OPTIMIZATION OF HYDROTHERMAL TREATMENT OF OIL PALM WOOD IN BUFFERED MEDIA USING ‎RESPONSE SURFACE METHODOLOGY

The purpose of the research was to develop the response surface methodology (RSM) models for the treatment conditions ‎optimization of modulus of rapture (MOR) and modulus of elasticity (MOE) of treated oil palm ‎wood (OPW) with buffer solutions.‎The optimum conditions were determined using RSM to improve of OPW by hydrothermal treatment in ‎buffered solutions. ‎Central composite design(CCD) was used as statistical multivariate method for process optimization in the buffered media. The central composite design consists of three variables (buffer solutions, temperature ‎and time at pH of 5 to 8, 80-140 °С and 40-120 mins, respectively) and two responses ‎‎(MOR, MOE) were employed to perform the experiments in hydrothermal treatment. ‎The independent variables have been optimized using RSM to obtain the optimal conditions. ‎The models indicated that the optimum conditions for preparation of the hydrothermal ‎treatment having the desirable factors including buffer solutions, temperature and time. ‎Based on the optimal conditions, the corresponding predicted response value for MOR, MOE ‎were estimated to be 39.09 MPa, and 5613.1Mpa, respectively. ‎Nevertheless, the models were suggested that the optimum conditions were pH of 7.12 (the ‎buffer neutral), temperature of 110 °C, and time of 120 minutes. The actual response according to proposed treatment illustrated excellent agreement with the ‎predicted value with residual standard error (RSE) of less than 5%.‎