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Biofuels, Science and Society

Abstracts and Presentations

Session 4 - 'Environmental Considerations'

'Microalgae, Biofuels and how to Kill an Ecosystem'

Professor Kevin J. Flynn
Centre for Sustainable Aquatic Research, Head of Biosciences Department, Swansea University

The modification of microalgal physiology in order to optimisation biofuels production could entail a series of steps. An analysis of various physiological features, conducted using a comprehensive multinutrient, photoacclimative mechanistic model of microalgae operated under different scenarios, identifies the following desirable traits. A high potential growth rate, a low potential for photoacclimation (restraining the "greenness" of the algal suspension), low need for phosphate (a nutrient predicted to become increasingly limiting as rock phosphate is exhausted), and a low need for nitrogen (leaving more scope within the cells for elevated levels of carbohydrate and lipid for biofuels). These features do not co-occur in natural organisms, and indeed the limitation of "greenness" appears an unstable trait if it were developed in genetically modified (GM) algae. While such a GM organism could raise biofuels production greatly, simulations in which such an organism is released into nature indicates that blooms of this organism would be able to grow to higher densities than could wild species, and more importantly would become ungrazable due to stoichiometric constraints in predator-prey interactions. Extreme caution should be exercised in developing GM microalgae for biofuels applications as it would be all but impossible to contain such a microbe.

 

'Making Biofuels Sustainable'

Professor Gail Taylor
Centre for Biological Sciences, University of Southampton

Several recent reports suggest that bioenergy is likely to play an increasing role in the growth of renewable, low carbon technologies that enable the UK to meet stringent emission reductions for the major greenhouse gases (GHGs). At the same time, there are many concerns that land use for bioenergy may be at the expense of that for food crops, that bioenergy crops have a high water footprints and that other negative environmental impacts are likely, including carbon stock losses from disturbed soils and indirect effects on land-use. This talk will address the evidence underlying some of these claims and propose that ‘home-grown' second generation feedstocks provide an option to supply some of the likely future demand for bioenergy and that this may not necessarily be at the expense of land for food. Crops such as short rotation coppice and energy grasses have an improved GHG balance relative to arable crops and may be grown on poor-quality land and yet at the same time, can act to improve farm-scale biodiversity. Water-use remains a known unknown but current research is unravelling how these crops use water in relation to other land uses. Research from recent (TSEC-BIOSYS) and on-going (Carbo-BioCrop and EUROCHAR) projects will be presented.

‘Energy Security in an Emission-Constrained World - The Potential for Alternative Fuels‘

Tara Shirvani
Smith School of Enterprise and the Environment, University of Oxford

The search for alternative fuels is relentlessly underway with 90% of transport fuels being hydrocarbon sourced and uncertainty around depletion levels of conventional oil reserves mounting. Global vehicle ownership is forecast to reach two billion in the near future and climate change concerns, induced by anthropogenic GHG emissions, are expected to rise. Liquid fuels derived from gas, coal or unconventional oil sources may be able to offset the input problem of diminishing oil supplies, but inevitably exacerbate the output problem of GHG emissions. Biofuels can be a viable substitute for fossil fuels, most notably when produced in a sustainable manner and from feedstock which is not in direct competition with food or animal feed. Algae based fuel products in particular, have proven to be a more promising alternative which can avoid the issues faced by first generation biofuels from food crops, by excluding land use and food security issues.