Kitchen waste has the characteristics of high proportion of impurities, high sand content and oil content, which makes it difficult to sort. The pretreatment is the biggest challenge for the resource and utilization of kitchen waste. The HP hydraulic pulping process began to be applied in Europe in the 1980s, and after continuous improvement, optimization and upgrading, it is now widely used in the pretreatment of organic waste such as food waste, kitchen waste, and waste grease, etc.

The organic waste is unloaded into the HP pulper directly by the transport vehicle, or through the screw conveyor from the reception bin. The HP pulper integrates a variety of functions such as bag breaking, crushing & pulping, and sorting. The organic waste rotates with the rotor of the pulping machine in the operation, and the high-speed vortex generated in the continuous change of flow regime and flow velocity leads to the collision and rubbing between materials, which realized the bag breaking, organic materials crushing, as well as the separation of light impurities such as plastic bags and inorganic or metal heavy substances, such as knives and forks. 

After further treatment by the decanter and presser, the solid phase content of the separated impurities can reach more than 40%, and the liquid phase is combined with the degreased slurry for subsequent treatment.

The prepared organic slurry is pumped to desander unit for two stages grit removal, and then sent to the followed oil separation unit. The slurry is heated to a certain temperature through the heat recovery system and the cooking tank, and then pumped to the three-phase decanter for oil-water separation. The oil phase is sent to the crude oil temporary storage tank, the liquid phase is cooled by the heat recovery system and then sent to the followed anaerobic treatment system, and the solid phase can be sent to the anaerobic system or other resource utilization facilities according to the project requirement.

The great advantage of HP pulping process is short and simple process, small number of equipment, large processing capacity of one single line, and small footprint.

HP Features and Benefits:
- Minimal loss of organic matter to reject 
- Short process flow, small footprint, and stability system
- High quality slurry production
- Large processing capacity
- Low odor generation and low environmental impact
- High degree of automation and low demand for operating personnel