降低能耗，单纯冷凝方法要达到国家标准规定的排放浓度，需要深低温冷凝温度才能液化达标，同时也要对混合组分中的大量空气降低温度，这些需要降低的深低温配置在整机的能耗却接近30%。因此，这是单纯冷凝法的一个缺点。吸附法的主要作用是将低浓度油气富集为高浓度，其优点是能够控制尾气排放浓度。缺点是不能直接使油气产生相变，不能得到液化的回收物，需要二次工艺，以及吸附热效应有安全隐患、直接吸附高浓度油气时吸附剂用量大、吸附罐体积庞大、装置占地面积大，等等。两种工艺组合，整机能耗明显降低。

To reduce energy consumption, the simple condensation method requires a deep low-temperature condensation temperature to achieve the emission concentration specified by national standards for liquefaction. At the same time, it also needs to lower the temperature of a large amount of air in the mixed components. These deep low-temperature configurations require a reduction of nearly 30% in the overall energy consumption of the machine. Therefore, this is a drawback of the simple condensation method. The main function of adsorption method is to enrich low concentration oil and gas into high concentration, and its advantage is that it can control the concentration of exhaust emissions. The disadvantage is that it cannot directly cause phase change in oil and gas, cannot obtain liquefied recyclables, requires secondary processes, and has safety hazards due to adsorption heat effects. When directly adsorbing high concentration oil and gas, the amount of adsorbent used is large, the adsorption tank volume is large, and the device occupies a large area, etc. The combination of two processes significantly reduces the overall energy consumption of the machine.

是增强安全：油气冷凝至-70℃之后，余气为低温的空气和低浓度油气，采用吸附罐富集，能够改善吸附工况。吸附剂吸附冷凝后剩余的低浓度油气，拦截余气中的碳氢化合物，吸附后的尾气排放。吸附罐的吸附剂（活性炭）吸附饱和之后，进行抽真空脱附，将富集提浓的油气输送到前端再次冷凝液化处理，低温下富集处理油气更安全。

To enhance safety: After the oil and gas are condensed to -70 ℃, the remaining gas is low-temperature air and low concentration oil and gas, which can be enriched by adsorption tanks to improve adsorption conditions. The adsorbent adsorbs the low concentration oil and gas remaining after condensation, intercepts the hydrocarbons in the residual gas, and emits the adsorbed exhaust gas. After the adsorbent (activated carbon) in the adsorption tank is saturated, vacuum desorption is carried out to transport the enriched and concentrated oil and gas to the front end for further condensation and liquefaction treatment. Enrichment treatment of oil and gas at low temperatures is safer.

减小吸附罐体积和活性碳用量。冷凝之后的低温空气和低浓度油气中烃类物质含量减少，采用吸附方法富集时，所需吸附剂用量相应减少。与直接吸附高温高浓度油气的吸附装置相比，吸附罐体积不但大大缩小，而且改善了吸附工况，有利于克服吸附热温升、延长活性炭寿命。因此需要的活性炭量减少、吸附罐体积也大大缩小。

Reduce the volume of the adsorption tank and the amount of activated carbon used. After condensation, the content of hydrocarbon substances in low-temperature air and low concentration oil and gas decreases. When using adsorption methods for enrichment, the required amount of adsorbent is correspondingly reduced. Compared with adsorption devices that directly adsorb high-temperature and high concentration oil and gas, the adsorption tank volume is not only greatly reduced, but also the adsorption conditions are improved, which is conducive to overcoming the temperature rise of adsorption heat and extending the life of activated carbon. Therefore, the required amount of activated carbon is reduced and the volume of the adsorption tank is greatly reduced.