| CFB combustion technology has gotten comprehensive industry application because of its good furnace desulphurization performance and high combustion efficiency. But higher Ca/S ratio(about 2.5)is needed to meet better desulphurization efficiency, and even more higher Ca/S ratio can't satisfy SO2 emission standard while burning high sulfur content fuel. In the other hand, more stringent SO2 emission standard has been implemented in many countries as people has been paying more attention to environmental protection. So the intensified desulphurization technology based on CFB combustion system, which has high desulphurization efficiency and lower agent consumption, is quite valuable.This thesis, basing on The Science and Technique Program during the 10thFive-year Plan Period------Research on improving desulphurization efficiency infull-scale CFB boiler burning high sulfur content coal, is in order to get cost-effective desulphurization performance in full-scale CFB while combusting high sulfur content fuel, and use the unreacted CaO particles sufficiently existing in boiler fly-ash. This thesis put forward the intensified desulphurization technology which combined with furnace desulphurization by adding calcium agent in CFB boiler and circulation-suspension semi-dry FGD technology, and developed research in three parts as follows: (1)using thermogravity analyzer, to get the reaction characteristic of furnace desulphurization in high temperature and humidification desulphurization in low temperature, considering the impact of different water amount and different reaction temperature. It is investigated that humidification is in favor of low temperature desulphurization, and utility of CaO is increased as the water amout is increased, but which is reduced when water amount is increased further; Low temperature is in favor of humidification desulphurization in the range of temperature which we considered.(2)using the small-scale CFR, in order to get the desulphurization performance of CaO in high temperature reaction and in humidification reaction, and the humidification desulphurization performance of fly-ash; and also the paratemer of humidificatonwith different water amount, different reaction temperature and residence time. The result indicated that the unreacted CaO contained in fly ash, which came from the desulphurization in CFB boiler, can get the utility of 20% in low temperature humifidication desulphurization. (3)putting on the experimental investigation of furnace desulphurization in large-scale CFB combustion device and 310t/h CFB boiler while burning high sulfur content fuel. At the same time, the low temperature humifidication desulphurization effect of fly ash came from furnace desulphurization is investigated in the small-scale CFR. The result indicated that the unreacted CaO contained in fly ash can also get the utility of 20% in low... |
