江南网站_江南online(中国)提纯的技术路线，主流无非四条：变压吸附、膜分离、高压水洗、胺法吸收。选哪条，看规模、看气源、看终端用途。但有一条铁律所有路线都绕不开——提纯之前，先脱硫。

There are mainly four technical routes for biogas purification: pressure swing adsorption, membrane separation, high-pressure water washing, and amine absorption. Choose which one to consider based on scale, gas source, and end use. But there is an iron rule that all routes cannot be bypassed - desulfurization must be carried out before purification.

为什么脱硫放在前面？

Why does desulfurization have to be placed at the forefront?

膜分离工艺靠的是气体组分在膜材料中渗透速率的差异。二氧化碳渗透快，甲烷渗透慢，两者被分开。但硫化氢在膜系统中的行为很麻烦：它本身有腐蚀性，会损伤膜材料；更关键的是，如果硫化氢含量高，它在膜组件内的积累会干扰分离过程。有实测数据显示，膜分离对进气H?S的耐受阈值有限，超了就得先脱硫。

The membrane separation process relies on the difference in permeation rate of gas components in the membrane material. Carbon dioxide penetrates quickly, methane penetrates slowly, and the two are separated. But the behavior of hydrogen sulfide in membrane systems is very troublesome: it itself is corrosive and can damage membrane materials; More importantly, if the hydrogen sulfide content is high, its accumulation in the membrane module will interfere with the separation process. Experimental data shows that membrane separation has a limited tolerance threshold for inlet H2S, and if it exceeds this threshold, desulfurization must be carried out first.

变压吸附也一样。吸附剂对CO?有选择性吸附能力，但H?S同样会被吸附，而且脱附再生时不如CO?有效。残留在吸附剂上的硫化物越积越多，吸附容量就会衰减，甲烷回收率跟着往下掉。行业经验是：很多吸附剂失效，不是被CO?撑死的，是被H?S毒死的。

The same applies to pressure swing adsorption. Adsorbents have selective adsorption capacity for CO?, but H? S will also be adsorbed, and the desorption regeneration is not as thorough as CO. The more sulfides accumulate on the adsorbent, the lower the adsorption capacity and the lower the methane recovery rate. Industry experience is that many adsorbents fail, not because they are held up by CO, but because they are poisoned by H.

四条主流路线，各自擅长什么？

What are the strengths of each of the four mainstream routes?

膜分离的江南网站_江南online(中国) 是设备紧凑、撬装化、全自动运行，维护成本低，适合中小型项目。甲烷回收率通常在92%-95%之间，纯度上限大概96.5%，要达车用标准还得二次精制。它对高湿、含硅氧烷的江南网站_江南online(中国)适应性较强，但前面说的硫化氢问题不能忽视。

The advantages of membrane separation are compact equipment, modular installation, fully automated operation, low maintenance costs, and suitability for small and medium-sized projects. The methane recovery rate is usually between 92% and 95%, with a purity limit of approximately 96.5%. To meet automotive standards, secondary refining is required. It has strong adaptability to high humidity and siloxane containing biogas, but the hydrogen sulfide problem mentioned earlier cannot be ignored.

变压吸附（PSA）甲烷回收率非常高，能到97%左右，纯度可以做到98%以上。缺点是阀门多、动作频繁，控制系统精度要求高，适合中大规模集中处理。它对原料气预处理的要求也更严，硫化氢提前脱干净。

The pressure swing adsorption (PSA) methane recovery rate is the highest, reaching around 97%, and the purity can reach over 98%. The disadvantage is that there are many valves, frequent actions, and high precision requirements for the control system, making it suitable for centralized processing on a medium to large scale. It also has stricter requirements for the pre-treatment of raw gas, and hydrogen sulfide must be completely removed in advance.

高压水洗技术成熟，但耗水量大，而且需要处理废水，在缺水地区或环保要求严的地方不太合适。

High pressure water washing technology is mature, but it consumes a large amount of water and requires wastewater treatment, which is not suitable in water scarce areas or places with strict environmental requirements.

胺法吸收提纯精度非常高，甲烷浓度能做到98%以上，适合对气质要求出彩严的场景，比如并入长输管网。但胺液再生需要加热，能耗高，溶剂还会降解，运行成本不低。

The amine method has the highest precision in absorption and purification, with a methane concentration of over 98%, making it suitable for scenarios with extremely strict requirements for gas quality, such as integration into long-distance pipeline networks. But amine regeneration requires heating, high energy consumption, solvent degradation, and high operating costs.

提纯到多少才算“生物天然气”？

How much purification is considered as' bio natural gas'?

根据行业标准，生物天然气一类气的甲烷含量要求≥96%，二类气≥85%。进长输管道的是一类气，水露点、总硫、二氧化碳含量都有硬指标。如果只是就近做车用燃气或工业燃料，二类气经过压缩也能用。

According to industry standards, the methane content of Class I biogas is required to be ≥ 96%, and Class II biogas is required to be ≥ 85%. The gas entering the long-distance pipeline must be of a certain type, with hard indicators such as water dew point, total sulfur, and carbon dioxide content. If it is only used as car gas or industrial fuel nearby, Class II gas can also be used after compression.

选提纯路线之前，先算清楚三件事：气量多大、硫化氢多少、终端卖给谁。脱硫放在非常前面，是省钱，也是保命。

Before choosing a purification route, first calculate three things: the amount of gas, the amount of hydrogen sulfide, and who to sell it to at the terminal. Putting desulfurization at the forefront is both cost-effective and life-saving.

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