2016 Volume 57 Issue 3 Pages 423-427
The possibility of a new ammonia synthesis process has been investigated by utilizing V-based alloy membrane under moderate temperature and pressure conditions. Three membrane samples with different coating conditions of Pd-Ag alloy on the outlet side surface have been tested. It is found that the deposition of Pd-Ag alloy on the outlet side surface is needed for V-based alloy membrane for hydrogen permeation at 623 K. While keeping the hydrogen permeation condition, nitrogen gas is flowed to the outlet side surface of the membrane samples, and the reaction gas is bubbled into distilled water to detect ammonia formation by using Nessler’s reagent. Ammonia is not synthesized for the membrane sample coated thickly with Pd-Ag alloy on the outlet side surface, indicating that Pd-Ag alloy does not have a dissociation ability of nitrogen molecule. In contrast, ammonia is formed for the membrane sample coated in a grid pattern with Pd-Ag alloy on the outlet side surface. In this case, both V-based alloy and Pd-Ag alloy coexist on the outlet surface, and hydrogen atoms permeating through the membrane and nitrogen atoms dissociated on the surface of V-based alloy probably react with each other to form ammonia.