ClipperCreek to Supply Power Control Stations for Tesla Motors
BMW Study on Rankine Cycle for Waste Heat Recovery Shows Potential Additional 10% Power Output at Highway Speeds

Activated Carbon with High Gravimetric Hydrogen Storage

Researchers at the Chinese Academy of Sciences have developed a type of activated carbon with a high surface area of up to 3,190 m2 g-1 and a gravimetric hydrogen uptake capacity of 7.08 wt % at 77 K and 20 Bar—one of the largest for porous carbon materials. The results suggests that porous carbon with large amounts of active sites, high surface area, and high micropore volume related to optimum pore size could achieve high gravimetric hydrogen storage.

Wang
Hydrogen uptake of different activated carbons. Credit: ACS. Click to enlarge.

The activated carbons may also possess wide application in fields ranging from catalysts to energy conversion, the researchers noted. A paper on their work was published online 30 April in the Journal of the American Chemical Society.

There are two general types of activation procedures, physical and chemical. Physical activation involves gasification of the carbon materials in the presence of suitable oxidizing gasifying agents, such as CO2 and steam. Chemical activation relies on the reaction between a chemical agents such as KOH (potassium hydroxide) and the carbon materials.

Huanlei Wang, Qiuming Gao, and Juan Hu used both approaches in the study. They found that compared to CO2 activation, KOH activation can “remarkably” change pore structures of the activated carbon.

An enhanced hydrogen uptake of 7.08 wt % was successfully achieved for the as-obtained porous carbon AC-K5 at 77 K and 20 bar. The results indicate that the second activated carbons are promising materials for hydrogen storage, and higher gravimetric hydrogen uptake could be obtained if one can improve the microporosity with high surface area related to optimum pore size distribution and increase the number of active sites.

—Wang et al. (2009)

Resources

  • Huanlei Wang, Qiuming Gao, and Juan Hu (2009) High Hydrogen Storage Capacity of Porous Carbons Prepared by Using Activated Carbon. J. Am. Chem. Soc., Article ASAP doi: 10.1021/ja8083225

Comments

SJC

Maybe I am interpreting this wrong, but the graph looks like 7% of weight at 20 bar. If I have 200 pounds of the carbon, I can get 14 pounds of hydrogen at only 300 psi. This would be over 6 kg of H2 at much lower pressure?

Henry Gibson

When ethanol is fermented, CO2 is formed and it can be combined with hydrogen to make methanol which should be the standard reference fuel for cars. And all new cars should be able to run on straight methanol. Many car races required the use of methanol until the corn lobby came calling.

Perhaps a yeast will be found that can produce Butanol from hydrogen and CO2, then it can be the standard fuel for cars. The hydrogen is very dense in both of these zero net carbon fuels, and more dense than liquid H2. ..HG..

Calvin Brock

vated carbons may also possess wide application in fields ranging from catalysts to energy conversion, the researchers noted. A paper on their work was published online 30 April in the Journal of the American Chemical Society. http://bestporeminimizers.org/how-to-minimize-pores-effectively/

The comments to this entry are closed.