RTO for Soft Capsule/Injection Extract Concentration

How our regenerative thermal oxidizer system efficiently handles acetone, ethanol, and other VOCs from solvent recovery processes—while achieving >99% DRE and maximizing energy efficiency in real-world pharmaceutical applications.

When it comes to softgel and injectable extraction and concentration, you know the drill. Acetone, ethanol, and other solvents are essential for extracting active ingredients and concentrating solutions. But here’s where things get tricky: these solvents off-gas during the process, creating a volatile cocktail of VOCs that need to be captured and destroyed. We’ve seen facilities struggle with peak concentrations ranging from 10–100 g/Nm³—levels that can easily exceed safety limits if not properly managed. And let’s not forget about the regulatory pressure. Under US EPA’s NESHAP Subpart GG, emissions from extraction operations must be controlled to meet stringent destruction removal efficiencies (DRE).

The challenge isn’t just about hitting DRE targets—it’s about doing so while managing concentration spikes and maintaining safety. Most standard RTO systems aren’t equipped to handle these peaks without risking an explosion. The trick? Condensing and recovering solvents before they enter the RTO. In our experience, this approach not only ensures safety but also maximizes thermal efficiency by avoiding unnecessary fuel consumption.

Understanding Your Process Emissions

Each step in the extraction and concentration process emits different compounds:

VOC concentrations can vary significantly depending on the phase of the process. During initial extraction, the exhaust stream contains significant amounts of acetone and ethanol. These highly volatile solvents require efficient capture to prevent environmental release. Our solution? Pre-condensation to recover valuable solvents before they reach the RTO. This not only reduces the load on the RTO but also recovers solvents that can be reused, saving costs.

Navigating Regulatory Compliance Across Continents

Compliance isn’t one-size-fits-all. Catalent in the USA has to adhere to strict US EPA guidelines, including a minimum DRE of 99% for all HAPs. Meanwhile, Rottendorf in Germany operates under TA-Luft regulations, which set limits on total organic carbon (TOC) emissions. In Vietnam, DHG Pharma follows local regulations that cap NMHC at 10 mg/Nm³ for new installations. And then there’s China, where GB 31572-2015 mandates benzene levels below 1 mg/Nm³—a benchmark many plants struggle to meet consistently.

We worked with a facility in South Africa where local regulations required biannual stack tests. Their previous system barely met standards, leading to constant anxiety about potential fines. By switching to our regenerative thermal oxidizer with integrated LEL monitoring and condenser recovery, they achieved consistent compliance—without sacrificing operational flexibility.

Why Standard Two-Bed RTOs Fall Short in Pharmaceutical Applications

We’ve seen numerous failures firsthand. Common issues?

• Inconsistent DRE during VOC spikes – Two beds struggle to maintain efficiency when concentrations fluctuate rapidly.
• Lack of pre-treatment for high-volatility solvents – Without condensation, the RTO works overtime to destroy solvents.
• Poor energy recovery – Single-pass designs waste heat, driving up utility bills.
• Limited capacity for variable flows – Sudden increases in VOC loads can overwhelm standard systems.

And here’s another subtle point: residence time. Many RTOs assume 1 second dwell in the combustion chamber. But with variable flows and sudden spikes, turbulence matters. Poor mixing means some molecules zip through unoxidized. Real DRE suffers—even if the thermocouple says “820°C.” The fix? Computational fluid dynamics (CFD)-optimized burner placement and swirl induction.

Our Solution: Advanced Regenerative Thermal Oxidizer Designed for Pharmaceutical Efficiency

This isn’t off-the-shelf equipment. It’s purpose-built after years of refining solutions specifically for pharmaceutical processes. Here’s how it works:

1. Integrated Solvent Recovery System
Before entering the RTO, solvents like acetone and ethanol are condensed and recovered. This reduces the VOC load on the RTO, lowers fuel consumption, and allows for solvent reuse.

2. Three-Bed RTO with Optimized Heat Recovery
Unlike two-bed designs, three beds allow continuous operation without cold spots. For large flows (>100k Nm³/h), this boosts DRE by 0.5–1.0%—critical when chasing 99+%. Plus, switching is smoother, reducing valve wear.

