Reducing SO2 Emissions with the Flue Gas Desulphurization Unit
Syncrude built the Upgrader Expansion facilities with an important goal: to increase our crude oil production while improving local air quality.
A flue gas desulphurization unit (FGD) was built to virtually eliminate the sulphur dioxide (SO2) emissions created by our increased production and convert that SO2 into a marketable fertilizer. As a result, SO2 emissions are expected to decrease by a projected 20 percent despite an almost 50 percent increase in crude oil production.
How does the FGD work?
As part of the crude oil production process, bitumen is upgraded in Syncrude?s three fluid cokers. The FGD unit works in conjunction with our newest coker to absorb the SO2 created through this process.
The FGD reduces SO2 emissions through the following basic steps:
- Off-gas from the coker is routed through the CO Boiler to the FGD.
- Once in the FGD vessel, the gas is washed with a circulating solution containing ammonia which absorbs the SO2.
- Once the SO2 is fully absorbed, the solution is then injected with air and ammonium sulphate crystals are formed.
- The crystals are collected and used in fertilizer production.
- The remaining solution is recycled back into the FGD process.
Where did the odours come from?
During start-up of the FGD unit this spring, local residents voiced concerns about the presence of odours in the region. We believe the odours originated from this unit. While we were pleased to see the FGD was effective in SO2 recovery, it still had not yet attained its full design specifications. Syncrude adhered to the Alberta Environment order to shut down the operation of the unit and today continues to work diligently with regulators and diverse experts from across North America to gain a greater understanding of how the odours formed and help prevent further occurrences in the future.
The next steps

Once we and the regulators are satisfied that every possible course of action has been taken to reduce potential odours, we will again start up the FGD unit. We are making good progress and expect this to occur at some point before mid-July. We will update you as more specific timing becomes available.
How do I report odours?
We acknowledge there might be some odours associated with start-up activities, but are confident they will be minimal and short-lived. If you do detect any odours, they can be reported to the Alberta Environment Hotline at 1-800-222-6514. Your concerns will be acted upon immediately.
Where can I find information on local air quality?
The Wood Buffalo Environmental Association (WBEA) operates a network of 13 air monitoring stations located across the region. These stations monitor air quality 24 hours a day, 365 days a year. Data, including the local Air Quality Index, can be found on their website at www.wbea.org or through Alberta Environment at www.telusgeomatics.com/tgpub/ag_air/default.asp.
If you have any health-related concerns, please refer to Health Link Alberta at www.healthlinkalberta.ca or call toll-free 1-866-408-5465. Health nurse advice and information is available 24 hours a day, seven days a week.
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