Retrofit of cogeneration engines to use natural gas and hydrogen blends: Application of an optimization methodology to support decision-making

This paper addresses the development of a framework to support decision-making for retrofitting cogeneration systems to operate with natural gas-hydrogen blends. First, the original natural gas microturbine is sized using an optimization methodology, and then calculations are performed for operation with natural gas-hydrogen mixtures. The innovative approach builds upon the CGAM problem, a benchmark model frequently used for techno-economic analysis of cogeneration systems. With the ultimate goal of supporting retrofit decision-making, a set of important parameters are analyzed, such as fuel flow rate, adiabatic flame temperature, NO x emissions, and flame speed. The results show that mixture values up to 10% in the sized microturbine promote very limited changes in these parameters, indicating, from a theoretical point of view, little or no need for system retrofit. Values up to 30% promote greater changes in these parameters, and above these values, further studies are recommended. • Framework to aid decision-making for retrofitting microturbines to enable H2 blends. • Microturbine sized for natural gas fuel is tested under natural gas-hydrogen blends. • Key parameters modeled: fuel flow rate, flame temperature, NOx emission, flame speed. • The analysis is performed for lean premixed and diffusion flame combustion chambers. • Results show mixtures up to 10% cause minimal parameter changes, little/no retrofit.