Carbon is an atom with atomic weight of 12. During combustion it combines with two oxygen atoms with atomic weight each of 16. The outcome is a CO2 molecule with atomic weight of 44. The molecule that results from the reaction is 3.7 times as heavy as the carbon atom alone.
Coal is a sedimentary rock that varies by location and type. It is mostly carbon, but not pure. The proportion of carbon varies from 60% in Lignite to 90% in Anthacite. A typical value for discussion purposes is 80%. [Ref Wikipedia article] Burning one ton of this typical coal will produce about three tons of CO2.
Calculation: 1 ton x 3.7 x 80% = 3 tons
Many have proposed that a tax or fee be imposed on the CO2 that is emitted from the burning of coal and other fossil fuels. They often suggest that the fee start low, say at $10 per ton of CO2, and rise by this amount each year. The fee on CO2 in Year 10 would be $100 per ton.
With this fee schedule for CO2, the fee on typical coal would be $30 per ton in Year 1 and $300 per ton in Year 10.
The average price of coal in the US in 2008 was about $30 per ton. [Source: US EIA] With this fee schedule, the fee for the CO2 would quickly dominate over the price of the coal before the fee.
This article will be bundled with others in a file called “Facts and Confusion.”. I will add to this file from time to time.
Bill Allen, August 7, 2010