Environmental Technology

The Refrigerant Transition.
We Are Already There.

While the industry plans its migration from HFCs, Cueron is already manufacturing systems with natural and ultra-low-GWP refrigerants i.e., engineering for the regulatory trajectory, not just today's compliance baseline.

Refrigerant Roadmap

From HFCs to Natural Refrigerants.

The global refrigerant transition i.e., driven by the Montreal Protocol and Kigali Amendment i.e., is reshaping the industry. Here is where we have been, where we are, and where we are going.

Past (Pre-2010)

HCFC Era

R-22 (ODP=0.055, GWP=1810)R-123 (ODP=0.02, GWP=77)

Phase-out complete

Transition (2010-2025)

HFC Phase-Down

R-404A (GWP=3922)R-410A (GWP=2088)R-134a (GWP=1430)

Being replaced

Current (2020-2030)

HFO & Blends

R-449A (GWP=578)R-513A (GWP=573)R-1234ze (GWP=6)

Active deployment

Future (2025+)

Natural Refrigerants

R-290 Propane (GWP=3)R-744 CO₂ (GWP=1)R-717 Ammonia (GWP=0)

Cueron primary focus

Our Eco-Technology Platform.

Natural Refrigerant Engineering

System design optimized for natural refrigerants i.e., safety engineering for flammable (A3) refrigerants per IEC 60335-2-89, high-pressure CO₂ systems, and ammonia-water absorption cycles.

R-290 charge minimization (< 150g per circuit)

CO₂ transcritical cycle optimization for 45°C+ ambient

Ammonia-water absorption for waste heat recovery

Leak detection and ventilation safety systems

Ozone-Safe Insulation

Zero-ODP blowing agents for polyurethane and polyisocyanurate insulation i.e., transitioning from HFC-245fa to hydrocarbon and water-blown formulations.

Cyclopentane-blown PUF (ODP=0, GWP=7)

Water-blown PIR for temperature-sensitive applications

Thermal conductivity: λ = 0.022 W/mK maintained

Full compliance with Montreal Protocol

Refrigerant Lifecycle Management

End-to-end refrigerant stewardship i.e., from procurement and charging to recovery, reclamation, and responsible disposal at equipment end-of-life.

Refrigerant tracking and documentation

Recovery equipment at every service center

Partnership with certified reclamation facilities

Banking program for future-proof refrigerant supply

Measurable Environmental Impact.

12,000+tCO₂e

Avoided annually by our installed base

100%

Zero-ODP across all new systems

< 150GWP

Target for all new equipment designs

95%+

GWP reduction vs. legacy HFC systems

Cueron Project

Case Study

Ammonia-Based Treatment of High-Strength Industrial Effluent

Engineered and delivered by Cueron - two-stage ammonia stripping and biological nitrogen removal retrofit at a nitrogenous fertilizer & specialty chemicals complex, achieving full CPCB compliance and resource recovery.

Continental NitroChem Industries|Nitrogenous Fertilizer & Specialty Chemicals|Verified 98%+ NH₃-N Removal

Executive Summary

The Challenge

Continental NitroChem's ETP received ammonia-laden streams with NH₃-N far exceeding CPCB discharge limits, under increasing OCEMS enforcement scrutiny.

The Solution

A two-stage retrofit: physico-chemical air stripping with ammonium sulphate recovery, followed by biological nitrification-denitrification polishing.

Engineered & delivered by Cueron Global Pvt. Ltd.

<15 mg/L

Final NH₃-N

Down from ~1,650 mg/L

200+

Tonnes/yr Recovered

Ammonium sulphate by-product

35%

Water Reused

As cooling tower make-up

CPCB Discharge Standards (Inland Surface Water)

NH₃-N ≤ 50 mg/LCOD ≤ 250 mg/LBOD ≤ 30 mg/LpH 5.5–9.0

90-Day Sampling Design Basis

Parameter

Range

Design Average

NH₃-N

350–1,650 mg/L

950 mg/L

COD

1,100–3,600 mg/L

2,200 mg/L

BOD

350–1,100 mg/L

650 mg/L

TDS

3,800–6,200 mg/L

5,000 mg/L

Temperature

38–55°C

45°C

8.3–10.4

9.2

Combined average flow: 1,150–1,250 m³/day. Sources: process condensate, scrubber blowdown, ion-exchange regeneration, and stripper drains.

Technology Screening

Air / Steam Stripping

Primary StageSelected

Counter-current packed tower at pH 10.5–11 and 55–65°C. 70–95% NH₃-N removal. Warm, alkaline influent reduces energy and caustic demand. NH₃ recoverable as ammonium sulphate.

