Entrained flow gasification of coal: 2. Fate of nitrogen and sulphur pollutants as assessed from local measurements
✍ Scribed by John R. Highsmith; Nicholas R. Soelberg; Paul O. Hedman; L.Douglas Smoot; Angus U. Blackham
- Publisher
- Elsevier Science
- Year
- 1985
- Tongue
- English
- Weight
- 735 KB
- Volume
- 64
- Category
- Article
- ISSN
- 0016-2361
No coin nor oath required. For personal study only.
✦ Synopsis
A laboratory-scale, entrained flow gasifier was used to investigate the local details of the coal gasification process. Results were obtained from a series of mapping tests at an oxygen-coal ratio of 0.91 and a steamxoal ratio of 0.27, using a Utah high-volatile, low-sulphur bituminous coal. Sulphur pollutant (H,S, SO,, COS and CS,) and nitrogen pollutant (HCN, NH, and NO) concentrations were determined by detailed radial measurements. As was revealed by measurements of the main gasification products reported in Part 1, three separate flame zones were also found for pollutants: an intense oxygen-rich flame region where very rapid reaction took place, a recirculation region and a downstream region where slow heterogeneous reactions were observed. Oxygenated pollutant species (SO, and NO) were found to form in significant amounts (up to 3168 and 2767 ppm respectively) in the intense, oxygen-rich flame region. These oxygenated species were converted to varying amounts of H,S, COS, CS,, HCN and NH 3 towards the reactor exit, more consistent with expected values based on the overall stoichiometry.
Values of local carbon, sulphur and nitrogen conversion from the coal to the gas phase were determined from ash carbon. ash sulphur and ash-nitrogen material balances, respectively. Elemental conversion values near the reactor exit were = 79"/, for carbon, 78% for sulphur and 85% for nitrogen. These data allow the important reaction processes to be postulated and also provide insight into the chemical mechanisms of pollutant formation. The local data are also useful for comparison and validation of generalized entrained coal gasification models.