Skyonic Corp. of Austin, Texas, has just broken ground on a new facility in San Antonio that is designed to capture carbon dioxide (CO2) and other emissions from a cement factory and produce chemical products to be sold commercially. Called Capitol SkyMine, the new plant will be “the first commercial-scale facility of its kind that offers a way for emitters to deal with their CO2 and SOx-NOx emissions and do so profitably instead of as a cost,” I was told by Stacy MacDiarmid, communications director for the company.
The Capitol SkyMine facility is being retrofitted onto the 65-year-old Capitol Aggregates Cement Plant owned by owned by Zachry Corp., a construction and materials company in San Antonio. Although the new carbon capture plant is the first of its kind to be built at commercial scale, MacDiarmid told me “we’ve already run a few small-scale pilots.”
One of those pilots has been at Capitol, she said, “where we’ve been doing testing with the actual flue gases that will go into the commercial-scale plant.” She added that the pilot “has proven that we can capture and reuse CO2 profitably.” Capitol will capture an estimated 75,000 tons of CO2 and other emissions yearly and mineralize them into solid sodium bicarbonate, as well as hydrochloric acid and bleach. MacDiarmid says the company already has commercial and municipal customers lined up for most of its product.
Capitol SkyMine is named for the SkyMine technology Skyonic has developed, which “removes CO2 from industrial waste streams through co-generation of saleable carbonate and/or bicarbonate materials,” according to the company, and that also “cleans SOx and NO2 from the flue gas, and removes heavy metals such as mercury.” The electrolytic technology is designed to be retrofitted to industrial facilities and power plants. This approach “establishes pathways for mitigating CO2 in areas where geologic storage, the predominant competing CO2 sequestration technology, is not an optimal solution.” MacDiarmid said that Skyonic’s approach “avoids the compression and pipelining that a CCS [carbon capture and storage] plant might need, injecting the CO2 somewhere and leaving it there. It avoids the costs of those processes, and does it profitably.”
Skyonic says that its SkyMine process is also scalable, “as it allows an industrial or power plant owner to configure the degree of CO2 removal anywhere from 10 percent to 99 percent,” so the technology can adapt to all kinds of unique facilities. Skyonic was founded in 2005 by chemical engineer and entrepreneur Joe Jones. Jones has been quoted as saying that “The Capitol SkyMine plant will mark the first time that carbon-negative chemistry has reached the commercial stage,” and that his company’s technology “means that emission problems can become emission profits.”
Investors Paying Close Attention
In July, Skyonic announced that it had awarded a $117 million construction contract for the Capitol SkyMine project to Toyo-Thai Corp., an engineering and construction firm based in Thailand and specializing in power, petroleum and chemical facilities. In June, Skyonic closed on $128 million in funding to support the construction of the Capitol SkyMine facility and to fund the company’s R&D efforts. Skyonic’s funding announcement mentions equity investments in the company by Cenovus Energy (which has been conducting CCS operations at some of its oil fields), along with ConocoPhillips, BP, Northwater Capital, PVS Chemicals, BlueCap Partners, Berg & Berg Enterprises and Zachry Corp., as well as Toyo-Thai itself. The project has also received $28 million of grant funding from the U.S. Department of Energy’s (DoE) National Energy Technology Laboratory. All of this strongly suggests that larger forces are at work in this project and that, if it is successful, it could serve as a model for more extensive deployments in the future. It’s sure to be closely-watched.
In a discussion recently with Oil and Sands Review, Jones described Skyonic’s technology as relative low-energy-intensive: “The feature of our chemistry approach is embodied in the word ‘ionic.’ We use the weak ionic bonds of salt chemistry to capture CO2 in carbonate forms, which has an overall thermodynamic advantage over working with true atom-to-atom and covalent chemical bonds.” Put another way, said Jones, “The process starts with an unwanted acid gas, CO2, and a neutral salt. We perform some operations that produce a neutral carbonate and a stronger acid gas and, in almost all cases, hydrochloric acid.”
Jones said that Skyonic’s process is more efficient than employing an amine pump, the primary competing technology for carbon capture. The “energy penalty” for the amine process, he said, including the full CCS process associated with it, is about 45 percent, referring to the portion of a fuel that has to be expended to make the rest of it carbon-free. SkyMine’s energy penalty is about 31 percent and is expected to decline to 25 percent over time. Beyond that, Skyonic is working on an even more advanced technology called SkyCycle which is expected to reach an energy penalty of less than 10 percent.
CCS as a Carbon Mitigation Strategy
According to the Columbia University Climate Center, about 5 percent of global CO2 emissions come from cement production. Cement represents about 18 percent of industry greenhouse gases (GHGs). Columbia says that cement’s emissions result from:
Direct energy-related emissions, through fossil-fuel consumption to heat the kiln (abouit 40 percent of emissions)
Indirect energy-related emissions for powering machinery (5 to 10 percent)
Process-related emissions as CO2 is directly released from limestone heated in the kiln (about 50 percent)
The new Climate Change 2013 report from the Intergovernmental Panel on Climate Change (IPCC) estimates that annual CO2 emissions from fossil fuel combustion and cement production came to 9.5 gigatonnes of carbon (GtC) in 2011.
The International Energy Agency (IEA) believes that CCS “will be a critical component in a portfolio of low-carbon energy technologies if governments undertake ambitious measures to combat climate change.” In IEA’s low-carbon scenario projection, CCS would account for one-sixth of CO2 emission reductions by 2050.
The agency’s 2013 report on CCS says that “The individual component technologies required for capture, transport and storage are generally well understood and, in some cases, technologically mature.” As an example, the report cites the commercial practice of natural gas and hydrogen sweetening, in which CO2 is captured and transported by pipeline. The biggest obstacle to deployment is “the integration of component technologies into large-scale demonstration projects.” Industrial pilots for CO2 capture make up a key component of IEA’s technology roadmap.
IEA doesn’t mention the Skyonic technology specifically. However, its report does discuss “CO2 utilization” as “a possible alternative or complement to geologic storage of CO2 that could enhance an economic value for captured CO2.” Some CO2 is used commercially, for example, “as chemical solvents, for decaffeination of coffee, carbonation of soft drinks and manufacture of fertilizer.” Enhanced oil recovery (EOR) represents the largest commercial use of CO2, carbon injection at Cenovus’s Weyburn oilfield being one example.
CO2 could offer an abundant source of carbon for chemical uses, says IEA. The difficulty is that “CO2 is unreactive and usually requires large amounts of energy to break its chemical bonds.” This points to the potential value of technology such as Skyonic’s. If the company can continue to drive down the “energy penalty” for processing carbon — and prove feasibility at scale — its technologies could help industry reduce carbon emissions and provide a useful source of raw materials at the same time.