Process Simulation and Design of Green Ammonia Production Plant for Carbon Neutrality

Abstract

This study investigated the viability of green hydrogen as an essential component in the global energy transition. Despite intensified efforts prompted by the ongoing global energy crisis, impediments have arisen, notably in the area of green hydrogen storage techniques. The inherently hazardous nature of hydrogen gas, resembling an explosion when stored conventionally, presents a significant challenge. In response, this study proposed an environmentally friendly, carbon-neutral, and secure storage technique. The focus is on utilizing green hydrogen in the production of ammonia, serving as both a hydrogen carrier and energy storage medium on an industrial scale. The versatile application of green ammonia extended beyond storage, encompassing fertilizer production, refrigeration, and chemical manufacturing, all aligned with principles of sustainable development, green energy transition, and achieving net-zero carbon emissions. The comprehensive study involved the plant design, process flow diagrams, Aspen HYSYS simulation, plant layout, HAZOP study, and an in-depth economic analysis to evaluate feasibility and profitability. The Haber-Bosch simulated process encompassed the entire production line, starting from sustainably sourced hydrogen to the separation unit ensuring a green nitrogen source. Further optimization was achieved through a heat exchanger network utilizing Aspen Energy Analyzer. The study yielded a substantial ammonia production rate of 7058 kg/hr with an impressive conversion rate of nearly 85%, minimizing waste through the recycling of excess hydrogen within the process. The resultant liquid form of stored ammonia in the refrigeration loop facilitates convenient and safe storage of hydrogen.