filter.
- The slurry was continuously filtered while collecting the filtrate.
- Filtration pressure and filtration time were monitored throughout the process.
- Additional rinsing water was applied to improve product recovery.
Test Results
| Sample Volume | Filtration Time | Pressure |
| 100 mL | 1 min 52 s | 0.02 MPa |
| 200 mL | 2 min 16 s | 0.02 MPa |
| 400 mL | 9 min 11 s | 0.025 MPa |
| 600 mL | 18 min 36 s | 0.2 MPa |
| 1000 mL + 200 mL rinse water | Total 1 h 58 min | 0.3 MPa |
Performance Summary
- Stable filter cake formation achieved
- Effective recovery of folic acid solids
- Filtration throughput reached 237 L/h/m²
- Filter sheets maintained good retention performance during the trial
Result Analysis
The filtration test demonstrated that the selected filter sheets successfully formed a complete and stable filter cake, which is critical for efficient solid recovery in pharmaceutical processing.
The BIO-PH20 filter sheets provided:
- Reliable particle retention
- Consistent filtration performance
- Good compatibility with folic acid slurry
- Efficient recovery capability for downstream processing
The trial results provided valuable operational data for future process optimization and industrial-scale production.
Conclusion
Great Wall Filtration successfully supported the customer in evaluating an effective filtration solution for folic acid recovery applications. The filtration system achieved stable operation, efficient filter cake formation, and reliable throughput performance.
This case highlights the advantages of Great Wall filter sheets in pharmaceutical solid-liquid separation processes where clarity, recovery efficiency, and operational stability are essential.
Post time: May-07-2026
