Clean Coal Resurgent
For decades the US government has funded research into “clean coal” technology. Billions of dollars have been spent with the only visible result being employment for a small army of government coal researchers and academics. Now scientists at Ohio State University have announced that, after 15 years of effort, they have produced a breakthrough—a new technology capable of turning coal green and carbon dioxide emission free. This was widely reported in the news media and passed practically without critical comment. Is it true? Is coal no longer the dirty, devil spawned fuel of evil industrialists everywhere?
According to an announcement online, a team of researchers led by Liang-Shih Fan, professor of chemical and biomolecular engineering and director of Ohio State's Clean Coal Research Laboratory, have made a breakthrough in clean coal technology. For 203 continuous hours, they operated a scaled-down version of a power plant combustion system with a unique experimental design—one that chemically converts coal to heat while capturing 99 percent of the carbon produced by the reaction.
Called coal-direct chemical looping, it reportedly uses iron oxide to provide oxygen to reduce coal to ash inside of a sealed vessel. The only waste products are reportedly water and coal ash—no dreaded greenhouse gases. The clean coal technique was developed by scientists over a period of 15 years, with $5 million in funding from the federal government.
“In the simplest sense, combustion is a chemical reaction that consumes oxygen and produces heat,” Fan says. “Unfortunately, it also produces carbon dioxide, which is difficult to capture and bad for the environment. So we found a way to release the heat without burning.”
PhD student Elena Chung (left) and master's student Samuel Ayham (right) display chunks of coal along with pulverized coal and the iron oxide beads that enable the chemical reaction.
Doctoral student Elena Chung claimed the 203-hour experiment could have continued even longer. “We voluntarily chose to stop the unit. Honestly, it was a mutual decision by Dr. Fan and the students. It was a long and tiring week where we all shared shifts.”
The experimental apparatus generated 25 kilowatts of thermal energy during the tests. The next phase of development is to build a larger proof-of-concept plant in Alabama. The Alabama site will generate 250 kilowatts. The federal Department of Energy believes that the process can create 20 megawatts to 50 megawatts by 2020, said Jared Ciferno, the agency’s director of coal and power-production research and development. This all sounds great, but is it?
It turns out that things are not exactly as reported by Fox and others. First off, the reaction—basically a slow oxidation of the coal—does give off CO2, a lot of CO2. In a chemical-looping system, a metal oxide, in this case iron oxide, provides the oxygen for combustion. The metal oxide releases its oxygen in a fuel reactor with a reducing atmosphere, and the oxygen reacts with the fuel. Fan is being disingenuous when he says they discovered how to reduce coal without burning, they are just oxidizing the fuel in a slower, more controlled reaction than an open fire.
OSU reports that the CDCL plant’s 200+ hours of operation, using metallurgical coke and subbituminous and lignite coals, resulted in nearly 100 percent solid fuel conversion and a CO2 stream more than 99% pure. Since CO2 separation occurs simultaneously with coal conversion, chemical looping offers a low-cost scheme for carbon capture. The process can produce power, synthesis gas, or hydrogen in addition to high-purity CO2. The thing that has the DOE excited is that the CO2 is contained by the reactor, making it easy to capture.
Simplified schematic of the coal direct chemical looping (CDCL) system.
This research was funded by the DOE Carbon Capture Program. The goal is to lower the energy penalty of capturing CO2, not to eliminate the greenhouse gas. Once the dreaded gas is captured it still needs to be disposed of in some way, perhaps by injection into old oil and gas wells (see “CO2 Buried But Destined To Rise Again”). This method does not really solve the perceived problem of GHG emissions from coal plants, it merely postpones it. The problem of sequestration remains.
This blog has commented several times in the past about the dangers of coal, the least of which is its contribution to global warming. The mining of coal is a dangerous, dirty business that continues to take its toll. Though mining has become safer over the decades, in 2011, 48 miners died in America's 1,500 coal mines—including 29 who were killed April 5th in a blast at Massey Energy Co.'s Upper Big Branch mine. That qualified as the highest death toll since 55 were killed in 1992, according to information compiled by the federal Mine Safety and Health Administration.
