Year: 2025
Type: preprint
Abstract: This study evaluates the technical, economic, and logistical feasibility of producing blue ammonia on Very Large Floating Structures (VLFS) in Brazil’s pre-salt region as an innovative approach to sustainable offshore natural gas monetization. The proposed configuration integrates Autothermal Reforming (ATR), amine-based CO₂ capture, and the Haber–Bosch synthesis process within a single floating platform designed for high energy efficiency, compact modularity, and near-zero emissions. A steady-state mass–energy balance and a two-level economic model were developed to assess performance and scalability. At the reference industrial scale of approximately 2,100 tons of ammonia per day (about 700,000 tons per year), the system consumes around 60,000 Nm³ of natural gas per hour and 1,200 tons of water per day, achieving a specific energy demand of 7.2–7.8 GJ per ton of NH₃. CO₂ capture efficiency exceeds 90%, equivalent to roughly 1.6 tons of CO₂ per ton of ammonia, while integrated heat and power recovery provide more than 70% energy self-sufficiency. The analysis shows that economies of scale are the key determinant of financial viability, with specific CAPEX falling from nearly USD 75,000 per ton-year in modular configurations to about USD 2,000 per ton-year at industrial scale, resulting in a total capital cost near USD 1.45 billion. The base economic scenario indicates a Net Present Value of approximately USD 2 billion under realistic market conditions. Beyond economic and technical performance, the VLFS concept benefits from Brazil’s extensive expertise in CO₂ reinjection in the Santos Basin and its advantageous position for low-carbon ammonia exports. The main challenges relate to systems integration within a dynamic floating structure and the absence of a regulatory framework for offshore chemical plants. Overall, VLFS-based blue ammonia production offers a promising pathway for transforming pre-salt gas into a competitive low-carbon export commodity, reinforcing Brazil’s role in the global energy transition and the development of a sustainable blue economy.
Source: Preprints.org
Authors: Rodrigo Pereira Botão¹, Hirdan Katarina de Medeiros Costa¹, Marilin Mariano dos Santos¹, Delanney Vidal Di Maio Neto¹, Edmilson Moutinho dos Santos¹, Vanessa Pecora Garcilasso¹, Romario de Carvalho Nunes¹
Institution: Universidade de São Paulo
Language: English
Subfield: Energy Engineering and Power Technology
Field: Energy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4417445488