Green Business Bureau Blog
Clean Coal: A Debatable Oxymoron
Coal is Carbon. This is the basic fact we will begin with. Diamonds are carbon too. However, nothing exists in a pure and native state. In nature Coal is found admixed with various impurities that get converted to gases when coal is burnt. Now, if we substitute the word carbon for coal, logic stands that Carbon is oxidized (burnt) to become Carbon dioxide (CO2). If incompletely or inefficiently burnt, it becomes Carbon monoxide (CO).Carbon dioxide is one of the five gases held accountable for atmospheric heat trapping (the greenhouse effect) and global warming. Carbon monoxide is a dangerous gas which can cause fatal poisoning. So, why on earth is coal burnt then?
Simple. Because it is a cheap source of fuel and till recently has been easy to mine at a low cost. The only environmental issue then is the gases released when coal is burnt. These are CO2, CO, Sulfur dioxide and mercury compounds. Of these the most pressing and immediate concern is with Carbon dioxide. We will currently ignore the problem of Acid rain. This happens when sulfur dioxide reacts with moisture in the atmosphere to create Sulfuric Acid that rains down. Incredible as it may seem, CO2 is the bigger evil here.
Assuming that vast supplies of good quality coal are available in locations that are practical and cost-effective to mine, the most significant problem that remains is the Carbon footprint. As far as Carbon foot-printing is concerned, America is Big Foot to the world.
Now we come to the oxymoron, ‘Clean Coal’.
Carbon Capture and Sequestration is a technology aimed at capturing carbon dioxide gas, compressing it to a liquid state, and injecting it underground for storage. This is easier said than done. Very simply put, this sounds like the exact opposite of drilling for natural gas. Therefore, it has to be cost-effective, viable and must not create newer evils as far as the environment is concerned. Without getting into technicalities of carbon capture, let me mention two common-sense facts here. Unless kept pressurized, the CO2 will revert to the gaseous state. And secondly, if the CO2 ever reacts with ground water supplies under pressure, we will have new underground soda pop factories. The EPA has published a proposed rule under the Safe Drinking Water Act to protect underground drinking water sources from such injection activities.
To get a better idea of the size of the problem here is an understanding of it.“Sequestration in the context of coal power refers to long–term storage of CO2 from coal power plants in non–atmospheric reservoirs, mainly geologic formations that trap the CO2. Geologic carbon sequestration involves injecting carbon dioxide, usually in a liquid form, into underground media like deep saline formations, depleted oil and gas reservoirs, and unmineable coal seams. Sequestration is the last stage of the CCS process after CO2 has been captured at a coal power plant, compressed from a gaseous phase to a fluid, transported by pipeline (if the plant is not near a sequestration site), and then finally injected into deep subsurface formations.” The cost itself is mind boggling. Will coal still be a ‘cheap’ energy source? If not, then why waste millions which can be better invested in cleaner alternative energy sources like sun and wind?
The problem of global warming and polar ice-cap melting is here and now. Carbon capture and sequestration is still in its infancy. To quote one of my favorite ad lines: “don’t bring a knife to a gunfight’. If ‘clean coal’ becomes reality even 20 years from now, the purpose will have been defeated.