Overview
ARBOK-URIA recovers urea, uric acid, and nitrogen compounds from source-separated human urine via vacuum evaporation, concentration, and crystallization. Rather than treating urine as dilute waste (10–15 g/L nitrogen), it recognizes it as valuable commodity. Process: the urine is chemically stabilized to prevent ammonia loss and microbial breakdown, then vacuum-evaporated at ambient temperature — the reduced pressure lets water flash off without added heat, which is what preserves the urea instead of degrading it — and finally crystallized. Recovered urea (>95% purity) suitable for fertilizer, industrial chemistry, or medical applications. Closes nutrient loop in cities; reduces wastewater burden; circular input for agriculture/industry.
Applications
Municipal nutrient recovery (separate collection), fertilizer production (urea commodity replacement), industrial supply, agricultural nutrient cycling, biosolids valorization. Typical: modern residential buildings with separate plumbing, retrofit of existing buildings, industrial streams with urine content. Users: municipal utilities, fertilizer manufacturers, building developers, farms, closed-loop facilities.
Operating Principle
Source separation: separate plumbing collects urine. Stabilization: a controlled acid dose is added to prevent ammonia loss and microbial decomposition. Vacuum evaporation: carried out under deep vacuum at ambient temperature, which preserves the urea that would otherwise break down under heat. Concentration: water evaporates and dissolved salts (urea, phosphates, potassium) accumulate into a concentrate. Crystallization: the cooled concentrate crystallizes urea; other salts separate. Product: urea crystals (>95%), phosphorus concentrate, potassium-rich liquor.
Key Parameters
| Parameter | Value |
|—|—|
| Urine Nitrogen Content | 10–15 g/L (60% urea, 20% uric acid, 20% other) |
| Urea Yield per Person/Day | 5–10 g/day (1.8–3.6 kg/year) |
| Phosphorus Recovery | 0.5–0.8 g/L as PO₄ |
| Potassium Recovery | 2–4 g/L as K₂O |
| Vacuum Operating Pressure | Deep vacuum, sufficient to enable evaporation without added heat |
| Evaporation Temperature | Ambient — no external heat input required |
| Urea Product Purity | >95% |
| Energy Intensity | 0.5–1.5 kWh/kg urine |
| Acid Stabilizer Dose | A controlled acid dose calibrated to stabilize dissolved nitrogen |
| Cycle Time | A same-day batch cycle |
| Storage Stability (stabilized) | Over 6 months in a stable, acid-conditioned state without nutrient loss |
Architecture and Components
Collection system (urine-diverting toilets or separate plumbing). Stabilization unit (acid dosing pump, mixing tank). Storage (sealed tanks sized to throughput). A vacuum evaporator sized to the required daily throughput. Condenser for recovering the water vapor. A vacuum pump maintaining the operating pressure. Crystallizer (optional). Control/instrumentation (temperature, pressure, pH, conductivity sensors). Installation: decentralized (building-level), centralized (municipal), modular/transportable.
Advantages
Technical: closed-loop recovery, low-temperature operation (solar thermal compatible), simple chemistry, modular scalability. Economic: urea value $200–500/ton, 1 person recovers €0.36–3.60/year or €36–360 for 100-person building, municipal-scale €36k–360k/year. Environmental: eliminates synthetic urea (Haber-Bosch 2% global energy), reduces eutrophication, closes nutrient loop. Operational: automated, stable product (indefinite storage), no odor/biohazard, incremental deployment.
Integrations
Urine-diverting sanitation, renewable energy (solar thermal), municipal wastewater treatment, fertilizer supply chains, building management systems, circular economy platforms. Related: Source Separation · Vacuum Evaporation · Nutrient Recovery · Urine-Diverting Toilets
Deployment & Operation
Path: feasibility study → pilot (single building, 100–1,000 L/day) → optimize protocol → commission evaporator → scale-up
Operating: decentralized (10–500 L/day) or municipal (10,000+ L/day), batch cycles 4–8 hours, minimal staffing
Maintenance: pump calibration monthly, vacuum pump service annually, scale removal as needed, tank inspection quarterly
TRL
TRL 5 (Pilot validation)
Evidence: lab testing (stabilization, evaporation, crystallization completed), pilots operating in multiple regions (100–1,000 L/day), product quality validated by agricultural standards
Remaining: large-scale municipal deployment (10,000+ L/day, 2–3 years operation), building code integration, protocol standardization, market linkages, economic validation, LCA approval
Market Potential
Target: new construction in Nordic/Dutch/German markets, municipal wastewater operators, organic farming, developing regions with nutrient deficiency, closed-loop institutions. Drivers: global urea demand 150M tons/year (energy-intensive), phosphorus scarcity, nutrient limits in EU/USA/Japan, circular economy mandates. Market: 500M m³ human urine/year globally = 5–7.5M tons recoverable nitrogen = €1–3.75B/year potential (realistic penetration 2026: 0.1–1% in source-separation infrastructure).
Risk Factors
Technical: stabilization reliability, vacuum system durability in urine vapor, product contamination (pharmaceuticals/pathogens), energy intensity. Market: regulatory uncertainty (source-separation not standardized), social acceptance (urine reuse stigma), collection logistics (retrofit expensive), synthetic urea competition (cheap $200–300/ton). Operational: end-market development risk, scale-up reliability, liability framework for nutrient products uncertain.
Related Technologies
Part of ARBOK's broader nutrient-recovery and vacuum-evaporation technology family, sharing its core low-temperature, low-pressure separation approach with other ARBOK waste-valorization processes.