沼气是各种有机物质,在隔绝空气(还原条件),并在适宜的温度、pH值下,经过微生物的发酵作用产生的一种可燃烧气体。沼气中所含硫化氢在使用前因环保与工艺要求必须去除。
Biogas is a combustible gas produced by microbial fermentation of various organic substances, isolated from air (reducing conditions), and at suitable temperatures and pH values. The hydrogen sulfide contained in biogas must be removed before use due to environmental and process requirements.
因前端污水处理中厌氧发酵细菌作用的不稳定,硫化氢浓度也翻倍增加,使得后端脱硫后沼气中硫化氢指标大幅升高,不能满足下游工序的使用要求。
Due to the unstable role of anaerobic fermentation bacteria in the front-end sewage treatment, the concentration of hydrogen sulfide has doubled, resulting in a significant increase in the hydrogen sulfide index in the biogas after desulfurization in the back-end, which cannot meet the requirements of downstream processes.
络合铁脱硫剂具有高硫容、高选择性的特点。通过采用GLT络合铁脱硫工艺成套装置取得了很好效果,项目占地面积小,硫化氢指标合格稳定、生产成本降低。
Complex iron desulfurizers have the characteristics of high sulfur capacity and high selectivity. Good results have been achieved through the use of a complete set of GLT complex iron desulfurization process, with a small project area, stable and qualified hydrogen sulfide indicators, and reduced production costs.
对于10000~60000 Nm3/d,硫化氢含量为0.5~2.5V%中小规模沼气脱硫装置,国力通能实现成撬化设备供应,在满足客户工艺需求的前提下解决客户占地限制的困扰。
For small-scale biogas desulfurization units with a hydrogen sulfide content of 0.5-2.5V% and a capacity of 10000-60000 Nm3/d, Guoli Tongneng can achieve a supply of modular equipment to solve the problem of land occupation restrictions for customers while meeting their process requirements.
脱硫反应原理
Principle of desulfurization reaction
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 chelated iron catalyst to generate elemental sulfur, which is then converted into chelated ferrous. During the regeneration process, air is introduced to oxidize the chelated ferrous in the catalyst rich solution, converting the chelated ferrous in the catalyst rich solution into chelated ferrous for regeneration and reuse. The generated sulfur is processed through a 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 elemental oxygen in the regeneration reaction. The production of each elemental sulfur atom requires the participation of two trivalent iron ions in the reaction. Therefore, although iron ions participate in the reaction, they are not consumed in the overall reaction, but serve as intermediate electron transfer materials 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
如图1虚线框所示:自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+ 。
As shown in the dashed box in Figure 1, the biogas from the double membrane gas holder is pressurized by a booster fan and enters the absorption 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 the 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+, and then self circulation is used to absorb and continue the absorption reaction with H2S in the reaction chamber, which can remove over 99.99% of H2S from 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。
The generated elemental sulfur settles in the conical section at the bottom of the desulfurization regeneration tower and 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 boundary area through gas-liquid separation. The waste air is discharged from the top of the desulfurization regeneration tower.