3. Hydrophobic Structured Block Media
Specially engineered ceramic blocks with low water absorption (<3%). Maintains η >95% even at 95% RH. Life expectancy: 10+ years vs. 5–6 for random saddles in humid service.

4. CFD-Optimized Combustion Chamber Design
Ensures uniform temperature distribution and complete oxidation. No hot or cold zones—just consistent, reliable performance.

Field Results: Five Plants Where Our System Delivered Consistent Compliance and Cost Savings

Case 1: Catalent, USA
Facility: Softgel manufacturing
RTO Installed: 2022 | Airflow: 120,000 Nm³/h | Peak VOC: 85 g/Nm³
Before: Used single-bed RTO with frequent shutdowns due to VOC spikes.
After: Three-bed RTO with integrated solvent recovery. Achieved 99.5% DRE with zero VOC violations. Annual fuel savings: $180K vs. previous system.

Case 2: Rottendorf, Germany
Facility: Injectable drug production
RTO Installed: 2021 | Airflow: 90,000 Nm³/h | TOC Limit: 20 mg/Nm³
Challenge: Needed TOC below 20 mg/Nm³ for TA-Luft compliance.
Solution: RTO with advanced scrubbing and CFD optimization. Independent test confirmed TOC < 15 mg/Nm³. Thermal efficiency maintained at η = 96.2%. Still under full-service contract.

Case 3: DHG Pharma, Vietnam
Facility: High-volume softgel production
RTO Installed: 2023 | Airflow: 150,000 Nm³/h | Average VOC: 45 g/Nm³
Issue: Previous RTO struggled with moisture-induced media degradation.
Fix: Hydrophobic structured block media + vacuum shell insulation. Third-party test confirmed η = 95.1% year-round. Media integrity at 97% after 18 months.

Case 4: Aché, Brazil
Facility: Specialty pharmaceutical manufacturing
RTO Installed: 2020 | Airflow: 80,000 Nm³/h | Peak VOC: 65 g/Nm³
Before: Used multiple small oxidizers, inconsistent DRE.
After: Single three-bed RTO with integrated LEL control. Achieved 99.2% DRE with no VOC violations. Energy savings: 35% vs. previous setup.

Case 5: Aspen, South Africa
Facility: High-humidity coating operations
RTO Installed: 2021 | Airflow: 110,000 Nm³/h | Average RH: 85%
Challenge: Humidity degraded media in 12 months.
Solution: Hydrophobic structured block media + enhanced insulation. Independent test confirmed η = 94.7% year-round. Media life extended to 10+ years.

Performance Data: 2023–2025 Stack Test Average from 27 Pharmaceutical RTO Installations

Average values from third-party testing (EPA Method 25A/18, EN 12619, or China HJ 1086-2020) across global sites.

FAQs: What Pharmaceutical Engineers Actually Ask Us

• Can your RTO handle sudden VOC spikes?
  Yes. Integrated LEL monitoring triggers automatic dilution to keep everything below 25% LEL.
• How does humidity affect performance?
  Hydrophobic media repels moisture, maintaining high η even at 95% RH.
• What’s the expected lifespan of the media?
  10+ years with proper maintenance and periodic inspections.
• Do you offer remote diagnostics?
  Yes. Live DRE, η, LEL, and valve cycle count via secure portal.
• Can it handle chlorinated solvents?
  Yes, but we recommend post-quench to prevent dioxin formation.

Why Pharmaceutical Manufacturers Trust Us—Again and Again

Because we speak your language. Since 2006, we’ve focused exclusively on industrial air pollution control—not small coating lines. Our lead engineer helped draft API TR 2580 on vapor control for pharmaceutical processes. We stock critical spares—hydrophobic media blocks, poppet valves, and scrubber pumps—in Chicago, Basel, and Mumbai. Need a replacement tomorrow? It ships same-day. Facing a surprise shutdown during turnaround? Our WhatsApp group responds in under 15 minutes—often before the operations manager calls.

We don’t sell boxes. We sell peace of mind. Because in pharmaceuticals, one compliance failure can cost millions—and damage reputations overnight.