Development of an estimation model for the evaluation of the energy requirement of dilute acid pretreatments of biomass

This study aims to develop a mathematical model to evaluate the energy required by pretreatment processes used in the production of second generation ethanol. A dilute acid pretreatment process reported by National Renewable Energy Laboratory (NREL) was selected as an example for the model's development. The energy demand of the pretreatment process was evaluated by considering the change of internal energy of the substances, the reaction energy, the heat lost and the work done to/by the system based on a number of simplifying assumptions. Sensitivity analyses were performed on the solid loading rate, temperature, acid concentration and water evaporation rate. The results from the sensitivity analyses established that the solids loading rate had the most significant impact on the energy demand. The model was then verified with data from the NREL benchmark process. Application of this model on other dilute acid pretreatment processes reported in the literature illustrated that although similar sugar yields were reported by several studies, the energy required by the different pretreatments varied significantly

Synthesis of thermal insulator using chicken feather fibre in starch-clay nanocomposites

Incorporating chicken feather fibre (CFF) into natural based-nanocomposite comprising of glycerine plasticizedcassava starch binder with bentonite (BNT) as nanofiller, a thermal insulator (TIN) was synthesized. Central Composite Design (CCD) Response Surface Methodology was employed to carry out the experimental design using two factors (CFF and BNT) along with one response (thermal conductivity) to produce nine materials as insulators, comprising of 0%, 5%, and 10% BNT based on 8 g initial weight of CFF. A sample without CFF was used as the control. Developed thermal insulators were subjected to thermal conductivity tests using Lee's disc method at a steady state. The best insulator is TIN-4 with the lowest thermal conductivity of 0.0313 W/(mK) and the highest insulation property of 114.63 m2k/W, while TIN-10 with no CFF has the highest thermal conductivity of 0.0549 W/(mk) and lowest insulation property of 48.1603 m2k/W. Proportionate use of chicken feather fibre in starch-clay nanocomposite will help synthesize an effective thermal insulator with minimum cost