The impact of hydrogen sulfide on generator sets

硫化氢（H2S）是一种无色有毒的可燃性气体，具有强烈的臭鸡蛋气味，当空气中硫化氢的体积含量超过0.1%时，就能引起头疼晕眩等中毒症状。硫化氢（H2S）对铁等金属有强腐蚀性，也易吸附金属表面与多种金属离子作用，生成不溶于水的硫化物沉淀。沼气在燃烧时，其中的H2S还能转化为腐蚀性很强的亚硫酸气雾会污染环境和腐蚀机器设备，同时H2S在潮湿的环境下对金属管道、燃烧设备、检测设备和仪表等都具有强烈的腐蚀性，所以沼气在利用前必须脱出其中所含的H2S。利用沼气发电时沼气中的硫化氢会对沼气发电机组的进气管道、增压器、中冷器、火花塞、气缸套、排气管和消音器等造成严重腐蚀影响机组寿命。所以沼气在进入发电机组之前必须进行沼气预处理，将H2S降到机组允许的范围内才能保证机组的可靠运行。

Hydrogen sulfide (H2S) is a colorless, toxic, flammable gas with a strong odor of rotten eggs. When the volume content of hydrogen sulfide in the air exceeds 0.1%, it can cause poisoning symptoms such as headaches and dizziness. Hydrogen sulfide (H2S) has strong corrosiveness to metals such as iron and is also prone to adsorbing metal surfaces and interacting with various metal ions to form insoluble sulfide precipitates. When biogas is burned, the H2S in it can also be converted into highly corrosive sulfite mist, which can pollute the environment and corrode machinery and equipment. At the same time, H2S has strong corrosiveness to metal pipelines, combustion equipment, detection equipment, and instruments in humid environments. Therefore, before biogas can be used, the H2S contained in it must be removed. When using biogas for power generation, the hydrogen sulfide in the biogas will cause serious corrosion to the intake pipeline, turbocharger, intercooler, spark plug, cylinder liner, exhaust pipe, and muffler of the biogas generator set, affecting the lifespan of the unit. So before biogas enters the generator unit, it must undergo biogas pretreatment to reduce H2S to the allowable range of the unit in order to ensure the reliable operation of the unit.

水分对发电机组的影响

The impact of moisture on generator sets

在利用沼气发电过程中，沼气水分含量过大的话，会导致发电机组的进气压力损耗过大，严重的情况下，会引起发动机功率波动、敲缸、停机等严重地影响其使用寿命。其具体表现为：

In the process of using biogas for power generation, if the moisture content of biogas is too high, it will lead to excessive loss of intake pressure of the generator set. In severe cases, it can cause engine power fluctuations, cylinder knocking, shutdown, and seriously affect its service life. Its specific manifestation is:

发动机点火困难；

Difficulty in engine ignition;

降低燃烧室温度，降低内燃机的效率；

Reduce the temperature of the combustion chamber and reduce the efficiency of the internal combustion engine;

由于水蒸气等无功气体的存在，增压耗功增大；

Due to the presence of reactive gases such as water vapor, the power consumption of turbocharging increases;

水蒸气与其他酸性物质的化合产生中间产物，对机器本身产生腐蚀，缩短机器的使用寿命，降低机器的可靠性。

The combination of water vapor and other acidic substances produces intermediate products that corrode the machine itself, shorten its service life, and reduce its reliability.

固体杂质对发电机组的影响

The impact of solid impurities on generator sets

粉尘是大气环境中涉及面广、危害严重的一种污染物。粉尘是发动机明确限制的杂质，它主要影响在于：

Dust is the most widespread and harmful pollutant in the atmospheric environment. Dust is a clearly restricted impurity in engines, and its main impact is:

堵塞管路，流通不畅，加大压损，增加运行费用；

Blocking the pipeline, poor circulation, increased pressure loss, and increased operating costs;

增大机械磨损，降低设备使用寿命。

Increase mechanical wear and reduce equipment service life.

