Paper pulp rejects are a waste stream originating from the recycling process of paper. Besides some fibers, these rejects include a large amount of non-recyclable plastics that are separated from the wet paper pulp. These are extremely suitable to be used as alternative energy. However, after its removal from the wet paper pulp, the rejects have a high amount of moisture, leaving waste processing facilities with the challenge to optimise the drying process.
Unnecesary costs due to moisture
Depending on the facility, paper pulp rejects contain around 70% moisture when they enter the drying process. In the initial dewatering step, around a third of the moisture is removed. The rejects then typically have two destinations. When not destined for alternative fuel, rejects are often transported and disposed of with the remaining moisture, increasing transport and gate fee costs due to the weight of the moisture. When prepared for alternative fuel, a second drying process is often required costing additional time, money and energy.
Optimising the dewatering process
What if the initial dewatering step could be improved? With contents reaching lower moisture levels in the initial step, a lot of energy and money could be saved in further treatments such as drying as well as on transport and gate fee costs.
Pellet production or reuse of paper rejects in general could become much more economical and sustainable while preventing material going to landfill.
Separation of liquids and solids under extreme pressure
Royal Dutch Kusters Engineering aims to provides this solution with its separation technique, the Organic Liquefying Press (OLP). The technology allows the user to separate moisture from solid waste fractions in a smart and energy efficient way. recent tests revealed its potential in dewatering paper pulp rejects, enabling at least 40 to 50% moisture reduction for any input and any level of initial moisture.
Dewatering test with the OLP at 40% initial moisture