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ERA's Environmental Compliance Management Blog

Tank Emissions Guessing Game: Are Default Values Skewing Your Reports?

Posted by Alex Chamberlain

Alex Chamberlain is a writer for ERA Environmental Management Solutions.

Tank Air Emissions: Are Default values your crutch?
It’s no secret that petrochemical manufacturers and refiners simply cannot know the exact chemical breakdown of some of their petrochemical liquids. Crude oil is perhaps the best example of this: every tank of crude oil will have different ranges for chemical components, and the majority of that data is unknown or imprecise.

The petrochemical industry has had some tremendous breakthroughs in terms of understanding the environmental impact of its operations, developing reliable (though difficult) tank emission calculation methodologies that are now accepted by regulatory bodies across North America.

For crude oil, this means the industry has developed some industry default values for chemical properties, like True Vapor Pressure, for difficult-to-manage liquids like crude oil.

When it is time to write an emissions report, like accounting for Volatile Organic Compounds (VOCs) from tank working and standing losses, many Oil & Gas EH&S professionals rely on default values to fill in the gaps in their material data.

And in most cases, using these default values is fine: emission reports are considered accurate enough by regulators and can be used to demonstrate air permit requirements. However, there’s no denying that default values don’t necessarily reflect the reality of your air quality impact – your true emissions could be higher or lower than what you are reporting.

Instead, it’s possible to use more precise calculations, like using Riedel and Antoine constants to determine True Vapor Pressure, or like using advanced American Petroleum Institute (API) methodologies, to get better and more accurate tank emission estimations. However, these superior calculations take a bit more time and effort to perform – your best option is to automate these tasks using a digital platform.

It’s time to come clean: are you over-dependent on default values? 

When Default Values Become a Problem

In the majority of cases, using default values shouldn’t present an issue. An auditor isn’t going to penalize you for using industry-established default values. However, there are risky situations in which relying on default values could create a serious problem.

Here are the top 4:

  1. When you’re operating under tight permit limits and every pound of emissions counts.
  2. When you’re planning on significantly expanding operations or increasing productivity.
  3. When environmental performance is brand strength.
  4. When you’re investing in or purchasing an enterprise/EH&S third-party tool.

Operating Under Tight Permit Limits

Oil & Gas executives are used to working under tight regulations and under pressure. And depending on where you do business, your air permits might be stricter than others.

When your business was initially permitted, you might have indicated that default values would be used in emission estimations, and so using default values shouldn’t be a regulatory issue… however, you don’t really know where your emissions stand and you could be in for a surprise if your regulatory requirements operations change.

If your operations are always nearing that air emissions limit, you’re in a risky position as is. But if you’re estimating those “close-call” emissions using default values instead of more accurate testing data or data derived from site-specific scientific calculations the you might be cutting it closer than you think.

Don’t let yourself get caught by surprise if your emissions skirt the edge of acceptable limits take the time to get a clearer picture of your emissions.

Planning to Expand or Change Operations

Default values are fine for maintaining the status quo but whenever you want to grow or increase productivity you really need a snapshot of your true performance metrics. That way you can maximize your growth without worrying about exceeding your air permit limits.

The same is true when you plan on changing the materials processed on site or changing the type of control technologies used. A seemingly small change in materials can increase your air emissions beyond compliant limits.

Any business decision is only as strong as the information you use to inform your choices. Using default values means you only get a generic estimate or best guess about your operations – and that doesn’t serve you well for making vital decisions.

When Environmental Performance is Part of Your Brand

The Petrochemical industry and its clients are particularly sensitive to environmental scrutiny, with stock prices and businesses being very sensitive to even small compliance hiccups. Some businesses use this to set their brand apart by having a squeaky clean compliance record and using transparency as a selling point.

If you use environmental responsibility as a brand strength, it’s important that you start drilling down into the nitty-gritty of your storage tank emissions data instead of using generic petrochemical values. Why? Because the industry is changing and more and more petrochemical refineries are using more and more advanced tools to do their emissions accounting. New spreadsheets exist to calculate more accurate emission from certain types of tanks and new tank emissions software solutions are replaced outdated reporting tools (like the EPA TANKS web program).

To keep using eco-consciousness or even just basic compliance as part of your sales strategy you have to realize that the market is evolving rapidly and trending toward better, more accurate data. In this market, relying on default values doesn’t make the cut.

Purchasing an Enterprise or EH&S Tool

Many successful Petrochemical businesses are using a third-party emissions accounting tool, like a spreadsheet or EMS software. It’s the new normal for efficient EH&S departments.

If your business is going to spend time and money on an EH&S tool, make sure that it has the advanced capability to use more accurate data sources or perform more precise determinations than simply using default values all the time.

If the tool you’re looking at doesn’t have functionality beyond basic default values, then it’s not really innovating on your EH&S management.

Instead, select an EH&S tool that has all the necessary API methodologies and the calculations that can be used to improve accuracy. Ask the provider to show proof that their tool’s results are superior to the generic results you could do on your own.

Purchasing a new tool or EMS Software for your tanks management can be a big change in EH&S processes, so make sure the software you select delivers better results and gives you more accurate reports.

How ERA Approaches the Default Value Issue     

From a regulatory standpoint, there’s nothing inherently wrong with using default values, but ERA takes the approach that petrochemical businesses get more out of having the full range of estimation methods in order to get the most accurate results. That means we’ve built in all the API tank calculations, TVP calculations, all the EPA AP-42 tank requirements, and the default values for petrochemical substances so that we can generate the best possible reports and give you full transparency about how our software reached those estimations.

Because advanced methodologies can be more difficult and take more time, ERA’s tank software also automates the calculations so that an entire tank emissions report can be done in a few minutes (even for a large tank battery). That way you aren’t compromising productivity for accuracy – with ERA’s platform you can have both.

Learn the Science of Tanks Click Here

 Image used with permission from Juan Andres Martinez

Topics: Oil & Gas