No. 2 in coal series: N.D. power co-op leads CCS race

Basin Electric aims to capture carbon emissions from coal-fired power plant

 

BY ROSE RAGSDALE FOR GREENING OF OIL

In the quest to determine how clean coal can get, the trail leads north toward the Canadian border. Thanks to more than a decade of cross-border cooperation, this region is becoming a hotbed for carbon capture and storage research projects.

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Dakota Gasification Co. is a key source of captured carbon dioxide in the region and a major participant in one of the world’s largest carbon sequestration projects. An operating unit of Basin Electric Power Cooperative, one of the largest consumer-owned electric cooperatives in the United States, Dakota Gas runs the Great Plains Synfuels Plant near Beulah, N.D., often referred to as the Weyburn-Midale CCS project.

Great Plains Synfuels captures carbon dioxide while converting coal to synthetic natural gas—up to 50 percent of the plant’s daily emissions and, it claims, more CO2 than any other facility in the world.

Basin Electric purchased the synfuels plant from the federal government in 1988 and since has invested $834 million in upgrades and improvements in the facility. Today, the facility converts 18,000 tons of lignite coal daily into about 145 million cubic feet of synthetic natural gas, which is used for home heating and electricity generation.

“It works (for us) because of the gasification process,” said Basin Electric spokesman Daryl Hill. This process, according to the synfuels plant's Web site, results in a CO2 stream that is very dry and 96 percent pure, so it requires no further processing. This is in contrast to CO2 from power plants, which is very wet and diluted with nitrogen and oxygen, and would require further processing.

Though it is technically possible to capture more of the CO2 emissions, Hill said it would require a substantial investment and no market exists for the additional CO2 that could offer a return on that investment.

The existing project, however, has propelled Dakota Gas into an international leadership role among organizations that capture, compress, and transport CO2 emissions from a coal gasification process. The operation currently captures about 3 million tons of CO2 annually and sends some 8,000 metric tons of the greenhouse gas through a 205-mile pipeline daily to oil fields across the border near Saskatchewan, Canada.

Basin Electric also invested more than $100 million to build the pipeline in 1999.

Leading CCS research

In Canada, the CO2 is injected into underground reservoirs at Apache Corp.’s Midale and EnCana Corp.’s Weyburn oil fields to boost oil production while permanently sealing much of the CO2 into underground pockets vacated by the crude as it is pumped out of the ground.

Malcolm Wilson, director of the Office of Energy and Environment at the University of Regina in Saskatchewan, said the project has succeeded in “putting the carbon back where it came from in the first place.”

“… We can use existing or depleted oil and gas reservoirs or deep saline aquifers, and by saline aquifers I mean water that’s non-potable, so we can push the carbon dioxide into the ground and displace fluids that are in there and store the CO2 in that environment. It’s storage for an extended period of time after which it becomes permanent, and then I think we can say it’s truly sequestered.”

Malcolm Wilson: “We’re ready to go to the commercial scale”

The University of Regina has researched carbon capture and also geological storage systems for CO2 for nearly 20 years, longer than many of the world’s universities, according to Wilson.

“I think the thing that really sets us apart from the rest is that we’re ready to go to the commercial scale. Our technology is ready to go to the next level and really demonstrate that we can bring down the costs and that this is viable whether we use the CO2 for enhanced oil recovery or for geological storage, he said in a May 2009 interview.

In response to skeptics who question whether the CO2 will eventually leak into the atmosphere after it is stored underground, Wilson said he believes underground carbon storage projects present little risk because the CO2 is stored 1-3 kilometers, or 0.62-2 miles, below the earth’s surface and is contained in multiple seals. At the Weyburn field for example, the carbon is stored 1.5 kilometers or about 1 mile beneath the surface.

“So, if for some reason the CO2 does begin to leak out of the container in which we put it, then it won’t get past the next seal,” he said. “In effect, it’s kind of like having your jar of peanut butter in the fridge wrapped in a plastic bag, wrapped in another plastic bag, wrapped in another plastic bag, each sealed independently to make sure that the smell or the oil doesn’t get out and contaminate anything else in the refrigerator.”

The carbon storage component, an innovative combination of enhanced oil recovery and carbon geologic sequestration, is monitored closely by the International Energy Agency in what is known at the IEA Weyburn-Midale CO2 Monitoring and Storage Project. The eight-year, $80 million project began in 2000, and CO2 flooding and storage is expected to boost oil recovery in the two Canadian fields by a projected 222 million barrels. Currently, oil recovery from the fields is exceeding those projections.

Taking CCS to next level

Back in North Dakota, CO2 emissions from the synfuels plant were chopped nearly in half (45 percent) by the project, with Dakota Gas capturing about 19 million tons of CO2 between 2000 and 2009. In terms of impact, that’s the equivalent of taking off the road annually some 545,000 cars, or more than one vehicle for every adult resident of North Dakota.

Moreover, CO2, formerly a waste gas emitted from the synfuels plant’s gasification process, now provides a source of revenue, accounting for $51.7 million in sales at Dakota Gas in 2008, or nearly 9 percent of the plant’s total revenue of $586.5 million.

But the Weyburn-Midale CO2 Project is only the beginning in Basin Electric’s carbon capture and storage ventures.

Technology for capturing carbon dioxide has been around for 50 years. The same basic technology is used to produce food grade carbon dioxide. For example, the CO2 in the fizzy soft drinks we enjoy on hot days likely originate as lumps of coal, researchers say.

Capturing the carbon emitted by coal-fired power plants, however, is still a long way from being commercially feasible because of high costs—up to 75 percent of the entire capture and storage process—associated with retrofitting existing facilities.

