Date of release: Thursday, February 20, 2014
New research to turn seaweed into liquid biofuel aims to overcome two main barriers to the plant becoming a major source of renewable energy.
The University of Greenwich is a key player in a consortium of 12 UK universities and companies to develop manufacturing processes that can remove the high water content, and preserve seaweed for year-round use.
Ensilage – a method traditionally used by farmers to turn grass into hay for winter animal feed – has potential to stop the seaweed rotting. The research, backed by £1.6m from the Engineering and Physical Sciences Research Council, will also explore the conversion of wet seaweed to gas, which can in turn be converted to liquid fuel.
There is a global race on to develop the technologies to make seaweed a viable source of green power. The plant, a macroalga, turns sunlight into chemical energy three times more efficiently than land plants.
“Current biofuels may not be sustainable,” says Dr John Milledge, Research Fellow at Greenwich and an expert in the commercialisation of algae. “First generation fuels such as bioethanol from sugarcane and corn, or biodiesel from rapeseed and palm oil, are in direct competition with food for arable land and water. They have an adverse effect on food prices and supply.
“Salt-water algae are therefore a very attractive proposition as an alternative biofuel if we can overcome the challenges.”
Dr Milledge is working closely with group coordinator Professor Pat Harvey at Greenwich, which is responsible for finding out whether UK’s coasts can sustain large-scale biofuel production. The consortium is led by Durham University and builds on a range of the university’s previous collaborative projects, which span its departments of Chemistry, Biology, Earth Sciences, and the Durham Business School.
The consortium, known as MacroBioCrude, received EPSRC funding to establish an integrated supply and processing pipeline for the sustainable manufacture of liquid hydrocarbon fuels from seaweed. MacroBioCrude brings together researchers from six universities: Greenwich, Durham, Aberystwyth, Swansea, Harper Adams, and Highlands and Islands, as well as industrial partners Johnson Matthey Catalysts, Johnson Matthey Davy Technologies, Silage Solutions Ltd, Shell, and the Centre for Process Innovation (CPI).
Professor Pat Harvey, Head of Bioenergy Research, is responsible for developing an integrated and sustainable value chain built on macroalgae: under her leadership, the team at Greenwich will examine the energetic viability of a number of microalgal biofuel production scenarios, and identify the most critical parameters affecting net energy production to develop proposals for an optimised, sustainable large-scale process for the production of liquid fuel from seaweed; and the team from the Durham University Business School will focus on the equivalent socio-economic parameters.
Dr Milledge explains the importance of the ‘energy return on energy investment’ or EROI, in the research: “EROI is the ratio of the energy produced compared to the amount of energy invested in its product, and this net energy gain is central to any evaluation of biofuels. A ratio of less than one indicates that more energy is used than produced. We are aiming for an EORI greater than one.”