Dynamic simulation and techno-economic assessment of hydrogen utilization in dual fuel (Hydrogen/biogas) micro gas turbine systems for a wastewater treatment plant

Abstract

Due to the commitments of many governments, electrical power production from renewables hopefully continues to become widespread at a rapid rate to revolutionize energy infrastructures. Nevertheless, this green power seems to be wasted due to seasonal power swings, grid restrictions, and curtailment. The present research investigates the practicability of hydrogen injection into biogas from anaerobic digestion to generate electricity for a deployed wastewater treatment plant. A Polymer electrolyte membrane electrolyzer powered by Photovoltaic panels would produce hydrogen. An array of commercialized micro gas turbines has been suggested to create electrical power and thermal demand. Transient modeling was carried out using TRNSYS software to analyze the plant's performance from the thermodynamics and techno-economic perspectives. It is found that when biogas mass flow rate fluctuates, hydrogen could be effectively injected into biogas to fuel micro gas turbines. The results revealed that injecting hydrogen into biogas results in up to a 30% reduction in CO2 emissions, with two micro gas turbines producing more than 265 kW of electrical power at full load. LCOH and payback time would be 8.3 $/kg H2 and 6.5 years, respectively, for a hypothetical scenario in which electrolyzer size is anticipated to supply the maximum necessary hydrogen. Also the results indicate that electrical power and thermal energy of 70kWe-400kWe and 120kWth-500kWth could be reached annually, and the highest efficiency for the power generation, CHP, and the overall system becomes 37.5%, 83%, and 78%, respectively.