Carbide slag modifier for circulating fluidized bed boiler desulfurization, modified carbide slag and preparation method thereof

Abstract

The invention relates to the field of circulating fluidized bed desulfurization, in particular to a carbide slag modifier for circulating fluidized bed boiler desulfurization, modified carbide slag and a preparation method thereof. The carbide slag modifier for circulating fluidized bed boiler desulfurization comprises the following components in percentage by mass: 1-35% of a binder, 1-35% of a dispersing agent and the balance a cerium-containing rare earth catalyst. By adopting the carbide slag modifier for circulating fluidized bed boiler desulfurization and the modified carbide slag provided by the invention, the defect caused by application of carbide slag in circulating fluidized bed boiler desulfurization in the past can be avoided, the desulfurization efficiency is relatively high,resource secondary utilization is realized, the efficiency of the circulating fluidized bed boiler is improved, and the abrasion of heating surface pipes is reduced; and compared with the traditionalcirculating fluidized bed boiler combustion desulfurizer limestone, the advantage is that the desulfurization treatment cost is reduced.

Description

technical field [0001] The invention relates to the field of circulating fluidized bed desulfurization, in particular to a carbide slag modifier for circulating fluidized bed boiler desulfurization, modified carbide slag and a preparation method thereof. Background technique [0002] The circulating fluidized bed boiler adopts the clean coal combustion technology with a high degree of industrialization, which has the advantages of high efficiency, wide fuel adaptability, flexible load adjustment, and good environmental protection performance. At present, large-capacity, high-parameter supercritical and ultra-supercritical units are already in mature operation. The desulfurization method of circulating fluidized bed boiler is dry desulfurization, using CaCO 3 As a desulfurizer, limestone is added to the furnace, and the limestone is calcined into calcium oxide (850°C) at the normal operating bed temperature (850-900°C). 2 Reaction combined to achieve desulfurization. Since...

AI Technical Summary

Problems solved by technology

Carbide slag is gradually calcined and decomposed from the surface in the furnace under high temperature, and releases H 2 0, the process of water release makes it form porous solid particles CaO, the porosity of the particles increases to facilitate the desulfurization reaction, and the simultaneous desulfurization reaction makes the generated CaSO 3 Coated on the surface of CaO particles, it is easy to cause the particle porosity to gradually decrease until it is closed. As the reaction progresses, it gradually transfers from the initial chemical reaction resistance to the diffusion resistance of the product layer and the diffusion resistance of the inner pores, so the particle size distribution and fineness have extremely high requirements, otherwise the desulfurization effect is extremely unsatisfactory

Based on this, although calcium carbide slag has good chemical activity, it is limited in the dry desulfurization of circulating fluidized bed boilers due to its fine particles and light density.