Some images are technical illustrations. Real installation photographs where marked.
Overview
The CG IC Reactor™ (Internal Circulation) is a third-generation high-rate anaerobic treatment system achieving organic loading rates of 15–35 kg COD/m³/day — three to four times the loading capacity of a conventional UASB reactor. The IC Reactor uses a unique biogas-driven internal circulation mechanism: biogas generated in the lower treatment compartment rises through a central riser pipe, lifting sludge to a degassing vessel at the top, from where the degassed sludge-water mixture returns down through a downcomer pipe to the base. This powerful internal circulation dramatically increases contact between incoming wastewater and active granular sludge, enabling treatment of extremely high COD loads (5,000–80,000 mg/L) in a tall, slender reactor with a very small plan footprint.
Working Principle
Wastewater enters at the base and flows upward through the first treatment compartment where high-rate anaerobic digestion generates significant biogas. The biogas rises rapidly through a central riser pipe, lifting sludge and liquid upward with it. At the top of the riser, the mixture enters a degassing vessel where biogas separates and exits to the gas collection system. The degassed sludge-rich slurry flows back down through the outer annular downcomer pipe to the base — creating a powerful self-sustaining internal circulation driven entirely by biogas energy with no pumps or motors. A second upper polishing compartment provides additional digestion and clarification.
Key Technical Features
- OLR: 15–35 kg COD/m³/day (3–4× UASB)
- COD removal: 70–90% in single stage
- Biogas-driven internal circulation — no recycle pumps
- Tall slender design 16–25 m — minimal footprint
- Two treatment compartments: high-rate lower + polishing upper
- Granular sludge bed at 60–80 g VSS/L
- Handles COD 5,000–80,000 mg/L
- Biogas: ~0.35 m³ CH₄/kg COD, 65–75% CH₄
- Self-regulating circulation proportional to organic load
Design Parameters
| Parameter | Value |
|---|---|
| OLR | 15–35 kg COD/m³/day |
| Inlet COD | 5,000–80,000 mg/L |
| COD Removal | 70–90% |
| Reactor Height | 16–25 m |
| HRT | 2–6 hours |
| Sludge Conc. | 60–80 g VSS/L |
| Biogas Yield | ~0.35 m³/kg COD |
| CH₄ Content | 65–75% |
Applications
- Distillery vinasse (molasses-based, grain-based)
- Paper and pulp mill effluent
- Brewery and fermentation high-strength streams
- Pharmaceutical high-COD effluent
- Starch and glucose production wastewater
- Chemical plant organic discharge
- Any wastewater with COD >5,000 mg/L
Advantages
- Smallest footprint per unit COD treated of any anaerobic technology
- No recycle pumps — biogas drives circulation
- 3–4× volumetric efficiency vs UASB
- High biogas yield — maximum energy recovery
- Very low sludge production
- Self-regulating responds to load changes
- Long reactor life 20–30 years
Frequently Asked Questions
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