运行厌氧反应器的工程师知道，厌氧反应会产生沼气，该沼气通常包含一定量的硫化氢(H2S)。 不同的工业废水中沼气中硫化氢的含量也不同。 如果硫化氢含量太高，则在进入锅炉之前必须去除沼气中的硫化氢，以免腐蚀管道和锅炉。 今天，大家将先容当前先进的沼气技术。
Engineers running anaerobic reactors know that anaerobic reactions produce biogas, which usually contains a certain amount of hydrogen sulfide (H2S). The content of hydrogen sulfide in biogas is different in different industrial wastewater. If the content of hydrogen sulfide is too high, the hydrogen sulfide in biogas must be removed before entering the boiler, so as to avoid corrosion of pipes and boilers. Today, we will introduce the current advanced biogas technology.
1. Biogas source
沼气通常来自于污水的厌氧处理，粪便，秸秆发酵，石油和天然气等。提纯后的沼气可以用作清洁能源，代替天然气和煤炭用于发电，供热，蒸汽生产等。 分离出的硫化氢气体被转化。 它是一种固体生物硫，可以用作化肥和化学工业的原料。 沼气可通过吸取和净化用于能源净化，既节省能源，减少排放，又节省了生产成本。
Biogas usually comes from anaerobic treatment of sewage, manure, straw fermentation, oil and natural gas, etc. The purified biogas can be used as clean energy instead of natural gas and coal for power generation, heating and steam production. The separated hydrogen sulfide gas is transformed. It is a kind of solid biological sulfur, which can be used as raw material of chemical fertilizer and chemical industry. Biogas can be used for energy purification through absorption and purification, which not only saves energy, reduces emissions, but also saves production costs.
2. The value of Biogas
1 m3 biogas ≈ 0.65m3 natural gas ≈ 0.7kg standard coal ≈ 7.5kg steam ≈ 1.8kwh electricity, calculated by 3.0 yuan / m3 of industrial natural gas, 1.95 yuan can be saved by using 1 cubic meter of biogas.
2. The difference between biogas desulfurization and flue gas desulfurization
尽管沼气脱硫和烟气脱硫都是脱硫，但它们是完全不同的过程。 烟气脱硫从工业废气中去除了二氧化硫，SO2和SO3。 大家经常说脱硫和反硝化是指去除二氧化硫。 沼气脱硫是指从沼气中去除硫化氢(H2S)，以减少后续管道，燃烧锅炉或发电机的腐蚀。
Although both biogas desulfurization and flue gas desulfurization are desulfurization, they are totally different processes. Flue gas desulfurization removes sulfur dioxide, SO2 and SO3 from industrial waste gas. We often say that desulfurization and denitrification refer to the removal of sulfur dioxide. Biogas desulfurization refers to the removal of hydrogen sulfide (H2S) from biogas to reduce the corrosion of subsequent pipelines, combustion boilers or generators.
3. What is biogas?
Biogas (biogas desulfurization) is a method to remove highly corrosive and toxic hydrogen sulfide from biogas by biological strains. The process has the advantages of high automation, simple process and low operation cost.
厌氧发酵产生的沼气进入洗涤塔，并与碱性循环喷雾器进行吸取反应，从沼气中去除硫化氢。 吸取富液的硫化氢返回到生物反应器中，通过生物转化将硫化氢转化为固体元素硫，并将溶液再生为碱性吸取液(也变为稀液)，可用于洗涤沼气， 从而实现了吸取剂的再循环和再循环。 硫固体的分离通过硫沉淀器实现。
The biogas generated by anaerobic fermentation enters the washing tower and absorbs and reacts with the basic circulation sprayer to remove hydrogen sulfide from the biogas. The hydrogen sulfide absorbed from the rich liquid is returned to the bioreactor, and the hydrogen sulfide is converted into solid sulfur by biotransformation, and the solution is regenerated into alkaline absorption solution (also into dilute liquid), which can be used to wash biogas, so as to realize the recycling and recycling of absorbent. The separation of sulfur solid is realized by sulfur precipitator.
该过程将弱碱性条件下硫化氢的物理化学吸取与碱性溶液在空气中的生物再生结合在一起。 含有硫化氢的沼气进入洗涤器，在洗涤器中被吸取硫化氢的碱性溶液洗涤，处理后的沼气中硫化氢的去除率高达99.5%。 经过系统处理后，沼气可用于气体发生器发电，用作锅炉燃料或输入当地的小型燃气供应网络。
This process combines the physical and chemical absorption of hydrogen sulfide under weak alkaline conditions with the biological regeneration of alkaline solution in air. The biogas containing hydrogen sulfide enters into the scrubber and is washed by the alkaline solution of hydrogen sulfide absorbed in the scrubber. The removal rate of hydrogen sulfide in the treated biogas is as high as 99.5%. After being processed by the system, biogas can be used for gas generator power generation, boiler fuel or local small gas supply network.
Almost no hydrogen sulfide gas escapes from the top of the scrubber, and the solution containing hydrogen sulfide flows into the bioreactor. Under the condition of limiting oxygen supply, it is oxidized to elemental sulfur and alkali. A small amount of waste water (including sodium salt) and by-product sulfur in the system do not contain sulfide, and there is no problem to discharge.
4. Technical advantages of
-Automatic unattended, highly stable and reliable.
-Deep removal of hydrogen sulfide (outlet hydrogen sulfide content 50-100ppm)
-Gas flow and sulfur load fluctuation within tolerance range
-Biogas is not diluted by air: there is strict physical isolation between biogas and air
-Only a small amount of alkali, water and nutrients
-There is no risk of clogging and fouling, so maintenance is reduced
-Normal temperature and normal pressure operation
-Produce elemental sulfur: can be used as fertilizer and pesticide
5. Application fields
Biogas technology is widely used in various fields. The content of hydrogen sulfide in sewage anaerobic treatment, feces, straw fermentation and biogas produced by oil and natural gas is too high.