Optimal Conditions of Thermal Treatment Unit for the Steam Reforming of Raw Bio-oil in a Continuous Two-step Reaction System
The separation of pyrolytic lignin in a previous thermal treatment step is essential for the viability and efficiency of the continuous hydrogen production by steam reforming (SR) of raw bio-oil. This work aimed to establish the conditions of this thermal step that maximize the bio-oil fraction liab...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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AIDIC Servizi S.r.l.
2017-03-01
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| Series: | Chemical Engineering Transactions |
| Online Access: | https://www.cetjournal.it/index.php/cet/article/view/2098 |
| _version_ | 1798017308651683840 |
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| author | B. Valle Pascual B. Aramburu A. Remiro A. Arandia J. Bilbao A. Gayubo |
| author_facet | B. Valle Pascual B. Aramburu A. Remiro A. Arandia J. Bilbao A. Gayubo |
| author_sort | B. Valle Pascual |
| collection | DOAJ |
| description | The separation of pyrolytic lignin in a previous thermal treatment step is essential for the viability and efficiency of the continuous hydrogen production by steam reforming (SR) of raw bio-oil. This work aimed to establish the conditions of this thermal step that maximize the bio-oil fraction liable to valorization in the subsequent SR reactor, and that lead to a better behavior of the catalyst. The influence that temperature (400- 800 °C) and steam-to-carbon ratio S/C (1.5-6.0) have on the composition of resulting volatile stream and on the solid fraction (pyrolytic lignin) deposition was analyzed by feeding raw bio-oil, and a mixture of raw bio-oil and with 20 wt% of ethanol. The thermal treatment temperature affects both the yield of pyrolytic lignin (which decreases with temperature, especially in the range 400-500 °C) and its composition (so that the H/C ratio decreases as the temperature is higher). The yield of liquid fraction and its total content of oxygenates decrease notably above 500 °C. Levoglucosan content decreases, while that of phenols (especially above 650 °C), carboxylic acids (mainly acetic acid) and acetaldehyde increase markedly as temperature is raised. Temperature rise enhances formation of gaseous products (mainly CO and CO2), with H2, CH4 and hydrocarbons being promoted above 600 °C. The effect of thermal step temperature on the Ni/La2O3-??Al2O3 catalyst behavior was studied by analyzing the evolution with time-on-stream of bio-oil conversion and product yields. Consequently, 500 °C is the thermal treatment temperature that leads to a better compromise between H2 yield and catalyst stability, since the resulting oxygenated composition causes less deactivation of the reforming Ni/La2O3-??Al2O3 catalyst, thereby attaining complete and stable bio-oil conversion and H2 yield close to 90 %. |
| first_indexed | 2024-04-11T16:05:04Z |
| format | Article |
| id | doaj.art-5c297e01ef114f5c92b5da026acb1c07 |
| institution | Directory Open Access Journal |
| issn | 2283-9216 |
| language | English |
| last_indexed | 2024-04-11T16:05:04Z |
| publishDate | 2017-03-01 |
| publisher | AIDIC Servizi S.r.l. |
| record_format | Article |
| series | Chemical Engineering Transactions |
| spelling | doaj.art-5c297e01ef114f5c92b5da026acb1c072022-12-22T04:14:52ZengAIDIC Servizi S.r.l.Chemical Engineering Transactions2283-92162017-03-015710.3303/CET1757035Optimal Conditions of Thermal Treatment Unit for the Steam Reforming of Raw Bio-oil in a Continuous Two-step Reaction SystemB. Valle PascualB. AramburuA. RemiroA. ArandiaJ. BilbaoA. GayuboThe separation of pyrolytic lignin in a previous thermal treatment step is essential for the viability and efficiency of the continuous hydrogen production by steam reforming (SR) of raw bio-oil. This work aimed to establish the conditions of this thermal step that maximize the bio-oil fraction liable to valorization in the subsequent SR reactor, and that lead to a better behavior of the catalyst. The influence that temperature (400- 800 °C) and steam-to-carbon ratio S/C (1.5-6.0) have on the composition of resulting volatile stream and on the solid fraction (pyrolytic lignin) deposition was analyzed by feeding raw bio-oil, and a mixture of raw bio-oil and with 20 wt% of ethanol. The thermal treatment temperature affects both the yield of pyrolytic lignin (which decreases with temperature, especially in the range 400-500 °C) and its composition (so that the H/C ratio decreases as the temperature is higher). The yield of liquid fraction and its total content of oxygenates decrease notably above 500 °C. Levoglucosan content decreases, while that of phenols (especially above 650 °C), carboxylic acids (mainly acetic acid) and acetaldehyde increase markedly as temperature is raised. Temperature rise enhances formation of gaseous products (mainly CO and CO2), with H2, CH4 and hydrocarbons being promoted above 600 °C. The effect of thermal step temperature on the Ni/La2O3-??Al2O3 catalyst behavior was studied by analyzing the evolution with time-on-stream of bio-oil conversion and product yields. Consequently, 500 °C is the thermal treatment temperature that leads to a better compromise between H2 yield and catalyst stability, since the resulting oxygenated composition causes less deactivation of the reforming Ni/La2O3-??Al2O3 catalyst, thereby attaining complete and stable bio-oil conversion and H2 yield close to 90 %.https://www.cetjournal.it/index.php/cet/article/view/2098 |
| spellingShingle | B. Valle Pascual B. Aramburu A. Remiro A. Arandia J. Bilbao A. Gayubo Optimal Conditions of Thermal Treatment Unit for the Steam Reforming of Raw Bio-oil in a Continuous Two-step Reaction System Chemical Engineering Transactions |
| title | Optimal Conditions of Thermal Treatment Unit for the Steam Reforming of Raw Bio-oil in a Continuous Two-step Reaction System |
| title_full | Optimal Conditions of Thermal Treatment Unit for the Steam Reforming of Raw Bio-oil in a Continuous Two-step Reaction System |
| title_fullStr | Optimal Conditions of Thermal Treatment Unit for the Steam Reforming of Raw Bio-oil in a Continuous Two-step Reaction System |
| title_full_unstemmed | Optimal Conditions of Thermal Treatment Unit for the Steam Reforming of Raw Bio-oil in a Continuous Two-step Reaction System |
| title_short | Optimal Conditions of Thermal Treatment Unit for the Steam Reforming of Raw Bio-oil in a Continuous Two-step Reaction System |
| title_sort | optimal conditions of thermal treatment unit for the steam reforming of raw bio oil in a continuous two step reaction system |
| url | https://www.cetjournal.it/index.php/cet/article/view/2098 |
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