目前沼氣脫硫的方法有兩大類,即物理化學(xué)法和生物法。物理化學(xué)法包括干法脫硫和濕法脫硫,已被廣泛地應(yīng)用且積累了豐富的經(jīng)驗(yàn),但該方法存在運(yùn)行費(fèi)用高、投資大、產(chǎn)生二次污染等缺點(diǎn);而生物法以不需催化劑和氧化劑、不需處理化學(xué)污泥、少污染、低能耗、高 效 率、可回收單質(zhì)硫等優(yōu)點(diǎn),引起了人們的廣泛關(guān)注。為此,筆者以某有限公司熱電聯(lián)產(chǎn)沼氣工程為例,介紹了該沼氣工程調(diào)試與運(yùn)行時(shí)生物脫硫技術(shù)的具體運(yùn)用。
At present, there are two kinds of biogas desulfurization methods, namely physical-chemical method and biological method. Physicochemical methods, including dry desulfurization and wet desulfurization, have been widely used and accumulated rich experience, but this method has the disadvantages of high operation cost, large investment and secondary pollution; Biological process has attracted extensive attention because of its advantages such as no catalyst and oxidant, no treatment of chemical sludge, less pollution, low energy consumption, high efficiency and recyclable elemental sulfur. Therefore, taking the cogeneration biogas project of a limited company as an example, the author introduces the specific application of biological desulfurization technology during the commissioning and operation of the biogas project.
生物脫硫的裝置主要由生物脫硫塔和曝氣水箱構(gòu)成,從厭氧罐內(nèi)導(dǎo)出的沼氣由脫硫塔底部進(jìn)入,脫硫循環(huán)水由泵打入脫硫塔頂,兩者在塔內(nèi)逆向接觸反應(yīng),且塔內(nèi)充有填料以供脫硫菌附著生長,同時(shí)也利于氣水均勻分布以充分接觸。生物脫硫塔及曝氣水箱都采用耐酸玻璃鋼制作,循環(huán)泵也使用耐酸性泵。脫硫塔的負(fù)荷為8m3(沼氣)/(m3·h)左右。
The biological desulfurization device is mainly composed of biological desulfurization tower and aeration water tank. The biogas derived from the anaerobic tank enters from the bottom of the desulfurization tower, and the desulfurization circulating water is pumped into the top of the desulfurization tower. The two react in reverse contact in the tower, and the tower is filled with filler for the attachment and growth of desulfurization bacteria. At the same time, it is also conducive to the uniform distribution of gas and water for full contact. The biological desulfurization tower and aeration water tank are made of acid resistant FRP, and the circulating pump also uses acid resistant pump. The load of desulfurization tower is about 8m3 (biogas) / (M3 · h).
本工程采用生物脫硫的方法對沼氣進(jìn)行脫硫處理,主要利用無色硫細(xì) 菌在適宜的溫度、濕度和微氧條件下的代謝作用將H2S氧化成單質(zhì)硫或亞硫酸。生物脫硫分為3個階段:
In this project, biological desulfurization method is adopted for desulfurization of biogas, which mainly uses the metabolism of colorless sulfur bacteria under appropriate temperature, humidity and micro oxygen conditions to oxidize H2S into elemental sulfur or sulfite. Biological desulfurization is divided into three stages:
1.H2S氣體的溶解過程,即由氣相轉(zhuǎn)化為液相;
1. Dissolution process of H2S gas, i.e. conversion from gas phase to liquid phase;
2.溶解后的H2S被微生物吸收,轉(zhuǎn)移微生物的體內(nèi);
2. The dissolved H2S is absorbed by microorganisms and transferred to microorganisms;
3.進(jìn)入微生物細(xì)胞內(nèi)的H2S作為營養(yǎng)物被微生物分 解、轉(zhuǎn)化和利用,從而達(dá)到去除H2S的目的。
3. H2S entering microbial cells is decomposed, transformed and utilized by microorganisms as nutrients, so as to achieve the purpose of removing H2S.
雖然生物脫硫具有能耗少、去除率高等特點(diǎn),但必 須給硫細(xì) 菌營造一個適宜的環(huán)境,才能確保其具有較高的生物活 性,以達(dá)到好的脫硫效果
Although biological desulfurization has the characteristics of low energy consumption and high removal rate, it is necessary to create a suitable environment for sulfur bacteria in order to ensure its high biological activity and achieve good desulfurization effect