1. Thermodynamic potential of a novel plasma-assisted sustainable process for co-production of ammonia and hydrogen with liquid metals
- Author
-
Evgeny V. Rebrov, Mohammad Mohsen Sarafraz, Nam Nghiep Tran, Volker Hessel, N. Pourali, Chemical Reactor Engineering, and EIRES Systems for Sustainable Heat
- Subjects
TP ,Zero carbon process ,Materials science ,Hydrogen ,020209 energy ,Analytical chemistry ,Energy Engineering and Power Technology ,chemistry.chemical_element ,02 engineering and technology ,7. Clean energy ,Ammonia production ,Ammonia ,chemistry.chemical_compound ,symbols.namesake ,020401 chemical engineering ,Nitrogen fixation ,Plasma-assisted chemical looping ,0202 electrical engineering, electronic engineering, information engineering ,QD ,SDG 7 - Affordable and Clean Energy ,0204 chemical engineering ,Gallium ,Hydrogen production ,Plasma reactor ,Renewable Energy, Sustainability and the Environment ,Nitrogen ,6. Clean water ,Gibbs free energy ,Fuel Technology ,Nuclear Energy and Engineering ,chemistry ,TA ,Sustainability ,symbols ,Chemical looping combustion ,SDG 7 – Betaalbare en schone energie - Abstract
In the present article, the thermodynamic potential of a sustainable plasma-assisted nitrogen fixation process for co-production of ammonia and hydrogen is investigated. The developed process takes advantage of chemical looping system by using a liquid metal such as gallium to drive nitrogen fixation reaction using three reactors including reactor R1 to produce gallium nitride from gallium and nitrogen, reactor R2 to produce ammonia and hydrogen from gallium nitride, and plasma reactor R3 to convert gallium oxide to pure gallium. The results of the thermodynamic assessments showed that the proposed reactions are spontaneous and feasible to occur in the reactors. Likewise, the first two reactions are exothermic with ΔH=-230[Formula presented] and ΔH=-239[Formula presented] in the reactors R1 and R2, respectively with an equilibrium chemical conversion of 100%. The plasma reactor requires thermal energy to drive an endothermic reaction of gallium oxide dissociation withΔH=+870[Formula presented]. Thermochemical equilibrium analysis showed that the molar ratio of steam to GaN, as well as the operating pressure and temperature of reactor R2 are the main operating parameters identifying the product composition in the reactor such that by increasing the temperature, the molar ratio of hydrogen to ammonia increases. However, by increasing the molar ratio of steam/GaN (φ value) from 0.1 to 1, the hydrogen content of the reactor increases from 45% to 70% at 400 °C. For φ > 1.0, the hydrogen content decreases while more hydrogen participate in the formation of NH3 thereby increasing the mole fraction of ammonia in the reactor. The equilibrium chemical conversion of all three reactors is expected to reach the completion point (χ = 100%) due to the highly negative Gibbs free energy of the liquid metal-based reactions together with a large thermal driving force supported by thermal plasma reactor. Finally, a scalability study points at a possible use of the new disruptive process design at small scale, and possible industrial transformation scenarios for a distributed production at a local site of consumption are depicted.
- Published
- 2020
- Full Text
- View/download PDF