提纯率99%+不易堵塞！沼气提纯全流程揭秘，变废为宝还能创收益

　　Purification rate of 99%+not easily clogged! The whole process of biogas purification is revealed, turning waste into treasure and creating profits

　　很多朋友对沼气的印象，还停留在“农村做饭取暖”的初级阶段，其实经过专业提纯，沼气能变成高纯度生物天然气，广泛用于工业、交通甚至家庭管网，真正实现“变废为宝”。今天就用大白话+实打实的数据，给大家唠透沼气提纯的完整流程，重点说说提纯过程中最关键的含硫废气脱硫工艺，不管你是行业从业者，还是单纯好奇，看完都能彻底搞懂，原来沼气提纯不仅环保，还藏着不小的收益空间。

　　Many friends' impression of biogas is still at the initial stage of "cooking and heating in rural areas". In fact, after professional purification, biogas can be turned into high-purity bio natural gas, which is widely used in industry, transportation, and even household pipelines, truly realizing the "turning waste into treasure". Today, using plain language and concrete data, we will explain the complete process of biogas purification to everyone, with a focus on the most critical sulfur-containing waste gas desulfurization process in the purification process. Whether you are an industry practitioner or simply curious, after reading it, you can thoroughly understand that biogas purification is not only environmentally friendly, but also has considerable profit potential.

　　先跟大家科普下，沼气本身是个“潜力股”，主要由甲烷（约50%-60%）、二氧化碳（约40%）和少量硫化氢等杂质组成，其中硫化氢是“绊脚石”——不仅有剧毒、腐蚀性强，还会污染设备、影响提纯后天然气的品质，所以沼气提纯的第一步，也是最核心的一步，就是含硫废气脱硫，这一步做好了，才能保证后续提纯顺利进行。

　　Let me first explain to you that biogas itself is a "potential stock", mainly composed of methane (about 50% -60%), carbon dioxide (about 40%), and a small amount of impurities such as hydrogen sulfide. Among them, hydrogen sulfide is a "stumbling block" - not only is it highly toxic and corrosive, but it can also pollute equipment and affect the quality of purified natural gas. Therefore, the first and most crucial step in biogas purification is desulfurization of sulfur-containing waste gas. Only by doing this step well can the subsequent purification proceed smoothly.

　　咱们常用的脱硫工艺，是高效又环保的生物脱硫法，全程不用复杂的化学试剂，靠“细菌”就能搞定，而且成本低、无二次污染。脱硫用的生物溶液，是专门配置的碳酸氢盐水溶液，为了维持溶液的碱度和PH值稳定（控制在7.5-8.5之间），系统会定期加入氢氧化钠；同时还要补充少量营养物质和水分，满足脱硫细菌的生长需求，这里有个省心的点——这些脱硫细菌在系统初始启动时，只需要添加一次，后续就能靠自身繁殖维持活性，不用反复添加。

　　The commonly used desulfurization process is the efficient and environmentally friendly biological desulfurization method, which does not require complex chemical reagents throughout the process and can be solved by "bacteria", with low cost and no secondary pollution. The biological solution used for desulfurization is a specially prepared bicarbonate aqueous solution. In order to maintain the alkalinity and pH stability of the solution (controlled between 7.5-8.5), the system will regularly add sodium hydroxide; At the same time, it is necessary to supplement a small amount of nutrients and water to meet the growth needs of desulfurization bacteria. Here is a worry free point - these desulfurization bacteria only need to be added once at the initial start-up of the system, and can maintain their activity through self reproduction without repeated addition.

　　脱硫流程分为三个核心阶段，全程自动化运行，不用人工过多干预。第一个阶段是吸收分离，生物溶液会从生物反应器中，通过泵输送到洗涤塔顶部，在接触器的作用下，均匀喷洒在洗涤塔的填料填充床上，填料床能增大接触面积，确保生物溶液和含硫沼气充分接触，接触效率达98%以上。通过洗涤塔内的物理化学反应，沼气中的硫化氢会以硫化物的形式，快速溶解在生物溶液中，而处理后的沼气（已去除大部分硫化氢），会向上流动到洗涤塔顶部的出口，进入下一道提纯工序。这里要注意，这个阶段的硫细菌不参与反应，只负责“分离”硫元素，最后聚集在洗涤塔底部。

　　The desulfurization process is divided into three core stages, which operate automatically throughout the process without excessive manual intervention. The first stage is absorption separation, where the biological solution is pumped from the bioreactor to the top of the washing tower. Under the action of the contactor, it is evenly sprayed onto the packed bed of the washing tower, which can increase the contact area and ensure full contact between the biological solution and sulfur-containing biogas, with a contact efficiency of over 98%. Through the physical and chemical reactions inside the washing tower, hydrogen sulfide in the biogas will quickly dissolve in the biological solution in the form of sulfides. The treated biogas (which has removed most of the hydrogen sulfide) will flow upward to the outlet at the top of the washing tower and enter the next purification process. It should be noted that sulfur bacteria at this stage do not participate in the reaction and are only responsible for "separating" sulfur elements, which eventually gather at the bottom of the washing tower.

