This paper proposes a solution to address the challenges of high storage and transport costs associated with using hydrogen (
) as an energy source. It suggests utilizing ammonia (
) as a hydrogen carrier to produce
onsite for hydrogen gas turbines.
offers higher volumetric hydrogen density compared to liquid
, potentially reducing shipping costs by 40%. The process involves
pyrolysis, which utilizes the heat waste from exhaust gas generated by gas turbines to produce
and nitrogen (
). Numerical simulations were conducted to design and understand the behaviour of the heat recapture
decomposition system. The design considerations included the concept of the number of transfer units and heat exchanger efficiency, achieving a heat recapture system efficiency of up to 91%. The simulation of
decomposition was performed using ANSYS, a commercial simulation software, considering wall surface reactions, turbulent flow, and chemical reaction. Parameters such as activation energy and pre-exponential factor were provided by a study utilizing a nickel wire for
decomposition experiments. The conversion of
reached up to 94% via a nickel-based catalyst within a temperature range of 823 K to 923 K which is the exhaust gas temperature range. Various factors were considered to compare the efficiency of the system, including the mass flow of
, operating gauge pressure, mass flow of exhaust gas, among others. Result showed that pressure would not affect the conversion of
at temperatures above 800 K, thus a lower amount of energy is required for a compression purpose in this approach. The conversion is maintained at 94% to 97% when lower activation energy is applied via a ruthenium-based catalyst. Overall, this study showed the feasibility of utilizing convective heat transfer from exhaust gas in hydrogen production by
pyrolysis, and this will further enhance the development of
as the potential
carrier for onsite production in hydrogen power generation.
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