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24/01/2011
Segundo o prof. Petri Kukkonen - Diretor de Desenvolvimento de Negcios da
UPM-Kymmene Corporation - muitos especialistas dizem que o mal que os
biocombustveis de primeira gerao causam ao nosso planeta pode ser maior do
que o bem. Alm do mais, outros especialistas citam que o desvio mesmo que
parcial de alimentos para a produo de biocombustveis est gerando um aumento
recorde no preo dos leos comestveis, acar e de outros alimentos no mercado
e a crescente especulao nas bolsas.
Com isto, como diversas outras
empresas e entidades, a UPM da Finlndia tambm est investindo em tecnologias
de segunda gerao para transformar biomassa em combustveis lquidos. Segundo
ele, a criao de diesel sinttico e de outros bioqumicos a partir de resduos
florestais representa uma oportunidade fundamental e brilhante e que,
certamente, mudar em curto tempo a geografia econmica e energtica dos
pases.
No Brasil, a grande vantagem das usinas de cana que essas novas
tecnologias, no primeiro momento, podem ser incorporadas aos processos atuais.
Isto permitir, por exemplo, utilizar os elevados volumes de C02 gerados no
processo industrial de fermentao em biorreatores de algas, proporcionando uma
produo adicional de at 30,0% mais de etanol com 01 tonelada da mesma cana. Em
pouco tempo, tambm ser possvel processar o bagao para a produo total ou
parcial de etanol.
Tambm com tais tecnologias, proximamente, nossos
grandes complexos de eucalipto do interior, ou mesmo de locais que chovam abaixo
de 1.200 mm/ano (o menor nvel para a celulose), sero inteiramente viabilizados
ao poderem produzir, de forma sustentvel, elevados volumes de diesel sinttico
mais eletricidade e/ou mais gases industriais raros e, melhor, prximos s
cidades do interior e em franco desenvolvimento, ou mesmo para
exportaes.
Vejamos as definies e as possibilidades reais (no mais
experimentais) de cada configurao tecnolgica:
BIOMASSA - Um termo
abrangente que significa qualquer fonte de carbono orgnico (materiais de
plantas) que renovado rapidamente como parte do ciclo do
carbono.
COMBUSTVEIS DE PRIMEIRA GERAO - Combustveis feitos de
produtos alimentcios com alto contedo de amido (por exemplo, beterrabas,
cana-de-acar, batatas) ou de leo (leo de soja, leo de
canola).
COMBUSTVEIS DE SEGUNDA GERAO - Combustveis de fontes
lignocelulsicas (por exemplo, resduos florestais). Os materiais de segunda
gerao sero convertidos em combustveis lquidos por meio da tecnologia BTL
(vide a seguir).
ETANOL - O etanol produzido pela fermentao do acar
de plantas em uma soluo aquosa, que depois separada por destilao. Uma
mistura normal de 10% de etanol de milho na gasolina dos EUA pode reduzir as
emisses totais de CO2 em seu ciclo de vida, da origem descarga dos
automveis, em cerca de 3% (recente foi autorizado o aumento para 15% da
mistura). No Brasil, a atual gasolina tem 25% de lcool anidro e 20% de nossa
frota de veculos leves movida por puro etanol (lcool
hidratado).
COMBUSTVEIS DE TERCEIRA GERAO - Iguais aos de segunda
gerao, mas tambm utilizando microalgas, cianobactrias geneticamente
alteradas (GMO) e enzimas para ainda maiores produes de biocombustveis em
menores espaos de tempo. Estes projetos j se encontram em fase de produo e
comercializao, e no mais experimental, em alguns pases como na Dinamarca,
Alemanha e Canad.
GASEIFICAO - Processo que converte materiais que
contm carbono (hidrocarbonetos) em monxido de carbono mais hidrognio, ao
reagir os materiais a altas temperaturas (> 700C) com uma quantidade
controlada de oxignio. A mistura gasosa resultante chamada de gs de sntese,
sendo matria prima para inmeros processos e aplicaes industriais.
