Biomassa e energia

Abstract

Biomassa e energia José goldemberg Universidade de São Paulo, São Paulo -SP, BrasilRecebido 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.

Influence of temperature and nutrient content on lipid production in freshwater microalgae cultures

“…The extensive use of fossil fuels is considered unsustainable because of its finite nature and the accumulation of carbon dioxide in the atmosphere (Plá 2002, Borges et al 2007, Walker 2009, Goldemberg 2009. From this, comes the need for effective options to replace these fuels with viable alternatives that are renewable, clean, inexpensive and sustainable.…”

Study of Alcohol Production Using as Feedstock the Cyperus esculentus (Tiririca)

“…7 Na atual conjuntura do mercado nacional de etanol, é notória a existência de uma competição entre a produção de açúcar e a de biocombustível, e desta forma cria-se a necessidade de buscar maneiras de minimizar a dependência da produção nacional de etanol em relação a cana-de-açúcar. 6,7 As fontes amiláceas são alternativas viáveis à obtenção do etanol combustível, porém, se faz necessário que a matéria-prima passe pelo processo de hidrólise prévia, cuja finalidade é a conversão do amido em açúcares fermentecíveis. 8 A hidrólise pode ocorrer pela rota enzimática, empregando as enzimas amilases, ou pela rota química, que utiliza ácidos inorgânicos.…”

Tar Removal From Biomass Gasification Streams: Processes and Catalysts

“…1,2 No entanto, o gás combustível gerado no processo de gaseificação deve ser purificado de forma a atender aos critérios de qualidade para as diversas aplicações. Dentre os contaminantes gerados estão: sulfeto de hidrogênio, amônia, metais, alcatrão, entre outros.…”