Since 1992, Envent Corporation has provided mobile vapor control, tank degassing, and emission control services to refineries, chemical plants, terminals, and pipeline facilities across North America. Over three decades of field experience has taught us exactly what questions facility operators, environmental managers, and maintenance planners need answered before selecting a vapor control contractor.
This FAQ addresses the most common questions we receive about thermal oxidation technology, regulatory compliance, project timelines, safety protocols, and equipment capabilities. Whether you’re planning a routine storage tank degassing, responding to an emergency pipeline evacuation, or coordinating a multi-unit refinery turnaround, you’ll find detailed technical answers from our engineering team.
Can’t find what you’re looking for? Call our 24/7 emergency hotline at 888-997-9465 or request a quote online. Our engineers respond to emergency calls within minutes and provide written quotes for planned projects within 24 hours.
Envent Corporation specializes in mobile vapor control, tank degassing, and water treatment services for industrial facilities across North America. Our core services include storage tank degassing, pipeline evacuation and degassing, refinery turnaround vapor control, marine vapor recovery, chemical scrubbing for H₂S and odor control, mobile water treatment, soil vapor extraction, and natural gas cross-compression for pipeline maintenance.
We operate the largest fleet of mobile thermal oxidizers and emission control systems in North America, serving refineries, chemical plants, terminals, pipeline operators, and marine facilities throughout the United States and Canada since 1992.
Tank degassing duration depends on tank size, product vapor pressure, ambient temperature, and target vapor concentration.
Representative timelines include:
Timeline varies based on residual heel volume, internal obstructions, and whether nitrogen purging is used to accelerate vapor displacement. Our engineering team provides project-specific timeline estimates after reviewing your tank specifications and product characteristics.
Envent provides services throughout the continental United States and Canada, with strategic equipment depots enabling rapid response:
Major Service Areas:
We have successfully completed projects in all 50 states and across Canada. Remote locations receive service through expedited equipment transport from our nearest regional depot.
Yes. Envent provides 24/7/365 emergency response and continuous project operation. Our emergency hotline (888-997-9465) is staffed around the clock by engineers who can immediately dispatch equipment and OQ-qualified operators.
Once on-site, our technicians provide continuous 24-hour coverage throughout project duration. This is essential for tank degassing and refinery turnaround operations where stopping vapor control would create safety hazards or regulatory violations.
For planned projects, we coordinate start times with your facility operations team and provide whatever coverage schedule your project requires continuous 24/7, day shift only, or custom coverage patterns.
For accurate project quotes, our engineering team needs:
Tank/Vessel Information:
Project Requirements:
Regulatory Context:
Contact us at 888-997-9465 or submit a request through our website. We provide detailed written quotes within 24 hours.
Both EMTOS and EMECS achieve 99.9%+ destruction removal efficiency through thermal oxidation at 1,400°F+, but they serve different capacity needs:
EMTOS (Envent Mobile Thermal Oxidizer System):
EMECS (Envent Mobile Emission Control System):
Many projects use both: EMTOS for initial degassing, then EMECS during high-rate refilling when vapor generation peaks.
All Envent mobile thermal oxidizers achieve 99.9% minimum destruction removal efficiency (DRE) on volatile organic compounds when operated at 1,400°F minimum chamber temperature.
Performance Verification:
Regulatory Acceptance: This 99.9% DRE satisfies EPA Best Available Control Technology (BACT) standards, EPA Maximum Achievable Control Technology (MACT) requirements, California SCAQMD and BAAQMD strictest local rules, and all state environmental agency requirements.
All projects include complete temperature documentation proving sustained 1,400°F+ operation for regulatory submittal.
Thermal oxidation destroys volatile organic compounds (VOCs) through controlled, high-temperature combustion at 1,400°F minimum. The process converts hydrocarbon pollutants into water vapor (H₂O) and carbon dioxide (CO₂) through complete molecular oxidation.
The Process:
Why 1,400°F? This temperature exceeds the autoignition point of all common petroleum and chemical VOCs, ensuring complete molecular destruction rather than partial conversion to harmful intermediate compounds.
Key advantages: 99.9%+ destruction efficiency, continuous performance monitoring, no breakthrough risk (unlike carbon), no hazardous waste generation, EPA-recommended BACT technology.
Thermal oxidation provides complete vapor destruction rather than temporary capture, eliminating regulatory risk and ensuring permanent emission control.