Coal miners are tough, proud, independent minded people. I know this because my grandfather was a coal miner. He spent his later years tethered to an oxygen tank because of the effects of black lung disease. Reducing American dependence on coal can cost coal miners their jobs. Unfortunately, their jobs can cost them their lives or lead to cripling deases. And the cost in miners' lives is not the only problem. Coal is mined in a number of ways, each of which has its dangers.
Methods of mining coal.
Coal mining in China and India is even deadlier than in the US. Underground shafts can collapse or flood with water. Above ground strip mining ruins the natural environment and reclamation never puts things back as they were. Entire mountain tops have been removed and nearby valleys filled in with the overburden. Uncontrollable mine fires are a problem around the world as well, contributing greatly to CO2 emissions without any redeeming benefit.
Fly ash is a fine particulate pollutant produced by the combustion of pulverized coal, which is collected rather than allowing it to escape into the atmosphere. It is often mixed with water so it can be pumped into a retaining pond. Over time, toxic metals leach out and into ground water. More dramatically, ash slurry pits have broken in the past, as one did at Kingston, Tennessee, devastating the land down stream. It looks like this “new” breakthrough technology also uses pulverized coal, the remains of which will have to be disposed of.
The quest for clean coal mostly ignores the other factors that make coal a dangerous power source. Humanity would be better served if governments around the world concentrated on alternatives to coal—fracking to enhance supplies of clean burning natural gas and expanding safe, pollution free nuclear power.
This story does fit in with President Barack Obama's energy plans. Recently, the White House announced a Presidential Memorandum creating an Interagency Task Force on Carbon Capture and Storage to develop a comprehensive and coordinated federal strategy to speed the development and deployment of clean coal technologies. President Obama said:
Now, I happen to believe that we should pass a comprehensive energy and climate bill. It will make clean energy the profitable kind of energy, and the decision by other nations to do this is already giving their businesses a leg up on developing clean energy jobs and technologies. But even if you disagree on the threat posed by climate change, investing in clean energy jobs and businesses is still the right thing to do for our economy. Reducing our dependence on foreign oil is still the right thing to do for our security. We can’t afford to spin our wheels while the rest of the world speeds ahead.
Why is the American President pouring scarce public funds into coal? While it is true that Obama has no love for fossil fuels—witness his stalling on the Keystone Pipeline from Canada—there are good reasons for a politician to back coal. First is the fact that the US has a lot of coal, as much as a 400 year supply, still in the ground. Promoting clean coal allows the administration to claim it is working to secure America's energy future.
Second, coal is a major industry in a number of states, Wyoming, West Virginia, Kentucky, Texas and Indiana being the top 5 producers according to the Energy Information Agency Quarterly Coal Distribution Report. In the third quarter of 2012, total domestic coal distribution was an estimated 230.0 million short tons (mmst). This was 30.4 mmst (i.e. 15.2 percent) higher than the 2nd Quarter of 2012 and 19.7 mmst (i.e. 7.9 percent) lower than the 3nd Quarter of 2011 estimates.
While some of these states are sparsely populated they each have two Senators, and the Senate is essential to Obama's plans for his second term. If the Democrats lose the Senate and Republicans hang on to the House in 2014, Obama will be the lamest of lame ducks. Also, as we documented in our book, The Energy Gap, nearly half of US electrical generation comes from coal, and 40% of the traffic on America's railways is moving coal from producers to consumers across the nation. These are big industries that have a vested interest in coal, and that equates to political contributions.
While it doesn't hurt Obama's claim to green orthodoxy, clearly the clean coal gambit has more to do with domestic politics than it does with fighting climate change. Any skeptic should have suspicions about a program that garners praise from both Fox News and the Obama Administration. The politics of coal do indeed make strange bedfellows—and usually produces bad public policy.
This breakthrough is basically a sham. It does not eliminate CO2, it merely makes it easier to trap. It does not eliminate fly ash and the groundwater pollution that goes with it. It does not remove the danger from underground mining or the environmental rape of surface mining. In short, this breakthrough only hides the most innocuous of coal's unwanted side effects. This is what happens when fools fixate on the red herring that is carbon dioxide. This latest announcement should not be seen as the resurgence of clean coal, because clean coal is just an illusion.
Be safe, enjoy the interglacial and stay skeptical.