Sustainability

Clean coal may prove viable energy source

To many, the concept of clean coal does not exceed that of a green-washed advertising campaign, but I have learned that the practice is far more extensive and beneficial to the U.S. energy supply. The American Coalition for Clean Coal Electricity describes clean coal technology as those “that can be used to reduce the environmental footprint of coal… as well as reduce [greenhouse gas] emissions.” The IPCC estimates coal plants with available carbon capture technology will reduce emissions by 85 percent while keeping cost increases below 50 percent and increased coal usage below 30 percent. Even in a 30-year low, coal provided 39 percent of our electricity in 2011 (natural gas was a distant second at 26 percent). Gradually replacing largest source of electricity with other forms will not be enough to ensure the path to a low-carbon future clean coal must become a reality.

I recently worked as a process engineering intern for Alstom Power, Inc. While my statements do not speak for those of the company, the internship improved my views of the coal industry and its pollution reduction initiatives. Alstom, a multinational power generation and transport conglomerate, produced several carbon capture facilities worldwide. It developed the chilled ammonia process, which is a commercially mature method of capturing and sequestering over 90 percent of carbon dioxide emitted. The process requires NOx, SOx, particulate matter, acid gases, and mercury to be cleaned from the product stream. Furthermore, the waste products of carbon capture can be benignly recycled into other processes. One of the byproducts of the CAP is ammonium sulphate, an agricultural chemical. Only trace amounts of selenium are found in the ammonium sulphate, so widespread implementation of Alstom’s carbon capture process would in turn improve drinking water quality and lower the two-headed deformity rate in fish. The CAP is one of many new carbon capture technologies that could revolutionize the way Americans think of coal.

Bloggers and pundits frequently bring up “versus” arguments in regards to electricity (coal versus solar, Keystone XL Pipeline versus Solyndra). It might be slightly beneficial in regards to new generating capacity, but the key to a comprehensive energy policy is diversifying rather than “versus-fying” our energy sources. Coal oxycombustion uses relatively pure oxygen as opposed to air as an oxidant. Instead of taking several hours to start up, oxygen plants have the ability to go from 10 percent to 100 percent of its generating capacity in half an hour. Thus, clean coal can supplement rather than compete with variable electricity sources such as wind turbines and solar panels. Pumping the carbon dioxide underground impedes hydraulic fracturing, but still allows for extraction of natural gas. Although few see this as a “green” achievement, it undoubtedly preserves land from becoming scarred from the thousands of gas wells across the country. Methanol, which is produced predominantly by fossil fuels, burns safer and cleaner than gasoline. The New York Times reports that the use of methanol as a fuel, even accounting for different energy densities, is far cheaper and more efficient than burning gasoline. Using coal CO2 as a chemical feedstock would provide locally-sourced energy with lower emissions than oil. Industry representatives with fossil fuels and renewables could procure their green status rather than debating the economy versus ecology squabble.

Integration does not fall solely on industry, though. Emissions reductions of 85 percent or greater are possible with carbon capture technology, which would lower the CO2 emissions from 1000 gCO2/kWh to roughly 120 gCO2/kWh. The resulting emissions would be about four times greater than that of solar photo voltages, which is negligible. As a result, lobbyists and legislators from coal-friendly areas would be much more receptive to implementing a carbon policy in the United States. The current political battles have led to minimal carbon policies, and even the nation’s largest consumer of coal is beginning to speak out: American Electric Power cancelled phase two of the Mountaineer Station Carbon Capture Sequestration Project, which Alstom constructed, due to unknown climate policy. Politicians have the opportunity to work across party lines, though. Last June, I was fortunate enough to talk to Lamar Alexander (R-TN) over the phone about supporting the Maximum Achievable Control Technology regulation for coal plants. Alexander was one of the few Republicans to co-sponsor the regulation, and spoke in great detail about how the regulation was actually beneficial to the usage of coal:

“We have 546 Tennesseans working in coal mining according to the Energy Information Administration, and every one of those jobs is important.  There are also 1,200 Tennesseans who work at the Alstom plants in Knoxville and Chattanooga that will supply the country with pollution control equipment required by this rule. Every one of their jobs is important, too…

“While some have said this rule is anti-coal, I say that it is pro-coal because pollution control equipment guarantees coal a future in our clean energy mix. Long term, the Tennessee Valley Authority will be able to produce at least one third of its electricity from clean coal plants.”

In addition to hearing from the senator in person, and see him reference my company, I was amazed at the potential of bipartisan energy policy to pass in the federal government.

President Barack Obama stresses an “all of the above” energy policy, but forgets to mention coal, currently the largest supplier of U.S. and global electricity at that. The Energy Information Administration forecasted that coal would decline in the percentage of U.S. generation by 2035, but the amount generated actually increased from 2010 levels. An EIA report of the same year predicted that no new coal plants will be constructed from now until 2035, meaning that an already-aging coal fleet would be running longer at higher capacity. Retiring old plants and subsequently building newer, more efficient generating units would greatly reduce carbon emissions. Very few will disagree that coal power, at its present and former states, is dirty. Thousands die from air pollution, occupational hazards, and destruction of land. If regulators enacted policy that encouraged efficiency in coal plants and enacted carbon policy that would preserve the positive aspects of the coal industry, a much greater number of legislators, workers, and citizens would participate in fixing those problems. In order to keep the global temperature rise less than two degrees celsius, the International Energy Agency lists 22 percent of the emissions cuts to come from CCS technology. Let’s make that number a reality.

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