0.5t/h biopharmaceutical MVR low-temperature evaporation crystallization system

I. Project Overview 

In biopharmaceutical production, the processes of fermentation broth concentration, extraction, separation, and purification often generate large quantities of dilute solutions containing salts or active ingredients. These materials are generally characterized by high heat sensitivity, significant batch-to-batch variability, and stringent hygiene requirements. Traditional evaporation methods, due to their high temperatures, high energy consumption, and susceptibility to cross-contamination, are ill-suited to the stringent standards of biopharmaceutical manufacturing.

This project is a supporting facility for a biopharmaceutical company, designed to handle 0.5 t/h of dilute biological product solution evaporation, concentration, and crystallization recovery, with an annual operating time of no less than 6000 hours. The raw material is the salt-containing mother liquor from antibiotic fermentation extraction. The system is required to complete evaporation and concentration under low-temperature, clean conditions, recovering crystalline salts while ensuring that the condensate meets reuse standards.

II. Process Background and Challenges Analysis

2.1 Material Characteristics

The biopharmaceutical mother liquor processed in this project has the following characteristics:

Highly heat-sensitive: The solution contains small amounts of residual bioactive components and organic matter, which are easily decomposed, denatured, or produce odors at high temperatures. The evaporation temperature must be strictly controlled below 60℃.

High hygiene requirements: Biopharmaceuticals have clear requirements for equipment cleanliness, material traceability, and prevention of cross-contamination. It must support Clean In-Place (CIP) and Sterilization In-Place (SIP) processes.

Batch fluctuations: The concentration, pH value, and impurity content of the mother liquor vary between different fermentation batches. The system needs to have flexible operational flexibility.

Scale and foaming: Residual proteins, polysaccharides, and other organic matter easily lead to foaming on the evaporation surface and scale formation on the heat exchange surface, affecting heat transfer efficiency and product quality.

2.2 Technical Challenges

1. The contradiction between low-temperature evaporation and energy saving: Biopharmaceuticals require low-temperature operation to protect active ingredients, but the energy efficiency of steam compressors decreases at low temperatures. A balance must be struck between low temperature and energy saving.

2. Sanitary design: The surface roughness, dead zone control, sealing method, and material certification of the equipment must meet biopharmaceutical industry standards.

3. Foaming control: Organic residues cause foaming during the evaporation process, with a high risk of secondary steam entrainment. Highly efficient defoaming and antifoaming measures are required.

4. Small-scale high-efficiency operation: 0.5t/h is considered a small-scale evaporation unit. It is necessary to avoid energy loss and operational inconvenience caused by overloading the equipment.

III. Solutions and Process Routes

Based on the characteristics of biopharmaceutical materials, our company adopts a "sanitary MVR low-temperature evaporation + continuous crystallization" integrated process solution. The core process is as follows:

3.1 Pretreatment and Preheating

After the incoming liquid is filtered to remove suspended solids and bacterial residues, it enters a sanitary plate preheater. The preheater uses the waste heat of the system condensate to gently heat the feed, avoiding localized overheating that could lead to denaturation of the active ingredients.

3.2 MVR Low-Temperature Evaporation and Concentration

The preheated solution enters a sanitary MVR forced circulation evaporator. The system operates under high vacuum (evaporation temperature controlled between 45℃ and 55℃), achieving efficient evaporation while protecting heat-sensitive substances. Secondary steam is compressed and heated by a sanitary steam compressor and then reused as a heat source, forming a closed-loop thermal energy cycle. The evaporator employs a forced circulation design with a moderate circulation velocity to avoid damage to the material from high shear forces.

3.3 Continuous Crystallization and Crystal Slurry Separation

The supersaturated solution enters a small continuous crystallizer, where salts (mainly sodium chloride or ammonium sulfate) crystallize uniformly under low temperature and gentle stirring conditions. The crystal slurry is thickened by a thickener and then separated into solid and liquid components by a sanitary centrifuge. The wet salt enters the drying section, while the mother liquor is returned to the system for circulation or sent to the mother liquor treatment unit, depending on its quality.

3.4 Condensate Recovery and Vacuum Maintenance

The evaporation condensate is treated by a sanitary condensate collection system and reused for fermentation ingredient preparation or equipment cleaning. The system uses a sanitary vacuum pump set to maintain a high vacuum, ensuring stable operation of the low-temperature evaporation process.

