络合铁脱硫工艺利用碱性络合铁催化剂的氧化还原性质，吸收原料气中的H2S。H2S被络合铁催化剂直接氧化生成单质硫，络合铁转化为络合亚铁，然后在再生过程中鼓入空气，以空气氧化催化剂富液中的络合亚铁，使催化剂富液中的络合亚铁转化为络合铁，从而再生回用。产生的硫磺通过硫磺回收系统处理。
The complex iron desulfurization process utilizes the redox properties of alkaline complex iron catalysts to absorb H2S from the feed gas. H2S is directly oxidized by a complex iron catalyst to generate elemental sulfur, which is converted into complex ferrous. During the regeneration process, air is blown in to oxidize the complex ferrous in the catalyst rich solution, converting the complex ferrous in the catalyst rich solution into complex ferrous, thereby regenerating and reusing. The generated sulfur is processed through the sulfur recovery system.
络合铁脱硫反应原理如下：
The principle of complex iron desulfurization reaction is as follows:
在总反应中，络合铁离子的作用是将吸收反应中得到的电子在再生反应中转移给单质氧。每一个单质硫原子的产生需要两个三价铁离子参与反应。由此，铁离子尽管参与反应，但在总反应中并不消耗，而是作为硫化氢和氧气反应的中间电子传递物，是催化剂体系的组成部分。
In the overall reaction, the role of chelating iron ions is to transfer the electrons obtained from the absorption reaction to the elemental oxygen during the regeneration reaction. The production of each elemental sulfur atom requires two trivalent iron ions to participate in the reaction. Therefore, although iron ions participate in the reaction, they are not consumed in the total reaction, but serve as intermediate electron carriers in the reaction of hydrogen sulfide and oxygen, and are a component of the catalyst system.
脱硫工艺流程
Desulfurization process flow
双膜气柜过来的沼气经增压风机加压之后进入脱硫再生塔的吸收脱硫隔室酸气中的H2S进入反应隔室与催化剂中的Fe3+反应并转化为单质硫，与此同时Fe3+还原成Fe2+ 。
The biogas from the dual membrane gas tank is pressurized by a booster fan and enters the absorption and desulfurization compartment of the desulfurization regeneration tower. H2S in the acid gas enters the reaction compartment and reacts with Fe3+in the catalyst, converting it into elemental sulfur. At the same time, Fe3+is reduced to Fe2+.
反应后的溶液通过自循环进入氧化隔室，通过风机向氧化再生隔室鼓入空气中的氧，将Fe2+氧化为Fe3+后再自循环回吸收和反应隔室继续与H2S进行吸收反应可脱除酸性气中99.99%以上H2S。
The solution after reaction enters the oxidation chamber through self circulation, and oxygen in the air is blown into the oxidation regeneration chamber through a fan. Fe2+is oxidized to Fe3+, which is then self circulated back for absorption and the reaction chamber continues to absorb and react with H2S to remove over 99.99% of H2S from the acidic gas.
生成的单质硫在脱硫再生塔底部的锥形段沉降后，由硫磺浆泵送至板框过滤机进行硫磺过滤；脱硫后净化气经气液分离送出界区外。废空气在脱硫再生塔顶部排出装置。

After the generated elemental sulfur settles in the conical section at the bottom of the desulfurization regeneration tower, it is pumped by the sulfur slurry to the plate and frame filter for sulfur filtration; The purified gas after desulfurization is sent out of the battery limit through gas-liquid separation. The waste air is discharged from the top of the desulfurization regeneration tower.
技术特点
Technical characteristics
成套络合铁脱硫技术对于沼气净化具有如下优点：
The complete set of complex iron desulfurization technology has the following advantages for biogas purification:
（1）原料气脱硫中硫化氢一步转化为硫磺，净化气硫化氢浓度低于10ppm。
(1) In the desulfurization of raw gas, hydrogen sulfide is converted into sulfur in one step, and the concentration of hydrogen sulfide in the purified gas is less than 10ppm.
（2）装置操作弹性大，硫化氢浓度从0.5～2V%波动均不影响装置运行。
(2) The device has high operational flexibility, and fluctuations in hydrogen sulfide concentration from 0.5 to 2V% do not affect the operation of the device.
（3）吸收、再生及硫磺沉降均在一个设备中，设计一体化，工艺简单，节省占地。
(3) The absorption, regeneration, and sulfur deposition are all in one equipment, with integrated design and simple process, saving land.
（4）催化剂环境友好，脱硫过程无“三废”排放。
(4) The catalyst is environmentally friendly, and there are no "three wastes" emissions during the desulfurization process.
（5）运行可靠，保证长周期稳定运行。
(5) Reliable operation, ensuring long-term stable operation.
（6）采用橇装方式供货，可根据需要移动。
(6) Supplied in a skid mounted manner and can be moved as needed.
（7）每立方沼气脱硫系统的单位运行成本可低至0.03～0.07元。
(7) The unit operating cost of each cubic meter of biogas desulfurization system can be as low as 0.03-0.07 yuan.