LIMA, E. E.; http://lattes.cnpq.br/7552463845937226; LIMA, Ezenildo Emanuel de.
Abstract:
At present, researches about the second generation biofuels; in this case, the cellulosic
ethanol extracted from biomass, has been appointed as the focus of several studies in
Brazil and all over the world. The cellulosic ethanol is generally produced by
fermentation of fermentable sugars that are obtained using the process of acid or
enzymatic hydrolysis of lignocellulosic materials. As raw material for this chemical
process, several biomass are available, however, it is necessary to use cultures that have
high cellulose content, low cost and it could be converted into fermentable sugars. The
use of the cashew bagasse for the production of bioethanol allows the use of a regional
culture that has about 85% of waste. Due to the complex structure of this material, it is
necessary to submit it to the pre-treatment physical and/or chemicals before the process
of hydrolysis for ethanol production. Pre-treatment, usually, is used to remove the lignin
and hemicellulose, reduce cellulose crystallinity and increase the porosity of the
materials. The objective of this work was to study the pre-hydrolysis and acid
hydrolysis of lignocellulosic raw cashew bagasse peduncle (Anarcadium occidentale
L.), removal of toxic compounds from the liquor hydrolyzate using the residual lignin as
adsorbent, alcoholic fermentation of liquors for the production of second generation
bioethanol with two types of yeast and alcohol production estimate this from the raw
material under study. The cashew bagasse, based on their chemical characterization and
physical chemistry, presented himself as a promising source of cellulose to hydrolysis,
in order to produce bioethanol. In the process of pre-hydrolysis, the results obtained
suggest that the best concentrations of glucose, xylose and arabinose, are obtained at
120 ° C, acid concentration of 5% and a weight ratio of 1:6 bagasse, this process was
effective in the removal of hemicellulose mainly in the extraction of arabinose and the
temperature was variable of bigger influence in the extraction of pentose. For the acid
hydrolysis done with the following hydrolysis conditions: temperature 200 °C, acid
concentration equal to 6% and ratio of 1:6 has the combination of the highest
concentration of sugars with a minimum concentration of toxic compounds. In the study
by adsorption (detoxification) congeners of furfural, and hydroxymethylfirrfural (HMF)
and acetic acid by the residual lignin in the hydrolysis process, it had the pH as the
variable of major influence in order to remove the compounds in the liquor. The
kinetics study of the alcoholic fermentation of the hydrolyzed liquor to the two types of
yeast, the strain of Saccharomyces cerevisiae trade was efficient fermentation than in
any of the fermentations studied (three treatments). The yield and efficiency of
production of ethanol from cellulosic pulp of processing stalk cashew maximum dry
were respectively 0.445 g ethanol/g of pulp and liquor to 87.1% hydrolyzed with the
addition of cashew apple juice.
