Modeling of char oxidation in fluidized bed biomass gasifiers : effects of transport and chemical kinetics
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | eng |
| Published: |
Massachusetts Institute of Technology
2015
|
| Subjects: | |
| Online Access: | http://hdl.handle.net/1721.1/98959 |
| _version_ | 1826190397009821696 |
|---|---|
| author | Brooks, Amelia (Amelia Samek) |
| author2 | Ahmed F. Ghoniem. |
| author_facet | Ahmed F. Ghoniem. Brooks, Amelia (Amelia Samek) |
| author_sort | Brooks, Amelia (Amelia Samek) |
| collection | MIT |
| description | Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015. |
| first_indexed | 2024-09-23T08:39:38Z |
| format | Thesis |
| id | mit-1721.1/98959 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T08:39:38Z |
| publishDate | 2015 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/989592019-04-09T19:01:35Z Modeling of char oxidation in fluidized bed biomass gasifiers : effects of transport and chemical kinetics Brooks, Amelia (Amelia Samek) Ahmed F. Ghoniem. Massachusetts Institute of Technology. Department of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering. Mechanical Engineering. Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015. Cataloged from PDF version of thesis. Includes bibliographical references (page 36). Technologies for the conversion of biomass to liquid fuels are important to develop because the demand for liquid fuels remains unchanged even with the necessity of limiting dependence on fossil fuels. Fluidized Bed Biomass Gasification (FBBG) is one such technology that can perform the initial step of converting raw biomass into syngas as an intermediate to liquid fuels. The char that is left in the reactor after devolatilization can be oxidized in order to maximize the amount of biomass carbon that is converted to gaseous carbon and generate heat to drive endothermic gasification reactions. This paper examines the rate of each of the three processes that occur during char conversion (external diffusion, chemical reactions, and intraparticle diffusion) to determine which process limits the rate of the reaction under a range of conditions. It was determined that at most FBBG operating points, the rate of char conversion will be limited by the rate of diffusion of oxygen through the particle's boundary layer and through its pores. Only at low reactor temperatures and small particle diameters will the reaction rate be purely kinetically limited. An overall rate expression accounting for all three processes has been formulated which can be implemented in more detailed reactor models. by Amelia Brooks. S.B. 2015-09-29T18:55:30Z 2015-09-29T18:55:30Z 2015 2015 Thesis http://hdl.handle.net/1721.1/98959 921147632 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 36 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Mechanical Engineering. Brooks, Amelia (Amelia Samek) Modeling of char oxidation in fluidized bed biomass gasifiers : effects of transport and chemical kinetics |
| title | Modeling of char oxidation in fluidized bed biomass gasifiers : effects of transport and chemical kinetics |
| title_full | Modeling of char oxidation in fluidized bed biomass gasifiers : effects of transport and chemical kinetics |
| title_fullStr | Modeling of char oxidation in fluidized bed biomass gasifiers : effects of transport and chemical kinetics |
| title_full_unstemmed | Modeling of char oxidation in fluidized bed biomass gasifiers : effects of transport and chemical kinetics |
| title_short | Modeling of char oxidation in fluidized bed biomass gasifiers : effects of transport and chemical kinetics |
| title_sort | modeling of char oxidation in fluidized bed biomass gasifiers effects of transport and chemical kinetics |
| topic | Mechanical Engineering. |
| url | http://hdl.handle.net/1721.1/98959 |
| work_keys_str_mv | AT brooksameliaameliasamek modelingofcharoxidationinfluidizedbedbiomassgasifierseffectsoftransportandchemicalkinetics |