Two-step desulfurization technology of coal burning process

Abstract

The invention discloses a two-step desulfurization technology of the coal burning process. The technology comprises the following steps that S1, pulverized coal is mixed with a desulfurizing agent A to prepare desulfurized coal A, and the desulfurized coal A is sprayed into a boiler to be burnt, wherein the desulfurized coal A is prepared by mixing coal slags, calcium oxide, calcium hydroxide and aluminum oxide according to proportions; S2, pulverized coal is mixed with a desulfurizing agent B to prepare desulfurized coal B, and then the desulfurized coal B is sprayed into a main burning zone of the boiler through a material spray pipe, wherein the material spray pipe and a secondary air pipe are arranged in a crossed mode, the desulfurizing agent B is prepared by mixing aluminum sulfate, sodium carbonate, potassium chloride, iron carbonate, vanadium pentoxide and zinc borate according to proportions, the desulfurizing agent B is added to water and mixed to be prepared into mixed suspension with the mass percent of 12%-20%, the mixed suspension is mixed with the pulverized coal, standing is conducted till the water content ranges from 3% to 5%, and the desulfurized coal B is prepared. According to the two-step desulfurization technology of the coal burning process, the desulfurizing agents are added in a segmented mode, the effect of calcium-based desulfuration agents is fully exerted, and the desulfurization efficiency is greatly improved.

Description

technical field [0001] The invention relates to coal combustion desulfurization, in particular to a two-step desulfurization process of coal combustion. Background technique [0002] Sulfur in coal includes inorganic sulfur, organic sulfur and elemental sulfur. Inorganic sulfur mainly exists in the form of disulfide and sulfate, most of the disulfide is pyrite, a small part is marcasite, and the sulfate is mainly calcium sulfate CaSO 4 ; The organic sulfur is directly bonded to the coal matrix in the form of mercaptan, sulfide, disulfide and aromatic ring sulfur represented by thiophene series. The use of calcium-based desulfurizers for desulfurization during coal combustion is currently the most widely used desulfurization method. Due to the complexity of the sulfur fixation reaction process and the re-decomposition of sulfate at high temperatures, the effective utilization rate and sulfur fixation efficiency of combustion calcium-based desulfurizers are generally low. I...

AI Technical Summary

Problems solved by technology

However, in reality, calcium-based desulfurizers use calcium sulfate as the main sulfur-containing ore phase, which will decompose below 1100°C under the combustion condition of pulverized coal, so that the sulfur fixation efficiency is still mostly lower than 50%.