Does sludge need dewatering before pyrolysis?

Sludge dewatering is a crucial step in sludge pyrolysis. Its core objective is to remove as much water as possible from the sludge, thereby significantly reducing its space and mass, thus lowering the cost and difficulty of the disposal process, improving pyrolysis efficiency, and reducing energy consumption.

The moisture content of sludge directly affects the energy consumption and product recovery rate of the pyrolysis process. High moisture content increases the energy required for water evaporation, reduces pyrolysis efficiency, and may also affect product quality (such as the purity of pyrolysis oil).

Common methods of sludge dewatering:

1. Mechanical dewatering: Removing water using equipment such as centrifuges and filter presses; suitable for sludge with high moisture content.

2. Thermal dewatering: Further reducing moisture content using equipment such as dryers, but this is more expensive.

Pretreatment steps after sludge dewatering: After dewatering, sieving is usually required to remove large particles (such as stones and metal) to avoid contaminating the pyrolysis equipment and products.