Can Biomimicry Be a Useful Tool for Design for Climate Change Adaptation and Mitigation? - Biotechnologies and Biomimetics for Civil Engineering - page 95

Every tonne of cement made in the process sequesters between 0.5 and 1.0
tonnes of CO 2 . This supposedly eliminates additional carbon emissions caused by
producing and transporting cement (Lovins and Cohen 2011 , p. 285; Nidumolu
et al. 2009 ; Andersen et al. 2011 ). The sea water used in the process is not polluted
and can be returned to the ocean or used as pre-treated water to make drinking
water through desalinisation because the hardness has been removed (McKeag
2010 ). Trace metals in emissions are also removed during the process and mercury
is captured and converted into a non-leachable form (Calera 2012 ). Calera has
developed several new processes to enable their system to work, one of which is a
process to create the alkaline solution needed for the electrochemical part of the
system. This uses one-third to one-fifth of the energy of comparable state-of-the-
art practices. Testing began in 2011 on the suitability of the products of the Calera
process for building and construction processes 8 and cement-based products have
been used in several demonstration projects. Non-structural applications (foot
paths, tiles) are likely to be end uses for the cement (Monteiro et al. 2013 ).
A final example of efforts to increase the sequestration of carbon using bio-
mimicry is illustrated by research conducted by Dr Jeffrey Brinker at the Sandia
National Laboratories in the United States, investigating how the abalone or paua
is able to grow a crack resistant shell approximately 200 % harder than human
ceramics using only sea water and a series of proteins (Brinker et al. 1999 ). The
research could lead to lightweight, extremely strong, optically clear building
materials (Sellinger et al. 1998 ) or to alternatives to concrete. Cement production
accounts for approximately 5 % of the world's anthropogenic CO 2 emissions
(Vanderley 2003 ). This process of biomineralisation stores carbon much like the
growing of forests locks carbon into the structure of the trees and soil until
released. The concept of a new material able to grow through self-assembly over a
structure, with the simple additive of sea water, by activating proteins on the
structure imitated from the abalone has been investigated, but results are not
available (Koelman 2004 ). Biomimetic biomineralistion is also discussed by
Vincent ( 2010 ) and Armstrong ( 2009 ).
The utilisation of detritus, or waste, is an important part of the process of cycling
nutrients and is a fundamental part of maintaining the health of an ecosystem. In
using biomimicry to address excess carbon in the atmosphere it may be possible to
use carbon as a resource rather than it being a source of pollution or waste. The
obvious example from biology is how plants utilise CO 2 during the photosynthesis
process, converting it into the products needed for plant growth and development,
such as cellulose. For plants, CO 2 in the correct quantities is a necessary resource,
rather than a pollutant. A company formed out of research by Dr Geoff Coates at
Cornell University called Novomer is mimicking this aspect of carbon sequestra-
tion in plants, by using CO 2 , mostly captured as factory emissions, as a resource for
new carbon-based polymers (McKeough 2009 ). The resulting plastics are 40 %

8

Compressive strength data is available on the Calera website: http://calera.com/ (accessed May
2014).