| dc.contributor.author | Mansaray, Kelleh Gbawuru. | en_US |
| dc.date.accessioned | 2014-10-21T12:37:41Z | |
| dc.date.available | 1998 | |
| dc.date.issued | 1998 | en_US |
| dc.identifier.other | AAINQ31530 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55547 | |
| dc.description | Gasification of rice husks in a dual distributor fluidized bed gasifier using air as the sole gasifying agent was investigated. The study was conducted in four stages: (a) modification of existing fluidized bed gasifier and data acquisition system, (b) preliminary experimentation to assess the suitability of rice husks for gasification, to determine the feasible range of operating conditions for fluidized bed gasification of rice husks and to obtain data for proper design of thermochemical conversion systems, (c) development of mathematical models to predict the performance of the fluidized bed gasification system and (d) experimentation to investigate the effects of various operating variables on the performance of the gasifier and provide data to evaluate the validity of the models. | en_US |
| dc.description | The physical and chemical properties of rice husks, agglomeration characteristics of inert bed materials in the presence of rice husk ash, and thermal degradation and kinetics of rice husks were determined. | en_US |
| dc.description | The agglomeration tests conducted on silica and alumina sand particles in the presence of rice husk ash showed that rice husk ash particles treated at higher particles resulting in soft and friable agglomerates. | en_US |
| dc.description | The thermogravimetric analyses (TGA) performed on rice husks at three heating rates (10, 20, and 50$\sp\circ$C/min) in air, oxygen and nitrogen atmospheres from ambient temperature to 700$\sp\circ$C showed two distinct reaction zones. | en_US |
| dc.description | Gasification experiments carried out at three bed heights (19.5, 25.5 and 31.5 cm), three fluidization velocities (0.22, 0.28 and 0.33 m/s) and three equivalence ratios (0.25, 0.30 and 0.35) showed that both the fluidization velocity and equivalence ratio have a major influence on the distribution and yield of products. The fluidization velocity of 0.22 m/s and equivalence ratio of 0.25 appeared to be the optimum conditions with respect to the quality of gas. The mole fractions of the combustible components reached their maximum values at these conditions. A typical gas composition at the fluidization velocity of 0.22 m/s and equivalence ratio of 0.25 was 4% H$\sb2$, 5% hydrocarbons (CH$\sb4$, C$\sb2$H$\sb2$, C$\sb2$H$\sb4$ and C$\sb2$H$\sb6$), 15% CO$\sb2$, 20% CO and 57% N$\sb2$. | en_US |
| dc.description | Two mathematical models were developed to simulate the performance of the dual distributor fluidized bed gasifier. The first model has a single parameter (overall carbon conversion) that can be used to improve the fit between predicted and experimental gas compositions. On the other hand, the second model has two parameters (carbon conversion in the core and annular regions) that can be independently adjusted to account for the effect of various operating and design conditions on the composition of the gasification products. The mean error between the predicted and measured product gas composition ranged from 2.45 to 3.05% when the one-compartment model was used. (Abstract shortened by UMI.) | en_US |
| dc.description | Thesis (Ph.D.)--DalTech - Dalhousie University (Canada), 1998. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Engineering, Agricultural. | en_US |
| dc.subject | Engineering, Mechanical. | en_US |
| dc.title | Gasification of rice husk in a fluidized bed reactor. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
