Closing the Gap Between Design and Operational Reality in RNG Odourization Systems 

By Midland Resource Recovery (MRR)

As renewable natural gas facilities continue to scale across North America, odorization systems are increasingly being asked to operate under dynamic conditions that differ significantly from traditional natural gas environments. While design specifications often assume steady-state flow and pressure, field performance tells a different story. 

RNG facilities frequently experience fluctuating flow rates, variable discharge pressures, and intermittent injection into distribution systems. These dynamics directly impact odorant injection accuracy. Systems designed around nominal operating conditions may struggle during ramp-ups,  turndown scenarios, or low-flow events. 

At Midland Resource Recovery, we routinely encounter facilities where injection systems technically meet nameplate design criteria yet struggle to maintain consistent dosing accuracy under real-world operating conditions. Injection pumps that perform well at mid-range flows may lose proportional accuracy at turndown. Pressure changes can alter injection dynamics. Temperature swings can affect chemical behaviour. 

Bridging this gap requires more than selecting a capable pump. It demands: 

• Flow-proportional injection with verified turndown capability 
• Pressure compensation that reflects real-time conditions 
• Control logic capable of responding to rapid system changes 
• Field validation across the full operating envelope 

Injection accuracy must be tested, calibrated, and verified under actual operating scenarios.  Commissioning cannot be treated as a one-day event. It must include performance testing at multiple flow conditions and ongoing monitoring. 

RNG also introduces gas composition variability. Trace contaminants such as siloxanes, sulfur compounds, or residual process chemicals can contribute to odour masking or odour fade. Meeting calculated injection rates does not guarantee detectability downstream. Understanding the gas matrix and its chemical interactions with odorants is essential.

MRR supports operators not only with system design and commissioning, but with ongoing performance evaluation, carbon changeouts, tank changeouts, and injection audits. Our field teams see firsthand how systems behave months and years after startup. That feedback loop between field performance and engineering refinement is critical to maintaining long-term odour reliability. 

As RNG infrastructure expands, odorization cannot be treated as a static subsystem. It is a dynamic safety layer requiring continuous validation. Aligning system design with operational reality ensures compliance, protects communities, and preserves public confidence.

You can find more insights like this in the 2026 Canada edition of Biogas Community Magazine.