A pollution-free coal based electric power plant – Futuristic view and Skepticism:
Coal is the workhorse of global electric power sector and is used to generate more than half of the electricity world consumes. It is also world’s most abundant fossil fuel, with supplies projected to last almost 250 years or more. As coal-fired power plants generally produce the lowest-cost electricity and coal is abundant, most of the country’s economic and energy security depend on the continued use of the fuel. But most disadvantage part of this fuel is: coal is an inherently dirty fuel; it contains more pollutants than oil or gas, and burning coal or any fossil fuel releases the pollutants into the atmosphere. Fossil-fuel combustion also releases carbon dioxide, the primary greenhouse gas that causes global warming.
A. One way to clean the electric power generation system is to separate out carbon at the point of combustion and capture and isolate it in a process known as sequestration. Sequestration techniques now under study range from injecting CO2 underground or deep into the ocean to having forests absorb the gas. One objective of the, much talked about, ‘FutureGen’ project is to explore the feasibility of several of these techniques. High cost of sequestration technology is the most intriguing factor, at present. As per the estimation of DOE (Department of Energy of Federal Govt. of US) the cost of sequestration using existing technologies is in the range of $100 to $300/ton of carbon emissions. A goal of the FutureGen program (FutureGen's developers - an alliance of a dozen big power and coal companies such as American Electric Power Inc., BHP Billiton, Consol Energy Inc., Foundation Coal Corp., Peabody Energy Corp. and Rio Tinto Energy etc.) is to employ advanced technologies to reduce that figure to $10 or less by 2015.
B. Facts about the program – a discussion:
(i) Coal gasification is a mature technology in the chemicals industry, which uses the process to create feedstock for ammonia and other chemicals and fine chemicals.
(ii) For generating electricity, this technology has not yet been fully used by industry. In fact, the most economical way to make hydrogen is from methane natural gas.
(iii) In case of extracting hydrogen from coal, 30% of fuel’s latent energy is lost.
(iv) It is expected to initially capture at least 90% of the CO2 that system produces; adding that advanced technologies could eventually achieve nearly 100% capture.
(v) Once captured, the CO2 will be injected deep underground.
(vi) Potential graves include saline aquifers thousands of feet below the surface, depleted oil or gas reservoirs, and unmineable coal seams or basalt formations.
(vii) Once buried, the greenhouse gas would have little chance of escaping into the atmosphere.
C. Skepticism about the program – a discussion:
(i) It's easier to eliminate the pollutants in coal such as nitrogen oxides (NOX) and sulfur dioxide (SO2) at the front end than at the back, where they end up dispersed in flue gas.
(ii) The plan is to clean SO2 and NOx from the coal gases and convert them to byproducts such as fertilizers and soil enhancers.
(iii) Mercury also would be removed, and CO2 would be captured and sequestered in deep, underground geologic formations.
(iv) People are coming to the realization that making sequestration work is going to be very expensive and efficiency of removal of SO2 and NOx.
(v) There was no guarantee of carbon sequestration technology that rock formations, destined for the carbon, would seal-in the offending material.
(vi) We may have to spend billions and billions of dollars chasing technology that, even when perfected, is not nearly as perfect as the renewable energy (such as wind, solar, geothermal) in creating energy that gives us the added benefit of saving our environment.