Study of the Hydrogen Production From Catalytic Reforming of Ammonia in Aqueous Solution Utilizing Microreactors

• Grant number: 23/18143-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2024
• End date: February 28, 2025
• Field of knowledge: Engineering - Chemical Engineering
• Principal Investigator: Rubens Maciel Filho
• Grantee: Verena Soares Bombonatti
• Host Institution: Faculdade de Engenharia Química (FEQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Due to the growing demand for clean energy, hydrogen (H2) appears as a promising alternative, which can be used in the storage, use and conversion of energy. There is enormous interest in introducing hydrogen into several sectors, with emphasis on the automobile industry, since it is now possible to produce electric cars with compressed H2 which powers a fuel cell (FC), generating electricity to move the engines. In this way, the efficiency of these cars can be considerably increased, even when compared to vehicles with internal combustion engines. On the other hand, one of the biggest limitations found for this technology is the difficulty of compressing hydrogen, which occurs at pressures close to 700 bar, demanding high energy consumption and raising safety concerns, due to the risk of leaks and explosions. Furthermore, almost 99% of the H2 currently generated comes from fossil sources, which contributes to the carbon footprint right at the beginning of the production chain. In this aspect, as a way to reverse these limitations, the production of H2 from synthetic fuels which are available on the market, such as ethanol, biogas and ammonia, is proposed. These materials are hydrogen carriers and can be used to fuel vehicles, in a solution that allows on-board and on-demand hydrogen production, in equipment called reformers, which are coupled to the fuel cell. Therefore, H2 does not need to be stored in the car and is only produced for direct consumption in the FC. With this in mind, the present work aims to study the generation of hydrogen from reforming reactions of ammonia in aqueous solution (Ammonium Hydroxide, NH4OH), using microreactors impregnated with nickel-based catalysts. Ammonia was chosen because it is one of the most abundant chemicals in the world, due to the simplicity of its molecule and the absence of carbon in the chain, avoiding the emission of CO2 as a product of the reaction. At the same time, this gas is highly soluble in water, so the transport of NH4OH is facilitated by being in a liquid state, in addition to reducing the toxicity of NH3 gas. In this project, microchannel reactors fabricated via 3D printing technology will be used, which were developed by the research group (Patent number BR10201203232) and have as advantages high performance and reduced size. Furthermore, Ni, Ni-Co and Ni-Fe catalysts will be explored, in order to evaluate which material is more efficient in terms of NH4OH conversion and H2 yield.