Degassing Chemicals for Refineries: How to Get LEL Down Faster
Every refinery turnaround has the same bottleneck: waiting for vessels to degas. You can plan every other task down to the hour, but if your LEL readings aren’t coming down, nobody’s going inside. Crews are standing around. The clock is running. And your turnaround schedule is already slipping.
Degassing is not optional. But it doesn’t have to take as long as it does.
What Degassing Actually Means
Degassing is the process of removing flammable and toxic vapors from a vessel, tank, or piece of equipment so it’s safe for human entry and hot work. In a refinery environment, that means getting the LEL (lower explosive limit) below acceptable thresholds — typically below 10% LEL for entry and below 1% for hot work — and getting toxic gas concentrations like BTEX below their permissible exposure limits.
Traditional degassing involves steaming, ventilation, and sometimes chemical application. It works. But it’s slow, especially on vessels that held heavy crudes, slop oil, or anything with a high aromatic content. BTEX gases — benzene, toluene, ethylbenzene, xylene — are stubborn. They hang around in sludge, scale, and residual films on vessel walls.
The longer your degassing takes, the more your turnaround costs.
The Problem with Conventional Degassing Chemicals
Most degassing chemicals on the market are petroleum-based solvents. They dissolve residual hydrocarbons, which helps release trapped gases. But here’s the catch — they also contribute their own vapor to the space. You’re adding VOCs to remove VOCs.
That’s why you’ll see LEL readings bounce around during conventional degassing. The readings drop, then spike, then drop again. Every spike resets the clock on your entry permit.
On top of that, these products are flammable. You’re spraying a flammable chemical inside a vessel that already has a flammable atmosphere. The safety implications should be obvious.
How Hasten Cleanse Handles Degassing
Hasten Cleanse attacks the degassing problem from a different angle. Instead of dissolving hydrocarbons with more hydrocarbons, it uses fatty acids and surfactants to bond to hydrocarbon particles and physically suppress their vaporization.
Here’s what that looks like in practice:
1. Apply Hasten Cleanse to the vessel interior — spray, fog, or circulate depending on the application.
2. The product bonds to residual hydrocarbons on walls, floors, internals, and in sludge.
3. Flash point rises immediately. The vapor being released from those hydrocarbons drops off because the chemistry is preventing vaporization.
4. LEL readings drop and stay down. No bouncing. No spikes. A steady decline to safe entry levels.
Because the product is water-based and non-flammable, it adds zero vapor load to the space. You’re only removing gases, not adding them.
Time Savings That Actually Show Up on the Schedule
We’ve seen refineries cut their degassing time by up to 80% using Hasten Cleanse compared to conventional methods. On a turnaround where every hour of downtime costs tens of thousands of dollars, that’s not a marginal improvement — it’s a game changer.
Here’s why it’s faster:
- No vapor contribution from the chemical itself. LEL drops are clean and consistent.
- Works on BTEX gases specifically. The surfactant chemistry is effective against the aromatic compounds that are hardest to degas.
- Less residual hydrocarbon left behind. Because the product is also cleaning while it’s degassing, you get a cleaner vessel with fewer passes.
- 50% less wastewater generated. Less rinse water means less time managing waste and less disposal cost.
Safe for Your Crews and Your Equipment
Hasten Cleanse is non-hazardous, non-flammable, non-corrosive, and biodegradable. It’s TSCA compliant. It won’t damage vessel internals, coatings, or metallurgy. It works in both freshwater and saltwater rinse applications.
No bacteria, no microbes — just chemistry. Fatty acids and surfactants doing what they’re designed to do.
Your gas testing crew will notice the difference on the first vessel. LEL comes down faster, benzene readings come down faster, and the vessel is ready for entry and hot work sooner than anyone expected.
Prove It on Your Next Turnaround
We’re not asking you to rip and replace your entire degassing program on faith. We’re asking you to let us run a side-by-side comparison on one vessel during your next turnaround. Our product against whatever you’re currently using.
If Hasten Cleanse doesn’t outperform it, you haven’t lost anything. If it does — and it will — you’ll know exactly how much time and money you can save across the rest of the turnaround.
Call 832-655-7763 or email info@hastenchemical.com to set up a demo before your next turnaround.
Why Degassing Is the Turnaround Bottleneck
In any refinery turnaround, the sequence of events follows a predictable pattern: isolate the unit, drain residual product, degas the vessels, verify safe atmosphere, begin maintenance. On paper, each step has a planned duration. In reality, degassing almost always takes longer than planned.
