Simulation and Optimization of Bio-Methanol Production from Steam Gasification of Sugarcane Bagasse Using Aspen Plus

The detrimental environmental impacts of fossil fuels are increasing due to the growing global energy consumption. Thus, energy recovery from waste materials will inevitably become the dominant option in the future with population growth and the reduction in fossil resources. A model for the production of Bio-methanol was developed using Aspen Plus and design of experiment and optimization were carried out using Design Expert software. Factors selected for the design of experiment were the gasification temperature, gasification pressure and steam / biomass ratio with their values ranging from 500 – 800oC, 1 - 3 bar and 0.5 - 2.5 respectively. The effects of interaction between the variables and the response were studied using the Box-Behnken design. The developed model was validated using the yield of bio-methanol from experimental data in literature. The model gave bio-methanol yield as 4.54% while the bio-methanol yield from experimental data obtained was 5.93%. The results from Response surface methodology (RSM) gave the quadratic model as best fit for the production of bio-methanol. The coefficient of determination for bio-methanol yield was found to be 0.9435. The optimum gasification conditions were found to be; temperature of 800oC, pressure of 1 bar and steam / feed ratio of 0.5 and these gave rise to the maximum bio-methanol yield of 86.32%. High temperature, low gasification agent (steam/feed ratio) and low pressure favours optimum bio-methanol yield.