方案

Solution

针对发动机对沼气的要求，在沼气发动机前安装处理系统以了气源侧与用气侧的矛盾是目前沼气发电机组利用问题的有效方法，主要表现在以下两个方面：

In response to the requirements of the engine for biogas, installing a processing system in front of the biogas engine to solve the contradiction between the gas source side and the gas consumption side is currently an effective method to solve the utilization problem of biogas generator sets, mainly manifested in the following two aspects:

降低气体的相对湿度

Reduce the relative humidity of the gas

水分的脱除，考虑到具体的情况，简单分为凝结水的脱除以及未凝结水脱除两大部分，前者可以采用汽水分离器来实现，后者的实现较为复杂，目前主要有下面几种方式：

The removal of moisture, considering specific circumstances, can be simply divided into two parts: the removal of condensed water and the removal of uncondensed water. The former can be achieved by using a steam water separator, while the latter is more complex to achieve. Currently, there are mainly the following methods:

低温：通过制冷设备降低气体的温度，使得其中的水蒸气凝结，然后排除系统；

Low temperature dehumidification: By using refrigeration equipment to reduce the temperature of the gas, the water vapor inside is condensed and then discharged from the system;

吸附：采用对水有较强吸附作用的吸附剂，将气体中的水分析出；

Adsorption: Use an adsorbent with strong adsorption effect on water to analyze the water in the gas;

膜过滤：采用特殊结构的膜材料，在特定的条件下将水从气体中分出。

Membrane filtration: A membrane material with a special structure is used to separate water from the gas under specific conditions.

降低气体杂质成分含量

Reduce the content of gas impurities

气体中的杂质是比较复杂的成分，由于是针对发动机的利用，所以对杂质的判断主要以发动机的要求为准，主要有下面几种：

Impurities in gases are relatively complex components, and as they are specific to the utilization of the engine, the determination of impurities is mainly based on the requirements of the engine, including the following:

硫的去除：

Sulfur removal:

以硫化氢为主的硫化物的去除主要有物理、化学以及生物三种方式。其中物理方法主要指物理吸附方式脱硫，这种方式操作简便，但往往需要占地较大的设备，而且吸附剂需要再生。化学方式指以化学反应的方式将硫固化下来，目前有干法及湿法，其差别主要是反应物的物理形态是固体还是液体的差别。生物法脱硫是目前比较新兴的一种方式，其主要原理是在反应罐中培养出合适的菌种，这些菌种以硫化物为养料，将其中的硫固定下来。 对于硫含量不高的气体，采用物理吸附或者干法脱硫一般比较经济实用，而且操作简便。

The removal of sulfides mainly composed of hydrogen sulfide mainly involves three methods: physical, chemical, and biological. The physical method mainly refers to the physical adsorption method for desulfurization, which is easy to operate but often requires a large area of equipment, and the adsorbent needs to be regenerated. Chemical method refers to the solidification of sulfur through chemical reactions. Currently, there are dry and wet methods, and the main difference is whether the physical form of the reactant is solid or liquid. Biological desulfurization is currently a relatively emerging method, whose main principle is to cultivate suitable bacterial strains in reaction tanks, which use sulfides as nutrients to fix the sulfur in them. For gases with low sulfur content, using physical adsorption or dry desulfurization is generally more economical and practical, and the operation is simple.

此外，根据我国的标准规定：沼气作为能源利用时，沼气中的H2S含量不得超过200mg/Nm3。因此沼气经过脱硫处理后需要采用沼气分析仪对沼气中H2S含量进行实时在线监测，为业主提供实时准确的数据参考，帮助其对沼气预处理工艺进行优化调整，提高沼气发电机组进气品质，以保证H2S含量达到沼气发电的要求。

In addition, according to China's environmental standards, when biogas is used as energy, the H2S content in biogas should not exceed 200mg/Nm3. Therefore, after the desulfurization treatment of biogas, a biogas analyzer needs to be used for real-time online monitoring of the H2S content in the biogas, providing real-time and accurate data reference for the owner, helping them optimize and adjust the biogas pretreatment process, improve the intake quality of the biogas generator unit, and ensure that the H2S content meets the requirements of biogas power generation.