Ammonia Trap

Overview

Ammonia Trap is a standalone nitrogen-capture technology that also serves as the nitrogen module of AZOW. During evaporation, volatile ammonia (NH₃) leaves the effluent with the water vapor; the circulating water ring of the vacuum pump is used as a temperature-controlled absorber, and the ammonia is then chemically fixed into ammonium sulfate. This gives the operator a choice at the outlet: keep the ammonia in the water (ammonia-rich water, good for irrigation) or strip it for clean water plus a marketable nitrogen fertilizer — with no ammonia emissions.

Applications

Primary use cases: nitrogen recovery from biogas digestate, municipal and industrial wastewater, manure streams, and brine collectors (this subsumes the former "ARBOK-Ammonia" wastewater-recovery use); production of ammonia-irrigation water or ammonium-sulfate fertilizer.

Optional extension: recovered ammonia (NH₃ = one nitrogen + four hydrogen atoms) can serve as a low-cost feedstock for green-hydrogen generation (NH₃ → H₂).

Industries and users: biogas plants, utilities, agriculture, food-industry effluent operators, developing regions with high fertilizer cost.

Scale: integrated into AZOW units (e.g., 150–200 t/day feed); 20-ft container modules; modular.

Operating Principle

The trap rides on AZOW vacuum evaporation, where water boils at ambient temperature under deep vacuum. Volatile NH₃ evaporates with the water and is managed by the vacuum pump's circulating water ring, which is actively temperature-controlled to alternate between an absorption phase and a desorption phase: while cooler, the ring absorbs NH₃ (high solubility); once warmed, the ammonia desorbs and is sent fully to a scrubber, where it is chemically fixed as ammonium sulfate through reaction with an acid-based fixation reagent. Nitrogen recovery ~90 %, with minimized corrosion and zero ammonia emission.

Outlet options: (a) ammonia retained in product water → irrigation water; (b) ammonia stripped → clean technical water + ammonium-sulfate fertilizer.

Key Parameters

Nitrogen recovery: ~90 %. Ammonia emissions: zero.

Ammonium sulfate output: 21 % N, 24 % S (solution or crystals); ~20–40 kg/day per unit; ~40–80 kg/day at 150–200 t/day feed (≈14.6–29.2 t/year).

Energy: rides on the AZOW vacuum pump (no extra thermal input); the same circulating ring serves as the NH₃ absorber.

Outlet modes: ammonia-irrigation water or clean water + fertilizer.

Architecture and Components

Water-ring vacuum pump (doubles as temperature-controlled NH₃ absorber); scrubber with acid-based ammonia fixation; ammonium-sulfate collection (solution/crystallization); control of ring temperature and desorption. Integrated into the AZOW evaporation/condensation train.

Advantages

Technical: turns a corrosion/emission problem into a controlled recovery step; reuses the pump's water ring (no separate absorber); ~90 % N capture.

Economic: ammonium sulfate ~€150/t adds revenue (~€2 200–4 400/year per 150–200 t/day unit); or ammonia-rich irrigation water as a free fertilizer carrier.

Environmental: zero ammonia emission; nitrogen kept out of waterways.

Strategic: gives AZOW outlet flexibility (irrigation vs clean water + fertilizer) per site need.

Integrations

Component of AZOW; pairs with the vacuum evaporator, condenser, and dry-concentrate ("chips") extraction; SCADA/PLC ready.

Deployment & Operation

Configured inside an AZOW unit; outlet mode (irrigation water vs stripped + fertilizer) set per site. Continuous, automated; acid-reagent dosing for the scrubber is the main consumable.

TRL

TRL 8 (confirmed by Michael). System complete and qualified: mechanism, recovery rate, and product figures validated on the ARBOK vacuum platform, with operation proven within AZOW deployments. Remaining: broader standalone rollout and certification per market.

Market Potential

Nitrogen recovery is increasingly mandated (nutrient/discharge limits) across biogas, wastewater, and agriculture. As an AZOW component it adds a saleable fertilizer stream and irrigation-water option wherever AZOW is deployed.

Typical Project Economics

Ammonium sulfate: ~14.6–29.2 t/year per 150–200 t/day unit at ~€150/t → ~€2 200–4 400/year, on top of AZOW's water and organo-mineral fertilizer revenue. Main consumable: the acid-based fixation reagent. (Site economics modelled within the parent AZOW project.)

Risk Factors

Acid-reagent handling/supply; ammonium-sulfate offtake/pricing; ties to AZOW deployment; needs a documented field reference.

Related Technologies

ARBOK-PAT · AZOW-Domus · ARBOK-FERTILIZER · ARBOK-VC (Vacuum Cracking)