Steam reforming (SR) and catalytic partial oxidation (CPO) are promising processes for syngas production from different hydrocarbons. Fossil fuels can be used for this purpose, but the production of hydrogen is accompanied by the emission of carbon dioxide. Biomasses can be adopted to overcome this problem, since biomass takes in carbon dioxide from the atmosphere for its growth. Biomasses are rich in oxygenated hydrocarbons which can be employed as fuels for such processes. Among the various renewable feedstock alternatives, ethanol has been regarded as an attractive feedstock due to its relatively high hydrogen content, availability, non-toxicity, storage or handling ease and safety. More importantly, ethanol production from celluloses will shed light on the possibility for the utilization of low-cost non-edible biomass such as agro-industrial wastes, forestry residue materials in order to resolve the competitive problem between food production and bio-ethanol formation. CPO and SR tests were conducted with ethanol as a fuel at different operating conditions and with rhodium and platinum-based catalysts in order to analyze the kinetic dependences of the reactions involved in these processes. Particular focus has been put on carbon deposition phenomena and their inhibiting effect on the rate of steam reforming. Furthermore, a thermodynamic model has been adopted for the calculation of equilibrium composition of ethanol CPO and SR products.
Lo steam reforming (SR) e l'ossidazione parziale catalitica (CPO) sono processi promettenti per la produzione di syngas da diversi idrocarburi. I combustibili fossili possono essere utilizzati per questo scopo, ma la produzione di idrogeno è accompagnata dall'emissione di anidride carbonica. Le biomasse possono essere adottate per superare questo problema, dal momento che la biomassa assorbe l'anidride carbonica dall'atmosfera per la sua crescita. Le biomasse sono ricche di idrocarburi ossigenati che possono essere impiegati come combustibili per tali processi. Tra le varie alternative di materie prime rinnovabili, l'etanolo è stato considerato come una materia prima interessante a causa del suo contenuto relativamente elevato di idrogeno, della sua elevata disponibilità, non tossicità, facilità di stoccaggio e di manipolazione e sicurezza. Ancora più importante, la produzione di etanolo da cellulose farà luce sulla possibilità per l'utilizzo di biomassa non commestibile a basso costo come rifiuti agro-industriali e materiali residui di attività forestali al fine di risolvere il problema competitivo tra produzione di cibo e formazione di bio-etanolo. Le prove di CPO e SR sono state condotte con etanolo come combustibile in diverse condizioni operative e con catalizzatori a base di rodio e platino per analizzare le dipendenze cinetiche delle reazioni coinvolte in questi processi. Particolare attenzione è stata dedicata ai fenomeni di deposizione di carbonio e al loro effetto inibente sull’attività dei catalizzatoti nello steam reforming. Inoltre, è stato adottato un modello termodinamico per il calcolo della composizione di equilibrio dei prodotti di CPO e SR di etanolo.
Kinetic study of partial oxidation and steam reforming of ethanol over Rh/Al2O3 and Pt/Al2O3 catalysts
HOCHKOEPPLER, ENRICO;BRAGLIA, DAVIDE
2017/2018
Abstract
Steam reforming (SR) and catalytic partial oxidation (CPO) are promising processes for syngas production from different hydrocarbons. Fossil fuels can be used for this purpose, but the production of hydrogen is accompanied by the emission of carbon dioxide. Biomasses can be adopted to overcome this problem, since biomass takes in carbon dioxide from the atmosphere for its growth. Biomasses are rich in oxygenated hydrocarbons which can be employed as fuels for such processes. Among the various renewable feedstock alternatives, ethanol has been regarded as an attractive feedstock due to its relatively high hydrogen content, availability, non-toxicity, storage or handling ease and safety. More importantly, ethanol production from celluloses will shed light on the possibility for the utilization of low-cost non-edible biomass such as agro-industrial wastes, forestry residue materials in order to resolve the competitive problem between food production and bio-ethanol formation. CPO and SR tests were conducted with ethanol as a fuel at different operating conditions and with rhodium and platinum-based catalysts in order to analyze the kinetic dependences of the reactions involved in these processes. Particular focus has been put on carbon deposition phenomena and their inhibiting effect on the rate of steam reforming. Furthermore, a thermodynamic model has been adopted for the calculation of equilibrium composition of ethanol CPO and SR products.File | Dimensione | Formato | |
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https://hdl.handle.net/10589/141512