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

2019 ◽  
Vol 3 (4) ◽  
pp. 87
Author(s):  
Massimo Rivarolo ◽  
Gustavo Riveros-Godoy ◽  
Loredana Magistri ◽  
Aristide F. Massardo

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.

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4638
Author(s):  
Simon Pratschner ◽  
Pavel Skopec ◽  
Jan Hrdlicka ◽  
Franz Winter

A revolution of the global energy industry is without an alternative to solving the climate crisis. However, renewable energy sources typically show significant seasonal and daily fluctuations. This paper provides a system concept model of a decentralized power-to-green methanol plant consisting of a biomass heating plant with a thermal input of 20 MWth. (oxyfuel or air mode), a CO2 processing unit (DeOxo reactor or MEA absorption), an alkaline electrolyzer, a methanol synthesis unit, an air separation unit and a wind park. Applying oxyfuel combustion has the potential to directly utilize O2 generated by the electrolyzer, which was analyzed by varying critical model parameters. A major objective was to determine whether applying oxyfuel combustion has a positive impact on the plant’s power-to-liquid (PtL) efficiency rate. For cases utilizing more than 70% of CO2 generated by the combustion, the oxyfuel’s O2 demand is fully covered by the electrolyzer, making oxyfuel a viable option for large scale applications. Conventional air combustion is recommended for small wind parks and scenarios using surplus electricity. Maximum PtL efficiencies of ηPtL,Oxy = 51.91% and ηPtL,Air = 54.21% can be realized. Additionally, a case study for one year of operation has been conducted yielding an annual output of about 17,000 t/a methanol and 100 GWhth./a thermal energy for an input of 50,500 t/a woodchips and a wind park size of 36 MWp.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 462
Author(s):  
Houssame Boujjat ◽  
Sylvain Rodat ◽  
Stéphane Abanades

Solar biomass gasification is an attractive pathway to promote biomass valorization while chemically storing intermittent solar energy into solar fuels. The economic feasibility of a solar gasification process at a large scale for centralized H2 production was assessed, based on the discounted cash-flow rate of return method to calculate the minimum H2 production cost. H2 production costs from solar-only, hybrid and conventional autothermal biomass gasification were evaluated under various economic scenarios. Considering a biomass reference cost of 0.1 €/kg, and a land cost of 12.9 €/m2, H2 minimum price was estimated at 2.99 €/kgH2 and 2.48 €/kgH2 for the allothermal and hybrid processes, respectively, against 2.25 €/kgH2 in the conventional process. A sensitivity study showed that a 50% reduction in the heliostats and solar tower costs, combined with a lower land cost of below 0.5 €/m2, allowed reaching an area of competitiveness where the three processes meet. Furthermore, an increase in the biomass feedstock cost by a factor of 2 to 3 significantly undermined the profitability of the autothermal process, in favor of solar hybrid and solar-only gasification. A comparative study involving other solar and non-solar processes led to conclude on the profitability of fossil-based processes. However, reduced CO2 emissions from the solar process and the application of carbon credits are definitely in favor of solar gasification economics, which could become more competitive. The massive deployment of concentrated solar energy across the world in the coming years can significantly reduce the cost of the solar materials and components (heliostats), and thus further alleviate the financial cost of solar gasification.


Author(s):  
Jongsup Hong ◽  
Ahmed F. Ghoniem ◽  
Randall Field ◽  
Marco Gazzino

Oxy-fuel combustion coal-fired power plants can achieve significant reduction in carbon dioxide emissions, but at the cost of lowering their efficiency. Research and development are conducted to reduce the efficiency penalty and to improve their reliability. High-pressure oxy-fuel combustion has been shown to improve the overall performance by recuperating more of the fuel enthalpy into the power cycle. In our previous papers, we demonstrated how pressurized oxy-fuel combustion indeed achieves higher net efficiency than that of conventional atmospheric oxy-fuel power cycles. The system utilizes a cryogenic air separation unit, a carbon dioxide purification/compression unit, and flue gas recirculation system, adding to its cost. In this study, we perform a techno-economic feasibility study of pressurized oxy-fuel combustion power systems. A number of reports and papers have been used to develop reliable models which can predict the costs of power plant components, its operation, and carbon dioxide capture specific systems, etc. We evaluate different metrics including capital investments, cost of electricity, and CO2 avoidance costs. Based on our cost analysis, we show that the pressurized oxy-fuel power system is an effective solution in comparison to other carbon dioxide capture technologies. The higher heat recovery displaces some of the regeneration components of the feedwater system. Moreover, pressurized operating conditions lead to reduction in the size of several other critical components. Sensitivity analysis with respect to important parameters such as coal price and plant capacity is performed. The analysis suggests a guideline to operate pressurized oxy-fuel combustion power plants in a more cost-effective way.


