A coal-fired desulfurization process

Abstract

The invention discloses a fuel coal desulfurization process. The fuel coal desulfurization process comprises the following steps that fuel coal is crushed to the particle size smaller than or equal to 30 mm and conveyed to a circulation fluidized bed boiler combustion chamber; a sulfur-fixing agent accounting for 2%-10% of the total amount of the fuel coal is conveyed to the circulation fluidized bed boiler combustion chamber; the temperature of the combustion chamber is controlled to be 850 DEG C-950 DEG C, after the fuel coal and the sulfur-fixing agent are combusted in a circulation fluidized bed boiler, smoke passes through a cyclone separator to be separated, solid ions are separated out to flow back to the combustion chamber, and the smoke passes through an air preheater and an electric dust remover and then is exhausted into the air; and sulfur-fixing slag is discharged out of a deslagging opening in the bottom of the combustion chamber. The desulfurization process is easy to operate and low in cost, the coal consumption of the boiler is averagely reduced by more than 5%, sulfur discharge is smaller than or equal to 30 mg / m<3>, the sulfur-fixing rate is larger than or equal to 97%, and zero discharge is basically achieved.

Description

technical field [0001] The invention belongs to the field of clean coal application and specifically designs a coal-fired desulfurization process. Background technique [0002] Coal is the most important energy source in my country. The sulfur content of coal in my country is generally 0.38% to 5.32%, with an average of 1.72%. High-sulfur coal accounts for about 33.33% of coal reserves and 16.67% of raw coal production. As mining depth increases, the sulfur content of coal in major mining areas in my country tends to increase. When coal is directly burned as a primary energy source, 90% of the sulfur in the coal is converted into SO 2 Exhausted into the atmosphere, causing a lot of pressure on the environment, the current coal-fired SO 2 The desulfurization process mainly includes wet desulfurization process and dry desulfurization process. The most commonly used wet process is the limestone-gypsum wet desulfurization process. This method is to send the flue gas from the el...

AI Technical Summary

Problems solved by technology

When coal is directly burned as a primary energy source, 90% of the sulfur in the coal is converted into SO 2 Exhausted into the atmosphere, causing a lot of pressure on the environment, the current coal-fired SO 2 The desulfurization process mainly includes wet desulfurization process and dry desulfurization process. The most commonly used wet process is the limestone-gypsum wet desulfurization process. This method is to send the flue gas from the electrostatic precipitator into the absorption tower through a booster pump. In the absorption tower, the circulating limestone slurry washes the flue gas to realize SO 2 React with calcium carbonate to achieve desulfurization effect; however, the equipment investment of this method is relatively large, the water consumption and power consumption required in the process of use are relatively high, and the maintenance cost of the equipment is relatively high

The dry process adopts the desulfurization process of spraying limestone tail humidification in the furnace. The desulfurization rate of this method can reach 80% to 90%, but the desulfurization by-product of this method is mainly calcium sulfite that exists in an unstable state. Desulfurization ash, the comprehensive utilization of by-products is affected

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