From fermentation broth concentration (10–20% solids feed, 40–70% concentrate) to vacuum cooling crystallization at 50–65°C — engineered for thermal sensitivity (decomposition thresholds at 70–80°C), food-grade hygienic design (SS316L, Ra <0.8 µm, CIP/SIP), and MVR-driven steam economy of 15–25 kWh per tonne of water evaporated.
Most food and fermentation products decompose, discolor or lose activity above 70–80°C — well below the boiling point. This single property dictates low-temperature falling-film evaporation (ΔT 5–10°C, MVR at 60–75°C) and vacuum cooling crystallization (50–65°C, adiabatic flash).
Decomposition and Maillard browning above ~70–80°C. Vacuum cooling crystallization at 50–65°C preserves purity (target >98.5%) and color (Y <10 Hazen).
Citric acid solubility rises steeply with temperature, but color formation (measured as UV absorbance at 420 nm) accelerates above 75°C. Vacuum cooling crystallization at 40–55°C maintains food-grade clarity and avoids Maillard side reactions with residual sugars.
Viscosity rises sharply above 60% solids — xylitol exceeds 200 cP at 60°C. Cooling crystallization with a programmed ramp and controlled seeding produces the target particle size distribution.
Aroma degradation (ester / terpene loss) and cooked off-flavors accelerate above 60°C. Short-residence-time falling-film evaporation under vacuum preserves the organoleptic profile, and MVR recompression recovers vapor latent heat at low ΔT.
Complete threonine broth downstream train: ceramic membrane clarification, multi-effect or MVR evaporation crystallization to 58-60% solids, two-stage centrifugation, and fluidized bed drying. Reference plants up to 80,000 tpy.
MVR/TVR evaporation and controlled crystallization systems for allulose (D-psicose) plants: concentrating chromatography eluate, protecting heat-sensitive rare sugar quality, and delivering uniform crystals at 50-100 TPD scale.
Integrated thin stillage evaporation, DDGS drying and condensate-to-biogas solutions for ethanol plants – process chain, MVR vs multi-effect selection and the numbers that decide operating cost.
Evaporation and crystallization systems for erythritol, sorbitol, and allulose: MVR falling film concentration to Maillard control, melt versus cooling crystallization routes, and viscosity boundaries.
Engineering guide to continuous cooling crystallization of tartaric acid: solubility-driven staging, DTB/Oslo vessel selection, mother-liquor purge strategy, and the failure modes that decide product grade.
Tryptophan fermentation finishing: chromatographic purification, deamination with ammonia water recovery, and dilute-feed (2.8-3 g/100mL) evaporation crystallization to a 58-60% slurry, centrifugation and drying.
Indicative flowsheet for amino acid or organic acid recovery from fermentation broth.
Clarified fermentation broth (~10–20% solids) enters a falling-film MVR concentrator operating at low ΔT (5–8°C) and 60–75°C, then a vacuum cooling crystallizer (50–65°C, adiabatic flash). Crystals are dewatered on a centrifuge, washed with cold deionized water and dried on a fluid-bed or conical dryer. Cell-rich broth goes through forced-circulation instead of falling film to manage viscosity (>50 cP) and fouling.
Simplified indicative process flow diagram — final configuration depends on feed characterization and crystallization trials.
Broth concentration is the largest energy consumer on a fermentation plant. Evaporator choice balances heat sensitivity, viscosity and energy economics.
The default for low-viscosity clarified broth — high heat-transfer coefficient, short residence time and low ΔT protect thermally sensitive streams.
For cell-rich or high-viscosity broth. High tube velocity suppresses fouling on the heat-transfer surface, and suppressed boiling (no boiling in tubes) prevents protein denaturation on hot tube walls.
Mechanical vapor recompression reuses the vapor latent heat, cutting steam demand by 80–90% vs. single-effect evaporation.
SS316L product contact, CIP/SIP integration, sanitary fittings, full drainability and material traceability are standard deliverables on food-grade systems.
