1、沼氣脫硫法

1. Biogas desulfurization method

沼氣中的硫主要以H2S形式存在，所含有機(jī)硫較少。脫除硫化氫的方法很多，一般可分為干法脫硫、濕法脫硫和生物脫硫。

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）濕法脫硫

(1) Wet desulfurization

濕法脫硫是利用特定的溶劑與氣體逆流接觸而脫除其中的H2S，溶劑通過再生后重新進(jìn)行吸收，根據(jù)吸收機(jī)理的不同，又分為化學(xué)吸收法、物理吸收法、物理化學(xué)吸收法以及濕式氧化法。濕式氧化法脫硫效率高，單質(zhì)硫可回收，流程較簡單，大多數(shù)脫硫劑可以再生，運行成本低等；同時該法流程復(fù)雜、投資大、適用于氣體處理量大，H2S含量高的場合。

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）干法脫硫

(2) Dry desulfurization

干法脫硫通常用于低含硫氣體處理，特別是用于氣體精細(xì)脫硫。大部分干法脫硫工藝由于需要更換脫硫劑而不能繼續(xù)操作，還有一些干法如錳礦法、氧化鋅法、氧化鐵、活性炭等，脫硫劑不能再生或再生次數(shù)很少，脫硫飽和后要廢棄，這樣一方面會造成環(huán)境問題，另一方面會增加脫硫成本。

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）生物脫硫

(3) Biological desulfurization

生物脫硫系統(tǒng)以各種微生物的容納力為基礎(chǔ)，利用微生物的生命活動將有機(jī)污染轉(zhuǎn)化為對人體健康和生態(tài)環(huán)境無害的化合物、生物法常用于污水處理工程中產(chǎn)生的硫化物。生物脫硫技術(shù)包括生物過濾法、生物吸附法和生物滴濾法，三種系統(tǒng)均屬開放系統(tǒng)，其微生物種群隨環(huán)境改變而變化。在生物脫硫過程中，氧化態(tài)的含硫污染物必須先經(jīng)生物還原作用生成硫化物或H2S，然后再經(jīng)生物氧化過程生成單質(zhì)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、沼氣脫氧法

2. Biogas deoxygenation method

沼氣生產(chǎn)中不可避免地會混入空氣，特別是垃圾沼氣。氧的脫除是沼氣加工的必經(jīng)步驟，沼氣中的氧必須脫至一定范圍內(nèi)，才能確保整個工藝過程的安全性。若生物沼氣生產(chǎn)GNG或天然氣，則需將其中所含的氧氣含量降至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%.

沼氣脫氧工藝一般有如下幾種：

There are generally several types of biogas deoxygenation processes:

（1）利用氣源中的原有氣體和氧氣反應(yīng)；

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

（2）通入氫氣與氧反應(yīng)，生成較易除去的水，此方法需要氫源，且要確定通入氫氣量；

(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）混合氣中的氧直接與催化劑發(fā)生氧化反應(yīng)，使催化劑活性組分轉(zhuǎn)化成高價氧化物，此方法較難達(dá)到合格的脫氧深度；

(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）通過膜分離或低溫變壓吸附法去除，此方法成本較高。

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

3、沼氣干燥法

3. Biogas drying method

未經(jīng)處理的沼氣通常含有飽和水蒸氣。其含量與溫度有關(guān)，如35℃時沼氣水含量約為5%。沼氣脫水技術(shù)主要分為物理分離和化學(xué)干燥兩類，這些方法也可以同時去除沼氣中的泡沫和粉塵。

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.

冷凝法是去除沼氣中水蒸氣簡單的物理方法，但由于水會在熱交換器上結(jié)冰，這種

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