Research on the Transformation of Nitrogen during Hydrothermal Carbonization of Sludge

The nitrogen in the sludge mainly exists in the form of inorganic nitrogen and organic nitrogen.In this paper, the transformation of nitrogen during the hydrothermal carbonization of sludge was studied.The results showed that during the hydrothermal carbonization of the sludge, both the total nitrogen and theinorganic nitrogen in hydrochar decrease with the increase of the carbonization temperature. The reason isthat part of the inorganic nitrogen compounds in the sludge undergoes thermal decomposition to releaseNH3, and some organic nitrogen will be hydrolyzed to produce ammonia nitrogen into the liquid phase