Processed primary bioresources

Note Not all plants can be considered as a primary bioresource. Examples are plants from parks and gardens which have primarily a recreational function.They are assigned to secondary or tertiary bioresources (Chapter 7, Section 2.2.3 and Section 2.2.4).The primeval forest plants are not primary bioresources either, because they are not grown for an application-oriented purpose. The same is true for wild living and pet animals. Primary bioresources are not considered as substrates for civilization biorefineries, but for the 1st, 2nd, and 3rd generation biorefineries. However, processing of primary bioresources should be closely connected within the system of a civilization biorefinery. 

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. 

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... 

To sum up, the primary bioresource for paper chain is the harvested tree respectively the tree s stem-wood. Secondary and tertiary bioresources are bark, other woody biomass, black liquor, paper production, and processing residues which are generated along the chain. If these are utilizedfor substantial or energetic purposes we have a multichain utilization. And if the quaternary postconsumer fibers from wastepapers are reused we have cascade utilization. 

An example for the complex interrelation between primary, secondary, tertiary, and quaternary bioresources is shown in Figure 7.5. The paper chain is a simplified visualization of the complex processes connected with the production of a paper-containing product. Figure 7.5 focuses on the main processes connected with bioresource transformations only. Processes of pulping including specific pathways for by-product utilization, e.g., valorization of tall oil, are discussed in more detail in Chapter 3. The processes involved in paper production are described in more detail in Ref 54. A good overview on aspects related to the whole cascade is to be found in Ref. 5. The paper chain was used as an example, since paper production has historical tradition and the processes are well established today, but still have room for improvements. 

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