Coal is the largest energy source in the United States, as well as one of the largest energy sources in the world. It is imperative that the coal industry works to ensure the continued availability and access to this life-sustaining fuel. Although claims of the negative environmental impacts of coal burning can be overstated, coal does produce potentially harmful emissions when burned. Clean coal technologies (CCT) seek to reduce environmental harm by using multiple technologies to clean coal and contain, or reduce, its emissions of sulfur dioxide and nitrogen oxide (Dowdey, 2007). Clean coal technologies have been built over several generations and continue to evolve. Today, there are more than 20 new, lower cost, more efficient, and environmentally compatible technologies for various industries (National Mining Association, 2015). Technology development will continue to be the primary driver for reducing emissions and its associated costs for coal’s future.
The Department of Energy (DOE) Coal RD&D program and National Energy Technology Laboratory (NETL), have partnered with the private sector since the early 1970’s to develop innovative technologies that greatly enhance energy production and improve air quality (National Mining Association, 2015):
Fluidized-bed combustion – Limestone and dolomite are added during the combustion process to mitigate sulfur dioxide formation. There are 170 of these units deployed in the U.S., and 400 throughout the entire world.
Integrated Gasification Combined Cycle (IGCC) – Heat and pressure are used to convert coal into a gas or liquid that can be further refined and used cleanly. The heat energy from the gas turbine also powers a steam turbine. IGCC has the potential to improve coal’s fuel efficiency rate to 50 percent. Two IGCC electricity generation plants are in operation in the U.S.
Flue Gas Desulfurization – Also called “scrubbers,” they remove large quantities of sulfur, other impurities, and particulate matter from emissions to prevent their release into the atmosphere.
Low Nitrogen Oxide (NOx) Burners – Reduce the creation of NOx, a cause of ground-level ozone, by restricting oxygen and manipulating the combustion process. Low NOx burners are now on 75 percent of existing coal power plants.
Selective Catalytic Reduction (SCR) – Achieves NOx reductions of 80-90 percent or more, and is deployed on approximately 30 percent of U.S. coal plants.
Electrostatic Precipitators – Remove particulates from emissions by electrically charging particles and then capturing them on collection plates.
Coal is a key component for a literally brighter future – clean coal technologies are the answer to the question of cheap, reliable energy in the U.S. and abroad.
Coal has gotten cleaner and cleaner over the past generation, utilizing the power and ingenuity of technologies like scrubbers, IGCC (Integrated Gasification Combined Cycle) and CCS (carbon capture and storage) to extract vital energy from coal with minimal negative environmental impact. “Power plants being built today emit 90 percent less pollutants (SO2, NOx, particulates and mercury) than the plants they replace from the 1970’s, according the National Energy Technology Laboratory (NETL). (National Mining Association, 2015).
The coal industry has demonstrated its eagerness to pioneer the technological advances necessary to keep coal safe, effective and environmentally responsible. With adequate public support, enhanced research efforts, and coal-friendly regulatory policies, the industry can satisfy environmental concerns and still be the cornerstone of electricity generation.
Objection: Environmentalists say that clean coal is a myth. Can coal ever really be clean?
Response: The term “clean,” much like the term “dirty,” is inherently subjective. But regardless of one’s definition, it is a myth that “coal is dirty.” In reality, the environmental benefits of using fossil fuels like coal far outweigh the risks (Epstein, 2014). With innovative technology, a zero-emissions process is within reach, and existing clean coal technology is already making enormous strides towards much cleaner coal. According to the EPA and other sources, coal-fueled power plants are capable of reducing up to 98 percent of sulfur dioxide emissions, 90 percent of nitrogen oxide emissions and 90 percent of mercury emissions. Using CCS to capture the CO2 from a single thousand-megawatt coal plant, for example, is equivalent to 2.8 million people trading in pickups for Priuses (Nijhuis, 2014).
Objection: CCS seems like a limited solution. How much CO2 can we actually store?
Response: In its 2008 Carbon Sequestration Atlas, the U.S. Department of Energy reported that, together, the U.S. and Canada have enough capacity at our current rate of production to store almost 1,100 years’ worth of carbon dioxide. This storage capacity is located deep underground across the continent in varying types of geological formations – including unminable coal seams as well as oil and gas reservoirs. So while the U.S. and Canada are the source of 3.2 billion tons of man-made CO2 each year, the two nations have storage space for 3.5 trillion tons of CO2. Do the math and we have a 1,093-year reservoir of CO2 storage (American Coalition for Clean Coal Electricity, 2015).
Objection: Clean Coal Technology is way too expensive. It makes more sense to invest in renewable energy sources.
Response: There are certainly costs associated with reducing emissions, but clean coal is not so expensive that it can’t already compete with renewables or other resources. Clean coal will require large infrastructure investments, but so will a major expansion of renewable-energy projects. Also, selling captured carbon for enhanced oil recovery can help reduce the cost of CCS, and new technologies will allow carbon to be captured with far lower energy expenditures (Herzog, 2014).