Hydrothermal Carbonization of Nonylphenol Ethoxylates Waste Liquid for Energy Source Generation

Abstract

Nonylphenol polyethoxylates (NPEOs) are widely used as nonionic surfactants in many industry fields. High concentration NPEOs waste water is produced in some production processes. It is often treated to realize reduction by distillation. Therefore, NPEOs waste liquid with higher concentration is produced and it is difficult to be treated by traditional water treatment process. In this study, hydrothermal carbonization process was used to convert NPEOs waste liquid to carbonaceous product (hydrochar) with sulfuric acid as additive in 24 h at 200˚C. The hydrochar was characterized by scanning electron microscope, Fourier-transform infrared spectrometer and thermogravimetric analysis. The element composition and the high heat value of the hydrochar were similar to lignite, showing that it could be used as an alternative fuel.