Recovery of excreted n-butanol from genetically engineered cyanobacteria cultures.pdf (804.12 kB)
Recovery of excreted n-butanol from genetically engineered cyanobacteria cultures: Process modelling to quantify energy and economic costs of different separation technologies
journal contribution
posted on 2018-12-03, 14:57 authored by Jonathan WagnerJonathan Wagner, Daniel Lee-Lane, Mark Monaghan, Mahdi Sharifzadeh, Klaus HellgardtThe photoautotrophic production of excreted biofuels from genetically engineered
cyanobacteria and microalgae represents a new and promising alternative to conventional
algal fuel technologies. N-butanol is a particularly promising fuel product, as it can be directly
used in petroleum engines, and has been successfully expressed in species of
Synechococcus elongates 7942 and Synechocystis sp. PCC 6803. However, the high energy
requirements of recovering butanol from dilute mixtures can easily outweigh the energy
content of the fuel and must be carefully assessed and optimized. Consequently, the recovery
of butanol was modelled using four of the most promising butanol separation technologies
(distillation, gas stripping, pervaporation and ionic liquid extraction) to calculate the minimum
butanol culture concentrations required to render the process energy-positive. With a breakeven
concentration of only 3.7 g L
-1
, ionic liquid extraction proved much more efficient than
the distillation base-case scenario (9.3 g L
-1
), whilst neither pervaporation (10.3 g L
-1
) nor gas
stripping (16.9 g L
-1
) could compete on an energy basis with distillation. Despite this, due to
the high costs of the ionic liquid solvent, the lowest capital costs are obtained for distillation
(pilot plant scale, butanol culture concentrations of 10 g L
-1
), whilst pervaporation carries the
lowest utility costs, as a result of its low electrical energy demand. Although currently achieved
maximum n-butanol culture concentrations are significantly below the calculated break-even
values for all four technologies, the present work provides an important threshold for future
strain development. Moreover, the recovery of side-products from purged biomass could help
to reduce the costs associated with biofuel production.
Funding
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 640720
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Chemical Engineering
Published in
Algal ResearchVolume
37Pages
92 - 102Citation
WAGNER, J.L. ... et al., 2019. Recovery of excreted n-butanol from genetically engineered cyanobacteria cultures: Process modelling to quantify energy and economic costs of different separation technologies. Algal Research, 37, pp. 92-102.Publisher
© ElsevierVersion
- AM (Accepted Manuscript)
Publisher statement
This paper was accepted for publication in the journal Algal Research and the definitive published version is available at https://doi.org/10.1016/j.algal.2018.11.008.Acceptance date
2018-11-22Publication date
2018-11-30ISSN
2211-9264Publisher version
Language
- en