Has the Discovery Channel found a solution to the CO2 capture problem?


Most of the Discovery Channel geo engineering experiments were failures.  One notable experiment that seemed to be brilliantly successful was the formation of CO2 ice and then shaping it into a cylinder and then sticking a weight on the front and fins on the rear and dropping it over the side of a ship.  The projectile must have been 15 feet long and 9 inches in diameter and made of solid CO2.  It was fizzing the whole time it was being assembled on the deck of the ship.  However, it took off like a rocket straight down and reached 55 mph speed.  At 300 ft it stopped fizzing and when it hit the bottom it completely buried itself in the ocean floor.  The temperature and pressure are supposed to keep it there in an ice form.  The CO2 ice was not encased in any type of cylinder.  It was just a long CO2 stick pointed at the front end with a metal tip on the front and fins on the rear.  CO2 ice has a density 50% greater than water so it will sink when dropped over board.

This got me to thinking of an engineering design.  A processing plant could be made to condense CO2 at some ideal location, preferably close to an oceanside dock.  Electricity from the coal plant would power the CO2 manufacturing plant.  The CO2 ice manufactured would equal the amount of CO2 being emitted at the coal plant, however the two do not need to be directly connected, only electrically connected.  The CO2 ice would be loaded onto a ship and then dumped into the ocean as high speed projectiles that bury themselves at a depth great enough to insure the CO2 stays put in the ocean floor for an eternity.

The real challenge in making this work is designing a CO2 ice plant that is efficient enough to require only a fraction of the output of the coal plant to run the CO2 ice plant.  "Dry Ice gives more than twice the cooling energy per pound of weight and three times the cooling energy per volume than the regular water ice (H2O)" according to http://www.butlergas.com/dryice/dryice.html .  A coal power plant releases around 2,000 lbs per MWh or 2 lbs of CO2 per kwh according to http://www.triplepundit.com/pages/askpablo-coalfired-power-plant-002591.php .  The most efficient H2O ice making machines use 3.4 kWh to make 1,800 pounds of ice per day according to http://www.fesmag.com/energy-aware/article/CA6549981.html .  If dry ice has twice the energy per lb needed to manufacture it, then we would expect more than twice as much energy would be needed to make the dry ice.   This would be >6.8 kwh per 1800 lbs.  2000 lbs dry ice would then require >7.6 kwh.  Lets round it up to 10 kwh per 2000 lbs of dry ice because of the greater difficulty and inefficiency.  It might be much higher than 10 kwh per ton.  But for now lets assume we could achieve that efficiency.  The 2000 lbs of CO2 released also generated a MWh of electrical energy.  Yet only .01 MWh of energy is needed to condense the dry ice.  This looks very promising.  The dry ice plant could be ten times less efficient than this and still be an overall efficient process for the production of electric power from coal without releasing CO2 to the atmosphere.

A 600 MW base loaded coal plant running 24 hours a day produces 14400 MWh each day.  At 2000 lbs CO2 per MWh this is 28.8 million lbs of CO2 ice that would have to be produced daily to match this one 600 MW coal plant.  Dry ice is a little less than 100 lbs per cu ft, therefore the volume of 28.8 million lbs of ice is roughly 300,000 cu ft.  This would be a cubic block of dry ice that is 67 feet on a side.  Possibly a large ship could hold a week’s worth of dry ice before going to sea.  It would be a block of dry ice 67 by 67 by 470 ft long!  This would take some time to form into rocket shapes and drop them overboard.  If each one was 15 ft long and 9 inches in diameter, it would require dropping 317,000 of them each week!  If they were dropped one each second, it would take a total time of 88 hours to drop all of them.  Considering the time it would take to sail out to a point and back, each ship would require at least a week at sea and probably a week in port.  It would require two ships of about 700 ft length to handle one 600 MW power plant.  Since there are thousands of these coal burning power plants, you are beginning to see how massive an operation the capture of CO2 actually is.


However, there is a serious flaw with the concept of storing frozen CO2 under the ocean.  Dr Andreas Ehinger, a French energy expert, pointed out to me that the CO2 would be in a liquid form which would form CO2 lakes under the ocean and would not be an acceptable way to store the CO2.

It seemed at first to be a good way to dispose of CO2.  The Discovery Channel seemed to have found the solution to the CO2 problem from coal burning power plants.  There is sufficient electrical energy from the burning of coal to make the dry ice.  However, the storage of the dry ice is still not known how to do this.  What this exercise has done though is reveal the massive amount of CO2 we are actually putting into the atmosphere.  The fact that’s its not a visible gas is misleading the public and even the proponents of burning coal into thinking that the quantity is small.  Its not.  And with the emergence of China and India as big time coal players, we are going to see a huge acceleration in the rate of global warming.


Gene Preston