Τεχνοοικονομική ανάλυση παραγωγής και μεταφοράς υδρογόνου μέσω μεθανόλης

Βουτσάς, Κωνσταντίνος; Voutsas, Konstantinos

dc.contributor.author	Βουτσάς, Κωνσταντίνος	el
dc.contributor.author	Voutsas, Konstantinos	en
dc.date.accessioned	2025-05-07T07:05:42Z
dc.date.available	2025-05-07T07:05:42Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/61872
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.29568
dc.rights	Αναφορά Δημιουργού - Μη Εμπορική Χρήση - Παρόμοια Διανομή 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-sa/3.0/gr/	*
dc.subject	Πράσινο Υδρογόνο	el
dc.subject	Διοξείδιο του Άνθρακα	el
dc.subject	Τεχνοοικονομική Ανάλυση	el
dc.subject	Hydrogen Carriers	en
dc.subject	Δέσμευση Διοξειδίου του Άνθρακα	el
dc.subject	Ηλεκτρόλυση	el
dc.title	Τεχνοοικονομική ανάλυση παραγωγής και μεταφοράς υδρογόνου μέσω μεθανόλης	el
dc.title	Production of green hydrogen through methanol: A technoeconomic analysis	en
heal.type	bachelorThesis
heal.classification	Χημική Μηχανική	el
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2024-10-01
heal.abstract	Methanol is emerging as a promising green hydrogen carrier due to its favorable chemical properties, ease of storage, and transportability. As a liquid at ambient conditions, methanol offers significant advantages over conventional hydrogen storage methods, such as compressed or liquefied hydrogen. This thesis explores methanol's role in hydrogen production through reforming processes, where it can be efficiently converted back into hydrogen with low energy demand. In the framework of the thesis, methanol is synthesized from captured CO₂ from the flue gas o a typical cement industry, making it a carbon-neutral option within a circular energy economy. Green hydrogen used for methanol production is generated via water electrolysis in an alkaline electrolyser, which provides a sustainable and carbon-free method essential for transitioning to a clean energy economy. Aspen Plus™ was employed to simulate the whole process: the electrolyser for the H2 production, the CO2 capture process and the methanol production process. The simulation of the elctrolyser utilized semi-empirical equations from the original work of Sanchez et al., which describe a 15-kW experimental electrolyser. The stack model was successfully validated, with the results closely matching those from the original paper. An integrated 58.6 MW electrolysis system was subsequently developed, with simulations performed at three different stack pressures (5, 7, and 9 bar) and three inlet temperatures (50°C, 75°C, and 80°C). The feed mixture entering the stack consisted of 65% w/w H₂O and 35% w/w KOH electrolyte. Comparison with a 1.5 MW commercial alkaline electrolyser showed consistent hydrogen production. The optimal operating conditions were identified as 5 bar and 80°C. A techno-economic analysis was conducted, using photovoltaics (PV) as the electrical supply source, resulting in a calculated Levelized Cost of Hydrogen (LCOH) of 6.99 €/kg. Concerning the carbon dioxide capture process, for a CO2 flow of 1055.5 ktonnes per year entering the system, it successfully captures 90% of the CO2 using an aqueous 30% wt. MEA solvent. The process requires 149 MW of heat energy in the stripper column reboiler, for CO2. A sensitivity analysis indicated an optimal loading of 0.2, which minimizes the reboiler duty while balancing costs such as pump work, heat exchanger surface area, and cooling duty. Increasing the number of stages in both the absorber and stripper columns reduces the reboiler duty and reflux ratio. However, the impact diminishes beyond 10 stages for the stripper column, suggesting that 8 stages are optimal for balancing performance and capital costs, while the absorber column operates with 12 stages. The total equipment cost for the CO2 capture unit is approximately 45.5 million euros, with the absorber, stripper, scrubber, and heat exchanger contributing the most to the total cost. Utility costs, including cooling water, steam, and electricity, amount to approximately 22 million euros per year. Additionally, the variable operating costs, including MEA makeup, add another 25.6 million euros annually. The levelized cost of the carbon capture process is about 46 €/ton CO2, which aligns with values found in the literature. However, due to the high annualized revenue from CO2 capture (73.4 €/ton CO2 captured), the process is profitable by 27.4 €/ton CO2. The methanol production process uses a slightly modified process flow diagram to the one proposed by Kiss et al., replacing the stripper column with a low-pressure separation vessel. A parametric analysis examines the effects of reactor pressure and temperature on methanol production, focusing on optimizing energy use and production efficiency. Optimal reactor pressure is found to be 50 bar, where energy demand is minimized. The reactor temperature of 250°C is chosen as it provides the best balance for methanol production and carbon dioxide conversion. The economic analysis includes CAPEX of €7.1 million, driven mainly by compression, distillation, and heat exchangers., while the OPEX is €20 million per year, with electricity as the largest contributor. The levelized cost of methanol was calculated to be 533.03 €/tonMEOH. In conclusion, for methanol production from H2 produced by electrolysis and CO2 captured from the flue gas of a typical cement industry, the cost of electrolysis was estimated at 2235.52 €/ton MeOH, the cost of CO2 capture at -92.66 €/ton MeOH, and the cost of methanol production at 533.03 €/ton MeOH, resulting in a final total cost of 2675.89 €/ton MeOH. Compared to the commercial cost of methanol, which is 535 €/ton MeOH, indicates that there are many steps ahead to achieve a ‘greener’ world.	en
heal.advisorName	Στεφανίδης, Γεώργιος	el
heal.committeeMemberName	Καβουσανάκης, Μιχαήλ	el
heal.committeeMemberName	Θεοδώρου, Θεόδωρος	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Χημικών Μηχανικών. Τομέας Ανάλυσης, Σχεδιασμού και Ανάπτυξης Διεργασιών και Συστημάτων (ΙΙ)	el
heal.academicPublisherID	ntua
heal.numberOfPages	116 σ.	el
heal.fullTextAvailability	false