GS
DE SNTESE - Gs de sntese criado durante o processo de gaseificao. O gs de
sntese limpo e a razo de hidrognio e monxido de carbono ajustada antes
da converso para combustvel sinttico no processo F-T.
FISCHER-TROPSCH
(F-T) - Reao qumica catalisada na qual o monxido de carbono e hidrognio so
convertidos em hidrocarbonos lquidos de vrias formas. O processo F-T uma
tecnologia j estabelecida e aplicada em larga escala ao carvo e ao gs
natural.
BIOMASSA-PARA-LQUIDOS (BIOMASS-TO-LIQUIDS, BTL) - Combustveis
sintticos produzidos a partir do gs de sntese da transformao e liquefao
de componentes da biomassa. Sua fonte de matria prima pode ser a biomassa, mas
tambm uma srie de resduos orgnicos, urbanos e industriais, inclusive lixos,
esgotos, restos culturais, serapilheira etc. Uma vantagem deste processo a
possibilidade de se produzir combustveis similares aos fsseis (chamados de
diesel sinttico). Portanto, podem ser usados nos sistemas existentes de
distribuio de combustvel e motores padronizados, ao contrrio do que acontece
com o biodiesel. Tambm, no reduzem a produo de alimentos e no contribuem
para a ainda maior fome dos povos.
WELL-TO-WHEELS (ciclo de vida completo
dos biocombustveis, desde a origem descarga do automvel) - Os
biocombustveis tm o potencial de diminuir as emisses de gases do efeito
estufa porque as plantas das quais so feitos absorvem CO2 durante o
crescimento. O levantamento do impacto do ciclo de vida chamado de estudo
well-to-wheels e calcula o valor lquido de CO2 emitido/retirado da atmosfera
entre o crescimento da planta e as emisses da descarga dos veculos.
No
Mundo e no Brasil, alguns cientistas, Entidades e Empresas, ainda continuam
negando tais realidades j pujantes em pases concorrentes, mas, no final de
2010, o BNDES (o Banco de Desenvolvimento do Brasil) publicou importante e
completo estudo em portugus e em que recomenda a necessidade de o Pas e de
suas Empresas ficarem mais atentos s tais possibilidades e riscos (vide em:
http://www.bndes.gov.br/SiteBNDES/export/sites/default/bndes_pt/Galerias/Arquivos/conhecimento/bnset/set32101
.pdf).
Concluindo, resta a pergunta: Como e quais de nossas Empresas
Energticas (incluindo usinas de cana e petroleiras) esto, realmente,
preparadas para tais realidades e concorrncias?
Fonte:
Prof.
Climaco Cezar de Souza e co-autores
AGROVISION Brasilia
Is Brazil ready for the reality and competition of fuels of the second and third generation?
According to prof. Petri Kukkonen - Director of Business Development at
UPM-Kymmene Corporation - many experts state that the evil, caused by the first
generation of biofuels, to our planet can be greater than the good. Moreover,
other specialists stated that even a partial substitution of food by biofuel
production is generating a record increase in the price of edible oils, sugar
and other foods on the market and causing growing speculation in the major
Commodities Exchanges.
With this, like several other companies and
entities, UPM of Finland is also investing in second generation technologies for
transforming biomass into liquid fuels (BTL). According to Kukkonen, the
creation of synthetic diesel and other biochemicals from forest residues
represents a major and brilliant opportunity to change in a very short time the
economic geography as well as energetic patterns of countries.
In Brazil,
the greatest advantage for the sugarcane mills is that these new technologies,
in a first step, may be incorporated into current processes. This allows, for
example, the use of high volumes of C02 generated in the industrial process of
fermentation in bioreactors of algae, providing an additional production of up
to 30.0% more ethanol with 01 tonne of the same cane. Consequently, you can also
process the bagasse for the production of all or a part of ethanol.
Also,
with such technology, in the near future our large complexes of eucalyptus in
the interior of Brazil, or even places that have an average precipitation below
1,200 mm / year (the lowest level for pulp), will be fully enabled to produce,
in a sustainable manner, high volumes of synthetic diesel and more electricity
or rarer industrial gases and, better, close to the inner cities in rapid
development, or, as a further alternative, even for exports.
