CCS Technology Supports Coal-to-Gas Switching and Carbon-Based Products

A power plant in Western Canada is showcasing carbon capture technology that can first be deployed at a coal-fired facility, and then adjusted to accept flue gas from a natural gas-fired system without the need for a plant rebuild. The technology is designed to facilitate the transition to natural gas-fired generation at plants making a switch from coal to gas.

The technology, developed by Delta CleanTech, could enable coal plants to implement carbon capture and sequestration (CCS) to reduce emissions, and the CCS system could continue to operate after a plant switches to burn natural gas. The project is underway at Capital Power's Genesee Generating Station located west of Edmonton, near Warburg, Alberta, as part of a larger Capital Power initiative to reduce the utility's carbon footprint. Capital Power, which owns more than 64 GW of generation capacity at 26 facilities across North America, is repowering the coal-fired Units 1 and 2 (Figure 1) at Genesee to utilize natural gas combined cycle (NGCC) technology, while adding Delta CleanTech's CCS system.

Unit 3 at Genesee, another coal-fired unit, is undergoing a dual-fuel transition and will be 100% gas-fueled in 2023. The plant's three units have more than 1,300 MW of generation capacity. Capital said the Genesee project is part of its effort to advance the commercialization of carbon capture, utilization and sequestration (CCUS) technology," and the utility said it plans to integrate direct air capture (DAC) into our portfolio of decarbonization technologies to further reduce emissions." Capital is part of the Carbon Capture Coalition, a collaboration of dozens of businesses and organizations building government policies to enable economywide, commercial scale deployment of carbon capture technologies, which includes carbon capture, removal, transport, utilization, and storage from industrial facilities, power plants, and ambient air." The utility also participates in the Canadian Carbon Capture Collaborative.

1. The Genesee Generating Station near Warburg, Alberta, Canada, is home to a carbon capture and sequestration (CCS) project utilizing an innovative CCS system from Delta CleanTech. Courtesy: Capital Power

The importance of a Genesee-style project is that it reflects the flexibility of new CO₂ [carbon dioxide] capture technology that can be installed for coal combustion and later adapted for natural gas combustion," said Lionel Kambeitz, executive chairman of Calgary, Alberta-based Delta CleanTech. Kambeitz told POWER, Many plants around the world are contemplating switching from coal to natural gas, but do not want to delay the opportunity for Delta's CO₂ capture technology to be installed today. Delta CleanTech has had an unprecedented demand for CO₂ capture plants in Alberta on decentralized power generation projects, whereby power is being produced with off-market natural gas and the power can be supplied to the grid at peak demand with the ancillary power being utilized to drive data miners for the production of bitcoin. These Delta projects are proving to deliver the low cost of power required for cost-effective bitcoin mining while also decarbonizing the electricity that is required."

Decarbonization is part of the equation for such projects; Kate Chisholm, senior vice president, Planning, Stakeholder Relations, and Chief Sustainability Officer for Capital Power, earlier this year said, It's our responsibility to do our part to help society meet the long-term challenges facing our planet. We have a long history of saying what we'll do, then doing what we say-and our actions to move off coal, invest in hydrogen- and CCUS readiness, and invest in a sustainable energy future for Canada demonstrate just that."

Delta CleanTech's role in the Genesee project comes after the company's participation in Canada's Carbon XPRIZE competition, designed to develop breakthrough technologies to convert CO₂ emissions into usable products." Delta CleanTech supplied the CO₂ for use in the competition.

Jeff Allison, the company's president, told POWER, Delta CleanTech's post-combustion CO₂ capture technology has been perfected over the past 15 years and is considered to be a cutting-edge, commercially available carbon capture technology." Delta CleanTech spun off from former parent HTC Extraction Systems in January as it prepared to be listed on the Canadian Securities Exchange. The company designs and manufactures modular equipment for capturing CO₂ emissions from smokestacks and other sources, along with solvent and ethanol purification, hydrogen production, and carbon credit certification and trading.

The company's technology, known as Low-Cost Design Post-Combustion CO₂ " capture technology-or LCDesign-is among the group's technologies for carbon capture across industries including oil and gas production, coal- and natural gas-fired power generation, and industrial food grade CO₂ markets. Allison told POWER, Our design of a CO₂ capture plant that can be used for a coal plant before and after converting to natural gas is the first we are aware of in the world."