　　第二个阶段是生物再生，也是整个脱硫工艺的“核心魔法”。底部富集了硫化物的液体，会通过泵再次输送到生物反应器中，反应器内的红外检测仪会实时探测硫化物的浓度，精度达0.1ppm，然后通过变频技术驱动鼓风机，为细菌输送适量的空气——空气量严格控制在每立方米溶液0.8-1.2立方米，既能满足细菌活性需求，又不会造成能源浪费。在氧气的帮助下，无数脱硫细菌会“吃掉”液体中的硫化物，然后排泄出单质硫，这种单质硫是亲水性的，不会附着在设备内壁，能彻底避免系统堵塞，解决了传统脱硫工艺的一大痛点。

　　The second stage is biological regeneration, which is also the "core magic" of the entire desulfurization process. The liquid enriched with sulfides at the bottom will be pumped back into the bioreactor. The infrared detector inside the reactor will detect the concentration of sulfides in real time with an accuracy of 0.1ppm. Then, the blower will be driven by frequency conversion technology to deliver an appropriate amount of air to the bacteria - the air volume is strictly controlled at 0.8-1.2 cubic meters per cubic meter of solution, which can meet the bacterial activity requirements without causing energy waste. With the help of oxygen, countless desulfurization bacteria will "eat" sulfides in the liquid and excrete elemental sulfur, which is hydrophilic and will not adhere to the inner wall of the equipment, completely avoiding system blockage and solving a major pain point of traditional desulfurization processes.

　　等细菌完成“消化”，生物溶液就实现了再生，纯度恢复到初始状态，会再次被泵送到洗涤塔顶部，进入下一个循环，循环利用率达95%以上，大幅降低了溶液消耗成本。第三个阶段是固液分离，一部分再生后的洗涤液会被分离出来，泵送到重力沉降器中，里面含有10%-15%的单质硫淤渣，再通过离心机或压滤机进行渣水分离，分离后的清液会重新回到系统循环使用，实现资源最大化利用。

　　After the bacteria complete the "digestion", the biological solution is regenerated and the purity is restored to its initial state. It will be pumped again to the top of the washing tower and enter the next cycle, with a recycling rate of over 95%, greatly reducing the cost of solution consumption. The third stage is solid-liquid separation, where a portion of the regenerated washing solution is separated and pumped to a gravity settler containing 10% -15% of elemental sulfur sludge. The sludge is then separated from water using a centrifuge or filter press, and the separated clear liquid is recycled back to the system for maximum resource utilization.

　　分离出来的生物硫，也不是废料，反而能创造额外收益。这些生物硫以硫浆的形式存在，按重量计算，硫的含量在55%-75%之间（剩余部分主要是少量硫酸盐，因部分硫化物被氧化生成），经过进一步处理后，能制成硫基杀菌剂或肥料的硫组分，广泛用于农业和化工领域，真正实现“变废为宝”。

　　The separated biological sulfur is not waste, but can create additional revenue. These biological sulfur exist in the form of sulfur slurry, with a sulfur content ranging from 55% to 75% by weight (the remaining part is mainly a small amount of sulfate, which is generated by oxidation of some sulfides). After further processing, they can be made into sulfur based fungicides or fertilizers as sulfur components, which are widely used in agriculture and chemical industries, truly achieving the goal of "turning waste into treasure".

　　这里补充几个关键数据，让大家更直观了解沼气提纯的优势：整套生物脱硫系统，硫化氢去除率达99.5%以上，能将沼气中的硫化氢浓度从几千ppm降至10ppm以下，完全满足后续提纯要求；脱硫后的沼气，再经过膜分离或PSA提纯工艺，甲烷纯度能提升至95%-99%，达到工业和民用天然气标准，每立方米提纯成本仅0.3-0.5元，而提纯后的生物天然气，市场售价可达3.8元/立方米，收益空间可观。

　　Here are a few key data points to provide a more intuitive understanding of the advantages of biogas purification: the entire biological desulfurization system has a hydrogen sulfide removal rate of over 99.5%, which can reduce the concentration of hydrogen sulfide in biogas from several thousand ppm to below 10ppm, fully meeting the subsequent purification requirements; After desulfurization, the methane purity can be increased to 95% -99% through membrane separation or PSA purification processes, meeting the standards of industrial and civilian natural gas. The purification cost per cubic meter is only 0.3-0.5 yuan, while the market price of purified biogas can reach 3.8 yuan/cubic meter, with considerable profit potential.

　　另外，系统运行过程中，因部分溶液会流出，需要定期补充补给水和氢氧化钠，确保系统电导率维持在2000-3000μS/cm之间，保证细菌活性和脱硫效率。整套系统自动化程度高，运行稳定性达99.8%，每年故障次数不超过2次，后期维护成本低，适配养殖场、垃圾处理厂等各类沼气产生场景，既解决了沼气污染问题，又能实现能源回收利用，契合环保和双碳理念。

　　In addition, during the operation of the system, due to the outflow of some solutions, it is necessary to regularly replenish water and sodium hydroxide to ensure that the system conductivity is maintained between 2000-3000 μ S/cm, ensuring bacterial activity and desulfurization efficiency. The entire system has a high degree of automation, with a stability of 99.8% and no more than 2 failures per year. It has low maintenance costs and is suitable for various biogas production scenarios such as breeding farms and waste treatment plants. It not only solves the problem of biogas pollution, but also achieves energy recovery and utilization, which is in line with environmental protection and dual carbon concepts.

　　总结来说，沼气提纯不是复杂的技术，核心就是先靠生物脱硫法去除硫化氢，再通过后续工艺提升甲烷纯度，全程环保、高效、低成本，还能实现资源循环利用。从含硫沼气到高纯度生物天然气，再到可利用的生物硫，每一步都能创造价值，既解决了环保难题，又能带来实实在在的收益，这也是沼气提纯越来越受欢迎的核心原因。

　　In summary, biogas purification is not a complex technology. The core is to first remove hydrogen sulfide through biological desulfurization, and then improve methane purity through subsequent processes. The whole process is environmentally friendly, efficient, low-cost, and can also achieve resource recycling. From sulfur-containing biogas to high-purity bio natural gas, and then to usable bio sulfur, each step can create value, solving environmental problems while bringing tangible benefits. This is also the core reason why biogas purification is becoming increasingly popular.