Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6630067 | Fuel | 2018 | 9 Pages |
Abstract
This paper presents gasification data for two Victorian brown coal chars (Yallourn and Morwell) in CO2 at temperatures between 700 and 1000â¯Â°C. The effects of temperature, gas-particle contact mode (entrained mode vs drop-tube mode), reactant gas concentration and residence time on carbon conversion, and syngas yield and composition was investigated. The results indicate that at a higher temperature and CO2 concentration, carbon conversion increases as expected, along with syngas yield and composition. It is found that gasification under entrained mode achieves higher carbon conversion and gas yield than that under the drop-tube mode, even at a shorter residence time. The finding suggests that the gasification experiments should be conducted under entrained flow condition (gas velocityâ¯>â¯particle velocity) to truly reflect gasification performance. At 1000â¯Â°C, with an increase in residence time, the carbon conversion and syngas yield gradually increases to nearly 100% and an estimated equilibrium value, respectively. The experimental data establishes that for a complete char conversion, around 17â¯s and 21â¯s residence times are required for Yallourn and Morwell, respectively, if gasification is conducted at 1000â¯Â°C in an environment of 20% CO2. This finding indicates that Victorian brown coals need to be gasified at a temperature above 1000â¯Â°C to shorten the residence time considering that the typical residence time of industrial entrained-flow gasifier is 6-10â¯s.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Tao Xu, Sankar Bhattacharya,