TITLE Development of hydrogen storage materials using carbon nanofiber obtained from Wood-base biomass
(Joint Program to Promote Technological Development with the Private Sectors)
AUTHOR

RITE-TAKASAKI LABORATORY in Gun Ei Chemical Industry Co.,Ltd.

SOURCE    
ABSTRACT

The aim of this development was to reduce CO2 emission utilizing wood-base biomass that is currently incinerated in large quantities in the world. This development is composed of 1) liquefaction and resinification of wood-base biomass, 2) spinning of carbon nanofiber out of the said resin, and 3) utilizing the nanofiber as hydrogen storage material. This development is set out as 3-year term project and the project implementation of last year is as follows.

(1) Liquefaction technology of wood-base biomass

In 2001, wood-base industrial wastes originated resin was obtained that can be used as a raw material for fiber. However, the stability of fiber spinning was depending on the kinds of wood-base industrial wastes. Then, a control of a molecular weight distribution of resin was studied for the stability of fiber spinning. As a result of our study, by controlling a molecular weight distribution of resin, carbon nano fiber of the same quality was obtained, and it was not dependent on kinds of wood-base industrial waste as materials.

(2) Mass production technology of carbon nanofiber

Solution of pyrolytic carbon adhesion

When the complex fiber as a precursor of carbon nanofiber that is a mixture of resin based on wood-base biomass and polyethylene is carbonized on a pilot scale, pyrolytic carbon adhered to carbon nanofiber. This was caused by the decomposed products of polyethylene which remains in electric furnace. Then, how to remove the decomposed products of polyethylene from the electric furnace was studied. Consequently, polyethylene fragment was completely removed by the heat-treatment of complex fiber at 400-500 degrees C in the furnace.

Study of curing time for complex fiber

A study of curing time for complex fiber as a precursor of carbon nanofiber, that is a mixture of resin based on wood-base biomass and polyethylene, was carried out. Curing time for complex fiber was found to be shorter than conventiona l phenolic resin fiber by our study.

(3) Improvement of hydrogen storage ability

Activation of nanofiber

Improvement of hydrogen storage ability of carbon nanofiber by increasing surface area by activation of nanofiber was carried out. Hydrogen storage ability of carbon nanofiber was not improved yet.

Drawing the nanofiber

Improvement of hydrogen storage ability of carbon nanofiber by increasing surface area by drawing fiber was carried out. Hydrogen storage ability of carbon nanofiber was improved to 0.5wt% under 35 atm at 25 degrees C. But, hydrogen storage ability of carbon nanofiber did not reach target value (6.5wt%).

Platinum dispersion on nanofiber

Improvement of hydrogen storage ability of carbon nanofiber by dispersion of platinum (which is known to have hydrogen adsorption ability) on nanofiber, was tried. Hydrogen storage ability of carbon nanofiber was improved to 0.5wt% under 35 atm at 25 degrees C. But, hydrogen storage ability of carbon nanofiber did not reach target value (6.5wt%).

Carbon nanofiber made from wood-base industrial waste was obtained by our three years investigation. But, we have not developed hydrogen storage materials, which has enough ability. However, we were able to find out a possibility that this carbon nanofiber could apply to another application, for example, electric double layer capacitor etc.