February 18, 2008 | 4 Comments
Los Alamos National Laboratory sent out its press release last week and has a link to a pdf that describes their new concept called “Green Freedom” for catching CO2 out of the air and sending the CO2 on to existing processes that can make fuels such as gasoline and diesel. The concept it seems is prepared enough for the press release and a patent application. The idea that man and his technology could participate in the carbon cycle in a recycling mode is encouraging news.
Green Freedom is a newly developed electrolytic stripping process that is claimed to be very selective. The technology is centered on a new process for separating CO2 from the atmosphere at a rate greater than 95% of the CO2 passing through the device. It also produces hydrogen gas as a byproduct which when incorporated into the downstream processes reduces the hydrogen for making fuel by 33%. Therefore, we’re looking at a new gas electrolytic stripping process, something I find highly probable.
But news isn’t a test bench device, a prototype or a working unit. In fact a close reading of the pdf illuminates the fact that the concept is that – a concept with a viability verification by Los Alamos National Laboratory technical reviews.
The new stripping cell features a large decline in the power needed to operate. The published estimate is that something like 410 kilo joules of electricity to get a mole of CO2 plus some low level heat of about 100 kilo joules for each mole of CO2. Now one-watt hour approximates 3600 joules, or one kilowatt-hour, a 100 watts bulb burning for an hour equals 3.6 mega joules. A mole of CO2 is about 44 grams or better than 1.5 ounces. Now I’m interested, as one kilowatt hour should get more than 13.6 ounces of CO2 to send on for processing. The pdf makes clear that this system can reduce the power to about 96% less energy than a thermal striping process. The authors note that new materials could well reduce the capital costs for manufacturing the new electrolytic stripping cells much below what they use in their economic analysis.
To temper ones excitement the pdf states, “. . .risks associated . . . are related to unverified performance characteristics of the unit operation. . . [A]dditional data are needed to verify efficiency, determine side steam demineralization requirements and identify life limiting aspects.” To say the concept is bankable for the future isn’t so just yet.
What makes the concept actually viable is the hydrogen production that takes place in the unit. Fuels, like we know them today in gasoline, propane and diesel are long carbon chains surrounded by hydrogen. To make fuel there will need to be a lot of hydrogen added. The Green Freedom concept offers that the electrolytic stripping will yield a hydrogen stream that can be sent on to be reformed into the fuel process. The expected hydrogen volume is calculated to be equivalent to about a third of that needed and would reduce the energy input.
This is the problem, freeing the hydrogen to be added as a feedstock consumes a lot of energy, making the Green Freedom process dependent on a source of cheap electricity. While atomic fission is proposed in the pdf the ability to get those plants on line is still difficult and rife with barriers.
On the other hand the known use and consumption of atomic fission output may well reduce the risks associated with investing in a fission facility. And off to the side is the prospect that one of the fission concepts can get into production, which would be an entire change to the calculation.
The diagram shows the trail of inputs and products for the Green Freedom process and the fuel manufacturing steps. Its known that the technology from the entry of the captured CO2 and freed hydrogen into the process are currently in use and easily adaptable to being feed from Green Freedom. We are looking for a working prototype next.
The stickler is going to be the capital cost and the electrical energy required. The Green Freedom concept looks good for a starting point and may prove to be a major player in recycling CO2 back into fuels. If innovation can get the electricity cheaper and the hydrogen freed more economically the price gap may close faster than we might think.
However, the starry eyed and conflict searchers will see a problem. Humanity will be competing with all the plant life on earth for the CO2! Wail and cry! Imagine man in competition with the plant kingdom. I’m laughing already, its not like we can’t get more freed carbon.