Landfill sites generate significant volumes of methane-rich gas as organic waste decomposes. Left uncontrolled, this gas poses both a greenhouse gas risk and a safety hazard. The MC Class Landfill Gas Flare Stack offers a robust, engineered solution: a shrouded flare system designed to destroy landfill gas at high temperature while keeping harmful emissions – particularly NOx – within tight limits.
The Challenge: Balancing Combustion Temperature and Emissions
Effective landfill gas destruction depends on two things: how hot the combustion gases get, and how long they stay hot. Push the temperature too low, and you risk incomplete combustion. Push it too high, and thermal NOx formation increases dramatically.
The MC Class is engineered around a well-understood combustion principle:
Raise combustion gases to 1,200°C and hold them there for a minimum of 0.6 seconds – the practical ceiling for emissions control via retention-time-and-temperature strategy.
Beyond this temperature threshold, NOx levels climb sharply due to thermal NOx formation, a well-documented phenomenon in high-temperature combustion chemistry. The MC Class is designed to sit right at this sweet spot, maximizing methane destruction efficiency without triggering excessive NOx generation.
How the MC Class Achieves This
Reaching and sustaining 1,200°C combustion isn’t possible with an open flare. It requires a shrouded flare design that minimises heat loss to the surrounding environment through the combustion chamber walls. The MC Class achieves this through:
Shrouded Combustion Chamber
The combustion chamber is sized to hold combustion gases at the design temperature for the specified retention period, with heat loss to the environment kept to an absolute minimum. The shroud is lined with ceramic blanket blocks that have no hot-surface fixings, improving durability and reducing maintenance concerns associated with fixing failures in high-heat zones.
Controlled Air-to-Fuel Ratio
Combustion relies on a non-visible, partially pre-aerated, turbulent diffusion flame. While the stoichiometric (ideal) ratio of air to methane is approximately 10:1, imperfect mixing in real-world conditions means the actual ratio is typically closer to 25:1. This additional air cools the flame and prevents excessive temperatures – making tight control of combustion air essential to the whole system’s performance.
Automatic Flame Temperature Control
The unit continuously monitors and adjusts flame temperature automatically, supported by duty/standby thermocouples and a self-checking UV flame detection sensor for reliable operation.
Key Features at a Glance
- Automatic flame temperature control
- Non-visible, partially pre-aerated, turbulent diffusion flame combustion
- 1,200°C minimum design temperature
- 0.6 seconds minimum retention time
- Emissions control compliant with UK, European and US standards
- Booster turn-down to zero flow without surging
- Fully stainless steel construction available as an option
- Skid-mounted for ease of site relocation
- Duty/standby thermocouples
- Ceramic blanket shroud lining with no hot-surface fixings
- Optional instrumentation for flow rate and gas concentration measurement
- Remote access and datalogging options
- High-reliability landfill gas pilot ignition
Technical Specifications
| Parameter | Specification |
|---|---|
| Flow rate range | 100 to 15,000 m³/hour |
| Pressure rise across gas booster | 150 mbar |
| Flame temperature | 1,000°C minimum |
| Retention time | 0.6 seconds |
| Minimum methane concentration for combustion | 25% |
| Number of inlets (standard) | 2 flanged inlets (additional available on request) |
| Flow control | Chemical duty butterfly valves |
| Pipework finish | Hot dip galvanised to industry standard |
| Burner material | High temperature stainless steel |
| Flame arrestor | Fitted on gas booster inlet and outlet |
| Flame detection | Self-checking UV sensor |
| Standard colour | Battleship Grey (or customer specification) |
The MC Class is engineered to provide the maximum specification for meeting Destruction Efficiency Rating (DER) requirements when using a retention-time-and-temperature emissions control strategy.
What’s Included in the Standard Package
The MC Class arrives as a skid-mounted package, ready for installation and commissioning on site. A typical package includes:
- Inlet knock-out pot for dewatering
- Gas blower for landfill gas extraction and delivery to the burner
- MC Class flare stack complete with safety functions and controls
- Flow metering (standard unless specifically excluded)
This turnkey approach reduces on-site installation complexity and shortens commissioning time considerably.
Flexible Control and Future-Proofing
Like Organics’ SC and RB flare classes, the MC Class control panel is built with flexibility in mind. Panels include a 20% expansion factor, allowing for future retrofits such as remote alarm modems connected via an RS232 port to the Public Switched Telephone Network (PSTN). This means alarm conditions can be isolated within the plant controller logic and reported remotely, without requiring a full control panel replacement down the line.
Typical Applications
The MC Class is suited to landfill sites requiring rigorous emissions control that meets or exceeds UK, European, and US regulatory standards for landfill gas destruction. Its skid-mounted, stainless-steel-optional construction makes it well suited to sites where equipment may need to be relocated as landfill cells are developed or decommissioned over time.
Key Takeaways
- The MC Class flare stack combusts landfill gas at a minimum design temperature of 1,200°C, held for at least 0.6 seconds, to maximise destruction efficiency while limiting thermal NOx formation.
- A shrouded combustion chamber with ceramic blanket lining minimises heat loss and supports sustained high-temperature operation.
- The system handles flow rates from 100 to 15,000 m³/hour and requires a minimum methane concentration of 25% for combustion at the specified temperature.
- Delivered as a skid-mounted package with flexible, expandable control panel architecture for future remote monitoring needs.
Get in Touch
If you’re evaluating flare technology for a landfill gas management project and want to understand whether the MC Class is the right fit for your site’s flow rates, gas composition, and emissions targets, get in touch with our team. We’re happy to walk through the specifications, discuss customisation options, and help you plan a compliant, reliable installation.