Secondary bioresources

As processing outcomes, they consist of parts from the primary bioresources. They may be mechanically removed residues from the primary bioresources during primary processing. Mechanical, but also biological, chemical, or physical processes could be used for separations in the follow-up processing chain. The main output of such processes are the primary bioresources, all others are secondary bioresources, if they met the previous noted criteria. 

As maintenance residues secondary bioresources are generated on green areas such as large parks, lawns, sport places, and dikes if harvested as genuine fractions in significant amounts under controlled conditions. For harvest and collection, the follow-up steps in the utilization chain should be considered in order to gain the maintenance residues in ample quality in terms of purity and fireshness. 

Note The primarily purpose of the green areas may be a recreational or protective function, and not the production of substantial products or energy. Maintenance residues from natural protection areas should not be considered as a secondary bioresource to avoid misuse of ecosystems. However, they could be considered in local utilization approaches as special biogenic input if there are no ecological hesitations. 

Tertiary bioresources are also parts from virgin materials, which were separated along the chain. But compared to secondary bioresources they are residues which occur rather in small amounts at the generation place and/or are mixed with undefined firactions or... 

For pulp production excorticated stemwood is hackled and the wood chips are treated thermochemically and mechanically in a pulp mill. The main output is the pulp consisting of virgin cellulose fibers the by-product is a defined lignin and hemicelluloses containing black liquor. It is a secondary bioresource, which is often used energetically today, but has high potential for substantial utilizations too. 

For paper production different bioresource categories are used primary bioresources—virgin cellulose fibers from pulp mills secondary bioresources—recovered residues from paper processing industry quaternary bioresource—recovered paper fibers, e.g., wastepaper from households, industry, commerces, trade, offices, and administration. Primary, secondary, and quaternary bioresources together make around 89% of the raw... 

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