生物脫硫是指在一定的反應(yīng)條件下，利用特殊微生物( 菌種) 的催化作用，在人為控制合理?xiàng)l件下將原料中的 H2S 或有機(jī)硫化合物轉(zhuǎn)化為元素硫或硫酸鹽的一種工藝過程。由于全球能源供應(yīng)緊張、排放標(biāo)準(zhǔn)日益嚴(yán)格，生物脫硫工藝的技術(shù)開發(fā)受到普遍重視。

Biological desulfurization refers to a process that utilizes the catalytic action of special microorganisms (strains) under certain reaction conditions to convert H2S or organic sulfur compounds in raw materials into elemental sulfur or sulfate under controlled and reasonable conditions. Due to the tight global energy supply and increasingly strict emission standards, the technological development of biological desulfurization processes has received widespread attention.

當(dāng)前，生物脫硫工藝的應(yīng)用涉及沼氣、油品加工，煉廠廢氣處理，天然氣、填埋氣及煤層氣等諸多化石能源與新型能源領(lǐng)域，并在化工、造紙和采礦等工業(yè)領(lǐng)域中也有應(yīng)用，故生物脫硫被譽(yù)為 21 世紀(jì)最有發(fā)展前景的脫硫新工藝。1) 與微生物固定在一定區(qū)域內(nèi)基體上的其它生化工藝不同，S-P 工藝生物脫硫過程中微生物是游離于溶液中，且脫硫溶液在 24 h 運(yùn)轉(zhuǎn)周期中需要經(jīng)歷 12 次常壓→ 8. 2 MPa 高壓→常壓的反復(fù)循環(huán)。長期工業(yè)運(yùn)轉(zhuǎn)表明: 脫硫微生物可以經(jīng)受劇烈的壓力變化而不影響其脫硫性能。

Currently, the application of biological desulfurization technology involves many fossil and new energy fields such as biogas, oil processing, refinery waste gas treatment, natural gas, landfill gas, and coalbed methane. It is also applied in industrial fields such as chemical, papermaking, and mining. Therefore, biological desulfurization is known as the most promising new desulfurization technology in the 21st century. 1) Unlike other biochemical processes in which microorganisms are fixed on a substrate within a certain area, the S-P process for biological desulfurization involves microorganisms being free in the solution, and the desulfurization solution needs to undergo 12 cycles of atmospheric pressure → 8 during a 24-hour operation cycle Repetitive cycle from 2 MPa high pressure to atmospheric pressure. Long term industrial operation has shown that desulfurization microorganisms can withstand drastic pressure changes without affecting their desulfurization performance.

2) 當(dāng)原料氣中CO2含量φ高達(dá)4 時(shí)，由于Na2CO3－NaHCO3良好的緩沖作用，仍能保持脫硫溶液 pH 值穩(wěn)定，并保證凈化氣H2S 含量φ降到6 mg /m3以下。當(dāng)單塔處理量降至66 萬m3/d，原料氣H2S 含量φ降至702×10－6時(shí)，凈化氣平均H2s φ含量降至1. 5 mg /m3，從而表明脫硫菌種的性能相當(dāng)優(yōu)越。

2) When the CO2 content in the feed gas reaches 4, due to the good buffering effect of Na2CO3-NaHCO3, the pH value of the desulfurization solution can still be maintained stable, and the H2S content in the purified gas can be reduced to below 6 mg/m3. When the processing capacity of a single tower drops to 660000 m3/d and the H2S content in the feed gas decreases to 702 × 10-6, the average H2S content in the purified gas decreases to 1 5 mg/m3, indicating that the performance of desulfurization bacteria is quite superior.

3) 由于生物硫黃良好的親水性，只要采取適當(dāng)?shù)拇胧?，S-P 生物脫硫工藝基本上不存在絡(luò)合鐵法工藝常見的溶液發(fā)泡和設(shè)備堵塞問題。在運(yùn)轉(zhuǎn)過程中，必須經(jīng)常以連續(xù)或間歇方式從脫硫溶液中除去產(chǎn)品硫黃，維持溶液中硫黃質(zhì)量濃度為0. 6 ～0. 8 的低水平可以改善操作并降低溶液的發(fā)泡傾向。同時(shí)，在閃蒸罐、緩沖罐和生物反應(yīng)器出口管匯處等容易發(fā)生硫沉積的地方，在所有工況條件下均應(yīng)仔細(xì)觀察管道中溶液的流速。閃蒸罐宜采用立式，緩沖罐應(yīng)采用錐形底部。

3) Due to the good hydrophilicity of biological sulfur, as long as appropriate measures are taken, the S-P biological desulfurization process basically does not have the common problems of solution foaming and equipment blockage in the chelated iron process. During operation, it is necessary to regularly remove product sulfur from the desulfurization solution in a continuous or intermittent manner, maintaining a sulfur mass concentration of 0 6 ～0.  A low level of 8 can improve operation and reduce the foaming tendency of the solution. At the same time, in places where sulfur deposition is prone to occur such as flash evaporation tanks, buffer tanks, and bioreactor outlet manifolds, the flow rate of the solution in the pipeline should be carefully observed under all operating conditions. Flash evaporation tanks should be vertical, while buffer tanks should have a conical bottom.

4) 設(shè)備的選型、整改與裝置的穩(wěn)定運(yùn)行密切相關(guān)。Teague 凈化廠投產(chǎn)初期即發(fā)現(xiàn)吸收塔有較強(qiáng)烈的發(fā)泡現(xiàn)象，并導(dǎo)致凈化氣不合格。掃描結(jié)果發(fā)現(xiàn)在高負(fù)荷操作條件下，脫硫溶液滯留的區(qū)域即成為泡沫形成并堆積的區(qū)域。因此，吸收塔頂部與中部的再分配塔盤上的滯留液體就成為泡沫起源，上升氣流夾帶著泡沫沿填料層向上發(fā)展，最終導(dǎo)致強(qiáng)烈霧沫夾帶或沖塔( 圖5) 。隨后對(duì)吸收塔內(nèi)構(gòu)件進(jìn)行整改，拆除再分配塔盤，并在此空間放置填料。經(jīng)此整改后，吸收塔阻力降明顯改善，H2S 凈化度也迅速降至 6 mg /m3以下。

4) The selection and rectification of equipment are closely related to the stable operation of the device. At the beginning of the production of Teague purification plant, it was found that the absorption tower had a strong foaming phenomenon, which led to the unqualified purified gas. The scanning results showed that under the high load operation conditions, the area where the desulfurization solution stayed became the area where foam formed and accumulated. Therefore, the trapped liquid on the redistribution tray at the top and middle of the absorber becomes the origin of foam, and the updraft carries foam upward along the packing layer, eventually leading to strong entrainment or tower flushing (Figure 5). Subsequently, the components inside the absorption tower were rectified, the redistribution tray was removed, and packing was placed in this space. After this rectification, the resistance of the absorption tower has significantly improved, and the purification degree of H2S has rapidly decreased to below 6 mg/m3.