Biogas production from grape pomace: Thermodynamic model of the process and dynamic model of the power generation system

In year 2010, the Province of San Juan – Argentina (South America) produced around 81 947 tons of grape pomace, which is a winery waste by-product. Wineries demand a great quantity of power during the three months that winemaking time lasts, which involve a high installed electric power. This power is used mainly for refrigerating the must during the fermentation. The control of temperature is crucial in winemaking as the low temperature preserves subtle fruit characters. An alternative for reducing the requirement of power from the utility electric grid is producing it locally, using the residuals generated by the own wineries. The technology for bioenergy conversion proposed to be implemented in this research for electricity generation is the anaerobic digestion of grape pomace. The aim of this research is to develop the thermodynamic equilibrium analysis of grape pomace anaerobic digestion based on the equilibrium constants for predicting the potential production of biogas and its composition. In addition, a dynamic model of a biogas-fuelled microturbine system for distributed generation applications is derived.