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| Typical DualTank condensation/storage unit. |
Oil and gas industry has been put on notice to either
clean up excessive emissions voluntarily,
or face regulations
By Reinhard Schuetz, P.Eng., President, DualTank Corp., Calgary
Benzene has recently been classified as a 'toxic' compound under the Canadian Environmental Protection Act (CEPA). The Alberta Energy and Utilities Board (AEUB), subsequent to its determination that glycol dehydrators represent a disproportionate single source of benzene emissions, has introduced specific reporting, monitoring and emission guidelines for immediate implementation in their Informational Letter IL-97-4.
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| Typical DualTank condensation/storage unit. |
Effective January 1, 1999, oil and gas industry officials have been put on notice to either clean up excessive emissions voluntarily, in staged reductions to the lowest practically achievable levels possible, or face government imposed regulations, facility shutdowns, and/or fines. These requirements are music to the ears of the general public and environmental groups, but not exactly good news for some company executives and facility operators.
Glycol dehydration units are normally designed on the basis of specific inlet gas analyses and outlet requirements. The inherent problem with these initial design parameters is that they are usually only temporary. In addition, as these parameters change, without proper dehy operational adjustments, the efficiency of the unit is drastically decreased, resulting in excessive contaminant emissions causing air and soil pollution.
Because the hazards of dehy emissions were not known in the past, according to Rod Sikora, P.Eng. (Pollution Control Coordinator, Gulf Canada Ltd.), "there presently exists a limited choice of readily available and economically viable solutions for this contamination dilemma. In addition, the problem is now compounded for some companies in that it requires immediate capital expenditure."
DualTank became interested and pro-actively involved in attempting to further enhance emission reduction, odour elimination and liquid recovery from dehydration units after one of our clients advised us that they had noticed benefits after connecting a typical TankSafe unit to a dehydration facility.
Relying on the basic 'KISS' principle we conceived a 'uni-package' condensation and storage tank assembly by simply adding an integral roof-mounted condensation component, complete with unique internal circular baffle system design, to our previously developed "aboveground, heated, dual-containment" TankSafe storage tank concept.
The 'combined' tank unit consists of an extremely large, uninsulated surface area (for cooling) and excessive internal volume (for increased retention time), neither of which require seasonal or operational adjustments. The concept also allows for year-round installation convenience, about 50% less area requirement, negligible installation cost and time, no soil or product contamination in case of primary tank leakage, virtually no maintenance or reclamation, and no excavation, dike or liner requirement. At the same time, the heated secondary containment system prevents liquid freezing and accidental spillage contamination.
DualTank's distinctive internal baffle system provides maximum external surface area contact for excellent benzene emission reduction and the elimination of odours and visual plumes.
In addition, increased volume of saleable condensate is recovered an advantage that will drastically shorten the payout period of the installed DualTank system.
The first 'combined' prototype was installed and tested in December, 1998, at an Enerplus Resources site. Test results indicated 91% benzene emission reduction and 25% condensate recovery (consisting of 10% benzene).
An unexpected, but welcomed, surprise occurred when it was discovered that the installed 15 barrel DualTank unit was condensing liquids at a greater rate than anticipated. However, replacement with a larger tank is not a problem since an added bonus of DualTank is its 'uni-package' design that allows for quick installation and relocation. The original prototype was installed and operational in about two hours.
In a subsequent Gulf Canada test site installation, Rod Sikora confirms that "based on our February 1999 test data results indicating 98% benzene emission reduction and 70% condensate recovery (27% of which being benzene), as well as the elimination of the visual plume and odour, we are definitely very pleased with DualTank's overall performance to date and are seriously considering additional installations."