常見的沼氣利用方式是提純天然氣。該方式是把沼氣中CO2通過高壓水洗、變壓吸附、膜分離等技術進行去除,從而將沼氣制成CH4純度更高的生物天然氣。制出的生物天然氣可經過壓力調節后接入城市輸氣網,也可以壓縮后制成車用燃料(CNG),或者制成液化天然氣(LNG)出售。
The common way to utilize biogas is to purify natural gas. This method is to remove CO2 from biogas through high-pressure water washing, pressure swing adsorption, membrane separation, and other technologies, thereby making biogas into biological natural gas with higher CH4 purity. The produced biological natural gas can be connected to the urban gas transmission network after pressure adjustment, and can also be compressed into vehicle fuel (CNG), or converted into liquefied natural gas (LNG) for sale.
由于厭氧項目肯定需要熱量,所以項目一般還要配套沼氣鍋爐,一部分沼氣用于鍋爐,剩余沼氣可全部用于沼氣提純。同時還應設置應急火炬,用于沼氣凈化系統或者沼氣利用系統故障時,沼氣的應急處理。
As anaerobic projects definitely require heat, projects generally need to be equipped with biogas boilers, with some of the biogas used for boilers, and the remaining biogas can be used entirely for biogas purification. At the same time, emergency flares should also be installed for emergency treatment of biogas when the biogas purification system or biogas utilization system fails.
隨著我國雙碳計劃的提出,氫能變得越來越熱,因此沼氣重整制氫近幾年也被越來越多的提出,同時也有部分項目開始實踐。
With the proposal of the dual carbon plan in China, hydrogen energy has become increasingly hot. Therefore, biogas reforming for hydrogen production has been increasingly proposed in recent years, and some projects have also begun to be implemented.
沼氣重整制氫,也有多種技術。目前用的多的還是先將沼氣進行脫碳提純,提純后的氣體再進行重整制氫,重整后的混合氣體再進行提純,終得到純度較高的氫氣。
There are also various technologies for reforming biogas to produce hydrogen. Currently, the most commonly used method is to decarbonize and purify biogas, and then conduct reforming of the purified gas to produce hydrogen. After reforming, the mixed gas is purified to ultimately obtain hydrogen with higher purity.
也有學者提出沼氣直接重整制氫,即省去沼氣脫碳提純這一步,從技術層面說也是可以的。不過目前我國氫能的應用場景還未構建完全,直接用沼氣重整制氫,具有一定的市場風險。從項目規劃的角度看,如果是沼氣提純后再制氫,可以先預留制氫場地,后期等氫能有應用場景了再上。
Some scholars have proposed that direct reforming of biogas to produce hydrogen, which eliminates the step of decarbonization and purification of biogas, is also technically feasible. However, at present, the application scenario of hydrogen energy in China has not been fully constructed, and directly reforming biogas to produce hydrogen poses certain market risks. From the perspective of project planning, if biogas is purified before hydrogen production, a hydrogen production site can be reserved for later use when hydrogen energy has an application scenario.