EVALUATION OF ACID PRETREATMENT OF CORN STRAW TO BREAKING LIGNOCELLULOSIC BIOMASS USING EXPERIMENTAL DESIGN

With the objective of sources energy diversification and improving environmental conditions due to the utilization of residues that would be wasted, lignocellulosic biomass has gained projection in global research of ethanol production. This type of biomass, including straw and corn cobs, has a difficult access to the structure, making the step of pretreatment essential, so there is a deconstruction of this structure, thereby facilitating the enzyme attack in the hydrolysis stage. This study evaluated the effectiveness of a pretreatment with sulphuric acid, made with corn straw, using a 2³ experimental design with triplicate at the central point. The aim was to verify which studied factors and their levels were more significant and thus optimize the pretreatment step. The factors studied were: time, temperature and concentration of sulphuric acid. The design responses were: percentage of total reducing sugars and acidity. The results showed that to obtain a high sugar concentration and low acidity, which is ideal, should use temperature around 120 °C, time 15 minutes and H₂SO₄ concentration about 0,5%.