Biomassa e energia

Quim. Nova, Vol. 32, No. 3, 582-587, 2009
Biomassa e energia
José Goldemberg
Universidade de São Paulo, São Paulo - SP, Brasil
Recebido em 2/12/08; aceito em 20/2/09; publicado na web em 17/3/09

BIOMASS AND ENERGY. Biomass was the dominating source of energy for human activities until the middle 19th century, when coal, oil, gas and other energy sources became increasingly important but it still represents ca. 10% of the worldwide energy supply.
The major part of biomass for energy is still “traditional biomass” used as wood and coal extracted from native forests and thus nonsustainable, used with low efficiency for cooking and home heating, causing pollution problems. This use is largely done in rural areas and it is usually not supported by trading activities. There is now a strong trend to the modernization of biomass use, especially making alcohol from sugar cane thus replacing gasoline, or biodiesel to replace Diesel oil, beyond the production of electricity and vegetable coal using wood from planted forests. As recently as in 2004, sustainable “modern biomass” represented 2% of worldwide energy consumption. This article discusses the perspectives of the “first” and “second” technology generations for liquid fuel production, as well as biomass gaseification to make electricity or syngas that is in turn used in the Fischer-Tropsch process.

Keywords: biomass; energy.

INTRODUÇÃO
A produção de energia no século 20 foi dominada por combustíveis fósseis (carvão, petróleo e gás) que representavam ainda no início do século 21, cerca de 80% de toda a energia produzida no mundo.1 Figura 1. Oferta de energia primária no Brasil em 20042

Além dos combustíveis fósseis, energia nuclear e energia hidroelétrica tinham pequenas participações, bem como as novas fontes renováveis de energia (solar, eólica, geotérmica e pequenas centrais hidroelétricas) que são as mais atraentes do ponto de vista ambiental, mas que lamentavelmente representavam