Dual RTO System Replaces Open Flare for Major Midstream Operation
Executive Summary
Epcon replaced an open-flare emissions disposal system with a dual Regenerative Thermal Oxidizer (RTO) configuration for a major mid-stream natural-gas operation. The new system handles VOCs, H₂S, and hydrocarbon vapors — achieving ~ 99.9 % destruction efficiency while reducing fuel consumption, improving emissions control reliability, and enabling better regulatory compliance. The dual-oxidizer setup delivers more consistent performance, greater energy efficiency, and a safer, more sustainable alternative to traditional flaring.
Project Overview
A mid-stream facility — involved in gathering, storing, and transporting natural gas / natural-gas liquids (NGLs) — was historically relying on an open-flare system to combust waste and fugitive gas streams (venting, loading/unloading, H₂S-rich sour-gas, etc.). Due to tighter environmental regulations, safety, community/neighboring-site concerns and inefficiency of flaring, the customer sought a modern alternative. Epcon was contracted to engineer, supply and commission a dual-RTO system sized for the facility’s variable vapor load, capable of treating a wide range of hydrocarbon and sulfur-containing streams, with better emissions destruction and lower fuel consumption compared to the flare.
The Challenge
To meet environmental, safety, and economic goals, the new emissions system had to deliver:
- A dual-RTO configuration sized to handle peak vapor and gas loads from vents, loading/unloading, and processing off-gassing — capable of treating volatile hydrocarbons and H₂S-containing sour-gas streams safely and reliably.
- High VOC/HAP/H₂S destruction efficiency — targeting ~ 99.9 % VOC removal or better, comparable (or better) than open-flare destruction but without visible emissions, soot, or uncontrolled combustion. As RTO technology is widely accepted for high-efficiency VOC destruction in industrial emissions control.
- Stable combustion, heat-recovery potential (if applicable), and efficient thermal management — reducing fuel consumption compared to continuous flaring and lowering operating costs and environmental footprint. RTOs are especially efficient when exhaust gas contains VOCs: combustion heat can be recuperated for preheating or other plant uses.
- Robust materials and construction, including corrosion resistance (to handle sour gas / H₂S), reliable controls, safety systems (e.g. for irregular loads, variable gas composition), and redundancy to avoid failure during critical operations.
- Turnkey design, fabrication, installation, and commissioning — minimizing downtime, ensuring seamless transition from flare to RTO-based emissions control.
Engineering Requirements
To meet environmental, safety, and economic goals, the new emissions system had to deliver:
- A dual-RTO configuration sized to handle peak vapor and gas loads from vents, loading/unloading, and processing off-gassing — capable of treating volatile hydrocarbons and H₂S-containing sour-gas streams safely and reliably.
- High VOC/HAP/H₂S destruction efficiency — targeting ~ 99.9 % VOC removal or better, comparable (or better) than open-flare destruction but without visible emissions, soot, or uncontrolled combustion. As RTO technology is widely accepted for high-efficiency VOC destruction in industrial emissions control.
- Stable combustion, heat-recovery potential (if applicable), and efficient thermal management — reducing fuel consumption compared to continuous flaring and lowering operating costs and environmental footprint. RTOs are especially efficient when exhaust gas contains VOCs: combustion heat can be recuperated for preheating or other plant uses.
- Robust materials and construction, including corrosion resistance (to handle sour gas / H₂S), reliable controls, safety systems (e.g. for irregular loads, variable gas composition), and redundancy to avoid failure during critical operations.
- Turnkey design, fabrication, installation, and commissioning — minimizing downtime, ensuring seamless transition from flare to RTO-based emissions control.
The Solution
Epcon provided a dual-RTO emissions-abatement system, incorporating:
- Two large-capacity regenerative thermal oxidizers, engineered to treat the facility’s combined vapor streams (venting, loading/unloading, sour-gas, hydrocarbon condensates). The dual units provide redundancy and capacity to manage load fluctuations.
- Robust ceramic-media heat-recovery beds (or thermal-oxidation ceramic modules) for high-temperature VOC destruction and efficient thermal energy reuse, increasing system energy effectiveness. RTO technology captures combustion heat, preheats incoming exhaust, markedly reducing fuel usage compared to open flaring.
