Method for co-production of nitrogen-doped lignin-based carbon nanotubes and biochar

The invention discloses a method for co-production of nitrogen-doped lignin-based carbon nanotubes and biochar, which comprises the following steps: obtaining a lignin and nitrogen-containing small molecule compound mixture with strong intermolecular force through solution impregnation and high-temperature treatment, and then realizing rapid heating pyrolysis of lignin by adopting a mobile chemical vapor deposition method to obtain the nitrogen-doped lignin-based carbon nanotubes. A small molecular gas carbon source generated by lignin pyrolysis is effectively utilized, so that the nitrogen-doped lignin-based carbon nanotube with high nitrogen atom content and uniform nitrogen element distribution is obtained. The biochar is obtained while the nitrogen-doped lignin-based carbon nanotube is obtained, co-production of the nitrogen-doped lignin-based carbon nanotube and the biochar is realized, and the method can become an important way for high-value utilization of lignin. The preparation method has the advanta