Carbon adsorbents are very commonly used for adsorption applications and
their use dates back to 1600BC. Carbons can be prepared from a wide
variety of sources including coal (anthracite or brown coal), lignite, wood, nut
shall, polymers, and other biomass. These materials are first pyrolyzed and
carbonized to remove the volatile fraction and then activated by using gases
such as steam at or above 800°C. Alternative activation procedures using
inorganic chemicals is also widely practiced leading to a different pore sizes.
In all of these activated carbon processes, a pore size distribution is
produced. Micropores, mesopores, and macropores are all produced to
varying degrees and a vast amount of literature has sprung up on how to
determine and characterize pore size distributions. For gas storage
applications, it is not always desirable to have a range in pore sizes - storage
of gases (often methane or hydrogen) frequently requires the micropore size only
and hence a uniform microporous carbon would be highly desirable. In this
project we are attempting to create microporous carbons for gas storage which
contain a single size micropore of a well defined shape using inorganic
templating methods. Our application of the materials will be to hydrogen
storage and to this end, a equilibrium test unit has been constructed allowing
high pressure hydrogen adsorption to be measured.
For more information on this project, contact
Yunxia Yang or Paul Webley.