Energy and exergy analyses of a biogas driven multigenerational system

In this study, energy and exergy analyses of a biogas driven multigeneration system is conducted for performance assessment and evaluation. In this regard, the multigeneration system with a biomass digestion process is developed for this purpose. Multigeneration system consists of different subsystems, such as two-stage biomass digester, open-type Brayton cycle, Organic Rankine Cycle (ORC), single-effect absorption chiller, heat recovery, water separation unit. This multigeneration system aims to generate electrical power for at least 300 houses, heating power for five greenhouses, cooling power and product water from flue gas for agricultural consumption in greenhouses. The results indicate that the overall energy efficiencies of the proposed system is 72.5% with 1078 kW electrical, 198 kW heating, and 87.54 kW cooling power, and daily around 40 kg water production. However, the maximum exergy efficiency of the multigeneration system is obtained as 30.44%, with 65% of the highest exergy destruction rate in combustion chamber. Crown Copyright (C) 2018 Published by Elsevier Ltd. All rights reserved.