For many years EPA implemented Tanks 4.09d as a traditionally steadfast tool that estimates the amount of tank emissions released. This computer software program calculates volatile organic compound (VOC) and hazardous air pollutant (HAP) emissions from storage tanks to stay in sync with compliance and constant regulatory changes.
The desktop software manages different types of tanks, as stated below:
- Vertical and horizontal fixed roof tanks
- Internal and external floating roof tanks
- Domed external floating roof tanks
- Underground tanks
It didn’t come as a shock when recently EPA announced their detachment from Tanks 4.09d and refuted to acknowledge it as a viable tool to estimate emissions for different tanks.Tanks 4.09d Main ShortcomingsFor a long time, the industry itself and EPA were well aware of the flawed limitations within the system. These small yet significant shortcomings could pose long term detrimental effects. Some of the well-known Tanks 4.09d shortcomings are:
- Bulk temperature calculations: – While calculating bulk temperature of non-heated tanks, the average annual ambient temperature of tank location was used in the software. This technical breakdown might sound reasonable in words; however, the underlying problem became apparent through calculation of monthly emissions. Variations of months and temperatures resulted in underestimation or overestimation. This calculation also affects the surface temperature calculation as it is derived from tanks bulk temperature.
- The interpolation method pinned down 100F as the cut off maximum temperature according to which vapor pressure of heated tanks was calculated. This is more than often inaccurate because in a majority of cases the temperature in heated tanks exceeds 100F. Subsequently, inaccurate emissions results were generated because temperatures above 100F were not considered.
- With heated tanks, Tanks 4.09d assumes full tank insulation which means that standing loss is always zero where in fact the tank roof might not be fully insulated; as a result, you will not be counting for standing loss in those cases.
- There was no feature or option in Tanks 4.09d to flag whether stock used in floating roof tanks was heated or not. Once again, this led to misleading emission results for floating tanks.
- Tanks landing and tanks cleaning calculations were not performed in Tanks 4.09d.
Evidently, there were many errors in the software but the primary problems were inaccuracy, over or under estimations based on bugs in the software and lack of optional features.Predict360 Air Emission & Sustainability powered by DREEM SolutionsDREEM Solutions recognizes all of the above issues when dealing with tanks, it not only offers a solution for those shortcomings but it also provides a more comprehensive way to deal with tanks and any other source type at your facility with higher accuracy, less complications, and a more user friendly interface. In summary:
- Calculation of monthly and annual emissions from tanks are more accurate.
- Emissions calculation for periods less than a month (when your tanks stock changes in the middle of the month for example).
- Calculations are based on AP-42 chapter 7 equations.
- Report of 12 months rolling total and average on throughputs and emissions.
- Capacity to run multiple tanks at once and no need to generate a report for each tank separately.
- Report customization to comply with either EPA or your local agency requirements.
- Comparison of metrics on a time basis for a source by source using a powerful business intelligence module.
- Allows you to compare against emission and throughput limits or any limit enforced by your permits.
- Ability to group your tanks based on permit grouping or actual physical locations within your facility.
How can predict360 help you?360factors, Inc. helps companies improve business performance by reducing risk and ensuring compliance. Our software keeps track of tank emission records and regulatory changes. This prevents any environmental or health hazards in the long run, and reassures compliance management for any future inspections that may come your way. It creates industry specific compliance workflows that are highly configurable and individually cater to your company requirements. We also have efficient calculation engines and dashboards that produce accurate numerical data and comparative analysis reports. If you prefer Microsoft Excel, then no problem! You can analyze and study all track records there with our highly integrated system.Predict360 Air Emission & Sustainability software powered by DREEM Solutions offers customers the ability to capture, calculate, analyze and report quantitative environmental data required for environmental and sustainability reports. It can manage and report on a wide range of data such as air pollutants, greenhouse gases, water, wastewater, waste, or other sustainability metrics. Predict360 manages regulations and requirements, policies and procedures, risks and controls, audit management and inspections, and on-line training and qualifications, using unique data mapping and artificial intelligence to provide regulatory insight, predict risks and drive operational excellence. Remain up-to-date on industry news / updates through our Twitter & Linkedin profiles.*All images are property of their respective owners.