Gas Desulfurization

The following information is provided by the Tangshan Green Environmental Technology Co. summary, do not reprint. 1, the gas furnace gas desulfurization method of sulfur from coal gasification, mainly in the form of H2S, the gasification of coal, about 80% of the sulfur is converted to H2S into the gas, if, sulfur coal gasification the amount of 1%, in gas form into the gasification H2S approximately 2-3g / Nm3, while the ceramics, kaolin and other industries on the sulfur content of gas requirements for the 20-50 mg / Nm3; if gas after combustion of H2S all SO2 is converted to about 2.6g / m3, the highest index of SO2 emission concentration much higher than the state. So, in terms of environmental emissions standards, or ensure that enterprises from the final product in terms of quality in this part of the H2S gas is a must to be removed. Gas desulfurization method in general up points in two ways: hot gas desulfurization and cold gas desulfurization. In China, the hot gas desulfurization is still in the pilot study stage, needs to be further improved, and the cold gas desulfurization is a relatively mature technology, the desulfurization also many ways. Cold gas desulfurization desulfurization can be divided into two kinds of dry and wet desulfurization method, dry desulfurization iron oxide, active carbon used widely, and wet desulphurization arsenic soda, ADA, ADA improvements and tannin extract representative. 2, dry gas desulfurization technology earlier dry desulphurization technology, first used in dry gas desulfurization technology is based on iron oxide ore biogas desulfurization sorbent, later, with the success of research and active carbon gas desulfurization relatively lower production costs, the activated carbon desulfurization technology began to be widely used. 2.1 iron oxide sorbent desulfurization technology was first used for the artificial marsh iron ore and iron oxide, in order to increase its porosity, desulfurizer with sawdust as filler, then spray the right amount of water and a small amount of lime, Fanshai repeatedly made it PH value is generally about 8-9, the lower the seed for desulfurization efficiency, we must tower regeneration, regeneration difficulties, it was soon replaced by other desulfurizer. TF desulfurizer now used widely, this kind of desulfurizer high desulfurization efficiency, and can be regenerated tower. Iron desulfurization and regeneration reaction is as follows: Information by the Tangshan Green Environmental Technology Limited Summary (1) desulfurization process 2Fe (OH) 3 + 3H2S == Fe2S3 + 6H2O Fe (OH) 3 + H2S == 2Fe (OH) 2+ S + 2H2O Fe (OH) 2 + H2S == FeS + 2H2O (2) regeneration 2Fe2S2 + 3O2 + 6H2O == 4Fe (OH) 3 + 6S 4FeS + 3O2 + 6H2O == 4Fe (OH) 2 + 4S iron sorbent regeneration is an exothermic process, if regeneration is too fast, intense heat, desulfurizer easily burst into flames, the fire phenomenon has occurred in several companies. Dry desulfurization desulfurization tower is packed in a cylindrical certain height desulfurizer, gas upwardly through the desulfurizer, H2S is removed to achieve desulfurization process, commonly used in desulfurization agent is iron oxide, which is cylindrical granular iron oxide Principle desulfurization follows: Fe2O3 · H2O + 3H2S = Fe2S3 · H2O + 3H2O can be seen from the above reaction equation, Fe2O3 absorb H2S into Fe2S3, along with the continuous generation of gas, iron oxide, H2S, when absorbed H2S reaches a certain amount, H2S removal efficiency will be greatly reduced, until failure. Fe2S3 can restore regeneration with O2 and H2O chemical reaction can be reduced to Fe2O3, works as follows: 2Fe2O3 · H2O + 3O2 = 2Fe2O3 · H2O + 6S Based on the above two 2 reactive gas desulfurization reaction is as follows: H2S + 1 / 2O2 = S + H2O (reaction conditions Fe2O3 · H2O) chemical reaction can be seen from the above equation, Fe2O3 absorb H2S into Fe2S3, Fe2S3 be reduced to Fe2O3, you need O2 and H2O, prior to the desulfurization tower through the air compressor to gas in the air to meet dosing desulfurizer of this original O2 requirements. 2.2 Activated Carbon Activated carbon desulfurization desulfurization technology is the use of activated carbon adsorption catalysis and catalytic activity of activated carbon is very strong, the H2S gas in the activated carbon catalyst, and a small amount of O2 gas oxidation reaction, the reaction of elemental S adsorption on the surface of activated carbon. When activated carbon saturated sorbent desulfurization efficiency decreased significantly, it must be regenerated. Regeneration of activated carbon adsorption based on substance and decide, S at atmospheric pressure, 190 ℃ beginning to melt, about 440 ℃ will sublimate into gas, therefore, generally use about 450-500 ℃ superheated steam activated carbon sorbent regeneration When desulfurizer temperature is raised to a certain extent, elemental sulfur precipitation begins with activated carbon, precipitated sulfur flowing into the sulfur recovery tank, after cooling to form a solid sulfur. Information from the Tangshan Green Environmental Technology Co. summary of activated carbon desulfurization desulfurization reaction process is as follows: 2H2S + O2 == S + 2H2O