March 2019
Volume 71    Issue 3

Updated look at the DCFC: the fuel cell technology using solid carbon as the fuel

Behling, Noriko Hikosaka; Managi, Shunsuke; Williams, Mark C.


Full-text paper:
Behling, N.H., Managi, S. & Williams, M.C. Mining, Metallurgy & Exploration (2019) 36: 181.

Whatever the social, political and environmental implications, carbon remains the world’s primary energy carrier and energy source. Coal, petroleum and natural gas, all sources of carbon, are extracted, refined and transported — energy carriers (carrying their energy) — to the electric power and transportation industries that use them as their energy source or fuel. The chemical energy of carbon is transformed through energy conversion networks (ECNs) into other energy forms, such as electricity, kinetic energy, heat, light, other fuels and energy carriers. For example, coal is combusted to make steam for steam turbine generators, which provide electricity. Fuel cells are one type of ECN that can operate directly on hydrogen, ammonia, methanol, methane and other fuels or energy carriers. In a fuel cell, most of the chemical energy in these fuels is directly, electrochemically converted to electrical energy. Most fuel-cell development has centered on developing fuel cells that operate on hydrogen or reformed methane. Most of the world’s hydrogen comes from the steam reforming of methane into hydrogen and carbon dioxide. This steam reforming process is only 85 percent efficient. The hydrogen fuel cell itself is theoretically only 80 percent efficient in extracting the chemical energy of hydrogen into electricity. The overall efficiency is 65 percent. It would be much more efficient to directly convert solid carbon to carbon dioxide in a direct carbon fuel cell (DCFC). The maximum intrinsic efficiency of the solid carbon to carbon dioxide is nearly 100 percent. This would be a 40 percent fundamental improvement in thermal efficiency if fuel cells could directly operate on carbon (see Fig. 1).


Follow these easy steps if you are an SME member:
  • Go to . Sign in with your email address and password.
  • Hover your mouse over “Publications and Resources” in the top banner. Click on “Mining, Metallurgy & Exploration (MME) Journal” in the pull-down menu.
  • Scroll down and click on the “Read the MME Journal Online” button, which will take you to the Springer site as an SME member who is eligible for free access. (To see published papers on the Springer site, click on “Browse Volumes & Issues” in the blue banner.)
If you are not an SME member, go to for paid access. Or join SME at