Page 19 - Biofuels for a More Sustainable Future

12 Biofuels for a More Sustainable Future

this reason, this technology is in the developing stage as of today. However,
if successfully validated in the future, it could be used to geosequester CO 2
by storing it in old oil and gas fields or saline aquifers. In this way, through
carbon capturing and storage, the fourth generation biofuels production
could be called carbon negative rather than carbon neutral. Thus environ-
mental advantages arise both from carbon storage and from replacing fossil
fuels with biofuels (University of Edinburgh, n.d.).
The remaining fuel from oxy-fuel combustion is cleaned and liquefied
and yields ultraclean biohydrogen, biomethane or synthetic biofuels that
can be used in the transport sector as well as for electricity generation.
Another potential technological combination for biofuels production has
been proposed by the Joule company with their renewable solar fuel gen-
eration (Fig. 1.4).
The company developed a process for hydrocarbon-based fuel genera-
tion through the application of nonfresh water, nutrients, cyanobacteria,
carbon dioxide, and sunlight. The process is based on helioculture using
photosynthetic organisms; however, it is distinct from the traditional
algae-based fuel in that the latter need to be refined into fuel, while helio-
culture directly produces fuel (either ethanol or hydrocarbons) not requiring

Fig. 1.4 Joule helioculture renewable solar fuel. (From St. John, J., 2010. Joule
Patents Secret Sauce for Diesel-Excreting Organisms. 2010. GigaOm, September 14.
https://gigaom.com/2010/09/14/joule-patents-secret-sauce-for-diesel-excreting-organisms
(24 November 2018).)