Hydrogen Production by Exploiting Diluted Second Generation Bio-ethanol: Process Design and Economic Assessment
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Data di Pubblicazione:
2018
Citazione:
Hydrogen Production by Exploiting Diluted Second Generation Bio-ethanol: Process Design and Economic Assessment / I. Rossetti, A. Tripodi, G. Ramis. ((Intervento presentato al convegno ANM tenutosi a Aveiro nel 2018.
Abstract:
INTRODUCTION
Hydrogen is an interesting energy vector and among the various renewable feedstocks, bioethanol is known to be a promising raw material for sustainable hydrogen production through steam reforming. It can be produced through a relatively well assessed biomass fermentation process and it is expected to be industrially available on a large scale in the near future, also starting from 2nd generation biomass, i.e. not competing with the food and food chain. However, in spite of a comprehensive advancement of the research on the related technologies, studies on the real feasibility of its application in economic terms are currently lacking. For this reason, an economic assessment was carried out in this study after the process simulation and optimisation of a bioethanol-to-hydrogen plant. Previous works about the feasibility of power cogeneration through fuel cells (5 kWel + 5 kWth) using bioethanol with different concentration were proposed1. The system was constituted of several reactors in series for hydrogen production (Steam Reforming unit), purification (High-Temperature Water Gas Shift, Low-Temperature Water Gas Shift, Methanator) and by a polymer electrolyte membrane fuel cell with the given power size. However, the process was studied for a small-scale hydrogen production (6.5 Nm3/h), only, to demonstrate the feasibility for a small scale residential use. The bioethanol steam reforming on a large scale represents a route for renewable hydrogen production. To better examine its potentialities, the process was here directed to hydrogen production, only, without considering any power generation downstream or other further uses of hydrogen. The plant was designed, optimised and sized as for the main economic evaluation parameters to estimate its feasibility.
EXPERIMENTAL/THEORETICAL STUDY
The process was assessed using the AspenONE Engineering Suite® (v.9.1). The flowsheet has been designed and optimized using the sequential-modular Aspen Plus® process simulator. A capacity of 40,000 ton/y of bioethanol has been chosen based on the nominal capacity of a second generation bioethanol production plant currently commercialized.
The economic assessment was evaluated using the databanks of Aspen Process EconomicAnalyzer® and updated to the current time using a project capital escalation of 2.
RESULTS AND DISCUSSION
Various economic indicators were used to assess the sustainability of the process. Among them the minimum hydrogen selling price stating from different types and purities of bioethanol was compared as follows (1G, 2G = 1st or second generation bioethanol; 100, 90, 40 = wt% of ethanol in water)2.
CONCLUSION
Concerning the 1st generation bioethanol, the use of 90% purity led to a selling price decreased by 8% compared to the pure Bio100-1G, whereas the use of Bio50 led to a 42% lower price. 2nd generation bioethanol is sustainable only by exploiting diluted solutions. These data refer to a total production of 7,793 ton/year of H2 (9,886 Nm3 h-1) starting from 40,000 ton/year of bioethanol.
REFERENCES
1. I. Rossetti et al., Chem. Eng. J. 281, 1036 (2015)
2. M. Compagnoni et al., Energy&Fuels 31, 12988 (2017)
Tipologia IRIS:
14 - Intervento a convegno non pubblicato
Elenco autori:
I. Rossetti, A. Tripodi, G. Ramis
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