Biological Nitrification-Denitrification

Polishing StageSelected

>90% removal achievable. Inhibited above ~500 mg/L free ammonia - not viable standalone, but ideal after stripping reduces concentration.

Ion Exchange

Rejected

High TDS (3,800–6,200 mg/L) causes rapid resin fouling. Pilot trials confirmed unsuitability as primary stage.

Breakpoint Chlorination / Struvite MAP

Rejected

Chlorination: high chemical cost and chlorinated by-product risk. Struvite: phosphate-poor effluent makes reagent dosing uneconomical.

Key Equipment & Design Parameters

All equipment rated for continuous 24/7 operation at a peak hydraulic load of 50 m³/hr and design NH₃-N influent of 1,800 mg/L.

Equalization Tank

1,200 m³; ~24 hr HRT; submersible mixers

Dampens flow and load variability from batch urea-plant condensate releases; mixers prevent NH₃ volatilisation at ambient temperature.

Caustic Dosing & Degassing

NaOH (48–50%) to pH 10.5–11.0; forced-draft CO₂ degassing tower

Shifts NH₄⁺/NH₃ equilibrium toward free ammonia (>90% free NH₃ at pH 11); CO₂ removal prevents CaCO₃ scaling in the stripping tower.

Air Stripping Tower

PP random packing, 6–7 m height; air:liquid ~2,500–3,500:1 (v/v); 55–65°C

Packed bed maximises gas–liquid contact; waste heat from process condensate eliminates need for external steam, reducing OPEX.

Acid Scrubber

20–30% H₂SO₄ irrigation; product 28–32% w/w ammonium sulphate

Captures stripped NH₃ as ammonium sulphate solution for fertiliser reuse; prevents atmospheric NH₃ emissions.

Bio Reactor (N/DN)

MLSS 3,000–4,000 mg/L; SRT 20–25 days; DO 2.0–3.0 mg/L; recycle 200–300%

Extended SRT supports slow-growing nitrifiers; internal recycle enables simultaneous nitrification/denitrification for total nitrogen removal.

Filtration & GAC Polishing

Multi-grade pressure filter + GAC bed; EBCT ~20–25 min

Removes residual TSS and trace organics (COD polishing) to meet CPCB ZLD-adjacent discharge standards.

Verified Performance

60-day integrated commissioning run. Overall NH₃-N removal exceeded 98%.

Parameter

Raw Influent

After Strip

Final Effluent

NH₃-N (mg/L)

950

95–140

8–14 (≤ 50)

COD (mg/L)

2,200

1,800–2,000

150–210 (≤ 250)

BOD (mg/L)

650

560–600

18–25 (≤ 30)

TSS (mg/L)

200

170–190

20–35 (≤ 100)

Cost Summary

Item

CAPEX

OPEX/yr

Stripping tower + blowers

₹1.1 Cr

Acid scrubber / recovery

₹0.65 Cr

Bio reactor retrofit

₹1.4 Cr

Filtration & GAC

₹0.5 Cr

₹0.20 Cr

Reagents + Power + O&M

₹1.75 Cr

Total

≈₹3.65 Cr

≈₹1.95 Cr

210–230 t/yr ammonium sulphate recovered offsets OPEX. Simple payback: 3–4 years.

Operational Challenges

CaCO₃ Scaling in Tower

Managed through quarterly acid-wash cycles and a higher self-cleaning packing geometry.

Nitrification Inhibition

NH₃ spikes >500 mg/L suppressed nitrifiers. Mitigated by increasing equalization HRT and an automatic feed-throttle interlock.

Caustic Consumption

Largest reagent cost. Reduced by routing only high-demand streams through the pH-lift step, lowering overall NaOH usage.

Lessons Learned

Match Technology to Strength

Stripping for high-strength streams; biological N/DN most cost-effective after concentration is reduced.

Equalization as Process Control

Adequate HRT upstream prevents ammonia spikes from inhibiting downstream biology.

Pilot Before Committing

Bench trials identified rapid ion-exchange resin fouling on high-TDS streams, avoiding a costly dead end.

Quantify By-Product Value Early

Ammonium sulphate recovery economics should be evaluated alongside the compliance case, not after.

Design In Interlocks

Automatic feed throttles tied to upstream NH₃-N protected the bioreactor more reliably than manual intervention.

Budget for Nitrifier Acclimation

Bio-augmentation with seed sludge and gradual loading ramp-up materially shortens commissioning vs. a cold start.

Discuss Your Refrigerant Strategy.

Whether you are planning a new installation or evaluating a refrigerant conversion for existing equipment, our team can model the environmental and economic implications.

Talk to Eco-Technology Team

The Refrigerant Transition.We Are Already There.