In 2020, 10 % of the fuel consumed for transport in Europe should be of renewable origin. To achieve this goal, the EU has just acquired a new tool, the Novel high-performance enzymes and micro-organisms for conversion of lignocellulosic biomass to bioethanol (NEMO) project, coordinated by Merja Penttilä, a researcher at the Valtion Teknillinen Tutkimuskeskus (VTT), the Technical Research Centre of Finland. This aims to facilitate production of second generation biofuels from agricultural and forestry waste. This is in contrast to first generation biofuels that, apart from having a questionable ecological balance, are often made from food products such as cereals and thereby add to price pressure on these resources and threaten the social and political stability of the poorest countries.⁽¹⁾ While the EU wants to guarantee its role in this field of strategic research, it is also counting on new projects of this kind to improve its future energy independence.

Ecology goal

No fewer than 18 partners in nine European countries (Germany, Belgium, Finland, France, Italy, the Netherlands, Slovenia, Sweden and Switzerland) are partners in the NEMO project with its mix of universities, research centres and private companies such as Green Sugar, a small business based in Germany. “Thanks to our contacts with Frankfurt University (DE), we were invited to a NEMO project meeting, where we were able to see that we had converging interests,” explains Frank Kose, project leader at Green Sugar. The research budget, scheduled over four years, is EUR 8.25 million, 5.9 million under the Seventh Framework Programme’s “Food, Agriculture and Fisheries, Biotechnology” theme that is concerned with development and the bio-economy.

The second generation biofuels that NEMO aims to develop are based on the use of plant lignocellulose. As this is found in all plant cells it means that the whole of the plant can be used, thus stems and leaves, residue (straw) and green waste when plants are cut or pruned. The edible part of the plant is therefore no longer the only part that can be used to make biofuel. This effectively ends the ‘eat or drive’ alternative inherent in the first generation. What is more, using plant waste in this way offers economic benefits.

Converting green waste

The researchers will seek to develop new ways of converting the lignocellulose (consisting of lignin, cellulose and hemicellulose) present in agricultural and forestry waste into liquid biofuel. This will normally be done in four stages: preprocessing, extraction, fermentation and distillation.

The preprocessing of lignocellulose serves to break down the very solid lignin to extract cellulose and hemicellulose molecules and obtain glucose from them. Fermenting the glucose using yeast then produces ethanol, an alcohol that when distilled will be used to produce the biofuel.

NEMO will concentrate essentially on the first stage. “Its main objective will be to convert the cellulose and hemicellulose carbon chains into simple sugars such as glucose, using new types of enzymes. This is known as saccharification,” explains Frank Kose. These enzymes are proteins that speed up the chemical reactions and make it possible to convert molecules into different molecules. The other advantage is that these have a low toxicity for the microbes that control the glucose fermentation. “For each enzymatic approach it is necessary to carry out a preprocessing to prepare the biomass for the action of the enzymes. The technology developed at Green Sugar, which is based on the use of inorganic acids, could increase their efficiency,” explains the project leader.

In addition to its scientific aims, NEMO is also seeking to verify that the enzymes that come out of the laboratories will be sufficiently effective to be used in industrial processes of interest to companies. “Our commitment is of course motivated by economic considerations,” explains Frank Kose. “We want to develop a saccharification technology that, in the future, can be installed in factories able to produce between 50 000 and 100 000 tonnes of sugar a year. To achieve this goal, we need major industrial partners. If NEMO develops a new technology to convert cellulose using enzymes and if this includes the Green Sugar technology, industrialists involved in the project will use this and for us that will amount to selling our know-how”.

It is in this way that NEMO is attracting the interests of industry as well as research. Because, in addition to hoping to help resolve the global energy problem, it is also a question of winning a share of the biofuel market, a fast-growing sector of the economy. What is more, not waiting for NEMO to realise its promises, a third generation of biofuels is already beginning to take shape. Based, among other things, on the extraction of oils from algae, this technology is also trying to emerge from the confines of the laboratory.

Stéphane Fay

1. See the article From promises to doubts in our April 2008 special issue Extracting ourselves from oil.