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Results for “thermal-chemical decomposition”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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Benchmarking plasma and electrolysis decomposition technologies for ammonia to power generation

Ammonia is a promising energy and hydrogen carrier due to its ease of liquification, high hydrogen content, and potential to be synthesized without carbon feedstocks. Despite its widespread use in agriculture, the utilization of ammonia to deliver hydrogen or for direct power generation is still under development. Sometimes referred to as “cracking”, the standard approach for recovering hydrogen from ammonia relies on harsh reaction conditions that limit its suitability for low-carbon transitions. Here, this work investigates the technology development status and potential cost of plasma and electrolysis-based ammonia decomposition, benchmarks them with thermal-chemical decomposition, and further compares them with direct ammonia-to-power solid oxide fuel cell systems. Results suggest that in order to reach cost parity with cracking technologies, plasma-based decomposition must achieve one order of magnitude improvement in energy efficiency (to 10 kWh/kg or lower), while electrolysis decomposition must achieve enhanced durability using cheap electrolytes.

30 DIRECT ENERGY CONVERSION↗

Finite Element Analysis of Poroelastic Composites Undergoing Thermal and Gas Diffusion

A theory for time-dependent thermal and gas diffusion in mechanically time-rate-independent anisotropic poroelastic composites has been developed. This theory advances previous work by the latter two authors by providing for critical transverse shear through a three-dimensional axisymmetric formulation and using it in a new hypothesis for determining the Biot fluid pressure-solid stress coupling factor. The derived governing equations couple material deformation with temperature and internal pore pressure and more strongly couple gas diffusion and heat transfer than the previous theory. Hence the theory accounts for the interactions between conductive heat transfer in the porous body and convective heat carried by the mass flux through the pores. The Bubnov Galerkin finite element method is applied to the governing equations to transform them into a semidiscrete finite element system. A numerical procedure is developed to solve the coupled equations in the space and time domains. The method is used to simulate two high temperature tests involving thermal-chemical decomposition of carbon-phenolic composites. In comparison with measured data, the results are accurate. Moreover unlike previous work, for a single set of poroelastic parameters, they are consistent with two measurements in a restrained thermal growth test.

Salamon, N. J.↗