Supplies of oil and natural gas are decreasing quickly.
However, the renewable energy sector seems not to grow
quickly enough to assure the present energy consumption rate.
Coal is considered a very dirty fuel, but its reserves are quite
abundant. Coal reserves are finite, but clean efficient coalbased
energy technology can give more time for transformation
into post-fossil fuel world.
The paper discusses a very ambitious idea of such a
technology, which was proposed a few years ago by ZECA
Corporation . However, after some time of development the
project has effectively stopped .
In this project the concept of coal power plant is totally
changed. Instead of being combusted, coal is gasified, then
hydrogen is produced, which feeds stacks of solid oxide fuel
cells (SOFC). Cyclic CaO/CaCO3 reaction is employed to
enhance hydrogen production and to separate carbon dioxide.
Virtually no pollution is emitted. All carbon dioxide is
produced as clean, concentrated and easy for sequestration
stream. SOFC by-product - heat is carefully recycled and
improves overall efficiency of the process, which can reach
The paper discusses various technical requirements, which
must be met, before the project comes to life.
These technical issues are mainly connected with
requirements for SOFC (very high operating temperature, high
sulphur tolerance, integrated heat exchanger) and CaO/CaCO3
process (performance decreases with the number of cycles and difficulties arise with heat transport into calcination vessel).
Although technical difficulties are discussed on basis of ZECA
Corporation project, the issues have rather universal character
and is very likely that identical or similar problems will appear
in other concepts of clean efficient coal technology.