from Greenpeace - Feb 2009
Unmasking the Truth Behind "Clean Coal"
Clean coal is an attempt by the coal industry to try and make itself relevant in the age of renewables.
What is (so-called) clean coal?
Coal is a highly polluting energy source. It emits much more carbon per unit of energy than oil, and natural gas. CO2 represents the major portion of greenhouse gases. It is, therefore, one of the leading contributors to climate change. From mine to sky, from extraction to combustion -- coal pollutes every step of the way. The huge environmental and social costs associated with coal usage make it an expensive option for developing countries. From acid drainage from coal mines, polluting rivers and streams, to the release of mercury and other toxins when it is burned, as well as climate-destroying gases and fine particulates that wreak havoc on human health, COAL is unquestionably, a DIRTY BUSINESS.
It is a major contributor to climate change the biggest environmental threat we face. It is the most carbon-intensive fossil fuel, emitting 29% more than oil, 80% more carbon dioxide (the main driver of climate change) per unit of energy than gas.
Mercury is a particular problem. According to the United Nations Environment Programme (UNEP), mercury and its compounds are highly toxic and pose a global environmental threat to humans and wildlife. Coal-fired power and heat production are the largest single source of atmospheric mercury emissions. There are no commercially available technologies to prevent mercury emissions from coal-fired power plants.
Clean coal is the industrys attempt to clean up its dirty image the industrys greenwash buzzword. It is not a new type of coal.
Clean coal technology (CCT) refers to technologies intended to reduce pollution. But no coal-fired power plants are truly clean.
Clean coal methods only move pollutants from one waste stream to another which are then still released into the environment. Any time coal is burnt, contaminants are released and they have to go somewhere. They can be released via the fly ash, the gaseous air emissions, water outflow or the ash left at the bottom after burning. Ultimately, they still end up polluting the environment.
Clean coal methods only move pollutants from one waste stream to another.
Communities after communities have lamented the hosting of coal-fired plants. They are often ignored due to governments' preference for polluting power plants yet they often bear the burden of adversely altered lives.
Despite over 10 years of research and $5.2 billion of investment in the US alone , scientists are still unable to make coal clean. The Australian government spends A$0.5 million annually to promote Australias clean coal to the Asia Pacific region. Clean coal technologies are expensive and do nothing to mitigate the environmental effects of coal mining or the devastating effects of global warming. Furthermore, clean coal research risks diverting investment away from renewable energy, which is available to reduce greenhouse gas emissions now.
The first CCT programs were set up in the late 1980s in response to concerns over acid rain. The programs focused on reducing emissions of sulphur dioxide (SO2) and oxides of nitrogen (NOX), the primary causes of acid rain. Now the elusive promise of clean coal technology is being used to promote coal as an energy source.
A price worth paying?
Many of the clean coal technologies being promoted by the coal industry are still in the development stage and will take hundreds of millions, if not billions, of dollars and many more years before they are commercially available. Clean coal technologies are also extremely expensive in terms of day to day running costs. The US Energy Information Administration (EIA) estimates the capital costs of a typical IGCC plant (an experimental low-emission coal power station) to be US$1,383/kW, $2,088/kW with carbon sequestration. This compares with US$1,015/kW for a typical wind farm.
Clean coal is an attempt by the coal industry to try and make itself relevant in the age of renewables. Existing CCTs do nothing to mitigate the environmental effects of coal mining or the devastating effects of global warming. Coal is the dirtiest fuel there is and belongs in the past. Much higher emission cuts can be made using currently available natural gas, wind and modern biomass that are already in widespread use. Clean, inexpensive. This is where investment should be directed, rather than squandering valuable resources on a dirty dinosaur.
Myths and facts of "clean coal" technologies
MYTH # 1 Efficient Combustion Technologies can increase efficiency and reduce emissions.
Supercritical Pulverised Coal Combustion (PCC) - uses high pressures and temperatures. This can increase the thermal efficiency of the plant from 35% to 45%. This reduces emissions as less coal is used.
Fluidised Bed Coal Combustion (FBC) - allows coal combustion at relatively low temperatures, which reduces NOX formation. A sorbent is used to absorb sulphur.
Coal gasification - coal is reacted with steam and air or oxygen under high temperatures and pressures to form syngas (mostly carbon monoxide and hydrogen). Syngas can be burnt to produce electricity or processed to produce fuels such as diesel oil.
The world standard for efficiency at a power plant using pulverised fuel technology, the most common technique, stands at 37.5%. Advanced pulverized fuel technology increases the average efficiency to just 41-44 percent with a forecast improvement to 50 percent in the next 100 years. Other clean coal combustion technologies are still in early stages of development and are unlikely to improve efficiency beyond 43%.
