"Grandfathered" sour gas plants achieve substantial sulfur emission reductions
Sulfur recovery has improved significantly at 41 "grandfathered" sour gas plants across Alberta, as indicated by results summarized in the 2005 Sulphur Recovery and Sulphur Emissions at Alberta Sour Gas Plants report (document ST 101-2005) released by the Alberta Energy and Utilities Board (EUB).
The 41 facilities are those that did not meet sulfur recovery requirements set out for new gas plants in the EUB's Interim Directive (ID) 2001-3, issued in August 2001. While ID 2001-3 did not change the recovery levels for new gas plants, it set out a phased approach through which the older, grandfathered plants must meet the same requirements as new plants. It also encouraged operators to take early action to improve performance.
ST 101-2005 reports on the progress of these facilities in complying with ID 2001-3. Improved performance, along with decreased sulfur throughput, resulted in decreased sulfur emissions from 2000 through 2004 for both grandfathered acid gas flaring plants (down 39%) and grandfathered sulfur recovery plants (down 28%).
Overall, says the report, emissions from grandfathered plants have fallen by approximately 30% from 2000 through 2004. This represents a decrease of approximately 60 tonnes of sulfur emissions (120 tonnes of sulfur dioxide emissions) per day in Alberta.
Of the 39% decrease in emissions from grandfathered acid gas flaring plants, about half, of 21%, was due to declining sulfur inlet. The other 18% was largely attributable to the acid gas injection facility installed at ConocoPhillips Vulcan plant, the installation of sulfur recovery at Petro Canada's Wilson Creek operation and installatino in 2004 of acid gas injection at Taylor's Retlaw and Apache's Virginia Hills facilities. Viking Energy's Bellshill gas plant also became an acid gas injection facility early in 2005, notes the report, adding that between 2000 and 2004, 27 of the 28 grandfathered acid gas flaring plants reduced their sulfur emissions.
Of the 28% reduction in emissions from grandfathered sulfur recovery plants, about 20% was the result of declining sulfur inlet, with improved operations at several facilities accounting for the remaining 8% decrease. Improvements were made at BP's Windfall, Husky's Ram River and Shell's Jumping Pound plants, while acid gas injection was installed at Keyera's Brazeau River facility. Between 2000 and 2004, 23 of the 28 grandfathered sulfur recovery plants reduced emissions.
Grandfathered sulfur recovery plants that surpass the ID 2001-3 requirements are eligible to apply for sulfur emission credits, which they may use to meet part of their sulfur recovery requirements at a future date. Credits cannot be transferred between facilities and do not apply to acid gas flaring plants.
Credit reports can enable an operator to operate at higher sulfur inlets, meet the required blended sulfur recovery efficiency, and defer upgrading for a longer period of time. Each sulfur emission credit represents one tonne of sulfur emissions which would have been released if the plant met its minimum requirement exactly.
Most of the grandfathered sulfur recovery plants are currently taking advantage of the emission credit program, and by the end of 2004, the eligible facilities had earned a combined total of more than 47,000 tonnes of sulfur emission credits. As the sulfur emissions from the grandfathered sulfur recovery plants totalled only 41,000 tonnes in 2004, the emission credits as of December 2004 equate to about a full year of emissions from these facilities.
The report further points out that since 2000, a number of plants have "degrandfathered:" 11 plants have made upgrades to meet the new requirements, four plants have been relicensed, and four plants have ceased operating.
Both the ST 101-2005 report and ID 2001-3 may be viewed on the EUB Web site, www.eub.gov.ab.ca. More information is also available from Davis Sheremata at EUB Communications, 403/297-2252, FAX 403/297-3757, E-mail firstname.lastname@example.org.