Waste Gas Burners & Flares

Safe combustion of excess vapors and gases.

What It Is & How It Works

Waste gas burners and flares are combustion devices that safely destroy gases and vapors that cannot be economically recovered or returned to process. They address two related hazards: the accumulation of flammable gas mixtures that could reach explosive concentrations if vented uncontrolled, and the release of volatile organic compounds and hazardous air pollutants that violate emission regulations. By converting waste gases to carbon dioxide and water vapor through controlled combustion, these devices eliminate both the explosion risk and the regulatory exposure.

Waste gas flows through supply piping to a burner head where a continuous pilot flame or automatic ignition system initiates combustion. The burner is designed to maintain a stable flame across a range of gas flow rates and compositions. Wind shields, retention rings, or enclosed combustion chambers protect the flame from extinguishment. A flame monitoring system, typically a thermocouple or UV sensor, confirms ignition and triggers automatic re-ignition or alarm if the flame is lost.

Burners and flares are sized based on maximum waste gas flow rate, gas heating value in BTU per cubic foot, and required destruction efficiency. Installation configurations range from elevated stack-mounted flares to enclosed ground-level units, selected based on site constraints, noise considerations, and local permitting requirements.

Waste Gas Burner vs. Flare

The terms are often used interchangeably, but in practice a “burner” typically refers to an enclosed or semi-enclosed combustion device designed for continuous, low-visibility operation at or near ground level. A “flare” typically refers to an open-flame device, often elevated, designed for intermittent or emergency vapor destruction. Both accomplish the same fundamental task: converting waste gas to combustion products safely and in compliance with emission limits.

When to Specify Waste Gas Burners & Flares

Waste gas burners and flares are specified when a facility produces combustible waste gas that must be destroyed rather than vented:

Wastewater Treatment Plants Producing Digester Gas Anaerobic digestion produces methane-rich biogas that must be flared when gas production exceeds engine or boiler demand, when gas quality is insufficient for energy recovery, or during equipment maintenance periods when the primary gas use system is offline.
Landfill Gas Collection Systems Landfill gas extraction wells produce variable-quality methane that must be destroyed continuously to comply with EPA 40 CFR 60 Subpart WWW and NSPS requirements, even when energy recovery equipment is not installed or is temporarily unavailable.
Chemical and Petrochemical Process Vents Process vessels, reactors, and storage tanks that generate waste vapors containing VOCs or HAPs subject to EPA 40 CFR 60/63 destruction requirements, where vapor recovery is not feasible due to low concentration, variable composition, or incompatible gas streams.
Tank Farm Vapor Destruction Multi-tank storage facilities where vapor recovery valves collect displaced vapors during filling operations and route them to a central burner or flare for destruction, replacing atmospheric venting through conservation vents.
Biogas Facilities Requiring Excess Gas Management Biogas upgrading and conditioning plants where the waste stream from gas cleaning, including off-spec gas and purge streams, must be safely combusted to prevent uncontrolled methane release and meet air quality permit conditions.

Why Shand & Jurs Waste Gas Burners & Flares Excel

Facilities with Variable Gas Flow and Composition

Burner designs that maintain stable combustion across wide turndown ratios accommodate the fluctuating gas volumes and heating values typical of digester gas, landfill gas, and intermittent process vents without requiring constant operator adjustment.

Sites Where Visible Flame and Noise Must Be Minimized

Enclosed ground-level burner designs contain the flame within a refractory-lined chamber, eliminating visible flame and significantly reducing combustion noise compared to open elevated flares, satisfying community and permitting constraints.

Installations Requiring Automatic, Unattended Operation

Integrated pilot ignition, flame monitoring, and automatic re-ignition systems allow continuous unattended operation with alarm notification, reducing the operator attention required to maintain compliant waste gas destruction.

Corrosive or Moisture-Laden Gas Streams

Stainless steel and alloy burner components, combined with condensate management features, handle the hydrogen sulfide, moisture, and siloxane content common in biogas and landfill gas without accelerated corrosion of burner internals.

Permit Applications Requiring Documented Destruction Efficiency

Burner designs tested and documented to achieve 98% or greater destruction efficiency provide the performance data regulators require when issuing air quality permits for new or modified waste gas sources.

Choosing the Right Waste Gas Combustion Device

Attribute	Elevated Flare	Enclosed Ground Burner	Utility Burner
Combustion Type	Open flame at elevated stack tip	Enclosed flame in stack chamber at grade	Semi-enclosed or open flame at low elevation
Typical Application	Emergency relief, high-volume intermittent venting	Continuous waste gas destruction, community-sensitive sites	Routine low-volume biogas or process gas flaring
Visible Flame	Yes, visible from distance	No, flame contained within enclosure	Minimal, low-profile flame
Noise Level	Higher due to open combustion and wind effects	Lower, chamber attenuates combustion noise	Moderate, depends on configuration
Destruction Efficiency	95–98% typical	98%+ with proper design	95–98% typical
Gas Flow Range	High capacity, wide turndown	Moderate capacity, wide turndown	Low to moderate capacity
Footprint	Small ground footprint, tall stack required	Larger ground footprint, no elevated stack	Compact, minimal site preparation
Best Fit	Choose for high-volume emergency or intermittent vapor destruction where an elevated stack is acceptable and visibility is not a concern.	Choose for continuous waste gas destruction at community-sensitive sites where visible flame and noise must be eliminated.	Choose for routine, low-volume gas destruction at wastewater plants, small biogas facilities, or process vents with modest flow rates.

What to Consider Alongside Waste Gas Burners & Flares

The Waste Gas Has Sufficient Heating Value for Energy Recovery When biogas or process gas quality and volume justify it, engine-generators, boilers, or micro-turbines convert waste gas to electricity or heat rather than destroying it. A flare or burner still serves as backup when the energy recovery system is offline. See Shand & Jurs Biogas Stream Equipment.
Vapors Can Be Captured and Returned to Process When displaced tank vapors have economic value or are compatible with a collection system, vapor recovery routes them back to storage or process rather than destroying them. See Tank Blanketing & Vapor Recovery.
The Gas Stream Requires Cleaning Before Any End Use When biogas contains high levels of hydrogen sulfide, siloxanes, or moisture that must be removed before combustion or energy recovery, gas conditioning equipment upstream of the burner improves combustion performance and extends burner service life. See Shand & Jurs Biogas Stream Equipment.
Complete Biogas Management System Pair waste gas burners with Shand & Jurs Biogas cover equipment for gas collection, biogas stream conditioning equipment for gas cleaning, and vapor recovery valves for tank vapor routing to create a complete biogas capture, treatment, and destruction system from digester to stack.
Emission Monitoring and Compliance Intelligence Combine burner operations with L&J Technologies flow and temperature instrumentation feeding Clairvoyance to log gas destruction volumes, pilot status, and combustion temperatures, supporting air quality permit reporting and continuous emission monitoring requirements.