|Coal Communications Kit - Airborne Emissions|
By 2017, the coal-based power industry will have invested more than $142 Billion to develop and implement antipollution technologies that have resulted in a dramatic downward trend in the Environmental Protection Agency’s (EPA) classified six major pollutants since 1970; even though we are using more fossil fuel than ever before. These pollution controls minimize the negative effects of burning fossil fuels, while allowing the use of this critical resource in a cleaner, more efficient way. Thanks to antipollution technology, coal has been getting healthier and cleaner. The use of coal has facilitated an unprecedented technological revolution allowing humans to improve their living conditions and live longer, more fulfilling lives. In the last 20 years alone, scientists have developed ways to capture the pollutants trapped in coal before the impurities can escape into the atmosphere. Today, we have technology that can filter out 99 percent of the tiny particles, and remove more than 95 percent of acid rain pollutants in coal.
Processes have been developed to literally clean coal. Most modern power plants, and all plants built after 1978, are required to have special devices installed that clean the sulfur from coal's combustion gases before the gases go through the smokestack. In most cases, before combustion, coal is crushed and then washed to decrease ash and pyrite levels. Additionally, “bag houses and electrostatic precipitators remove residual fly ash, wet scrubbers desulfurize, and activated charcoal removes mercury and arsenic before the (invisible but for scrubber steam condensation) flue gas is discharged.” (Istvan, 2014) The use of these technologies has allowed coal-fueled power plants to decrease emissions of SO2, NOx, and particulate matter by almost 90 percent since the 1970s. These reductions occurred despite the fact that, during the same period, coal use increased by more than 170 percent.
Figure: Coal-fueled generation emission rates have decreased dramatically due to the application of environmental technologies. Sources: EPA National Air Pollutant Emission Trends; EIA Annual Energy Review, EIA AEO 2011, Ventyx – Velocity Suite
The path forward to a long and prosperous future for coal depends largely on continued research and development for clean coal technologies. As environmental challenges and expectations grow increasingly stringent, clean coal technologies must continue to improve energy efficiency, and reduce or eliminate SO2, Hg, carbon dioxide (CO2), NOX emissions, and particulate matter. The keys to longevity and success are: adequate public support, enhanced levels of funding and commitment to clean coal technology, reduced government interference, greater private support/innovation, and a regulatory and public policy framework that is supportive of coal use (National Mining Association, 2015) (Yamagata, 2014).
As regulatory pressure mounts with the advent of new federal regulations such as the Clean Power Plan, the importance of staying on the leading edge of new technology cannot be overstated. Coal liquefaction and gasification technologies are being explored to produce viable alternatives to oil and natural gas for electricity generation and transportation. New technology R&D focuses on:
Efficiency Improvements – Technologies in this field raise plant efficiency and reduce CO2 and other emissions. While some efficiency technologies are commercially available, others, such as Ultra Supercritical Pulverized Coal (USPC) and IGCC require continued research, development, and demonstration. Improved efficiency at an existing plant can reduce CO2 emissions by 10-16 percent, and by 2025, new units could reduce CO2 emissions by as much as 30 percent.
High-Efficiency Fuel Cells – These operate on a range of domestic fuels with virtually emissions-free performance at unsurpassed efficiencies.
Hydrogen Production – A clean energy carrier—via gasification.
Currently a promising clean coal technology is CCS, a process by which CO2 emissions are captured and stored in geologic formations, or deep in the ocean where they dissolve under pressure (National Mining Association, 2015). The primary CCS technologies being developed include:
Post-Combustion Capture: CO2 is separated from combustion exhaust gases. It can be captured using a liquid solvent or other separation methods. Once absorbed by the solvent, CO2 is released by heating to form a high purity CO2 stream. This is the preferred technology for capturing CO2 for use in the food and beverage industry (Global CCS Institute). The process is shown below (National Mining Association, 2015):
Pre-Combustion Capture: A more complex process than post-combustion, involves converting fuel into a gaseous mixture of hydrogen and CO2. Mostly used in industrial processes (Global CCS Institute), an example system can be seen below. (National Mining Association, 2015):
Oxyfuel Combustion: Uses oxygen rather than air for combustion of fuel, producing exhaust gas that is mainly water vapor and CO2, which can be easily separated to produce a high purity CO2 stream (Global CCS Institute). The diagram below shows this process:
In 2005, the Department of Energy (DOE) announced “FutureGen,” a $1.3 billion project to design, build, and operate a nearly emission-free coal-based electricity and hydrogen production plant. The funding was to be provided by the DOE in partnership with multiple coal companies (World Nuclear Association, 2015). Confronted from its earliest days with extremely challenging objectives, budget issues, and transitions in the regulatory environment, funding for the project was cut twice, under two different presidential administrations; the DOE announced in February 2015 that funding would cease (Romm, 2015).
The path forward to a long and prosperous future for coal depends largely on continued research and development for CCTs. As environmental challenges and expectations grow increasingly stringent, CCTs must continue to improve energy efficiency, and reduce or eliminate SO2, CO2, and NOx emissions. The keys to longevity and success are: adequate public support, enhanced research and commitment to CCTs, and a regulatory and public policy framework that is supportive of coal use (National Mining Association, 2015) (Yamagata, 2014). The cautionary tale of FutureGen demonstrates the importance of regulatory cohesion with the objective of success for coal.
Coal has gotten much cleaner over the past generation with the use of technologies that enable the generation of energy with minimal negative environmental impact. Power plants being built today emit 90 percent less pollutants (SO2, NOx, particulates and mercury) than the plants they replaced from the 1970’s. The coal industry has demonstrated its eagerness to pioneer the technological advances that are necessary to keep coal safe, effective, and environmentally responsible. With adequate public support, enhanced research efforts, and coal-friendly regulatory policies, the industry can ensure that coal remains a staple of U.S. and global power generation for the foreseeable future.
Today, energy companies are working to develop, demonstrate, and deploy the next generation of advanced clean coal technologies. These technologies would make it possible to reduce emissions of traditional pollutants to very low levels and to capture and safely store carbon dioxide – all while ensuring a reliable supply of affordable electricity to meet America’s growing energy needs, while still using one of America’s most abundant, domestically produced fuels, coal. Thanks to technology, coal has been getting healthier and cleaner since the 1800’s. Modern coal technology has many different means of reducing pollutants. There are filtration systems that prevent undesirable substances from getting into the air; there are processes that use chemical agents, such as limestone, to bind pollutants and prevent them from being released. There are chemical devices like wet or dry scrubbers to separate out unwanted emissions. Modern clean coal technology harnesses this nation’s abundant coal-based energy in a relatively inexpensive manner. It is clearly possible to increase coal use while decreasing pollution, resulting in reliable, affordable and clean energy for humans. New clean coal technologies promise to balance environmental and economic concerns, while continuing to satisfy our growing world with energy output.