Pilot projects all over the world have tested various techniques but none, so far, has succeeded in cutting costs enough to offset up to a 50 percent hike in electricity rates that CO2 capture systems would require, according to the industry.

Developing an affordable technology is the challenge facing operators of carbon-emitting industrial plants, including the 6,000 coal-fired power plants around the world.

“What we’re trying to do is extract the carbon dioxide from the exhaust gases of major facilities whether that’s coal-fired electric power plants, gas-fired electric power plants, refineries, steel plants, cement plants, those kinds of things,” Wilson said.

Aims to retrofit CCS technology to existing infrastructure

At Basin Electric’s Antelope Valley coal-based power plant, a facility with twin towers ca

pable of producing 450 megawatts each of electricity, researchers hope to retrofit carbon capture technology to existing infrastructure. The power plant is next-door to the synfuels plant near Beulah.

The project that Basin Electric is proposing specifically would demonstrate 90 percent removal of CO2 from a 120-megawatt-equivalent flue gas stream from a lignite-based boiler in Antelope Valley’s Unit 1, according to the U.S. Department of Energy.

“We’re looking at capturing 25 percent of the exhaust stream coming off the plant and of that 25 percent slipstream, we’re hoping to get 90 percent of the CO2,” Hill said.

He said Basin Electric wants to deliver the CO2 it captures at Antelope Valley Station to EOR projects in North Dakota’s oil fields, particularly in the Williston Basin, using the same pipeline that currently delivers CO2 from the synfuels plant to the Canadian fields.

In January 2009, the Rural Utilities Service, committed to financing about $300 million in low interest loans toward the project. In July, DOE said it intended to enter into a cooperative agreement with Basin Electric for potentially a $100 million grant to help develop a CO2 capture technology.

Both preliminary funding commitments await a successful front-end engineering design study, due for completion later this year.

The purpose of the project will be to demonstrate the commercial efficacy of the carbon capture technology, said Jason Lewis, a contract officer for DOE’s National Energy Technology Laboratory.

Lewis said NETL is in the process of trying to gain a better understanding of the post-combustion amine-based system that Basin Electric wants to use to capture CO2 in the project. The cooperative initially proposed using a post-combustion ammonia-based technology for the project, but in December decided instead to work with two engineering firms, Regina, Sask.-based HTC Purenergy Inc. and Doosan Babcock Energy, United Kingdom, on the project’s design.

HTC has developed the Purenergy CCS Capture System™, a standalone carbon capture system that is pre-engineered, pre-built and modularly constructed by the firm’s strategic partner, Kings Steel of Regina/Calgary. The system uses technologies developed and validated for more than 15 years at the University of Regina. It is capable of capturing up to 3,000-plus tons per day of CO2, and because of its modular design, it can be manufactured, shipped and erected at the emitter sight at a much lower cost than other systems that have to be custom built on site, according to HTC.

The initial engineering phase at Antelope Valley was set to begin in January and is expected to provide Basin Electric with a comprehensive assessment that will enable the cooperative to make a decision on the final project notice to proceed with the demonstration project next fall.

To his knowledge, Hill said the Antelope Valley Station Post-Combustion CO2 Capture Project is the first of its kind in the world.

Because the project is demonstration scale, it is one step away from commercialization.

“Part of the challenge is how to fit this stuff into a plant that wasn’t designed for it,” Hill said.

If Basin Electric succeeds, the design will be available for replication at other coal-fired power plants.

Saskatchewan, Montana to test full-chain CCS project

The Office of Energy and Environment at the University of Regina recently took the lead in an agreement between the Government of Saskatchewan and the State of Montana to demonstrate and test large-scale post combustion carbon capture and storage in the world’s first full-chain carbon capture and storage project.

The project will provide a global prototype, positioning Saskatchewan and Montana as world leaders in research and training in CCS technology, according to lead researcher Wilson.

The Saskatchewan-Montana project will construct a 330- to 1,100-ton-per-day capture unit, which will be attached to an existing coal-fired power plant in Saskatchewan. The pipeline attached to the plant will deliver CO2 from Saskatchewan to a geological storage site in northeastern Montana on the western flank of the petroleum-rich Williston Basin.

The area proposed for the Saskatchewan-Montana storage project has been subjected to significant oil and gas exploration and production and contains a series of excellent reservoir units and multiple seals, Wilson said in a 2009 interview. The area also offers potential for enhanced oil recovery operations.

The project is intended to deliver as much as 1.1 million tons of CO2 over four years of the storage test.

The storage component will be led by researchers in the Montana University System. This work will include development of a permitting action plan (to identify the necessary permits and respective agencies and the information required for each permit), a project management plan and a risk management plan.

Wilson said experts from Montana’s university system have been studying CO2 storage extensively.

The Saskatchewan-Montana project is estimated to cost about US$270 million. Saskatchewan has requested C$100 million in funding from the Government of Canada. The Government of Saskatchewan has already committed C$50 million to the project. The State of Montana has requested US$100 million to support the project.

Links of interest

Basin Electric Power Cooperative

Weyburn-Midale CO2 Project

University of Regina Office of Energy and Environment

International Test Centre for CO2 Capture

Petroleum Technology Research Centre 2008/2009 Annual Report

National Energy Technology Laboratory

HTC Purenergy: Carbon Clear Solutions

Purenergy CCS Capture System™ – CO2 Capture Technology Illustration and Video

Dakota Gassification Co. Great Plains Case Study

 

Contact Rose Ragsdale at roseragsdale@live.com