Activated Carbon Limitations:
Thermal Oxidation Advantages:
Cost Comparison: While the perception may be thermal oxidizer rental rates are high, total project economics favor thermal oxidation due to faster completion (reduces facility downtime costs), no hazardous waste disposal fees ($500-$2,000/ton for spent carbon), regulatory certainty (zero permit violation risk), and no backup system needed if primary method fails.
EPA explicitly recommends thermal oxidation as Best Available Control Technology (BACT) for tank degassing operations.
Yes. Envent specializes in sour crude tank degassing and high-H₂S vapor control using combined thermal oxidation and chemical scrubbing.
Our H₂S Capabilities:
Safety Protocols:
Project Experience: Permian Basin sour crude terminals, Western Canadian Sedimentary Basin heavy sour crude, Gulf Coast refinery sour crude processing units, California sour crude storage operations.
Portable vapor bladders are temporary storage bags (3500 cu.ft. capacity) that buffer vapor flow between the tank and thermal oxidizer, improving efficiency and reducing costs.
How They Work: During peak vapor generation (when loading or product transfer creates high vapor rates), excess vapors fill the bladder. During low-activity periods, stored vapors discharge from the bladder into the thermal oxidizer, maintaining continuous stable operation.
Benefits:
When Recommended:
Bladders include flame arrestor protection, pressure relief valving, and grounding/bonding for static control. Our technicians provide complete setup, monitoring, and removal.
Tank degassing operations must comply with multiple federal EPA regulations depending on facility type and products handled:
EPA Best Available Control Technology (BACT):
EPA Maximum Achievable Control Technology (MACT):
New Source Performance Standards:
Greenhouse Gas Reporting:
Envent provides complete regulatory documentation for all applicable standards, formatted for EPA inspection or facility Title V permit compliance.
SCAQMD (South Coast Air Quality Management District) Rule 1149 governs “Degassing of Cargo Tanks, Trucks and Trailers” in Southern California’s Los Angeles basin—one of the strictest air quality regions in the United States.
Rule 1149 Requirements:
Envent Compliance:
We have successfully completed thousands of projects under SCAQMD jurisdiction including facilities at Carson, Wilmington, El Segundo, Torrance, and Long Beach.
BACT (Best Available Control Technology) is an EPA standard requiring the most effective emission control technology considering energy, environmental, and economic impacts. For tank degassing VOC emissions, EPA recognizes thermal oxidation at 1,400°F minimum as BACT.
EPA BACT Requirements for Thermal Oxidizers:
How Envent Meets BACT:
When BACT Applies:
Our BACT compliance documentation has satisfied EPA Region 6 inspectors, California Air Resources Board auditors, and state environmental agencies nationwide.
Yes. Comprehensive regulatory documentation is standard with every Envent project, formatted for EPA, state environmental agencies, and local air quality district requirements.
Standard Documentation Package Includes:
Pre-Project:
Real-Time Monitoring Records:
Post-Project Certification:
Agency-Specific Reports: Formatted submittals for Texas (TCEQ), Louisiana (LDEQ), California (SCAQMD, BAAQMD), EPA federal reports, and Canadian (ECCC) requirements.
All data retained for 7 years in our digital archive, accessible through our eReport Client Portal for audits, permit renewals, or compliance demonstrations.
Yes. Envent Canada ULC provides full-service vapor control throughout all of Canada with complete compliance under Environment and Climate Change Canada (ECCC) federal standards and provincial air quality regulations.
Canadian Service Areas (include but not limited to):
ECCC Regulatory Compliance:
Canadian-Specific Services:
Our Canadian depot in Edmonton enables 12-18 hour emergency response throughout Western Canada. We have successfully completed projects for Suncor, Canadian Natural Resources, Cenovus Energy, Imperial Oil, and Enbridge.
Yes. Envent compression technicians maintain federal Operator Qualification (OQ) certification under Department of Transportation (DOT) pipeline safety regulations.
OQ Certifications:
Additional Safety Certifications:
Industry Contractor Qualifications:
Our OQ program is audited annually by major pipeline operators including Enterprise Products, Kinder Morgan, Energy Transfer, and Williams Companies to verify best practice compliance.
Envent maintains zero-incident safety performance as our operational standard. Since 1992, we have completed thousands of tank degassing, pipeline evacuation, and vapor control projects without major safety incidents, OSHA recordable injuries, or environmental releases.
