In the last decade, China’s photovoltaic (PV) industry has developed rapidly, with the joint promotion of the world market and domestic policies, and China has now become the largest PV manufacturer in the world. Meanwhile, the international market has responded to China’s rapid development,...

Conventional thermochemical treatment of sewage sludge (SS) is energy-intensive due to its high moisture content. To overcome this drawback, the hydrothermal carbonization (HTC) process was used to convert SS into clean solid fuel without prior drying. Different carbonization times were applied...