IV. Key Equipment and Technical Parameters

1. Design Evaporation Capacity: 0.5 t/h

2. Feed Source: Mother liquor from biopharmaceutical fermentation extraction

3. Evaporation Process: Sanitary MVR forced circulation evaporation

4. Crystallization Method: Low-temperature continuous crystallization + centrifugal separation

5. Evaporation Temperature: 45℃～55℃

6. Operating Vacuum: -0.08～-0.09MPa

7. Main Body Material: 316L stainless steel (sanitary grade)

8. Surface Roughness: Ra≤0.8μm (flow surface)

9. Sealing Type: Sanitary mechanical seal/double-end face seal

10. Steam Compressor: Small Roots type/centrifugal steam compressor Compactor (Variable Frequency Control)

11. Evaporation Water Consumption: Approximately 25-35 kWh

12. Design Annual Operating Time: ≥6000 h

13. Cleaning Validation: Supports CIP/SIP, meets GMP requirements

14. Automated Control: PLC control, online monitoring of temperature/pressure/liquid level/density

V. Project Highlights

5.1 Low-Temperature Evaporation Protects Active Ingredients

The system uses high vacuum control to strictly limit the evaporation temperature to the range of 45℃-55℃, far lower than the operating temperature of traditional evaporators, effectively avoiding thermal denaturation of bioactive ingredients and decomposition and coking of organic matter, ensuring product quality and condensate cleanliness.

5.2 Sanitary Design and GMP Compliance

All flow-through components are made of 316L stainless steel with a surface roughness Ra≤0.8μm, eliminating dead corners and facilitating cleaning; Pipe connections use sanitary clamps or automatic welding, supporting CIP (Cleaning in Place) and SIP (Sterilization in Place); Materials have complete material certification and traceability documentation, meeting the quality management standards of the biopharmaceutical industry.

5.3 Miniaturized and High-Efficiency MVR System 

For a small-scale processing capacity of 0.5t/h, a small, high-efficiency steam compressor is selected, coupled with variable frequency speed control technology. This maintains high compression efficiency even under partial load, avoiding the energy loss of traditional large-scale MVR systems ("overpowered power for small loads"), resulting in a reasonable investment payback period.

5.4 Foaming Control and Defoaming 

The evaporator is equipped with a high-efficiency wire mesh demister to prevent secondary steam from carrying droplets and foam. An optional food-grade defoamer automatic dosing system can be added to control the foam height on the evaporating liquid surface, protecting the compressor's operational safety.

5.5 Energy Saving and Consumption 

Reduction MVR technology fully recovers the latent heat of secondary steam. Compared with traditional single-effect evaporation, the overall energy saving rate reaches over 60%, demonstrating significant economic advantages in the context of high steam costs in biopharmaceutical companies.

5.6 Automation and Batch Management 

The PLC control system enables automatic feeding, concentration control, automatic discharge, and fault alarms. It supports batch recording and data traceability, meeting the traceability requirements of the biopharmaceutical industry.

VI. Operational Performance

1. Evaporation Capacity: Stably reaches the design load of 0.5 t/h, with timely adjustment response during batch switching;

2. Low Temperature Control: Evaporation temperature remains stable within the set range of 45℃～55℃, with no thermal degradation of active ingredients;

3. Energy Consumption: Electricity consumption per ton of water evaporated is controlled between 25～35 kWh, meeting the energy efficiency expectations for a small-scale MVR system;

4. Continuous Operation Cycle: With regular CIP cleaning, single-cycle operation is stable, meeting production plan requirements;

5. Condensate Quality: Condensate COD and conductivity meet reuse standards for fermentation ingredient preparation or equipment initial cleaning;

6. Hygiene Validation: CIP/SIP effectiveness passes cleaning validation, meeting GMP requirements;

7. Automation Level: System operates smoothly, batch data is recorded completely, and manual operation intensity is low.

The biopharmaceutical industry places significantly higher demands on the hygiene standards, temperature control, and operational stability of evaporation and concentration equipment than the traditional chemical industry. This project utilizes a sanitary-grade MVR low-temperature evaporation crystallization system. Through high-vacuum low-temperature operation, sanitary-grade material selection, and comprehensive cleanroom validation design, it achieves efficient concentration and salt recovery of biopharmaceutical mother liquor while meeting GMP standards. Our company, with its deep understanding of the biopharmaceutical industry and refined engineering implementation capabilities, provides clients with safe, energy-efficient, and compliant evaporation crystallization solutions, helping biopharmaceutical companies achieve the dual goals of green production and quality improvement.