As we have successfully tested the process on a pilot (semi-industrial) scale it definitely has a potential for upscaling. However, there are important challenges that have to be addressed - the availability of biomass (or various types of it) in terms of quantity, seasonal availability (storage), dispersed sources (transport), variations in quality etc. The existing wood pulping installations are over capacitated and not necessarily adapted to such intense variations in the incoming raw materials. The majority of the alternative raw materials, in this case tomato plant stems, are diverse, variable and seasonable, therefore the incoming feedstock is not available in quantities for big-scale production in one place which is reflected in high logistic cost.
Upscaling is possible with small to medium scale installations (pulping capacity up to 100 t/day), easily adaptable to various raw materials and connected to upstream (biomass producers, transport and logistic services) as well to downstream value chain (mid-sized paper mills, packaging producers, retailers) and end users (agricultural producers, recycling companies).
An important constraint, recognized in different regions is the lack of the intermediates, RDI institutions that can support the development of new value chains and demonstration of the potential products. Pulp and Paper Institute, with its piloting equipment including biomass fractionation, paper production and a packaging demo centre has developed the paper, corrugated board and packaging products to the level that can be upscaled and replicated.
Have there been any trials with other types of agricultural waste?
Statistics show there is high potential of biomass waste and side streams in Slovenia for biorefining. At the Pulp and Paper Institute we have compiled a database of these raw materials along with their potentially available quantities and most promising fields of use, not only for papermaking but also in for chemicals extraction, enzyme production etc. So far, we have successfully obtained fibres and produced papers from several different sources. Those with most potential, around thirty of them, have been studied in-depth in terms of chemical and morphological structures and the process of cellulose fibre extraction and paper production at lab scale. From agricultural residues and side streams, for instance, we have analysed wheat, straw, hops, barley, corn, among others. The pilot trials and industrial production of paper and paper packaging were developed in cooperation with different partners, i.e., for the local community from the urban green cuts (invasive alien plants, Japanese knotweed, Canadian goldenrod, black locust) or different industries from their waste (i.e. sawdust, wasted jute coffee bags). Some of them are presented under the Institute’s trade mark CiP. All these products are evaluated in terms of their circularity and compliance with the legislative and market requirements. Corrugated cardboard was produced only from paper made from the fibers of tomato plants and Japanese knotweed. However, our knowledge, equipment and the excellent partner network allows us to experiment also with other types of biomasses.