Safety Performance Metrics:
Safety Program Elements:
Client Safety Integration: Our safety performance enables contractor approval at the most safety-conscious facilities including ExxonMobil, Shell, Chevron, BP, and other major operators with stringent contractor safety requirements.
Safety is never compromised for schedule or cost considerations. If conditions are unsafe, we stop work immediately until hazards are controlled.
Yes. Envent has safely degassed more transmission pipelines than any other vapor control provider in North America, with proven capabilities across all pipeline types and pressure ranges.
Pipeline Applications:
Specialized Capabilities:
Equipment: Mobile thermal oxidizers, chemical scrubbers for H2S and other sulfur compounds, nitrogen injection systems for purging.
Our pipeline degassing methodology enables hot work authorization within 48-72 hours of initial depressurization on standard diameter lines, compared to 96+ hour industry averages using conventional venting.
Envent serves the complete spectrum of industrial facilities generating VOC emissions requiring Best Available Control Technology compliance:
Petroleum Refining: Crude oil refineries, process unit turnarounds (FCC, reformer, hydrocracker), storage tank farms, marine terminals, product blending facilities
Midstream & Terminals: Pipeline terminals, bulk storage facilities, natural gas processing plants, compressor stations, custody transfer stations
Chemical Manufacturing: Petrochemical plants, specialty chemical facilities, polymer production, solvent manufacturing, pharmaceutical production
Marine Operations: Crude oil tankers, product barges, chemical parcel tankers, LNG carriers, marine terminal vapor control, vessel cleaning
Power Generation: Natural gas power plants, fuel oil storage, emergency generator testing
Environmental Remediation: Superfund sites, underground storage tank removal, soil vapor extraction, groundwater treatment, contaminated site cleanup
Oil & Gas Production: Upstream well sites, tank batteries, separation facilities, gas processing plants
Our client portfolio includes Fortune 500 companies, independent operators, municipalities, environmental contractors, and government agencies across all 50 states and Canada.
Yes. Refinery turnaround vapor control is one of Envent’s core specializations. We have supported hundreds of turnarounds at major refineries nationwide, often managing multiple simultaneous degassing operations.
Turnaround Services:
Typical Turnaround Applications:
Capacity: Multiple EMTOS and EMECS units deployed in parallel, providing combined vapor processing up to 50,000+ SCFM for large-scale turnarounds requiring simultaneous multi-unit degassing.
Pre-Turnaround Planning: We coordinate with your turnaround planning team months in advance to ensure equipment availability, pre-position equipment if needed, complete site-specific safety training, and finalize regulatory documentation before the turnaround starts.
Contact our turnaround services team to discuss your specific requirements and timeline.
Envent provides complete turnkey service including equipment AND qualified operators. We do not rent equipment without operators.
Why Turnkey Service:
What’s Included:
Operator Qualifications: Every technician maintains DOT Operator Qualification, 40-hour HAZWOPER certification, H₂S awareness and respiratory protection, confined space entry training, and facility-specific safety certifications (ISNetworld, Avetta, client-specific).
This turnkey approach ensures safety, regulatory compliance, and project success while eliminating liability concerns for your facility.
Getting started is simple. Contact our engineering team through any of these methods:
What Happens Next:
Step 1 – Engineering Consultation (Within 1 Hour for Emergencies):
Our engineers review your project requirements, discuss technical details, answer questions, and provide preliminary timeline and cost estimates.
Step 2 – Written Quote (Within 24 Hours):
Detailed proposal including equipment specifications, project timeline, pricing, regulatory compliance approach, and mobilization logistics.
Step 3 – Pre-Project Planning:
Once approved, we coordinate site access, electrical power, vapor tie-in points, safety requirements, and schedule equipment mobilization.
Step 4 – Equipment Mobilization:
EMTOS/EMECS units arrive with OQ-qualified operators, complete setup and leak testing, then begin vapor control operations.
Step 5 – Project Execution:
24/7 operation with continuous monitoring, daily status updates, and real-time regulatory documentation.
Step 6 – Project Closeout:
Final reporting, regulatory submittal packages, and equipment demobilization.
For immediate assistance: 888-997-9465
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Hi, I’m Steve Sellinger, CEO of Envent Corporation. We make it our policy at Envent
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