Definition of the Thermodynamic Cycle of a Biomass-Fueled Internal Combustion Engine

Climate change and the depletion of fossil fuels make it urgent to find an alternative to oil-based fuels, especially in machines powered by internal combustion engines. Biomass is currently a poorly used source of energy and meets the necessary conditions to replace a large part of oil-based fuels. However, current engines cannot burn solid biomass and a specific engine needs to be developed. This work proposes the thermodynamic cycle of a biomass-fueled internal combustion engine. The cycle is significantly different from the Otto cycle, since compression and heat absorption occur simultaneously, in a single stage. Since it is not possible to find a function that relates pressure to volume at this stage, an approximate method is proposed to solve the cycle without resorting to numerical methods. The results show that the maximum pressure and temperature of a biomass-fueled engine cycle are somewhat higher than those of the equivalent Otto cycle. However, more significantly, the cycle efficiency does not increase continuously with the compression ratio. There is an optimum compression ratio value for which the cycle efficiency is at its maximum. This fact will condition the design of the motors.

Automated summary

Climate change and the depletion of fossil fuels have created an urgency to find alternatives to oil-based fuels in internal combustion engines. Biomass provides a potential solution, but requires the development of specific engines as current engines cannot burn solid biomass. This study introduces a new thermodynamic cycle for a biomass-fueled engine, which differs significantly from the Otto cycle. The results demonstrate higher pressure and temperature in the biomass-fueled cycle, but importantly, the cycle efficiency does not increase consistently with compression ratio, indicating the need for optimized engine design.