Consider the
definitions and the current opportunities of each technology
configuration:
BIOMASS - A comprehensive term that means any organic
carbon source (plant material) that is rapidly renovated as part of the carbon
cycle.
FIRST GENERATION FUELS - Fuels made from grains or food products
with high content of starch (eg. sugar beet, sugarcane, potatoes) or oil
(soybean oil, canola oil).
SECOND-GENERATION FUELS - Fuels from
lignocellulosic sources (eg. forest residues, bagasse, algae produced in
bioreactors). These raw materials of the second generation are subsequently
converted into liquid fuels during two distinct processes: a) hydrolysis (acidic
or enzymatic) of lignocellulosic materials, or b) termo-chemical transformation
(gasification, pyrolysis or catalytical depolimerisation) of the biomass, a
process also referred to as Biomass- To-Liquids (BTL).
ETHANOL - Ethanol
is produced by fermentation of sugar plants (eg. sugarcane, corn) in an aqueous
solution, which is then separated by distillation. Adding 10 % of ethanol into
U.S. gasoline can reduce total CO2 emissions in its life cycle, from birth to
discharge the car about 3% (the recent increase was authorized for 15% of the
mixture). In Brazil, actual gasoline has 25% of anhydrous alcohol (ethanol) and
20% and our fleet of light vehicles is driven by pure ethanol (hydrated
alcohol).
THIRD GENERATION FUEL - Uses as raw material microalgae and
cyanobacteria which are genetically enhanced to achieve even greater production
values of biofuels in small amounts of time. These projects are being currently
in demonstrative stage in some countries like USA, Germany and
Brazil.
GASIFICATION - The process which converts materials containing
carbon (hydrocarbons) to carbon monoxide plus hydrogen by reacting the materials
at high temperatures (> 700 C) with a controlled amount of oxygen. The
resulting gas mixture is called synthesis gas, being raw material for many
industrial applications and processes.
SYNTHESIS GAS - Gas created during
the gasification process. The synthesis gas is cleaned and the ratio of hydrogen
and carbon monoxide is set before conversion to synthetic fuel in the FT
process.
FISCHER-TROPSCH (FT) - Catalyzed chemical reaction in which
carbon monoxide and hydrogen are converted into liquid hydrocarbons of various
forms. The FT process is an established technology and widely applied to coal
and to natural gas.
BIOMASS-TO-LIQUIDS (BTL) It refers to synthetic
fuels that are produced from the processing of synthesis and liquefaction of
biomass components. The principal source of raw material can be biomass, but
also a series of organic wastes, of urban and industrial nature, including
garbage, sewage, debris, litter, etc.. An advantage of this process is the
possibility of producing fossil fuels similar to synthetic diesel. Therefore,
they can be used in existing systems of distribution of fuel in standard
engines, unlike the case with biodiesel. Also, they do not reduce food
production and do not contribute to problems of mal-nutrition in poor
countries.
WELL-TO-WHEELS (full life cycle of fuels, from the origin to
the discharge of the car) - Biofuels have the potential to reduce emissions of
greenhouse gases because the plants from which they are made absorb CO2 during
their growth stages. The survey of the impact of the life cycle study is called
well-to-wheels - and calculates the relation between the CO2 emitted with the
amount of CO2 removed from the atmosphere between the growth of the plant and
the emissions of vehicles.
Worldwide, in general, and in Brazil, in
particular, some scientists, institutions and enterprises, continue to deny
these realities which were already successfully implemented in competing
countries, but at the end of 2010, BNDES (The Development Bank of Brazil) has
published an important and comprehensive study in Portuguese which recommends
the need for the country and its companies to become more aware of these
opportunities and risks (see at:
http://www.bndes.gov.br/SiteBNDES/export/sites/default/bndes_pt/Galerias/Arquivos/conheci
mento/bnset/set32101.pdf).
In conclusion, the question remains: Which of
our energetic companies (including sugar cane mills and Oil industries) and how
far are they really prepared for such situations and
competitions?
Fonte:
Prof. Climaco Cezar de Souza e
co-autores
AGROVISION Brasilia
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