System-level energy consumption modeling and optimization for cellulosic biofuel production

Abstract As a promising alternative to fossil fuels, cellulosic biofuel has obtained considerable interest due to its potential for mitigating global climate change and enhancing energy security. However, the widespread adoption of cellulosic biofuel is taking place in a slower pace than expected. One major challenge is that the cellulosic biofuel production is still highly energy-intensive. In fact, the energy contained in cellulosic biofuel is less than the energy required for its production. To address this issue, in this paper, an analytical system-level energy model is proposed to characterize the fundamental relationships between total energy consumption and biofuel production parameters in cellulosic biofuel production systems. Furthermore, an optimization strategy based on Particle Swarm Optimization (PSO) is adopted to minimize the energy consumption of cellulosic biofuel production while maintaining the desired biofuel yield. A baseline case is implemented for analyzing energy consumption, and the results show that pretreatment consumes most energy among all processes and the water/biomass ratio is the most significant energy driver. In addition, the optimal solution results in a 21.09% reduction in the total energy consumption compared to the baseline case.