Abstract
<jats:p>Green hydrogen produced from biogas reforming offers a low-carbon feedstock route to sustainable ammonia synthesis, coupling waste valorization with decarbonized fertilizer and chemical production. This review examines the technical foundations of this pathway: the composition and purification of biogas; the principal reforming routes to hydrogen — steam reforming, dry reforming, partial oxidation, and autothermal reforming — together with the catalysts that enable them; the cryogenic air separation required to supply oxygen and nitrogen to the process; and the reactor configurations and catalysts used for ammonia synthesis. The economic evaluation methodology commonly used to assess hydrogen production cost is outlined, alongside a SWOT analysis of green hydrogen production in Egypt, a country with substantial biogas feedstock potential and a strategic export position. Ammonia's principal industrial applications are also summarized. Taken together, this review provides a technical basis for evaluating biogas-derived green hydrogen as a route to sustainable ammonia production, particularly in regions with abundant organic waste streams and growing renewable energy ambitions.</jats:p>