Crystal quality — color, PSD, purity — defines the product value. Vacuum cooling and cooling crystallization are the dominant routes for thermal-sensitive bio-products.
Adiabatic flash cooling under vacuum — no heat-transfer surface in the crystallizer, so scaling risk is minimized. Standard for lysine, MSG and citric acid.
Surface cooling via jacket or heat exchanger (cooling water or chilled glycol). Used when solubility rises steeply with temperature and the product is moderately thermally stable — xylitol and erythritol.
Batch dominates smaller-scale pharma-style intermediates; continuous wins at production scale for lysine, MSG and citric acid where PSD consistency matters.
Controlled seeding and programmed cooling profiles keep the operation inside the metastable zone — avoiding spontaneous nucleation and bimodal PSD.
Food and bioprocessing customers verify hygienic design to international standards. These are the baseline specifications EvapCryst works to.
Product-contact construction with full material traceability
Baseline for product contact; Ra < 0.4 μm for high-purity or aseptic duty
Integrated clean-in-place / steam-in-place with full drainability
Hygienic design principles, sanitary fittings
FDA and EHEDG considerations apply to hygienic design principles. Process validation and food-safety certifications remain the responsibility of the producer. Material traceability and mill test reports are provided with every food-grade system.
| Product | Thermal Sensitivity | Crystallization Behavior | Typical Route |
|---|---|---|---|
| LysineC₆H₁₄N₂O₂ | High | Vacuum cooling, controlled seeding | Vacuum Cooling |
| MSG (Monosodium Glutamate)C₅H₈NNaO₄ | High | Vacuum cooling, narrow PSD | Vacuum Cooling |
| Citric AcidC₆H₈O₇ | Moderate-High | Vacuum cooling or cooling | Vacuum Cooling / Cooling |
| Xylitol / Sorbitol / ErythritolC₅H₁₂O₅ · C₆H₁₄O₆ · C₄H₁₀O₄ | Moderate | Viscous, slow growth | Cooling Crystallization |
| Mushroom / Yeast Extract | High | Concentration only (no crystal) | Falling Film MVR |
Routes are preliminary screening only. Final configuration requires solubility data, crystallization trials and project-specific engineering evaluation.
Where this industry meets the EvapCryst solution lines — start from your product, land on the right engineering conversation.
Both amino acids are thermally sensitive (decomposition, browning above 75°C) and surface cooling risks localized incrustation at the heat-transfer surface. Vacuum cooling at 50–65°C and 80–150 mbar abs removes heat adiabatically by flashing vapor under vacuum, eliminating the heat-transfer surface in the crystallizer itself and enabling uniform low-temperature operation at 0.3–1.0°C/min cooling rate.
Forced-circulation (FC) is preferred when the broth is cell-rich, has viscosity above ~50 cP, or is fouling-prone. Falling-film (FF) is preferred for low-viscosity clarified broth (<30 cP) where short residence time and low ΔT protect thermal-sensitive components. Many plants run both in series — FF for the initial 10–30% concentration, FC for the final 30–55% concentration where viscosity rises sharply.
The baseline specification is Ra < 0.8 μm for product contact surfaces. For high-purity or aseptic applications, Ra < 0.4 μm may be specified. Surface finish verification, CIP/SIP integration, sanitary fittings and full material traceability are standard deliverables.
MVR compresses the vapor to recover its latent heat at a slightly higher temperature (ΔT 5–10°C), enabling low-temperature operation at 60–75°C. Combined with falling-film evaporators (residence 1–3 min), MVR delivers both energy efficiency (15–25 kWh per tonne water vs. 0.25–0.40 t steam per tonne water for multi-effect) and the gentle thermal treatment thermal-sensitive products require.
Send us your product specification, broth composition and throughput. Within 2 business days you will receive a feasibility assessment and indicative sanitary-grade route.
Send your feed characterization (TDS, COD, main salts, viscosity), throughput and product targets — we respond with a preliminary process route within two business days.
