運(yùn)行過厭氧反應(yīng)器的工程師都知道，厭氧反應(yīng)會(huì)產(chǎn)生沼氣，而沼氣中往往含有一定量的硫化氫（H2S）。不同的工業(yè)廢水，沼氣中硫化氫的含量各有不同。如果硫化氫含量過高，就必須在進(jìn)鍋爐燃燒之前脫除沼氣中的硫化氫，以避免腐蝕管道和鍋爐。今天，我們就介紹一下當(dāng)前比較先進(jìn)的沼氣生物脫硫技術(shù)。

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.

沼氣的來源

The source of biogas

沼氣通常來源于污水厭氧處理、糞便、秸稈發(fā)酵、石油天然氣等，凈化后的沼氣可作為清潔能源，替代天然氣、煤炭，用于發(fā)電、取暖、生產(chǎn)蒸汽等；分離出的硫化氫氣體被轉(zhuǎn)換成固態(tài)的生物硫磺，可作為化肥、化工等行業(yè)的原料。沼氣經(jīng)過吸收凈化可資源利用，即實(shí)現(xiàn)了節(jié)能減排，也節(jié)約了企業(yè)的生產(chǎn)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.

沼氣的價(jià)值

The value of biogas

沼氣≈0.65m3天然氣≈0.7kg標(biāo)準(zhǔn)煤≈ 7.5kg 蒸汽≈1.8kwh電，按照工業(yè)天然氣3.0元/立方米計(jì)算，利用1立方沼氣可節(jié)約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.

沼氣脫硫和煙氣脫硫的區(qū)別

The difference between biogas desulfurization and flue gas desulfurization

沼氣脫硫和煙氣脫硫雖然都是脫硫，但確是完全不同的兩種工藝。煙氣脫硫是從工業(yè)廢氣中脫除二氧化硫SO2和SO3。我們常說的脫硫脫硝，就指的是脫除二氧化硫。而沼氣脫硫是指從沼氣中脫除硫化氫(H2S)，以減少對(duì)后續(xù)管道、燃燒鍋爐或發(fā)電機(jī)的腐蝕。

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.

什么是沼氣生物脫硫？

What is biogas biological desulfurization?

沼氣生物脫硫（簡(jiǎn)稱沼氣脫硫）是利用生物菌種去除沼氣中腐蝕性強(qiáng)、毒性強(qiáng)的硫化氫氣體的一種工藝方法，這個(gè)工藝具有自動(dòng)化程度高，流程簡(jiǎn)潔，運(yùn)行成本低等優(yōu)點(diǎn)。

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.

工藝原理

Process principle

如下圖，厭氧發(fā)酵產(chǎn)生的沼氣進(jìn)入洗滌塔，通過與堿性循環(huán)噴淋液發(fā)生吸收反應(yīng)，從而去除沼氣中的硫化氫。吸收硫化氫的富液回流至生物反應(yīng)器內(nèi)，通過生物轉(zhuǎn)化，將硫化氫轉(zhuǎn)化成固態(tài)單質(zhì)硫磺，并將溶液再生為可用于洗滌沼氣的堿性吸收液（亦成為貧液），從而實(shí)現(xiàn)了吸收劑的回收和再生循環(huán)利用。通過硫沉淀器實(shí)現(xiàn)硫磺固體的分離。

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.

此工藝將弱堿性條件下硫化氫的物理化學(xué)吸收與空氣作用下堿性溶液的生物再生相結(jié)合。含有硫化氫的沼氣進(jìn)入洗滌塔，在這里被吸收硫化氫的堿溶液洗滌，處理后的沼氣硫化氫去除率高達(dá)99.5%。經(jīng)系統(tǒng)處理后，沼氣可用于燃?xì)獍l(fā)電機(jī)發(fā)電，用作鍋爐燃料或輸入至當(dāng)?shù)匦⌒凸饩W(wǎng)絡(luò)。

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.

幾乎不含硫化氫的沼氣從洗滌塔頂部逸出，含硫化氫的溶液流入生物反應(yīng)器，在此細(xì)菌在限制供氧條件下將其氧化為單質(zhì)硫和堿。該系統(tǒng)的少量排出液（含鈉鹽）和副產(chǎn)品硫磺中都不含硫化物，排放沒有問題。

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.

生物脫硫的技術(shù)優(yōu)勢(shì)

Technological advantages of biological desulfurization

全自動(dòng)無人值守，高度穩(wěn)定可靠。

Fully automatic and unmanned, highly stable and reliable.

深度的硫化氫去除（出口硫化氫含量低于25 ppm）

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

可耐受氣體流量和硫負(fù)荷較寬范圍的波動(dòng)

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

沼氣不會(huì)被空氣稀釋：沼氣和空氣之間有嚴(yán)格的物理分離

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

只需少量的堿、水和營養(yǎng)物

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

沒有堵塞和污垢的風(fēng)險(xiǎn)，因此維護(hù)工作量少

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

常溫常壓運(yùn)行

Normal temperature and pressure operation

產(chǎn)生單質(zhì)硫：可作為肥料和殺蟲劑

Generating elemental sulfur: can be used as fertilizer and insecticide

應(yīng)用的領(lǐng)域

Field of application

沼氣生物脫硫技術(shù)應(yīng)用的領(lǐng)域非常廣泛。污水厭氧處理、糞便、秸稈發(fā)酵、石油天然氣產(chǎn)生的沼氣硫化氫含量過高，都可以應(yīng)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.