MYTH # 2 : Coal washing lowers the level of sulphur and minerals in the coal.
Coal washing results in the formation of large quantities of slurry. This is placed in waste piles. Rain drains through the piles, picking up pollutants which end up in rivers and streams. This runoff is acidic and contains heavy metals.
MYTH # 3 During combustion, clean coal technologies utilize pollution controls for existing power plants to reduce emissions of pollutants.
Particulate emissions can be reduced by Electrostatic Precipitators (ESPs) and fabric filters. ESPs are most widely used. Flue gases are passed between collecting plates. These attract particles using an electrical charge.
NOX emissions can be reduced by Low-NOX Burners (LNB). These reduce the formation of NOX by controlling the flame temperature and the chemical environment in which the coal combusts. Selective Catalytic or Non-Catalytic Reduction (SCR/SNCR) are expensive and less widely used.
SO2 emissions - can be reduced by Flue Gas Desulpurisation (FGD). Wet FGD, or wet scrubbing, is most common and absorbs SO2 using a sulphur absorbing chemical (sorbent), such as lime.
Trace elements emissions these include mercury, cadmium and arsenic. Some emissions can be reduced by particulate controls, fluidised bed combustion and FGD equipment. Activated Carbon Injection is being trialled to remove mercury.
Between 7 and 30 percent of coal consists of non-combustible material that just has to be eventually disposed of. Clean coal technologies attempt to trap these waste products before they leave the smokestacks; waste material that is trapped is then used (despite containing a number of toxic elements) or dumped as landfill.
The use of higher quality coal lower in ash and sulphur should reduce emissions and increase efficiency, but thermal efficiency is increased by only one percent. If clean coal is used to meet the increased electricity demand predictions of governments instead of cleaner renewable alternatives, there will in fact be a net increase in carbon dioxide emissions.
According to a report by the United Nations Environment Programme (UNEP) mercury and its compounds are highly toxic and pose a global environmental threat to humans and wildlife. Exposure to it has been associated with serious neurological and developmental damage to humans. The report also states that coal-fired power and heat production is the largest single source of atmospheric mercury emissions. According to the Coal Utilization Research Council there are no commercial technologies available for mercury capture at coal-fuelled power plants. Furthermore, a US Department of Energy commissioned report, states that the consistent, long-term performance of mercury control has yet to be
demonstrated. Experimental removal of mercury is prohibitively expensive at
$761,000/kg mercury removed and even then 10% of the mercury still remains.
MYTH # 4 Carbon capture and storage (CCS) can trap C02 from fossil fuel combustion and storing it in the sea or beneath the surface of the earth.
CCS is cost intensive. It increases the costs of power generation by 40 to 80% compared with conventional power plants, depending on the location of the plant and the storage site, and the transport and capture technology used.
CCS produces additional long-term costs. Monitoring and verification over decades is necessary to guarantee the retention of the stored carbon dioxide. Even then, opportunities to intervene in order to prevent or control unexpected leakage events are likely to be limited.
CCS is not a technology of today nor of the immediate future because of technical uncertainties as to whether it will work or not. Focusing on renewables is still the best way to go.
A Risky Business
Despite $5.2 billion of investment in the US alone , clean coal research has been plagued with difficulties. For example, of the 13 clean coal projects that the US General Accounting Office looked at, eight had serious delays or financial problems six were behind schedule by 2-7 years and two were bankrupt and will not be completed.
The operators of the $297 million Healy Clean Coal project in the USA intend to retrofit the current clean coal plant with traditional technologies. The plant has been closed since January 2000 because safe, reliable and economical operation was not possible with the experimental technology.
Hidden Social and Environmental Costs
Social and environmental problems caused by the use of coal begin at the point where coal is mined. Mine workers are at great risk of death, injury and illness. Local communities suffer from land degradation and pollution and in many cases are forced to relocate.
At a coal-fired power plant, coal is pulverised and burnt in a high temperature furnace. Various toxic gases and tiny particles are released from the furnace into the smokestalks; pollution devices are used to try to trap pollutants before they are released into the atmosphere. The use and disposal of solid wastes trapped in the furnace and the release of gases and fine particles from the smokestacks have severe impacts on terrestrial and aquatic ecosystems and people's health.
What Is this "Clean Coal" Obama and McCain Support?
By Tara DePorte, AlterNet
Posted on October 31, 2008, Printed on February 8, 2009
Both Presidential Candidates Obama and McCain have emphasized the need for Energy Reform as we face climate change, a sinking economy, and rising fuel costs. In a country where 85% of energy demands are from fossil fuels (oil, coal and gas), coal and "clean coal" are making a rhetoric comeback this election. However, the burning of coal has proven one of the leading human-based causes of global climate change due to resulting carbon dioxide emissions, let alone a diversity of air pollutants.
