Canada's CO₂ Capture and Storage TRM 
Technology Pathways: The Hub and Backbone Concept

An emerging research priority today is in gathering and aggregating CO₂ emissions from a number of high-quality and high-quantity sources, locations that are commonly referred to as emissions hubs, and the transportation of the captured emissions through a common carrier pipeline or backbone system.

Hubs are locations where large volumes of CO₂ can be collected by gathering it from a number of sources in close proximity. By aggregating the CO₂ in a central hub, end customers have greater assurance regarding the availability of a long-term supply. This means reduced supply risk, and therefore some reassurance to storage project developers.

A backbone pipeline could be built to connect all the major emissions hubs in western Canada to the variety of available WCSB storage sites, and the entire system could operate much like a pipeline gathering, transmission and distribution systems for oil and gas today. A number of existing and underutilized small diameter pipelines (2- to 4-inch lines) already criss-cross Alberta and Saskatchewan, and could be used to transport CO₂ from emissions sources to the backbone system. This existing infrastructure could potentially become the ribs that connect to the large-diameter backbone, which may one day run all the way from Fort McMurray to Fort Saskatchewan, Joffre-Red Deer, Medicine Hat and on to Regina-Belle Plaine.

Eligible sites for the first Canadian emissions hubs would include those that have a significant daily tonnage of CO₂, and would be in close proximity or connected by the backbone to large storage opportunities, preferably enhanced recovery opportunities. Potential hubs in the WCSB include the Fort McMurray region, Fort Saskatchewan, the Joffre-Red Deer area and Wabamun (and each is discussed in detail below). Additional work is needed to determine whether Regina-Belle Plaine may become another hub, especially considering the recent agreement between the Governments of Canada and Saskatchewan to co-fund projects that include elements of clean coal, industrial gasification and poly-generation. Other regions may fulfill the necessary source requirement, but local storage basins are either not as well known or not as economical for storage as the WCSB is today. A Halifax hub could potentially be connected to offshore CO₂-ECBM projects. A Sarnia emissions hub may one day connect to storage opportunities in the U.S.. Until CO₂ emissions reductions become a pressing societal priority, these other hubs will remain as potential opportunities; however, the WCSB presents options for cost-effective CCS today.

There is considerable support for the concept of hub and backbone infrastructure and systems as the foundation for a growing and robust CCS sector in Canada. An industry-government task group could be commissioned with implementing detailed development plans for such an endeavour. The first task would be the creation of a long-term vision of a Canadian backbone interconnected with emissions hubs across the WCSB. The characteristics and parameters (including physical and operational) of the hubs and backbone would need to be developed. Draft business rules for operating this infrastructure, including tolling and operating standards, could be established for pipeline operators and for CO₂ buyers and sellers.

Oil Sands Hub

Today, the Fort McMurray region of Alberta could supply 5500 t/d of high quality CO₂ and an additional 4000 t/d of medium quality CO₂. This supply will grow as new infrastructure is built. The future use of gasifier technology in the oil sands, which would provide medium-concentration CO₂ streams and CO₂ storage sites, would add to the region's potential as a hub.

Although Fort McMurray is far from any CO₂-EOR opportunities, the volume of CO₂ in the region may be sufficient to justify a gathering system and a pipeline to transport the CO₂ elsewhere in the WCSB. Such a pipeline could be designed for multi-product transport, to help deliver other co-benefits by moving underutilized hydrocarbon products (like benzene or other petroleum fractions) to the petrochemical facilities near Edmonton. Construction of such a pipeline would greatly impact CCS opportunities in the WCSB over the medium to long-term from 2015 to 2030.

The steps toward developing such a hub would begin by gathering the CO₂ from high purity sources (greater than 90 percent CO₂) between now and 2010. This means capturing the 5500 t/d from the Benfield hydrogen production units in existing plants. By 2015, operators could begin gathering the 4000 t/d of medium concentration CO₂ from the PSA units in hydrogen separation facilities. Upon further R&D, it may be possible to use physical absorption or oxy-fuel combustion in such applications. As new oil sands facilities are built and existing plants expand (post-2015) it would be possible to integrate new units into the existing capture and transportation infrastructure. Between 2015 to 2030 it will be possible to capture emissions from new gasification plants (such as petroleum coke fuelled plants), but this will require new solid sorbent, physical solvent and membranes technology, or hybrid processes, to capture medium to high-quality CO₂ sources.

