The production of biofuel from cellulose may be attained before estimated by specialists. Embrapa Agroindústria de Alimentos, the food agroindustry unit of the Brazilian Agricultural Research Corporation (Embrapa), based in the southeastern Brazilian state of Rio de Janeiro, is carrying out studies for ethanol production from enzymes extracted from sugar cane bagasse and other agricultural and forest residues, such as wood.
Researcher Sonia Couri, who is in charge of the Laboratory for Fermentative Processes at Embrapa Agroindústria de Alimentos, said that some of the cane bagasse is currently burned in boilers. Nevertheless, she said that a large share of the residues might be used, through bioconversion using specific enzymes, namely cellulose, for ethanol production.
The researcher acknowledges that the process for obtaining the enzyme is not very simple. "Some biorefineries are already producing it, but costs are very high compared with alcohol production from cane or starch, which have a much lower price than this material, because it entails coupling with another process, the hydrolysis of cellulose," she explained.
Couri estimates that, in order to be viable, the cost of the process would have to be reduced 50-fold. Nevertheless, the aim of Embrapa is to produce an enzyme that is both effective and much cheaper than it is today.
The production of such an enzyme in Brazil will allow the country to reduce its dependence on imports and bring down the operational costs, since most of these raw materials are purchased abroad, and arrive at Brazil at a price three times higher than charged in their countries of origin, said Sonia Couri.
The cost reduction would be linked, according to her, to production incentives for those enzymes by national industries, especially the industry that will produce ethanol. "It depends very much on incentive policies and investment," according to the assessment of the researcher at Embrapa Agroindústria de Alimentos. In the United States, scheduled investments in the biofuels sector total approximately US$ 1 billion.
The state-owned organization, linked to the Brazilian Ministry of Agriculture, decided to carry out this study after an experiment, running since 1986, in production of cell lytic enzymes (rich in cellulose) for the food industry.
Various fruits, oleaginous plants, and seeds were studied, and oil was extracted from them through an aqueous system, using enzymes instead of an organic solvent, which is highly toxic.
Couri also highlighted the fact that the ethanol production process using cellulose enzyme involves cleaner technology, which does not harm the environment. "Any type of residue is less pollutant, as long as it is of vegetable origin," said Couri.
In order to enable the production of the microorganisms that produce the enzymes, the researcher said that Embrapa is also launching a large project to plant energy forests. A study will be conducted on the use of eucalyptus and pine forest residue for biofuels production, as well as other more conventional uses, she said.
Couri also announced that other research institutes, such as the University of Campinas (Unicamp), and the Chemistry Institute at the Federal University of Rio de Janeiro are also conducting research on biofuels production in Brazil, backed by the Studies and Projects Funding Body (Finep), the Brazilian Ministry of Science and Technology, and Petrobras.