Enzymatic Hydrolysis of Instant Controlled Pressure Drop Pretreated Retama raetam for Bioethanol Production

Since mass diffusion within plant is very weak because of its inappropriate natural structure, Retama raetam biomass was pretreated by thermo-mechanical process “Instant controlled pressure drop” DIC texturing technology prior to submitting it to enzymatic treatment. DIC technology involves subjecting lignocellulosic biomass to saturated steam pressure for a short time followed by a sudden transition from high steam pressure to a vacuum (50 mbar). In this work, an enzymatic hydrolysis was carried out on the DIC pretreated samples by Cellic C-tec2. It was performed according to an experimental design in order to define the best conditions for a maximum glucose recovery. A response surface methodology was used to evaluate the effect of the processing parameters on the released sugar yields. The results showed that the maximum sugars and glucose yields were respectively 50.38 and 36.56 mg/g dry matter obtained at 0.3 M of sulfuric acid, 0.475 MPa of steam pressure for 1 min and four cycles. A minimum formation of undesirable by-products obtained was 0.98 mg/g DB with 0.1 mg/g DB and 0.06 mg/g DB respectively of furfural and HMF.