循环流化床锅炉脱硫工艺经济性分析

Economic analysis of desulfurization technology of circulating fluidized bed boiler

循环流化床锅炉炉内脱硫无法满足排放要求时,需要对排烟进行进一步净化。烟气净化工艺主要有石灰石-石膏湿法烟气脱硫和循环流化床半干法烟气脱硫。为了比较2种工艺的经济性,建立了技术经济分析模型,对比分析了满负荷时炉内脱硫效率70%条件下的经济技术指标。分析结果表明,循环流化床半干法烟气脱硫的运行成本和总成本相对较低时,要求硫含量分别低于1.1%和2.1%;循环流化床半干法烟气脱硫的脱硫剂成本占比较大,而石灰石-石膏湿法烟气脱硫的电费占比相对略大;石灰石价格、上网电价和年运行时间是影响脱硫成本的主要因素,石灰石对脱硫成本的敏感度大于上网电价;石灰石价格低于112元/t时,石灰石-石膏湿法烟气脱硫的运行成本更高;上网电价低于0.43元/kWh时,石灰石-石膏湿法烟气脱硫的运行成本相较更低;循环流化床半干法烟气脱硫总成本在石灰石价格、电价、年运行时间的研究波动范围内相对较小;相较于常规炉内脱硫技术,超细石灰石炉内脱硫技术的炉内脱硫成本较低,与循环流化床半干法烟气脱硫工艺相结合的综合优势更显著。

When the desulfurization in circulating luidized bed(CFB)boiler can not meet the discharge requirements,further purification of exhaust gas is needed.There are two options for the exhaust flue gas desulphurization(FGD)in the circulating fluidized bed boiler,such as limestone-gypsum wet FGD and CFB semi-dry FGD.In order to identify the most economical and suitable FGD technology for circulating fluidized bed combustion conditions,the techno-economic analysis model was suggested and the techno-economic index for two processes was predicted under the condition of full load and 70%desulphurization efficiency in theCFB combustion by limestone injection.The model results indicate that the operating cost and total cost of CFB semi-dry FGD technology are relatively low,require sulfur contents is required below 1.1%and 2.1%.The cost proportion of the desulfurizing agent for(CFB)semi-dry FGD is significantly large,while the electricity cost proportion of limestone-gypsum wet FGD is slightly large.Limestone price,on-grid power tariff and annual operation time are the main factors affecting desulfurization cost.The sensitivity of limestone to desulfurization cost is greater than that of on-grid power tariff.On the basis of the furnace desulfurization efficiency of 70%,the operating cost of limestone-gypsum wet FGD is higher than that of CFB semi-dry FGD when the price of limestone is less than 112 yuan per ton.When the on-grid power tariff is lower than 0.43 yuan per kilowatt hour,the operating cost of limestone-gypsum wet FGD is relatively low.The total cost of CFB semi-dry FGD is lower than that of limestone-gypsum wet FGD within the fluctuation range of limestone price,electricity price,and annual operating time.Compared with the conventional furnace desulfurization technology,the desulfurization cost of the ultra-fine limestone furnace desulfurization technology is lower,and the comprehensive advantages combined with the CFB semi-dry FGD technology are more prominent.