Capturing carbon from Genesee's generating units is part of Capital Power's effort to build what it considers the world's largest commercial-scale production facility of carbon nanotubes (CNTs), a product with electrical conductivity that also can act as a semiconductor. The Genesee plant will deploy C2CNT technology-a carbon utilization solution that transforms emissions into high-quality CNTs. CNTs have many uses, including in electronics, optics, and as a replacement or complement to carbon fibers. Capital said the project at Genesee-approved by the Alberta Utilities Commission in June of this year-will have an initial production capacity of 2,500 tonnes of CNTs annually, and when fully complete could produce up to 7,500 tonnes each year.

The production of CNTs is just part of the plan; Capital said it considers CCUS as an integral part of the long-term solution to tackle climate change globally and enable zero or near-zero emissions from natural gas generation. When combined with the integration of renewables, CCUS will ensure the ongoing affordability and reliability of our power systems while critically reducing emissions. The addition of DAC technology further supports our decarbonization goals by offering the potential to physically offset emissions from our portfolio that are not technically or economically feasible to eliminate at source."

Capital said the project at Genesee once fully operational could be delivering upwards of 3 million tonnes of annual CO ₂ reductions." Capital has said the utility thinks a combination of technologies will be necessary to achieve our goal of being net carbon neutral by 2050. DAC is a promising technology that will support our decarbonization efforts by physically reducing emissions across our portfolio. DAC complements the other technologies in our portfolio and offers the potential to reduce emissions from our facilities that may otherwise have limited opportunities for decarbonization due to technical or economic limitations."

The repowering of Units 1 and 2 also will provide an additional 560 MW of generation capacity from those units, which today have 860 MW of total capacity. Unit 2 was commissioned in 1989; Unit 1 came online in 1994. Capital Power said that based on the NGCC repowering project schedule, Genesee 1 would become a dedicated NGCC unit in 2023; Genesee 2 would become a dedicated NGCC unit by 2024. That would mean the three units at Genesee would end their use of coal in the next two years, well ahead of the Canadian government's mandate to end coal-fired power generation in the country by 2030.

Delta CleanTech had commercial carbon capture technology available as early as 2005, and participated in several projects over the next few years before the global financial crisis shelved much of the interest in CCS. The company optimized its technology in the intervening years, and has seen renewed interest in its services as interest in CCUS has been revived as part of environmental, social, and governance initiatives in the energy industry. An increase in coal-to-gas switching, along with efforts by utilities to reduce carbon emissions, has provided opportunities to deploy the group's system.

Allison said the fabricating partner for his company's technology is ALCO Oil and Gas, a longtime Alberta-based services and manufacturing company serving the energy industry. Delta CleanTech's technology is fabricated in a factory setting, making it possible to reduce capex [capital expenditure] costs and enable a quick setup," he said. We build our plant using skid-mounted, modular oil field technology, with off-the-shelf blowers, heat exchangers, pumps, and other components."

Allison said Delta CleanTech used multiple design tools including its process design PDOEngine to invent a solution that is able to accommodate both [coal and natural gas]. To achieve this, we needed to figure out how to deal with the different compositions of each flue gas. The coal-fired flue gas has a high CO₂ concentration, while the natural gas-fired flue gas has a smaller CO₂ concentration, making the required flue gas volume three times higher for the natural gas case than it would be for the coal case. With this technology, both plants can match the operating data with less than5% average absolute deviation. The captured CO₂, which contains more than 99.9 mol% dry... is suitable for manufacturing carbon nanotubes."

Allison told POWER the carbon nanotubes could be used in the concrete industry, where the CNTs could improve the mechanical properties of the material, including tensile and bond strengths. He said the captured CO₂ -already used in enhanced oil recovery operations-would have many uses, noting, today there are many new technologies that offer broader commercial applications for captured CO₂, such as the production of methanol/ethanol, the production of bioplastics, and more." Allison said the technology means that more emitters can begin reducing their emissions more quickly and affordably to mitigate their environmental impact while also reducing costs associated with carbon taxes." Canada's carbon tax is planned to increase to $170/tonne by 2030 and individual provinces have the authority to increase this further.

-Darrell Proctor is a senior associate editor for POWER (@POWERmagazine).

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