1、沼气脱硫法

1. Biogas desulfurization method

沼气中的硫主要以H2S形式存在，所含有机硫较少。脱除硫化氢的方法很多，一般可分为干法脱硫、湿法脱硫和生物脱硫。

The sulfur in biogas mainly exists in the form of H2S and contains less organic sulfur. There are many methods for removing hydrogen sulfide, which can generally be divided into dry desulfurization, wet desulfurization, and biological desulfurization.

（1）湿法脱硫

(1) Wet desulfurization

湿法脱硫是利用特定的溶剂与气体逆流接触而脱除其中的H2S，溶剂通过再生后重新进行吸收，根据吸收机理的不同，又分为化学吸收法、物理吸收法、物理化学吸收法以及湿式氧化法。湿式氧化法脱硫效率高，单质硫可回收，流程较简单，大多数脱硫剂可以再生，运行成本低等；同时该法流程复杂、投资大、适用于气体处理量大，H2S含量高的场合。

Wet desulfurization is the process of using a specific solvent to remove H2S through countercurrent contact with gas. The solvent is regenerated and reabsorbed, which can be further divided into chemical absorption, physical absorption, physicochemical absorption, and wet oxidation based on different absorption mechanisms. Wet oxidation method has high desulfurization efficiency, recyclable elemental sulfur, simple process, most desulfurizers can be regenerated, and low operating cost; At the same time, this method has a complex process, high investment, and is suitable for situations with large gas processing capacity and high H2S content.

（2）干法脱硫

(2) Dry desulfurization

干法脱硫通常用于低含硫气体处理，特别是用于气体精细脱硫。大部分干法脱硫工艺由于需要更换脱硫剂而不能继续操作，还有一些干法如锰矿法、氧化锌法、氧化铁、活性炭等，脱硫剂不能再生或再生次数很少，脱硫饱和后要废弃，这样一方面会造成环境问题，另一方面会增加脱硫成本。

Dry desulfurization is commonly used for low sulfur gas treatment, especially for fine gas desulfurization. Most dry desulfurization processes cannot continue to operate due to the need to replace the desulfurizer. There are also some dry methods such as manganese ore method, zinc oxide method, iron oxide, activated carbon, etc. The desulfurizer cannot be regenerated or the regeneration frequency is very small. After desulfurization saturation, it needs to be discarded. This will cause environmental problems on the one hand and increase desulfurization costs on the other hand.

（3）生物脱硫

(3) Biological desulfurization

生物脱硫系统以各种微生物的容纳力为基础，利用微生物的生命活动将有机污染转化为对人体健康和生态环境无害的化合物、生物法常用于污水处理工程中产生的硫化物。生物脱硫技术包括生物过滤法、生物吸附法和生物滴滤法，三种系统均属开放系统，其微生物种群随环境改变而变化。在生物脱硫过程中，氧化态的含硫污染物必须先经生物还原作用生成硫化物或H2S，然后再经生物氧化过程生成单质硫，才能去除。

The biological desulfurization system is based on the capacity of various microorganisms, utilizing their life activities to transform organic pollution into compounds that are harmless to human health and the ecological environment. Sulfides are commonly produced in wastewater treatment projects through biological methods. Biological desulfurization technology includes biological filtration, biological adsorption, and biological drip filtration, all of which belong to open systems, and their microbial populations change with environmental changes. In the process of biological desulfurization, oxidized sulfur-containing pollutants must first undergo biological reduction to generate sulfides or H2S, and then undergo biological oxidation to generate elemental sulfur in order to be removed.

2、沼气脱氧法

2. Biogas deoxygenation method

沼气生产中不可避免地会混入空气，特别是垃圾沼气。氧的脱除是沼气加工的必经步骤，沼气中的氧必须脱一定范围内，才能确保整个工艺过程的性。若生物沼气生产GNG或天然气，则需将其中所含的氧气含量降0.5%以下。

It is inevitable that air, especially waste biogas, will be mixed in during biogas production. The removal of oxygen is a necessary step in biogas processing, and the oxygen in biogas must be removed to a certain range to ensure the safety of the entire process. If biogas is used to produce GNG or natural gas, the oxygen content in it needs to be reduced to below 0.5%.

沼气脱氧工艺一般有如下几种：

There are generally several types of biogas deoxygenation processes:

（1）利用气源中的原有气体和氧气反应；

(1) Utilize the existing gas in the gas source to react with oxygen;

（2）通入氢气与氧反应，生成较易除去的水，此方法需要氢源，且要确定通入氢气量；

(2) The reaction between hydrogen and oxygen is introduced to generate water that is easily removed. This method requires a hydrogen source and the amount of hydrogen gas introduced must be determined;

（3）混合气中的氧直接与催化剂发生氧化反应，使催化剂活性组分转化成高价氧化物，此方法较难达到合格的脱氧深度；

(3) The oxygen in the mixed gas directly reacts with the catalyst to oxidize, converting the active components of the catalyst into high valence oxides. This method is difficult to achieve a qualified deoxygenation depth;

（4）通过膜分离或低温变压吸附法去除，此方法成本较高。

(4) The cost of using membrane separation or low-temperature pressure swing adsorption method for removal is relatively high.

3、沼气干燥法

3. Biogas drying method

未经处理的沼气通常含有饱和水蒸气。其含量与温度有关，如35℃时沼气水含量约为5%。沼气脱水技术主要分为物理分离和化学干燥两类，这些方法也可以同时去除沼气中的泡沫和粉尘。

Untreated biogas typically contains saturated water vapor. Its content is related to temperature, for example, the biogas water content is about 5% at 35 ℃. The biogas dehydration technology is mainly divided into physical separation and chemical drying. These methods can also remove foam and dust in biogas at the same time.

冷凝法是去除沼气中水蒸气简单的物理方法，但由于水会在热交换器上结冰，这种

The condensation method is a simple physical method for removing water vapor from biogas, but due to water freezing on the heat exchanger, this