运行过厌氧反应器的工程师都知道，厌氧反应会产生沼气，而沼气中往往含有一定量的硫化氢（H2S）。不同的工业废水，沼气中硫化氢的含量各有不同。如果硫化氢含量过高，就必须在进锅炉燃烧之前脱除沼气中的硫化氢，以避免腐蚀管道和锅炉。今天，我们就介绍一下当前比较的沼气生物脱硫技术。

Engineers who have operated anaerobic reactors know that anaerobic reactions produce biogas, which often contains a certain amount of hydrogen sulfide (H2S). The content of hydrogen sulfide in biogas varies depending on the type of industrial wastewater. If the hydrogen sulfide content is too high, it is necessary to remove the hydrogen sulfide from the biogas before combustion in the boiler to avoid corrosion of the pipeline and boiler. Today, we will introduce the relatively advanced biogas biological desulfurization technology.

沼气的来源

The source of biogas

沼气通常来源于污水厌氧处理、粪便、秸秆发酵、石油天然气等，净化后的沼气可作为清洁能源，替代天然气、煤炭，用于发电、取暖、生产蒸汽等；分离出的硫化氢气体被转换成固态的生物硫磺，可作为化肥、化工等行业的原料。沼气经过吸收净化可资源利用，即实现了减排，也节约了企业的生产成本。

Biogas usually comes from anaerobic treatment of sewage, feces, straw fermentation, oil and natural gas, etc. The purified biogas can be used as clean energy, replacing natural gas and coal, for power generation, heating, steam production, etc; The separated hydrogen sulfide gas is converted into solid biological sulfur, which can be used as a raw material for industries such as fertilizers and chemicals. Biogas can be absorbed and purified for resource utilization, which not only achieves energy conservation and emission reduction, but also saves production costs for enterprises.

沼气的价值

The value of biogas

沼气≈0.65m3天然气≈0.7kg标准煤≈ 7.5kg 蒸汽≈1.8kwh电，按照工业天然气3.0元/立方米计算，利用1立方沼气可节约1.95元。

Biogas ≈ 0.65m3 natural gas ≈ 0.7kg standard coal ≈ 7.5kg steam ≈ 1.8kwh electricity. Calculated based on industrial natural gas of 3.0 yuan/cubic meter, using 1 cubic meter of biogas can save 1.95 yuan.

沼气脱硫和烟气脱硫的区别

The difference between biogas desulfurization and flue gas desulfurization

沼气脱硫和烟气脱硫虽然都是脱硫，但确是完全不同的两种工艺。烟气脱硫是从工业废气中脱除二氧化硫SO2和SO3。我们常说的脱硫脱硝，就指的是脱除二氧化硫。而沼气脱硫是指从沼气中脱除硫化氢(H2S)，以减少对后续管道、燃烧锅炉或发电机的腐蚀。

Although biogas desulfurization and flue gas desulfurization are both desulfurization processes, they are completely different. Smoke desulfurization is the removal of sulfur dioxide SO2 and SO3 from industrial waste gas. What we often refer to as desulfurization and denitrification refers to the removal of sulfur dioxide. Biogas desulfurization refers to the removal of hydrogen sulfide (H2S) from biogas to reduce corrosion on subsequent pipelines, combustion boilers, or generators.

什么是沼气生物脱硫？

What is biogas biological desulfurization?

沼气生物脱硫（简称沼气脱硫）是利用生物菌种去除沼气中腐蚀性强、毒性强的硫化氢气体的一种工艺方法，这个工艺具有自动化程度高，流程简洁，运行成本低等优点。

Biogas desulfurization (abbreviated as biogas desulfurization) is a process method that uses biological bacteria to remove highly corrosive and toxic hydrogen sulfide gas from biogas. This process has the advantages of high automation, simple process, and low operating cost.

工艺原理

Process principle

如下图，厌氧发酵产生的沼气进入洗涤塔，通过与碱性循环喷淋液发生吸收反应，从而去除沼气中的硫化氢。吸收硫化氢的富液回流生物反应器内，通过生物转化，将硫化氢转化成固态单质硫磺，并将溶液再生为可用于洗涤沼气的碱性吸收液（亦成为贫液），从而实现了吸收剂的回收和再生循环利用。通过硫沉淀器实现硫磺固体的分离。

As shown in the figure below, the biogas produced by anaerobic fermentation enters the washing tower and undergoes an absorption reaction with the alkaline circulating spray solution to remove hydrogen sulfide from the biogas. The rich solution that absorbs hydrogen sulfide flows back into the bioreactor, where it is converted into solid elemental sulfur through biotransformation. The solution is then regenerated into an alkaline absorbent solution (also known as a lean solution) that can be used for washing biogas, thereby achieving the recovery and recycling of the absorbent. The separation of sulfur solids is achieved through a sulfur precipitator.

此工艺将弱碱性条件下硫化氢的物理化学吸收与空气作用下碱性溶液的生物再生相结合。含有硫化氢的沼气进入洗涤塔，在这里被吸收硫化氢的碱溶液洗涤，处理后的沼气硫化氢去除率高达99.5%。经系统处理后，沼气可用于燃气发电机发电，用作锅炉燃料或输入当地小型供气网络。

This process combines the physical and chemical absorption of hydrogen sulfide under weak alkaline conditions with the biological regeneration of alkaline solutions under air action. The biogas containing hydrogen sulfide enters the washing tower, where it is washed by an alkaline solution that absorbs hydrogen sulfide. The treated biogas has a hydrogen sulfide removal rate of up to 99.5%. After being processed by the system, biogas can be used for gas generator power generation, as boiler fuel, or input into local small-scale gas supply networks.

几乎不含硫化氢的沼气从洗涤塔顶部逸出，含硫化氢的溶液流入生物反应器，在此细菌在限制供氧条件下将其氧化为单质硫和碱。该系统的少量排出液（含钠盐）和副产品硫磺中都不含硫化物，排放没有问题。

Almost hydrogen sulfide free biogas escapes from the top of the washing tower, and the solution containing hydrogen sulfide flows into the bioreactor, where bacteria oxidize it into elemental sulfur and alkali under limited oxygen supply conditions. The small amount of discharge liquid (containing sodium salts) and by-product sulfur in the system do not contain sulfides, so there is no problem with the discharge.

生物脱硫的技术优势

Technological advantages of biological desulfurization

全自动无人值守，高度稳定可靠。

Fully automatic and unmanned, highly stable and reliable.

深度的硫化氢去除（出口硫化氢含量低于25 ppm）

Deep hydrogen sulfide removal (export hydrogen sulfide content below 25 ppm)

可耐受气体流量和硫负荷较宽范围的波动

Can tolerate fluctuations in gas flow rate and sulfur load over a wide range

沼气不会被空气稀释：沼气和空气之间有严格的物理分离

Biogas will not be diluted by air: there is strict physical separation between biogas and air

只需少量的碱、水和营养物

Only a small amount of alkali, water, and nutrients are needed

没有堵塞和污垢的风险，因此维护工作量少

There is no risk of blockage and dirt, so the maintenance workload is minimal

常温常压运行

Normal temperature and pressure operation

产生单质硫：可作为肥料和杀虫剂

Generating elemental sulfur: can be used as fertilizer and insecticide

应用的领域

Field of application

沼气生物脱硫技术应用的领域非常广泛。污水厌氧处理、粪便、秸秆发酵、石油天然气产生的沼气硫化氢含量过高，都可以应用。

The application of biogas biological desulfurization technology is very extensive. Anaerobic treatment of sewage, fermentation of feces and straw, and high hydrogen sulfide content in biogas produced from petroleum and natural gas can all be applied.