Biofuels and CO₂ neutrality: an opportunity

Abstract

CO₂-neutral bioprocesses are of immanent concern and can be coupled by using integrated bioprocess and biofuel production systems. Existing biofuel generations are, therefore, reclassified according to the current possible bioprocessing routes. Only the first biofuel generation has been successfully carried into a commercial scale, while the second is still being improved at laboratory scale or in pilot-scale processes. Biodiesel and biohydrogen, as third- and fourth-generation biofuels, respectively, are also being studied at the laboratory scale. Here, we introduce the fifth biofuel generation, which is based on biological CH₄ production from gaseous raw materials. The integration of bioprocess systems and the coupling between different biofuel generations under CO₂ neutrality is analyzed and presented to be of great interest for industry and science. Value-added production (i.e., recombinant proteins) can be coupled to CO₂-neutral integrated biofuel production systems and, hence, integration of different biofuel generations within a biorefinery concept could be translated into a reality.

Acknowledgements

E Martinez Porqueras has been awarded an annual fellowship from the Spanish financial institution Caja de Ahorros y Pensiones de Barcelona, ‘la Caixa’.

Financial & competing interests disclosure

The investigation, optimization and scale up of an integrated biofuel production system is being carried out by the working group of BioProcess Technology at the Vienna University of Technology, financially supported by Österreichische Forschungsförderungsgesellschaft (Grants 830003 and 830004). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.