What are the advantages and disadvantages of in-furnace desulfurization process of CFB boilers?

　　Compared with other desulfurization processes, the in-furnace desulfurization of circulating fluidized bed boilers has the advantages of simple structure, no water consumption, small footprint, no corrosion, wear and scaling problems, no waste water, low investment and low cost, and wide coal adaptability. However, there are disadvantages such as demand of high purity limestone, and limited utilization of desulfurization products. Because the efficiency of furnace desulfurization is lower than that of traditional wet desulfurization, it is difficult to meet the ultra-low emission requirements simply by using furnace desulfurization technology. It is generally used as a preliminary desulfurization process for newly-built units.