The Obama Energy Plan proposes to "develop and deploy clean coal technology." McCain's energy plan, "The Lexington Project," commits to "$2 billion annually to advancing clean coal technologies." As the candidates talk about "clean coal," alternative energy, and energy independence, what's the science behind the plans? In this article we'll look into one of the more environmentally controversial options that has been put forth by the two candidates and try to help you decide how much of our nation's energy plan we wanted devoted to "clean coal".
Coal and its byproducts are everywhere -- in plastics, tar, fertilizer, steel and as the energy source for major industries such as paper and cement. In the U.S., however, over 90% of coal is used for electricity generation, resulting in 83% of carbon dioxide emission from the power sector. Coal is burned in power plants to create steam, thereby powering turbines and generating both electricity and a diversity of harmful air pollutants. No matter how you look at it, there isn't much clean about coal. The extraction and burning of coal is considered the dirtiest of all fossil fuels, including oil and gas. So, what is this new, innovative and so-called "clean coal"?
Unfortunately, no one has discovered a new form of coal -- the black rock composed of carbon or hydrocarbons that is intensively mined throughout the world. The dangerous misnomers "clean coal" or "clean coal technology" are not about finding a cleaner form of fuel, instead they describe the reduction of air pollution from coal-burning power plants. For instance, some "clean coal technology" works to boost power plant efficiency in converting coal to energy, others physically filter emissions before release, and others are being developed to capture emissions upon release from the plants.
With each of these much less-than-perfect technologies, there's a diversity of research and development, money and time, and effectiveness in curbing coal's environmental and health impacts. Below you will find a sampling of "clean coal technologies" and some insights into their pros and cons:
Cleaning up the power plants: Scrubber and Increased Efficiency: Since the 80's, the U.S. Department of Energy (DOE) has been working to decrease particulate emissions, mercury, sulfur and nitrogen from coal-burning plants -- all materials that contribute greatly to air and water pollution. "Scrubbers" are brushes and filters that are installed in smoke flues of coal-burning facilities, which physically remove some emissions' components. The reduction of these emissions has shown some success due to increased scrubber technology, where smoke stacks have increased cleaning or screening mechanisms on them, and some other "clean coal technology" methods. Unfortunately, greenhouse gases such as carbon dioxide have proven to be more difficult, energy and cost intensive to reduce at the source.
Gasification: Integrated gasification combined cycle or IGCC gets to the coal before it's burned. According to the DOE, the process uses steam and hot pressurized air or oxygen to force coal particles apart, thereby resulting in carbon monoxide and hydrogen. This mix is cleaned and burned to make electricity with subsequent heat being used for powering steam turbines. Some good things about IGCC are that there is a biproduct of hydrogen that can be used in developing hydrogen fuel cells. Additionally, the process of gasification can also be used for biomass and other "renewables" technology. Alternatively, gasification technology is still quite expensive and not considered economically viable on mass scales.
Carbon sequestration or Carbon Capture and Storage (CCS). The basics of CCS are to capture carbon out of the air and to put it somewhere else. The methodology behind, and storage sites, vary and include underground storage, ocean storage, creating carbonate rock out of the carbon dioxide and others.
In a 2008 interview with Klaus Lackner, Columbia University Ewing-Worzel Professor of Geophysics and one of the foremost CCS scientists remarked, "The challenge is capture, not storage." He continued, "Our goal is to take a process that takes 100,000 years and compress it into 30 minutes." One of the good things about CCS is that it can help clean up the mess that we've gotten ourselves into in terms of carbon emissions already in the air. Many do question the long-term effectiveness and safety of storing this carbon in systems that aren't used to having it there. Furthermore, although leaps and bounds have been made in past years in capturing CO2 from the air, the process is still costly and many estimate that the technology will not be ready for large-scale capture for many years to come.
With goals of zero-emissions coal power plants, the U.S. has spent over $2.5 billion since 2001 in research and development for "clean coal technology." Unfortunately, none of the options on the table actually help coal--as a whole--become any cleaner. A misnomer at best, "clean coal technology" is key to the cleanup of existing coal-powered facilities, but it's a long shot from the clean energy bill of health. There are some promising technologies being tested and applied within the "clean coal technology" umbrella, such as those addressing "end of the pipe" issues with the burning of the most abundant of fossil fuels.
However, few address the issues of coal extraction and its' environmental and health impacts and none are currently viable at a mass scale. Perhaps if the Presidential Candidates start referring to it as "not quite as dirty once you burn it coal technology," voters would have a better idea of what to expect in the upcoming new energy plans.
© 2009 Independent Media Institute. All rights reserved.
View this story online at: http://www.alternet.org/story/105429/