Multi-industry Hub

More than 40 different industrial activities take place in Fort Saskatchewan and east Edmonton, in Alberta, ranging from power generation, to refining, to petrochemical and fertilizer production to cement manufacturing. Presently, 2500 t/d of high quality CO₂ could be aggregated locally, enough to justify a gathering system and a pipeline to nearby CO₂-EOR opportunities in Swan Hills or Pembina. Another 3000 t/d of medium quality CO₂ is available from the hydrogen production facilities in local refineries.

A multi-industry hub may start by first gathering the 2500t/d that is available from feed gas processing, ethylene oxide production and hydrogen production in ammonia plants, by using available dehydration and compression technology. The next step is to capture medium to medium-quality CO₂ streams from local hydrogen production facilities, and from Shell's upgrader (the 3000 t/d noted previously), perhaps using physical absorption or oxy-fuel combustion (both of which need to be demonstrated first). From 2012 to 2015, any new plants, such as coal or pet-coke gasification units, could be CO₂ capture-ready which might include physical solvent, solid sorbent, membrane or hybrid technologies. Post-2015 would continue with CO₂ capture from new or expanded hydrogen production facilities (in the refineries and upgraders), or from new commercial IGCC facilities (assuming the successful demonstration of this technology).

Petrochemical Hub

The petrochemical complex at Joffre, Alberta produces 1300 t/d of high quality CO₂, in addition to a CO₂ stream that it already supplies to Penn West Energy Trust for its CO₂-EOR project. The area includes an ethylene oxide facility, an ethane processing facility and an ethanol plant. Emissions from the complex would grow if oil sands by-products became available as feedstock, or if ethane and other natural gas products from the north (Alaska or the Beaufort-Mackenzie areas) became accessible.

The beginning of a petrochemical hub in Joffre could start with expanding the current CO₂ gathering system to include the full 1300 t/d. It is a very highly concentrated source in Joffre, at greater than 90 percent CO₂, which could be captured using existing dehydration and compression technology. This could follow with the capture of any new emissions from the increased processing of bitumen-derived or other feedstock after 2015. In addition, CO₂ emissions from on-site coal or bitumen gasification could be captured.

Electricity Hub

Since coal-fired power accounts for 35 percent of the CO₂ emissions from LFEs in Canada, it seems a natural activity around which to build an emissions hub, and perhaps Lake Wabamun in Alberta would be an ideal location. However, current coal-fired facilities use pulverized coal in sub-critical steam cycles and the resultant flue gas is only 13 to 15 percent CO₂. The cost of capturing CO₂ from such dilute streams makes it uneconomical today. Therefore, a number of dynamics need to play out, including technology breakthroughs, stringent CO₂ emissions regulations and the public's willingness to pay higher electricity prices.

The CCPC is currently looking to locate its first commercial-scale clean coal facility, which may be an IGCC plant that uses coal or pet-coke, a supercritical plant with amine scrubbing, or even a new oxy-fuel plant. Individual companies are considering small demonstration gasifiers in other applications. Until one of these opportunities comes through, it will be difficult to economically capture CO₂ from electricity until after 2015.

Some general steps towards building an electricity emissions hub would be to initiate CO₂ capture from an oxy-fuel combustion demonstration unit somewhere between 2008 and 2015. If the oxy-fuel demonstration is successful, a next phase might be to retrofit existing commercial plants for capture. Also post-2015, CO₂ might also be captured from the first demonstration IGCC gasifier noted previously. However, the real opportunity for capture from an electricity hub may not be realized until post-2020 when CO₂ streams from any new commercial gasifiers could be captured. The ultimate achievement would be the eventual roll-out of an entirely new fleet of clean coal-fired facilities, all of which are connected to CCS infrastructure.

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