Clean Hydrogen and Ammonia Synthesis in Paraguay from the Itaipu 14 GW Hydroelectric Plant

Massimo Rivarolo,Gustavo Riveros-Godoy,Aristide F Massardo,Loredana Magistri

doi:10.3390/chemengineering3040087

Massimo Rivarolo, Gustavo Riveros-Godoy + Show 2 more

Open Access

https://doi.org/10.3390/chemengineering3040087

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Abstract

This paper aims at investigating clean hydrogen production from the large size (14 GW) hydroelectric power plant of Itaipu, located on the border between Paraguay and Brazil, the two countries that own and manage the plant. The hydrogen, produced by a water electrolysis process, is converted into ammonia through the well-known Haber-Bosch process. Hydraulic energy is employed to produce H2 and N2, respectively, from a large-scale electrolysis system and an air separation unit. An economic feasibility analysis is performed considering the low electrical energy price in this specific scenario and that Paraguay has strong excess of renewable electrical energy but presents a low penetration of electricity. The proposal is an alternative to increase the use of electricity in the country. Different plant sizes were investigated and, for each of them, ammonia production costs were determined and considered as a term of comparison with traditional ammonia synthesis plants, where H2 is produced from methane steam reforming and then purified. The study was performed employing a software developed by the authors’ research group at the University of Genoa. Finally, an energetic, environmental, and economic comparison with the standard production method from methane is presented.

Highlights

Nowadays, fossil fuels still provide more than 80% of the global energy demand [1]
This paper aims at investigating clean hydrogen production from the large size (14 GW) hydroelectric power plant of Itaipu, located on the border between Paraguay and Brazil, the two countries that own and manage the plant
Hydrogen can be produced throughout the water electrolysis process, employing renewable energy sources (RES) and water as the only input: in this way, the environmental impact in terms of pollutant emissions would be strongly reduced compared to H2 production from steam methane reforming, as reported in [2,6]

Summary

Introduction

Fossil fuels still provide more than 80% of the global energy demand [1]. since their intensive utilization in the last two centuries, the reserves of fossil fuels (coal, petroleum, and natural gas) are decreasing, especially when considering the continuous growth of world energy demand, in particular in developing countries. Producing ammonia from electrolyzers fed by renewable energy sources allows for a significant reduction of the environmental impact as no fossil fuels are consumed and the electrical energy needed in the process is produced by a renewable energy source Another important advantage is the reduction of plant complexity as purification and gas treatment sections are not necessary anymore in this configuration (no SOx, CO, or CO2): capital costs and fuel costs decrease. The innovative aspect of the present study, compared to the ones reported in recent literature [18,19], is the analysis of a large size plant for ammonia synthesis employing renewable electrical energy only, evaluating the solution from the environmental standpoint, and considering the economic aspects, comparing the average synthesis costs to the standard method

Materials and Methods

Findings

MW Electrolyzers