Evaluation of the Interconnection of a Biomethane Microturbine in an Absorption Refrigeration System

This article evaluates the performance and environmental impact of a combined system of natural gas microturbine and absorption refrigeration system. The objective of the study is to evaluate the interconnection of a biomethane microturbine in an absorption refrigeration system. The study applies energy and exergy balances to each component of the system, using EES software for the simulation. The microturbine is a Capstone C600s model with a nominal power of 600 kW, and the absorption chiller is a single-stage LiBr-H2O system with a cooling capacity of 680.7 kW. The results show that the microturbine achieves a thermal efficiency of 34%, an exergetic efficiency of 86%, and a net power output of 585.4 kW. At the same time the absorption chiller has a coefficient of performance (COP) of 0.7 and 680.7 kW with generator water temperature inlet of 100 °C. On the other hand, this study identifies the most efficient points of interconnection between the two systems. The combined system reduces the CO2 equivalent emissions by 700 to 900 tons/year compared to conventional systems. The behaviour of the interconnection heat exchanger is also evaluated using Computed Fluid Dynamics. The investigation concludes that the interconnection of a natural gas microturbine and an absorption refrigeration system is a promising alternative that can optimize both technical and economic aspects of energy generation and utilization, while mitigating environmental problems.