Overview
ARBOK-PAT solves the central bottleneck of biogas energy — digestate disposal. It converts wet, malodorous post-fermentation residue into three commercial streams: drinking-grade technical water, solid fuel pellets (ENplus A1-equivalent), and nitrogen fertilizers (ammonium sulfate/nitrate/phosphates) or technical aqueous ammonia. It runs at ambient temperature under deep vacuum — no heating, catalysts, chemicals, cavitators, consumables, or filters — at 1–3 kWh/ton, an order of magnitude below MVR evaporation or membrane polishing. Deep vacuum also fully sterilizes the output (odorless). Field-validated on operating biogas plants in Southern Europe.
Applications
Primary use cases: biogas digestate valorization; nitrogen recovery; on-site technical-water reuse; solid-fuel pellet production.
Industries and users: biogas/AD operators, agriculture, waste utilities.
Scale: Arbok-100 unit = 100 t/day = 36 500 t/year; multi-unit for larger plants.
Operating Principle
Digestate is processed by deep-vacuum phase separation at ambient temperature: phases separate by differential volatility. Water vapor condenses on a dedicated loop to technical water; ammonia leaves the gas phase first and is captured in an absorption scrubber (the Ammonia Trap), fixed by mineral-acid absorption into fertilizer salts (or recovered as concentrated aqueous ammonia); the dry residue (DOC — dry organic carbon) is pelletized on site. Deep vacuum sterilizes biologically (100 % pathogen kill). The only consumable is acid at the Ammonia Trap stage.
Limitations: acid supply for the trap; feed-quality variation; residue/pellet offtake.
Key Parameters
Specific energy: 1–3 kWh/ton (baseline); 0.3–0.8 kWh/ton with waste-heat recovery.
Water recovery: up to 99.99 % (drinking-quality technical water). Pathogen elimination: 100 %.
DOC pellets: ENplus A1-equivalent, 17–18 MJ/kg, ash < 2 %, moisture < 10 %.
Ammonia capture: 95–98 % (acid absorption, or recovered as concentrated aqueous ammonia).
Unit sizing: Arbok-100 = 100 t/day (36 500 t/year). Footprint: two 10-ft containers; pad 20–30 m² (40–60 m² with redundancy). Staffing: 2–3 operators/shift.
Architecture and Components
Deep-vacuum separation chamber; water-condensation loop; Ammonia Trap absorption scrubber (acid fixation); DOC dryer + pelletizer; an optional waste-heat exchanger that recovers hot water or steam from an external combined-heat-and-power engine; control system. Two 10-ft containers; modular.
Advantages
Technical: ambient-temperature, no catalysts/membranes/filters; 100 % sterilization; 99.99 % water recovery.
Economic: 1–3 kWh/ton (0.3–0.8 with WHR); only consumable is acid; CAPEX an order of magnitude below MVR/membrane analogs ($5.5–7.7 million).
Environmental: zero discharge; odorless outputs; with WHR, atmospheric thermal emission cut 70–90 % (Scope 1 & 2).
Strategic: turns digestate liability into pellets + fertilizer + water revenue; BOOM-deployable.
Integrations
Natively compatible with CHP waste-heat recovery: a 1 MW biogas CHP set yields 1.2–1.5 MW thermal; feeding medium-temperature hot water or steam from the CHP engine gives up to 550–600 kWh/ton thermal gain, drops electrical demand to 0.3–0.8 kWh/ton, and (winter mode) pre-heats digestate for +5–12 % methane yield. Uses a standard industrial heat exchanger; no boilers or scaling risk.
Deployment & Operation
Steps: digestate assay → unit sizing → container placement (pad 20–30 m²) → commissioning. Ambient operation; 2–3 operators/shift. Business model: BOOM (Build-Own-Operate-Maintain), tipping fee $4–20/t, or outright sale/lease.
TRL
TRL 8 (confirmed by Michael). System complete and qualified: field-validated on operating biogas plants in Southern Europe, with a published preprint. Remaining to TRL 9: sustained commercial operation across multiple sites.
Market Potential
Every biogas/AD plant produces digestate that is costly to handle and increasingly regulated. PAT addresses this across Europe and beyond, adding pellet, fertilizer, and water revenue plus tipping fees.
Typical Project Economics
Reference (1 MW station, 25 000 t digestate/year): pellets ~$440 000/yr (2 000 t × $220/t); ammonium sulfate ~$105 000/yr (400 t × $260/t); technical water ~$25 000/yr (23 000 m³ × $1.1/m³); waste-heat recovery $70 000–110 000/yr; BOOM tipping ~$250 000/yr; avoided operator costs $1.1–1.65 million (transport) + $130 000–310 000 (regulatory). Net swing per site: +$1.75–2.3 million/year (with WHR). Payback 5–7 years (4–5 with WHR).
Risk Factors
Acid supply/handling for the Ammonia Trap; pellet/fertilizer offtake and grade qualification; feed-quality variation; scaling to sustained commercial operation.
Related Technologies
Ammonia Trap · Arbok-ZWD Gasification · AZOW-Domus · ARBOK-VC (Vacuum Cracking)