Propane Saving Smokestack Energy

May 30, 2004 – Vol.9 No.10

PROPANE: SAVING SMOKESTACK ENERGY.

Most thermal power plants, including nuclear, use high-temperature, high-pressure steam - gasified water - to spin turbines connected to electric generators. In the U.S. 75 percent of electricity is generated with high- pressure steam.

The steam that’s used in these power plants is not like the steam coming from your tea kettle. Power plant steam must 1000 degrees F (550 degrees C, or so) or more to generate electricity economically. Steam below 650 degrees F (350 degrees C) can no longer produce electricity.

It takes a lot of energy to boil water to those temperatures.

In looking for a way to capture waste heat for greater efficiencies from power plants and other industrial facilities, two inventors, Daniel Stinger and Farouk Mian, have determined that vaporized, pressurized propane gas could be used in the same way as steam is used in thermal power plants - to spin turbine generators.

Overall, since waste heat which can range from 300 - 700 degrees F (150 - 375 degrees C) would be captured and converted to saleable electricity, power plants would be more efficient. Greater efficiency, up to 60 percent from the common 35 percent would be possible, the inventors say. Greater efficiency - more power generated for the same amount of fuel - would also mean fewer greenhouse gas emissions. Further, as smokestack temperatures would be lowered to about 130 degrees F (55 degrees C) toxics, such as mercury, cadmium, lead, vanadium, which now enter the atmosphere would condense inside smokestacks for safe removal and disposal.

The inventors have named the process the Cascading Closed Loop Cycle (CCLC). Propane is kept inside the system, not released, and heated, expanding gases are fed through two sets of turbines for the greatest efficiency.

The inventors say the capture of waste heat could add 20 percent to the U.S. power generating capacity, about 200 gigawatts.

Cogeneration - combined heat and power - installations are also possible with CCLC and no new technology is required. The propane used is the same as that for a camp stove and turbo-generation equipment is off-the-shelf - already available.

Already BP and Chevron Texaco are looking at CCLC as a way to increase the energy efficiency of their industrial facilities.

Visit the inventors’ new company WOW Energy at http://www.wowenergies.com/ and the original article at New Scientist magazine at http://www.newscientist.com/ .