沼氣的利用越來越普遍。將含有有機質(zhì)的廢水、固體垃圾等經(jīng)過厭氧處理后,不僅可以將垃圾減量化,而且能產(chǎn)生大量沼氣。在這個厭氧發(fā)酵的過程中,硫酸鹽還原細菌的作用下,也產(chǎn)生大量硫化氫。
The use of biogas is becoming more and more common. After anaerobic treatment of wastewater and solid waste containing organic matter, not only the waste can be reduced, but also a large amount of biogas can be produced. In this anaerobic fermentation process, a large amount of hydrogen sulfide is also produced under the action of sulfate-reducing bacteria.
由于硫化氫有毒、腐蝕性強,如何有效且經(jīng)濟地處理這些沼氣中的硫化氫,是衡量一個沼氣利用項目成功的重要因素。隨著科技的發(fā)展、技術(shù)的更替,沼氣脫硫技術(shù)已發(fā)展到以生物脫硫為代表的第三代沼氣脫硫技術(shù)。其中生物脫硫又大體分為一體式生物脫硫和分離式生物脫硫兩大類。
Because hydrogen sulfide is toxic and corrosive, how to effectively and economically treat hydrogen sulfide in these biogas is an important factor to measure the success of a biogas utilization project. With the development of science and technology and the replacement of technology, biogas desulfurization technology has developed to the third generation of biogas desulfurization technology represented by biological desulfurization. Biological desulfurization can be divided into integrated biological desulfurization and separated biological desulfurization.
一體式生物脫硫是指:將一定量的空氣導(dǎo)入含有硫化氫的沼氣中,混合氣體通過生物濾池、生物滴濾池以去除硫化氫,脫硫副產(chǎn)物一般為硫酸或者硫酸鹽,由于運行成本低,被廣泛應(yīng)用于沼氣脫硫發(fā)電項目中。
Integrated biological desulfurization refers to the introduction of a certain amount of air into the biogas containing hydrogen sulfide, and the mixed gas passes through the biological filter and biological trickling filter to remove hydrogen sulfide. The by-product of desulfurization is generally sulfuric acid or sulfate, which is widely used in biogas desulfurization power generation projects due to low operating costs.
分離式生物脫硫工藝是指:含硫化氫的沼氣氣體首入生物洗滌塔,在塔內(nèi)與混合液中堿反應(yīng),先從沼氣中脫除硫化氫,然后生物洗滌液進入生物反應(yīng)器。將反應(yīng)器中的硫化物轉(zhuǎn)化為單質(zhì)硫,同時堿液得到再生,重復(fù)使用。隨著嗜鹽脫硫菌的發(fā)現(xiàn),分離式脫硫工藝得到長足發(fā)展。解決了一體式生物脫硫容易出現(xiàn)的硫填料易堵塞的問題。在沼氣提純CNG的工藝中、以及高濃度硫化氫的沼氣處理工藝中,分離式脫硫工藝占有優(yōu)勢。
Separated biological desulfurization process refers to that the biogas gas containing hydrogen sulfide first enters the biological scrubber, reacts with the alkali in the mixed liquor in the tower, first removes hydrogen sulfide from the biogas, and then the biological scrubber enters the biological reactor. The sulfide in the reactor is converted into elemental sulfur, and the alkali liquor is regenerated and reused. With the discovery of halophilic desulfurizing bacteria, the separated desulfurization process has been greatly developed. It solves the problem that the sulfur filler is easy to block in the integrated biological desulfurization. In the process of purifying CNG from biogas, and in the process of biogas treatment with high concentration of hydrogen sulfide, the separation desulfurization process has advantages.
沼氣生物脫硫過程可以用雙膜理論來解釋,大致可以分為溶解吸收---吸附---轉(zhuǎn)化三個過程。
The process of biogas biological desulfurization can be explained by the two-membrane theory, which can be roughly divided into three processes: dissolution absorption - adsorption - conversion.
溶解吸收:沼氣中的硫化氫氣體在氣液界面上,由氣相轉(zhuǎn)移到液相。
Dissolution absorption: hydrogen sulfide gas in biogas is transferred from gas phase to liquid phase at gas-liquid interface.
H2S + OH-—— H2O + HS-
H2S + OH-—— H2O + HS-
吸附:溶液中硫氫根離子被脫硫微生物吸附,從水中轉(zhuǎn)移微生物體內(nèi)。
Adsorption: the hydrogen sulfide ion in the solution is adsorbed by the desulfurization microorganism and transferred from the water to the microorganism.
HS-——[細胞膜+HS-]
HS - [cell membrane+HS -]
轉(zhuǎn)化:在脫硫微生物體內(nèi),硫氫根被轉(zhuǎn)化成單質(zhì)硫或硫酸根,作為吸收劑的堿液被再生,重新吸收硫化氫。
Transformation: in the desulfurization microorganism, hydrogen sulfide is converted into elemental sulfur or sulfate, and the alkali liquor used as absorbent is regenerated to reabsorb hydrogen sulfide.
[細胞膜+HS-]——S0+ HO-或 [細胞膜+HS]——SO42-+ HO
[Cell membrane+HS -] - S0+HO - or [Cell membrane+HS] - SO42 -+HO
在此過程中,有效控制一定的氧含量是脫硫細菌繁殖生存的必要條件,所以在這個生物脫硫工藝過程,對硫化氫(H2S)和氧氣(O2)的連續(xù)監(jiān)控是*的要求。
In this process, effective control of certain oxygen content is a necessary condition for the proliferation and survival of desulfurization bacteria, so in this biological desulfurization process, continuous monitoring of hydrogen sulfide (H2S) and oxygen (O2) is a * requirement.
This article is dedicated to the friendship of biogas purification. For more information, please click: http://www.fengkecheng.cn Sincere attitude. We will provide you with comprehensive services. We will continue to offer you more relevant knowledge. Please look forward to it