Performance analysis of biogas-fueled maisotsenko combustion turbine cycle

•A biogas-fueled Maisotsenko combustion turbine cycle (MCTC) system was analyzed.•Comparisons with conventional gas turbine cycle system were made.•This innovative MCTC showed better energy and exergy performances.•The MCTC performance was less sensitive to methane volume ratio in biogas. The utilization of biogas as a renewable energy source in power generation systems has been receiving much attention. While gas turbine cycle (GT) systems are commonly used in modern power plants, the reduction of system efficiency owing to the parasite composite in biogas has restricted its sustainable development. Alternatively, the Maisotsenko combustion turbine cycle (MCTC) technology, that recovers thermal energy from turbine exhaust gas for pressured air humidification, improves the turbine power and cycle efficiency significantly. The biogas-fueled MCTC system as their integration is expected to relive the biogas application on GT systems. Nevertheless, the evaluation of such integrative performance has been so far in absence. Accordingly, this paper reports our detailed investigation through exergy analysis. The numerical model of an integrated system was first developed and validated. Then the impacts of methane volume ratio ∅ in biogas, compressor pressure ratio, water injection rate, compressor/turbine inlet temperatures were studied. The simulation results showed that the MCTC outperforms the conventional GT. When fueled by natural gas (∅ = 0.9) and biogas (∅ = 0.45) alternatively, the exergy efficiency can be improved by more than 10% and 52% respectively. Also, unlike the conventional GT, the MCTC performance is less sensitive to the biogas methane content. Our findings consolidate the merits of biogas-fueled MCTC system for zero-carbon applications.