DFTO for Chemical Storage Tank Venting Operation
Executive Summary
Epcon provided a skid-mounted direct-fired thermal oxidizer (DFTO) for a chemical storage tank venting application — eliminating volatile organic compound (VOC) and vapor emissions during tank loading/unloading and storage operations. The system is designed for rapid vent-stream treatment with high destruction efficiency, while using a compact, cost-effective oxidizer. Through engineered vent-control strategy and system design (including an accumulator ahead of the DFTO to buffer and smooth peak vapor loads), Epcon delivered reliable emissions control, simplified operations, and optimized capital and operating costs for the chemical distribution facility.
Project Overview
A specialty-chemical distribution terminal in Texas expanded its facility, requiring an upgraded vent-control system to handle diverse chemical storage tank emissions and vapor streams — including high-concentration solvent vapors, intermittent venting during loading/unloading, and variable exhaust flows. The customer selected Epcon to engineer a comprehensive vent control strategy and supply a skid-mounted, L-shaped direct-fired thermal oxidizer (DFTO) with full controls and support systems. The deliverables included inlet isolation dampers, UL-certified control panel with HMI, factory acceptance testing (FAT), and on-site commissioning. This retrofit aimed to ensure regulatory compliance, flexibility in operations, and cost-effective emissions management.
The Challenge
The facility’s operations presented several critical challenges:
- Chemical storage tanks contain diverse chemicals, producing vapor emissions and fugitive VOC streams during venting, loading/unloading, and storage maintenance. These emissions need reliable destruction to meet stringent environmental regulations.
- The venting events are intermittent and variable in flow rate — from near-zero idle conditions to high-volume venting during loading or tank breathing events.
- The facility required a system that could handle high VOC concentration streams as well as rapid changes in vapor load, while maintaining safety, combustion stability, and minimal downtime.
- The solution had to be cost-effective and compact, as storage terminals typically have limited available footprint for emissions-control equipment.
- The oxidizer system needed to integrate with existing infrastructure, include proper control systems for safe startup/shutdown, and be commissioned with minimal disruption to terminal operations.
Engineering Requirements
To satisfy operational, safety, and environmental demands, the DFTO solution needed to:
- Provide a direct-fired thermal oxidizer suitable for tank vent and vapor streams, capable of reliably destroying VOCs and solvent vapors even at high concentrations or intermittent flows. DFTOs are commonly used when exhaust streams are rich in VOCs and high caloric value, making them ideal for storage tank venting and chemical loading/unloading applications.
- Include a vent-stream accumulator (vapor buffer) upstream of the DFTO to smooth out peak flows and prevent oversizing the oxidizer, thereby reducing capital and operating costs while supporting variable venting loads (loading, breathing, unloading cycles).
- Be skid-mounted and compact, with a layout (L-shaped in this case) designed to minimize footprint and adapt to the storage terminal’s spatial constraints.
- Feature full controls: independent process-air and combustion-air blowers, isolation dampers, safety interlocks, and a UL-certified control panel with HMI for operation and monitoring.
- Undergo Factory Acceptance Testing (FAT) before shipment, and on-site commissioning and testing under real operating conditions to validate performance and safety prior to startup.
- Maintain high destruction efficiency (DRE) for VOCs and solvent-laden vent vapors, converting them to combustion products (CO₂ and H₂O), with safe exhaust stack emissions.
The Solution
Epcon delivered a turnkey vent-control solution consisting of:
- A skid-mounted, L-shaped direct-fired thermal oxidizer (DFTO) tailored to treat vapor emissions from chemical storage-tank venting. The design includes insulated combustion chamber, burner system, and high-temperature oxidation to ensure full destruction of VOCs/HAPs.
- A vapor-accumulator (buffer) ahead of the DFTO to capture intermittent venting flows (tank breathing, loading/unloading), smoothing vapor load and allowing a smaller, more cost-effective oxidizer to be used.
- Full control system with inlet isolation dampers, process-air and combustion-air blowers, safety interlocks, and a UL-certified control panel with HMI, all engineered and manufactured in-house at Epcon’s facility.
- Factory Acceptance Testing (FAT) with customer participation, ensuring performance verification before shipment. After shipment, Epcon supervised on-site installation, commissioning, and startup — guaranteeing readiness and compliance.
- A complete vent-control strategy and implementation plan, developed during the project’s front-end engineering phase to ensure integration with terminal operations, safety protocols, and regulatory requirements.
Technical Specifications
System Type: Direct-Fired Thermal Oxidizer (DFTO) for Storage Tank Venting
Configuration: Skid-mounted, L-shaped DFTO (with vapor accumulator and isolation dampers)
Emission Type Treated: VOC and solvent-laden vapors from chemical storage tank venting, loading/unloading, breathing losses
Feed Conditions: Intermittent vent streams, variable flow, high VOC concentration — typical of tank venting operations and chemical loading/unloading events
Controls & Safety: Independent process-air and combustion-air blowers; inlet isolation dampers; UL-certified control panel + HMI; safety interlocks; designed for industrial chemical environments
Delivery & Commissioning: Factory Acceptance Testing (FAT), on-site installation supervision, commissioning, startup validation under actual operating conditions
The Results
After installation and commissioning, Epcon’s DFTO solution delivered:
- Reliable destruction of tank-vent and vapor emissions, converting solvent and VOC-laden air into non-hazardous exhaust (CO₂ and water), ensuring regulatory compliance and safe discharge.
- Flexibility in facility operations, with the vapor accumulator buffering vent loads — enabling efficient loading/unloading scheduling, venting operations, and reduced risks during peak vapor release events.
- Reduced capital and operating costs, thanks to optimized DFTO sizing (enabled by vapor buffering) and elimination of need for multiple smaller oxidizers or oversized units.
- Compact footprint and easy installation, because the skid-mounted, L-shaped layout simplified integration into existing terminal infrastructure.
- Turnkey delivery with minimal disruption, including full controls, FAT, commissioning, and start-up support — enabling rapid implementation without major downtime or operational interference.
- Demonstrated customer confidence and satisfaction, with the solution meeting performance needs and improving terminal emission control capabilities.
This project highlights Epcon’s expertise in designing and delivering robust, efficient vapor-venting and emissions-control solutions for chemical storage and distribution facilities.
Learn More
Epcon offers engineering, fabrication, and turnkey installation of DFTO systems, emission-control packages, and vent-management solutions for chemical storage terminals, loading/unloading facilities, and industrial vapor-handling operations.
Contact our engineering team to discuss a custom vent-control and thermal-oxidation solution tailored to your storage tank, vapor stream, and compliance requirements.