The reason is physics. Hydrocarbon residue clinging to vessel walls, trapped in dead legs, pooled in low points, and embedded in scale and fouling continues to release vapors long after the bulk product has been drained. The vapor release rate is unpredictable because it depends on the composition of the residue, the temperature, the vessel geometry, and how thoroughly the draining was performed.
While your crew waits for LEL readings to drop below the 10% action level, every other task in the turnaround sequence is on hold. Scaffolding crews are standing by. Welders are idle. Inspectors are waiting. The contractor clock is running. And every hour costs real money — often $10,000 to $50,000 per hour on a major unit turnaround, depending on the size of the crew and the revenue the unit generates when it’s running.
This is why degassing speed matters more than almost any other variable in turnaround planning.
How Conventional Degassing Chemicals Work — And Their Limitations
Most degassing chemicals (often called LEL scavengers) work by chemical reaction. They contain oxidizing agents or adsorbent compounds that react with hydrocarbon vapors in the atmosphere, converting them to less volatile forms or trapping them on a solid substrate.
The limitations of this approach:
- They treat the atmosphere, not the source. The vessel walls and residue continue producing vapors. The chemical scavenger must continuously neutralize new vapors as they’re released. If the application rate doesn’t keep pace with the vapor generation rate, LEL readings won’t drop.
- Many are hazardous themselves. Some LEL scavengers contain strong oxidizers or corrosive compounds that introduce their own safety and handling requirements. You’re solving one hazard by introducing another.
- They don’t clean. After degassing, you still need a separate cleaning step to remove the hydrocarbon residue. This is an entirely separate chemical application, additional time, and additional waste.
- Effectiveness varies with conditions. Temperature, humidity, vapor composition, and ventilation all affect how well chemical scavengers perform. Performance in a controlled lab setting often doesn’t translate to a 120°F vessel in August.
The Hasten Cleanse Approach to Degassing
Hasten Cleanse takes a fundamentally different approach. Instead of treating the vapors after they’re released, it suppresses the source.
When the diluted Hasten Cleanse solution is introduced to the vessel — via spray nozzles, circulation, or fog injection — the surfactant chemistry contacts the hydrocarbon residue on the vessel surfaces and immediately begins two simultaneous processes:
- Vapor suppression. The surfactant film reduces the rate of vapor release from the hydrocarbon surface. LEL readings begin dropping within minutes because the source of the vapors is being suppressed, not just the vapors themselves.
- Residue removal. The same surfactant action that suppresses vapors also breaks the hydrocarbon-surface bond, lifting residue into suspension for pump-out. The vessel gets cleaner while it gets safer — simultaneously.
By the time LEL readings reach safe-entry levels, the vessel has already undergone a significant portion of its cleaning. In many cases, the degassing and cleaning steps are effectively combined into a single operation, eliminating an entire phase from the turnaround timeline.
TSCA Compliance and Non-Hazardous Classification
Hasten Cleanse is fully TSCA (Toxic Substances Control Act) compliant and classified as non-hazardous for shipping, storage, and use. This matters for refinery turnarounds in several practical ways:
- No HazMat shipping requirements. The product can be transported to the job site without DOT placards, special containers, or HazMat-certified drivers. This simplifies logistics and reduces cost.
- No hazardous materials storage. The product can be stored on site without secondary containment, special ventilation, or HazMat permits.
- Simplified waste handling. Because the product is non-hazardous and biodegradable, the wash water it produces can typically be processed through the refinery’s existing wastewater treatment system without special classification or offsite disposal.
- Reduced crew exposure risk. Workers handling Hasten Cleanse don’t need the level of PPE required for chemical oxidizers or corrosive scavengers. Standard splash protection is sufficient.
For turnaround planners, this non-hazardous classification simplifies the permitting, logistics, and waste management planning that goes into every turnaround scope of work.
Get Your LEL Down Faster
Every refinery turnaround has the same question: how fast can we get these vessels safe for entry? The answer depends on the degassing chemistry you choose.
We run demonstrations at your facility, on your vessels, with your product residue. If Hasten Cleanse doesn’t outperform your current degassing chemical on LEL reduction speed, cleaning effectiveness, and total turnaround time, you’ve lost nothing but a few hours.
Schedule a turnaround demonstration or call 832-655-7763 to discuss your next turnaround timeline.