Industrialisation of saline cultivation for second-generation biofuels: progress and challenges

ABSTRACT

Heavy reliance of anthropogenic activities on fossil fuel is blamed for ever-increasing greenhouse gas emission and hence climate change. Biofuels appear to be a promising strategy for mitigating the environmental impact from emissions. However the current system of first-generation feedstock is straining the supply of food in developing nations. Therefore, it is more sustainable to use second-generation feedstock that do not use edibles but inedible crops. Considering the scarcity of fresh water reserves as well, saline cultivation has been suggested to back this up. However, attempts to industrialise saline cultivation have been intermittent. Carl Hodges’ vision of an integrated saline biofuel facility, who was a pioneer of saline cultivation projects for biofuel, was promising but still has not come to fruition. Despite the relative abundance of scientific studies into saline cultivation, the progress and challenges of industrialisation of such feedstock for biofuel production have not been reviewed so far. Saline cultivation needs to be bought into the realm of industrial engineering if it is expected to provide enough energy supply to make a difference to the global energy situation. This article reviews what is known about the various difficulties that brought about the failure of these projects. Recommendations will thus be made about what must be done to make progress in industrialising saline biofuel feedstock.

KEYWORDS:

• Second-generation biofuel
• saline cultivation
• halophyte crop
• saline aquaculture
• Hodges’ policy of developing Salicornia

Acknowledgements

We especially thank Prof. Frank W. Judd at The University of Texas Rio Grande Valley for his kind help and comments during the revision of this work.