Landfill sites generate gas as organic waste decomposes, and this gas must be safely combusted to prevent methane and other harmful compounds from escaping into the atmosphere. Traditional flaring, however, can produce significant quantities of nitrogen oxides (NOx) and carbon monoxide (CO) — pollutants that are increasingly scrutinised by environmental regulators. This is where SMART flare technology comes in.
Developed by Organics Limited, SMART flares are purpose-built to dramatically cut NOx emissions from landfill gas combustion while simultaneously ensuring cleaner burning overall. The result is a flaring solution that meets stringent environmental standards without sacrificing reliability or performance.
The Problem: NOx and CO Emissions from Landfill Gas Flaring
Landfill gas flares have traditionally been a necessary but imperfect solution. Standard combustion processes can generate high flame temperatures that promote the formation of Thermal NOx — the dominant source of nitrogen oxide emissions in this application. Poor air-fuel mixing can also lead to incomplete combustion, elevating carbon monoxide output.
Beyond NOx and CO, landfill gas often contains a cocktail of trace toxic compounds — including vinyl chloride, benzene, and non-methane organic carbons — as well as ammonia in some applications. Effectively neutralising these substances requires more than a simple burn; it demands carefully engineered combustion conditions.
How SMART Flare Technology Works
The SMART approach is built on two core technical principles: exhaust gas recycle and fuel-staging. Together, these techniques reduce the intensity and heat of combustion, ensure thorough mixing of air and fuel-gas, and minimise the free oxygen available to form NOx.
Fuel-Staging and Two-Zone Combustion
By splitting the combustion process into two distinct zones, SMART flares keep peak flame temperatures under control. Since Thermal NOx formation is highly sensitive to flame temperature, this staged approach is central to achieving the technology’s low-emission performance.
Natural-Draft Exhaust Gas Recycle
Rather than relying on mechanical fans or external energy input, SMART flares use a patented natural-draft driven exhaust gas recycle system. This recirculates combustion gases back into the process to provide cooling — without introducing additional free oxygen. The natural draft is generated by the height and temperature of the stack itself, and the degree of recirculation can be fine-tuned using flow control valves.
Organics has been refining this technology since the early 1990s, accumulating decades of field experience across a wide range of landfill gas applications.
Extended Retention Time for Trace Gas Destruction
For sites needing to address a broader spectrum of toxic trace gases, SMART flares can be specified with additional stack height to extend gas retention time. With a minimum retention time of 0.6 seconds, and longer options available, the system achieves Destruction and Removal Efficiencies (DRE) in excess of 95% for most trace compounds.
Performance Highlights
The combination of staged combustion and exhaust gas recycle delivers measurable, verifiable results:
At peak settings, SMART flares achieve NOx emissions of less than 25 mg/Nm³ (dry gas at 3% oxygen) — equivalent to approximately 0.025 lb NOx/MMBtu at 50% methane.
Carbon monoxide levels stay below 40 mg/Nm³ (dry gas at 3% oxygen), roughly equivalent to 0.6 lb/MMBtu at 50% methane.
Independent testing by a NAMAS-approved laboratory confirmed that vinyl chloride, benzene, and non-methane organic carbons are destroyed at greater than 98% efficiency.
Ammonia Destruction Without a NOx Penalty
One of the standout capabilities of this technology is its ability to handle high concentrations of ammonia gas without driving up NOx output. In testing, an inlet concentration of 100,000 mg/Nm³ (dry gas, 3% oxygen) resulted in a 99.95% removal efficiency, while total NOx load remained under 100 mg/Nm³ — comfortably within the requirements of the German TA Luft standard and the (then-proposed) UK Environment Agency landfill gas emission standards.
Technical Specifications
| Parameter | Specification |
|---|---|
| Flow rate range | 100 to 15,000 Nm³/hr |
| Shroud material | 304 stainless steel (standard); 316ss optional |
| Combustion chamber lining | 100 mm high-temperature ceramic blanket bricks, no hot-face fixings |
| Pressure rise across gas blower | 150 mbar (typical) |
| Flame temperature | 760°C to 1200°C, subject to application |
| Retention time | 0.6 seconds minimum |
| Minimum methane concentration | 20% |
| Standard inlets | 2 flanged inlets (additional available on request) |
| Flow control | Chemical duty butterfly valves |
| Pipework finish | Hot dip galvanised |
| Burner material | High-temperature stainless steel |
| Flame arrestors | Fitted on gas booster inlet and outlet |
| Flame detection | Self-checking UV sensor |
| Turn-down ratio | Up to 10:1 (optional) |
Key Features at a Glance
- Ultra-low emissions of CO and NOx
- Patented natural-draft exhaust gas recycle to minimise free oxygen in the combustion zone
- Optional extended retention time via additional stack height
- Fully stainless steel shroud construction
- Ceramic blanket brick lining with no hot-face surface fixings
- Optional 10:1 turn-down ratio for flexible operation across variable gas flows
- Flow range from 100 to 15,000 Nm³/hr
- Optional on-line monitoring, internet connection, and data logging
Applications
SMART flare technology is designed for landfill sites and gas treatment facilities where emissions compliance is a priority — whether driven by local regulation, community concerns, or corporate environmental commitments. Its scalability, from 100 Nm³/hr up to 15,000 Nm³/hr, makes it suitable for everything from small closed landfills to large active sites. The optional turn-down ratio and remote monitoring capability also make it well-suited to sites with variable gas generation profiles that require flexible, unattended operation.
Summary
SMART flares tackle one of the most persistent challenges in landfill gas management — reducing NOx and CO emissions — while also handling toxic trace gases and ammonia without compromising on environmental performance. By combining fuel-staging, natural-draft exhaust gas recycle, and a robust, ceramic-lined stainless steel construction, this technology delivers measurable compliance with demanding standards like Germany’s TA Luft and UK Environment Agency requirements.
Interested in learning whether SMART flare technology is the right fit for your landfill gas management strategy? Get in touch with our team today to discuss your site’s requirements and explore how this proven, decades-refined technology can help you meet your emissions targets.