During the use of biogas desulfurizer, the axial direction of sulfur in the bed can be divided into three areas. If the feed gas enters from the upper part, the upper part is a saturated zone. With the continuous reaction, the amount of sulfide generated in the zone gradually increases, while the reaction slows down. The height of the saturated zone increases with the increase of desulfurization time. The middle layer is the mass transfer zone (the main reaction zone). The reaction is quite rapid until the equilibrium concentration is reached. The lower layer is a clean area, that is, a fresh iron oxide desulfurization layer that has not reacted with H2S. With the increase of desulfurization time, the whole axial distribution gradually moves downward until the clean area disappears and the sulfur is released from the gas outlet. When the hydrogen sulfide content at the gas outlet is greater than the process index, it is penetration. In addition to the nature of the biogas desulfurizer itself, the main factors affecting the desulfurization reaction include the following factors:
(1) Other impurities in the gas: tar, naphthalene, dust and other impurities in the gas will cause the biogas desulfurizer to form hard blocks, resulting in increased resistance in the box, decreased desulfurization efficiency and reduced service life of the biogas desulfurizer. When the ammonia content in the gas is too much or too little, the biogas desulfurizer will be in an acidic state, resulting in the decline of desulfurization efficiency.
The temperature has a great influence on the desulfurization efficiency. If the temperature is too high (40 ℃ - 50 ℃), the oxidation speed will be greatly faster, the reaction speed of hydrogen sulfide will be relatively reduced, and fe2s3? H2O loses water and becomes fe2s3 without water; Sulfate will be produced during oxidation, which makes the biogas desulfurizer acidic. When the temperature is too low, the reaction speed between biogas desulfurizer and hydrogen sulfide will be greatly reduced, and the water in the gas will condense due to excessive temperature, which will reduce the desulfurization efficiency.
The role of appropriate amount of water in biogas desulfurizer is as follows:
1) Sufficient contact time between hydrogen sulfide and iron oxide can be maintained
2) It is one of the factors to avoid agglomeration of biogas desulfurizer
3) It can dissolve part of the salts produced in the purification process. Most of these salts are wrapped on the surface of iron oxide, affecting the desulfurization effect.
(4) Oxygen content
The gas contains a certain amount of oxygen before entering the desulfurization tank, so that the iron sulfide in the tank can be regenerated to a certain extent, which is conducive to extending the service life of the desulfurizer. However, if the oxygen content is too high, the corrosion of iron plate and the formation of gas glue can be accelerated; Too low is not conducive to regeneration of biogas desulfurizer.
(5) PH value (PH)
Because alkalinity has a stable effect on biogas desulfurizer, fe2s3? H2O can be oxidized to Fe203? H20 is an excellent desulfurization raw material, which can accelerate the reaction speed between iron oxide and hydrogen sulfide in alkaline environment.
(6) Influence of gas flow direction in tank on desulfurization efficiency
The flow direction of gas in the tank can be divided into upward and downward. The upward flow resistance rises rapidly, and the gas must pass through the grid and enter the bottom desulfurizer, causing serious sulfur in the bottom chromatography, so the resistance rises rapidly. If the tar removal effect is poor, the bottom biogas desulfurizer is quickly stuck and blocked, affecting the desulfurization efficiency. The downward flow resistance rises slowly, but after the resistance rises suddenly, it is only necessary to replace the upper desulfurizer.
The wonderful contents of this article are provided by the knowledge provided by biological desulfurization. There are many wonderful contents on this website. You can click to enter more contents: http://www.hdtvorigin.com We have special customer service to answer your questions