Statistical optimization of dilute acid pretreatment of pinus needles to be used as substrate for biofuel production

In this study response surface methodology (RSM) was applied to study the effect of H₂SO₄ concentration, temperature, and time on the production of reducing sugars, total sugars, and total phenolic compounds from pine needles. Three variables with three levels showed that maximum release of total phenolic compounds (31.20 ± 0.002 mM) was observed at 1% H₂SO₄ concentration, 130°C temperature for 75 min of residence time. Under these conditions, the predicted value of total phenolic compounds was 31.27 mM, which indicated that the model is valid, having negligible variation in observed and predicted values. These results suggested that this substrate could be potentially used as substrate for bioethanol production.