Author(s):  
Martin Hammerschmid ◽  
Stefan Müller ◽  
Josef Fuchs ◽  
Hermann Hofbauer

Abstract The present paper focuses on the production of a below zero emission reducing gas for use in raw iron production. The biomass-based concept of sorption-enhanced reforming combined with oxyfuel combustion constitutes an additional opportunity for selective separation of CO2. First experimental results from the test plant at TU Wien (100 kW) have been implemented. Based on these results, it could be demonstrated that the biomass-based product gas fulfills all requirements for the use in direct reduction plants and a concept for the commercial-scale use was developed. Additionally, the profitability of the below zero emission reducing gas concept within a techno-economic assessment is investigated. The results of the techno-economic assessment show that the production of biomass-based reducing gas can compete with the conventional natural gas route, if the required oxygen is delivered by an existing air separation unit and the utilization of the separated CO2 is possible. The production costs of the biomass-based reducing gas are in the range of natural gas-based reducing gas and twice as high as the production of fossil coke in a coke oven plant. The CO2 footprint of a direct reduction plant fed with biomass-based reducing gas is more than 80% lower compared with the conventional blast furnace route and could be even more if carbon capture and utilization is applied. Therefore, the biomass-based production of reducing gas could definitely make a reasonable contribution to a reduction of fossil CO2 emissions within the iron and steel sector in Austria.


Author(s):  
Wei Zhao ◽  
Jinju Sun ◽  
Hezhao Zhu ◽  
Cheng Li ◽  
Guocheng Cai ◽  
...  

A single stage cryogenic liquid turbine is designed for a large-scale internal compression air-separation unit to replace the Joule-Thompson valve and recover energy from the liquefied air during throttling process. It includes a radial vaned nozzle, and 3-dimensional impeller. Numerical investigation using 3-D incompressible Navier-Stokes Equation together with Spalart-Allmaras turbulence model and mixing plane approach at the impeller and stator interface are carried out at design and off-design flow. At design condition, recovered shaft power has amounted to 185.87 kW, and pressure in each component decreases smoothly and reaches to the expected scale at outlet. At small flow rates, flow separation is observed near the middle section of blade suction surface, which may cause local vaporization and even cavitation. To further improve the turbine flow behavior and performance, geometry parametric study is carried out. Influence of radial gap between impeller and nozzle blade rows, and nozzle stagger angle on turbine performance are investigated and clarified. Results arising from the present study provide some guidance for cryogenic liquid turbine optimal design.


Author(s):  
Ke Wang ◽  
Jinju Sun ◽  
Peng Song ◽  
Changjiang Huo

A single stage cryogenic liquid turbine expander is developed as a replacement for traditional Joule-Thomson valves used in the large-scale internal compression air-separation unit for the purpose of energy saving. Similar to the conventional hydraulic turbine, detrimental swirling and cavitation flow is also encountered at turbine expander impeller exit and its successive diffuser tube, but due to significant thermodynamic effect of cryogenic fluid flow, it is much more complicated than the conventional hydraulic turbine. In the present study, cavitating flow mechanism of the turbine expander is investigated first with a combination of the homogenous multiphase mixture model and the Rayleigh-Plesset model, where the former treats liquid and gas as a continuum mixture and the latter depicts the bubble dynamics. Then sensitivity study is conducted for the impeller fairing cone geometry on suppression of cavitating flow. The following are demonstrated: with a use of the fairing cone, flow behavior near and downstream the impeller exit is significantly improved, where the low static pressure region is reduced and the local temperature rise decreases, subsequently the cavitating flow is effectively suppressed. The cavitating flow is sensitive to a tuning of the fairing cone geometry, and an optimal design of the cone geometry is essential.


Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1180
Author(s):  
Licelly Canizales ◽  
Fredy Rojas ◽  
Carlos A. Pizarro ◽  
Nelson. H. Caicedo-Ortega ◽  
M. F. Villegas-Torres

SuperPro Designer® is a process simulator software used for analyzing the techno-economic feasibility of large-scale bioprocesses. Its predetermined built-in features allow for easy implementation by non-experts, but a lack of examples limits its appropriation. This study aims to validate the implementation of SuperPro Designer® by non-experts for the techno-economic analysis of anaerobic digestion in Colombia, using vinasse as feedstock. These results demonstrate the financial feasibility of such a process when a processing flow rate of 25 m3/h is ensured. Additionally, this study validates the manageability of the tool for assessing the economic feasibility of a technology, a key practice during technology development regardless of the area of expertise.


2016 ◽  
Vol 46 (7) ◽  
pp. 1295-1300 ◽  
Author(s):  
Felipe Luis Rockenbach ◽  
Adriano Mendonça Souza ◽  
João Helvio Righi de Oliveira

ABSTRACT: This study aimed to measure the economic feasibility and the time needed to return capital invested for the installation of a swine manure treatment system, these values originated the sale of carbon credits and/or of compensation of electric energy in swine farms, using the Box-Jenkins forecast models. It was found that the use of biogas is a viable option in a large scale with machines that operate daily for 10h or more, being the return period between 70 to 80 months. Time series analysis models are important to anticipate the series under study behavior, providing the swine breeder/investor means to reduce the financial investment risk as well as helping to decrease the production costs. Moreover, this process can be seen as another source of income and enable the breeder to be self-sufficient in the continuous supply of electric energy, which is very valuable nowadays considering that breeders are now increasingly using various technologies.


2012 ◽  
Vol 605-607 ◽  
pp. 288-291
Author(s):  
Rui Zhu ◽  
Guang Meng ◽  
Hong Guang Li

Large-scale air separation equipment is used widely in chemical industry. It can provide oxygen, nitrogen and argon for the production process. Based on the deep analysis of the working principle and using equipment, the air separation unit product data management (PDM) system is developed by Visual Basic (VB) in this paper develops. The modularized design procedure and grouping technique (GT) are adopted in this system. The morphological matrix is used to establish their coordination relationship among parts. The system has many characters, such as perfect function, reasonable database structure, and concise software interface layout. Optimizing equipment parts management properly and effectively has important practical significance in designing the subsequent product development work and establishing concurrent design environment of the air separation unit.


2016 ◽  
Vol 27 (3) ◽  
pp. 246-258 ◽  
Author(s):  
Anestis Anastasiadis ◽  
Georgios Kondylis ◽  
Georgios A Vokas ◽  
Panagiotis Papageorgas

Purpose – The purpose of this paper is to examine the feasibility of an ideal power network that combines many different renewable energy technologies such as wind power, concentrated solar power (CSP) and hydroelectric power. This paper emphasizes in finding the benefits arising from hydrothermal coordination compared to the non-regulated integration of the hydroelectric units, as well as the benefits from the integration of wind power and CSP. Design/methodology/approach – Artificial Neural Networks were used to estimate wind power output. As for the CSP system, a three-tier architecture which includes a solar field, a transmission-storage system and a production unit was used. Each one of those separate sections is analyzed and the process is modeled. As for the hydroelectric plant, the knowledge of the water’s flow rated has helped estimating the power output, taking into account the technical restrictions and losses during transmission. Also, the economic dispatch problem was solved by using artificial intelligence methods. Findings – Hydrothermal coordination leads to greater thermal participation reduction and cost reduction than a non-regulated integration of the hydrothermal unit. The latter is independent from the degree of integration of the other renewable sources (wind power, CSP). Originality/value – Hydrothermal coordination in a power system which includes thermal units and CSP for cost and emissions reduction.


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