沼氣中含有硫化氫,分子式為H2S,硫化氫為易燃?;?,與空氣混合能形成爆炸性混合物,遇明火、高熱能引起燃燒爆炸,加上硫化氫遇水后會(huì)對(duì)鋼材產(chǎn)生較強(qiáng)的腐蝕特性,因此沼氣提純精制生物天然氣的預(yù)處理工序的核心即是脫除硫化氫。
Biogas contains hydrogen sulfide with the molecular formula of H2S. Hydrogen sulfide is a flammable hazardous chemical. It can form an explosive mixture when mixed with air. It can cause combustion and explosion in case of open fire and high heat. In addition, hydrogen sulfide will have strong corrosion characteristics on steel when it meets water. Therefore, the core of the pretreatment process of biogas purification and refining biogas natural gas is to remove hydrogen sulfide.
不同的有機(jī)廢棄物在厭氧狀態(tài)下產(chǎn)生的沼氣中的硫化氫濃度有高有低,差異比較大。造紙工業(yè)、發(fā)酵工業(yè)等由于在生產(chǎn)過(guò)程中有含硫的介質(zhì)加入,生產(chǎn)廢水產(chǎn)生的沼氣含硫化氫的濃度便比較高。
The concentration of hydrogen sulfide in biogas produced by different organic wastes in anaerobic state varies greatly. Due to the addition of sulfur-containing medium in the production process of papermaking industry and fermentation industry, the concentration of hydrogen sulfide in biogas produced by production wastewater is relatively high.
如造紙行業(yè)的沼氣可高達(dá)10000-35000ppm,淀粉工業(yè)沼氣一般在10000ppm左右,生活垃圾填埋沼氣則由于產(chǎn)生過(guò)程中相對(duì)較少有硫介質(zhì)參與,因此硫化氫含量較低,一般在1000ppm以內(nèi)。
For example, the biogas in the paper industry can be as high as 10000-35000ppm, the biogas in the starch industry is generally about 10000ppm, and the biogas in the domestic waste landfill is relatively less involved in the production process, so the content of hydrogen sulfide is low, generally within 1000ppm.
在我國(guó),沼氣的生產(chǎn)加工技術(shù)和商業(yè)化運(yùn)行系統(tǒng)也已經(jīng)逐漸成熟,通過(guò)自主創(chuàng)新、引進(jìn)并消化吸收了國(guó)外成熟的高含固量的有機(jī)廢棄物厭氧消化技術(shù),其中以谷物秸稈、畜禽糞便、城市有機(jī)垃圾為處理對(duì)象的大型沼氣工程也取得了突破性進(jìn)展,因此,相應(yīng)的沼氣凈化工藝技術(shù)也得到發(fā)展,形成了一系列相對(duì)比較成熟的技術(shù)。
In China, the production and processing technology and commercial operation system of biogas have gradually matured. Through independent innovation, the introduction and digestion of foreign mature and advanced anaerobic digestion technology of organic waste with high solid content have been absorbed. Among them, the large biogas project with grain straw, livestock manure and urban organic waste as the treatment object has also made breakthrough progress. Therefore, The corresponding biogas purification technology has also been developed, forming a series of relatively mature technologies.
行業(yè)內(nèi)常用的沼氣脫硫方法有:干法脫硫、濕法脫硫、絡(luò)合鐵脫硫、生物法脫硫等幾種脫硫方法。
The commonly used biogas desulfurization methods in the industry include dry desulfurization, wet desulfurization, complex iron desulfurization, biological desulfurization and other desulfurization methods.