Amid a global national debate about the environmental impact of using fossil fuels to generate energy, a group of University of Kentucky researchers is quietly working to find ecofriendly uses and mitigation processes for coal, one of the state’s premier industries.
Scientists at the UK Center for Applied Energy Research are exploring ways to improve the ecological impact of fuel coal and investigating whether it is feasible to turn it into a versatile, non-fuel raw material for industry. CAER’s research focuses include employing algae to gobble up carbon dioxide from power plants’ emissions, better managing waste coal ash, and transforming coal into high-strength, lightweight carbon fiber.
The coal research complements a plethora of other energy studies CAER’s team of geologists, chemists and engineers of various disciplines are undertaking. They also are investigating biodiesel uses, advanced battery construction, renewable energy and more.
However, explorations into remediation of coal-fired power plants emissions is CAER researchers’ top job, a mission shared with energy scientists the world over, according to Matt Weisenberger, the center’s associate director.
“By far, the largest area of research at CAER is CO2 capture,” said Weisenberger, who also is principal engineer for carbon materials at CAER. Carbon dioxide “is a very stable compound. Once formed, it’s almost like rolling a ball down a hill; it becomes hard to push that ball back up the hill.”
All fossil fuels upon burning produce carbon dioxide, which in the atmosphere acts as a blanket holding in increasing amounts of solar energy that is changing global climate. Widely used worldwide to fuel electricity power plants, coal’s hydrocarbons produce more carbon dioxide than petroleum, natural gas and various gas liquids.
Multiplying annual Kentucky coal production by market prices still yields a figure of more than $5 billion in the past year, and was 30 or 40 percent higher a few years ago. It’s an economic impact CAER’s efforts might help sustain.
UK researchers doing their investigatory work across the highway from the Kentucky Horse Park north of Lexington are using carbon dioxide from power plant emissions to feed algae colonies that through photosynthesis convert CO2 into environmentally safe oxygen and various carbohydrates.
The question is whether this, plus additional strategies CAER and other energy institutes are reviewing, is financially viable and scalable enough to counter criticisms of coal as a fuel source.
“Well, it’s going to take a lot of algae,” Weisenberger said. “It’s not yet made a (significant) difference.”
Coal as a public policy football?
Kentucky’s commercial coal history dates to 1820, when the state’s first mine opened. The commonwealth ranks third among U.S. states in coal production, which in 2012 was 90.8 million tons of coal, according to the federal Energy Information Administration; national production was 1.016 billion tons. However, coal production and the number of well-paying mining jobs in Kentucky is decreasing, due both to tougher environmental regulations and increasingly abundant and cheap domestic natural gas.
In 2006, the state had produced 121 million tons of coal and employed over 17,000 workers, while U.S. coal production was 1.162 billion tons, according to the American Coal Foundation. At the beginning of October 2014 the number of Kentucky mining jobs was less than 7,250, according to the state Energy and Environment Cabinet.
As a fuel, coal has advantages. It is abundant, with some 260 billion tons of recoverable coal remaining in the United States – a 235-year national supply at current usage. Sixty percent of coal travels to its destination by railroad, supporting transportation sector jobs.
It is cost effective viewed as a fuel input to generate electricity.
Some 56 percent of U.S. homes draw their electricity from coal-fired power plants. Electricity is cheaper in states that derive substantial portions of their power from coal-fired plants, according to data from the American Coal Foundation. The national average cost for electricity is 9.88 cents per kilowatt-hour. In the states where at least 40 percent of the electricity is coal-generated, the average is 7.1 cents.
In recent decades, however, environmental scientists have sounded alarms about its indirect costs and identified coal as a prime source of heat-trapping greenhouse gases in the atmosphere credited with increasing temperatures enough to affect global weather patterns. A Greenpeace website (calls coal “dirty” and names it as a key threat to the environment due to emissions and post-incineration wastes.
“Coal ash – the waste material left after coal is burned – contains arsenic, mercury, lead and over a dozen other heavy metals, many of them toxic,” according to Physicians for Social Responsibility, the U.S. arm of an international group that received the 1985 Nobel Peace Prize. “And disposal of the growing mounds of coal ash is creating grave risks to human health.”
Criticisms persist despite technological advances to “scrub” coal’s emission and waste streams. Coal’s advocates counter that more of it is burned today with less pollution than ever before.
“Coal-fired power plants in the U.S. have reduced their sulfur dioxide produced per ton of coal burned by 80 percent from 1976 to 2004,” cites the Online Kentucky Coal Facts website. In Kentucky, the site reports, sulfur dioxide emissions have declined from about 1.5 million tons in 1976 to 460,000 tons in 2004, mostly due to the use of scrubbers and coal with lower sulfur content.
The Environmental Protection Agency has proposed increasingly stringent coal regulations. In 2010, the EPA proposed ending an exemption for coal ash that keeps it from being classified as hazardous waste. On June 2 this year, the EPA proposed to further tighten emissions limits for coal- and other fossil-fuel fired power plants.
Writing in The Wall Street Journal, U.S. Rep. Mike Kelly of Pennsylvania characterized the new regulation as “Obama’s War on Coal” and argued the proposed new emissions rule could put many coal-fired plants out of business.
In 2013, Kentucky’s U.S. Sen. Mitch McConnell proposed the Saving Coal Jobs Act, which would block or lessen EPA coal use regulations and speed permitting for mining operations. Democratic Senate leaders prevented consideration of the bill. However, the 2014 elections changed the Senate’s composition, and McConnell will become the body’s agenda-setting majority leader in January.
Controversy regarding coal use will persist, and research will continue to seek ways to make it a more environmentally acceptable fuel.
Non-fuel uses for coal and its byproducts
Multiple research projects at CAER aim to mitigate carbon emissions, Weisenberger said. A major one involves capturing and commoditizing CO2 for industrial use. In addition to having algae convert emissions to oxygen, other plans investigate storing carbon dioxide underground where it cannot harm the atmosphere or injecting the gas into oil well fields to increase their yield as they approach depletion.
The latter process is known as “enhanced oil recovery and is one of several methods that can make an additional 30 to 60 percent of a well’s fuel production available.
CAER also is examining new technology to create an alternative industrial use: converting it into carbon fiber, a material lauded by the automotive, aerospace and aviation industries for its combination of light weight and strength. Carbon fiber also is used for water filtration and in the insulation and construction industries.
In the case of carbon fiber, however, coal derivatives can contribute only about 10 percent of the raw material used to make it. Thus, conversion of coal tar pitch into carbon fiber remains a niche use, far too small in scale to replace coal’s multibillion-dollar market as an energy fuel.
None of the technological research has been done on a wide enough scale to fully mitigate carbon dioxide emissions. Nonetheless, the work of CAER researchers who explore alternative, non-energy uses for coal and coal byproducts is important.
Fortunately, the CAER is well funded for the future. It is one of only three U.S. universities (along with Clemson and Georgia Tech) with its own carbon-fiber spin line, a 100-foot-long device that can create fiber from coal tar pitch and various polymer precursors, and test the results for efficacy. So far, however, such carbon fiber remains a niche product that is capital-intensive to manufacture, unlike the ubiquitous aluminum it might replace as an aerospace and aeronautic building material.
“I think improvements in understanding the process of making carbon fiber and improving the efficiency of manufacturing (it) are central to its growth,” Weisenberger said. “Producers would love for it to remain not a commodity. If it becomes more like aluminum, the price has to come down.”
Robert Hadley is a correspondent for The Lane Report. He can be reached at [email protected].
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