The existence of CO2 in biogas will affect its practicality, so the methanation of CO2 is of great significance. Carrier materials play a key role in bioconversion of CO2 to methane during biogas upgrading. Herein, different materials were used to evaluate the bioconversion process of CO2 to methane, which consisted of black ceramsite (BC) and biochars prepared from corn straw and digestate. The results showed that after adding the carrier materials, the methane production rate increased by more than 20%, and the corn straw biochar (CSB) group even increased by more than 70%. This may be attributed to the large specific surface area and more functional groups in corn straw biochar which was suitable for the immobilization of hydrogenotrophic methanogens (HMs). Therefore, corn straw biochar is a good carrier material for the accelerated bioconversion of CO2 to methane.

中文翻译：

---

使用生物炭作为生物载体提高氢营养型产甲烷菌的甲烷生产率。

沼气中二氧化碳的存在会影响其实用性，因此甲烷化甲烷具有重要意义。在沼气升级过程中，载体材料在将二氧化碳从二氧化碳生物转化为甲烷方面起着关键作用。在本文中，使用不同的材料来评估CO2转化为甲烷的生物转化过程，其中包括黑陶粒（BC）和由玉米秸秆和消化物制成的生物炭。结果表明，加入载体材料后，甲烷生产率提高了20％以上，玉米秸秆生物炭（CSB）组甚至提高了70％以上。这可能归因于玉米秸秆生物炭中较大的比表面积和更多的官能团，它们适合固定氢营养型产甲烷菌（HMs）。因此，