- Comprehensive ducting and vapor-collection infrastructure to gather emissions/vapors from multiple plant sources (storage tanks, loading racks, processing units), ensuring all emissions are routed through the RTOs rather than vented or flared — improving overall emissions control and environmental compliance.
- Automated controls, safety interlocks and instrumentation to manage variable flow/ composition, guarantee destruction, monitor H₂S and VOC load, and switch between RTO units or stages as needed — ensuring safe, reliable operation under all conditions.
- Full turnkey delivery: engineering, fabrication, installation supervision, commissioning and operator training — enabling the mid-stream operator to retire the flare and bring the new system online with minimal disruption.
Technical Specifications
System Type: Dual Regenerative Thermal Oxidizers (RTO), skid / modular layout for mid-stream operation vapor load
Pollutants Treated: VOCs, hydrocarbon vapors, H₂S / sour-gas from natural-gas processing, venting, loading/unloading, condensate flash gas
Target Destruction Efficiency (DRE): ≈ 99.9 % VOC / H₂S / hydrocarbon destruction under design conditions
Combustion Temperature: ≥ 1,400 °F (typical RTO operating temperature) to ensure complete oxidation of VOCs/HAPs/H₂S streams
Airflow / Capacity: Sized for fluctuating high-volume vapor loads typical in mid-stream storage/processing & loading operations (peak & baseline)
Heat Recovery: Ceramic-bed heat exchange for pre-heating exhaust and optimizing fuel consumption, reducing energy use vs. flare
Safety & Materials: Corrosion-resistant construction (for H₂S, sour‐gas), redundant units for reliability, automated controls, emissions monitoring, fail-safe interlocks
The Results
Following commissioning, the dual-RTO system delivered substantial improvements over the previous flare-based configuration:
- High-efficiency emissions destruction: VOCs, hydrocarbons, and sour-gas vapors (including H₂S) are oxidized with ~ 99.9 % destruction efficiency — significantly reducing air-pollutant release and improving environmental compliance.
- Better energy and fuel efficiency: By recovering combustion heat and using efficient oxidation, fuel consumption decreased compared to continuous flaring; the system is more sustainable and cost-effective over time.
- Handling variable and high-load vapor streams reliably: The dual-RTO design accommodates fluctuations in flow and composition — from low idle venting to heavy loading/unloading or process upsets — without compromising destruction efficiency or system safety.
- Reduced environmental footprint and emissions visibility: The previous flare visible flares and combustion plumes were eliminated; emissions are now cleaned, compliant, and minimal external impact. Flares are known to produce more visible emissions, soot, and black-carbon compared to controlled oxidation.
- Improved long-term operational reliability and compliance: The turnkey RTO solution lowers maintenance burden compared to flare stacks, offers better process control, and positions the facility well for future regulatory tightening and sustainability goals.
Why Replace Flares with RTOs
- Environmental & regulatory pressure: Open flaring is increasingly scrutinized due to greenhouse-gas emissions, black carbon, VOC/air-pollution release, and community/health impacts. RTOs offer a cleaner, controlled alternative with high destruction efficiency and minimal visible emissions.
- Energy efficiency & cost savings: The ability of RTOs to recover waste heat and minimize fuel waste makes them economically advantageous over time compared to continuous flaring — especially for operations with recurring emissions or venting needs.
- Flexibility & reliability: Dual-RTO setups provide redundancy and capacity to handle fluctuating vapor loads — ideal for mid-stream operations that face variable throughput, intermittent venting, or batch-related emissions.
- Sustainability & community acceptance: Replacing visible flares with clean, controlled oxidation aligns with global efforts to reduce methane and VOC emissions, reduce black-carbon, improve air quality, and support ESG and sustainability goals — critical for mid/long-term asset value and regulatory compliance.
Contact Epcon
If your mid-stream or natural-gas operation is still relying on open flaring for vapor disposal, Epcon can engineer, supply and commission a turnkey dual-RTO system — delivering superior emissions control, energy efficiency, and regulatory compliance.
Contact Epcon engineering team to assess your vapor load, emissions profile, and site constraints — and let us prepare a custom RTO-based solution tailored to your operation.
