NRC report finds transporting diluted oil sands bitumen through pipelines does not increase likelihood of release
25 June 2013
Diluted bitumen has no greater likelihood of accidental pipeline release than other crude oils, according to a new report from the National Research Council (NRC). The committee that wrote the report found that diluted bitumen from oil sands has physical and chemical properties within the range of other crude oils and that no aspect of its transportation by pipeline would make it more likely than other crude oils to cause an accidental release.
The NRC findings echo those of an earlier report by Penspen Integrity, commissioned by the Canadian Energy Pipeline Association (CEPA), which found that diluted bitumen (dilbit, or synbit—bitumen extracted from oil sands and diluted with lighter crudes or synthetic crudes for transport through pipelines) is not more corrosive than comparable heavy sour crudes in pipelines—and in cases may be less corrosive. (Earlier post.)
The NRC committee was not asked to address whether the consequences of a diluted bitumen release differ from those of other crude oils.
Bitumen is a dense and viscous form of petroleum that will flow in oil pipelines only when it is diluted with lighter oils. Diluted bitumen has been imported from western Canada for more than 30 years and is transported through numerous pipelines in the United States.
With bitumen imports from Canada’s oil sands on the rise, Congress passed legislation in January 2012 calling upon the secretary of transportation to determine whether any increase in the risk of a release exists for pipelines transporting diluted bitumen. The US Department of Transportation asked the Research Council to convene an expert committee to analyze one aspect of this risk: whether pipelines transporting diluted bitumen have a greater likelihood of release compared with pipelines transporting other crude oils.
The study committee reviewed pipeline incident statistics and reports of investigations; analyzed data on the chemical and physical properties of diluted bitumen; examined the technical literature; consulted experts in pipeline failure mechanisms such as corrosion and cracking; queried pipeline operators on their operations and maintenance practices; and solicited comments from the public.
The committee did not find any causes of pipeline failure unique to the transport of diluted bitumen. In addition, it found no physical or chemical properties outside the range of other crude oils and no evidence that pipeline operators manage or maintain their systems any differently when transporting diluted bitumen compared with other heavy crude oils.
Diluted bitumen has density and viscosity ranges that are comparable with those of other crude oils. It moves through pipelines in a manner similar to other crude oils with respect to flow rate, pressure, and operating temperature. There’s nothing extraordinary about pipeline shipments of diluted bitumen to make them more likely than other crude oils to cause releases.—Mark Barteau, professor of chemical engineering at the University of Michigan and chair of the committee that wrote the report
The report also says that shipments of diluted bitumen do not contain higher concentrations of water, sediment, dissolved gases, or other agents that cause or exacerbate internal corrosion, including microbiologically influenced corrosion, and the organic acids in diluted bitumen are not corrosive to steel at pipeline operating temperatures.
In addition, the committee found no properties in diluted bitumen that could make transmission pipelines more vulnerable to erosion, external corrosion and cracking, or damage from mechanical forces.
The study was sponsored by the Pipeline and Hazardous Materials Safety Administration of the US Department of Transportation.
The National Research Council is the principle operating arm of the National Academy of Sciences and the National Academy of Engineering.
National Research Council. TRB Special Report 311: Effects of Diluted Bitumen on Crude Oil Transmission Pipelines. Washington, DC: The National Academies Press, 2013
They don't seem to mention to corrosive effect of high sulfur content - and it is a real problem, that very factor was behind the corrosion at Chevron's Richmond, CA refinery that led to the recent pipe failure and fire there.
Posted by: photosymbiont | 25 June 2013 at 04:38 PM
Will the use of 3 to 6 million barrels/day of imported diluted bitumen have the equivalent emissions than using 3 to 6 million barrels/day of local shale oil and/or imported heavy oil?
The answer seems to be a high probability or YES!
Posted by: HarveyD | 25 June 2013 at 05:33 PM
Another way of saying diluted bitumen has no greater likelihood of accidental pipeline release than other crude oils is "other crude oils have just as great a likelihood of accidental pipeline release as diluted bitumen."
The real problem is diluted bitumen is so much more of a bitch-umen to clean up when it does leak.
Posted by: ai_vin | 26 June 2013 at 11:08 AM
The real problem is the clean up when there IS an accidental release.
Posted by: ai_vin | 26 June 2013 at 03:18 PM