Development of a 3D Printer for Oxide-free Aluminum Transportation

Abstract

Hydrogen as an energy carrier is abundant, has a high caloric value and only produces water when combusted. A challenge is directly transporting hydrogen incurs high costs due to its low density. The low flammability limit also makes it dangerous to transport. Aluminum has been proposed as an alternative energy carrier for its high density and ability to be stored at ambient conditions, allowing for cheaper transportation. Hydrogen can be produced on-site by reacting the aluminum fuel with water. However, when exposed to air aluminum forms an inert oxide layer on its surface, preventing reaction. High reaction temperatures are required to overcome the oxide layer leading to a high energy penalty.

This thesis proposes a novel concept of aluminum encapsulation with water-soluble polymer. A 3d printer was designed and fabricated which creates aluminum-polymer structures that do not oxidize during storage and can achieve a wide range of reaction rates with water by varying the structure surface area. This new approach provides several benefits, by removing the oxide layer before the reaction happens, the aluminum is in an “activated” state and can react at room temperature. This reduces the energy required for reaction. Additionally, by having control over the reaction rate, ideal production rates can be achieved, reducing waste products and meeting consumption demands. The unique manufacturing flexibility of 3d printers enables the fabrication of structures with wide ranges of surface area to volume ratios. By shipping activated aluminum in the polymer structures, hydrogen can be produced locally and the need for expensive hydrogen transport can be eliminated.