Finding non-wood paper alternatives is crucial, since over 30 million acres of forest are cut down every year. Destroying forests for products such as pulp and paper creates long-term environmental disturbances in forest habitats. Arundo donax (the giant reed) is a good source of fibrous raw material for making quality paper and also appears to be suitable for the production of tissues, toilet paper and more importantly – paper cups.
Paper from Arundo donax: why do we need alternatives?
A huge problem of today’s consumerism is the irrational usage of disposable items made of paper – paper towels, tissues, facial tissues, toilet paper, paper plates and paper cups. All these require millions of trees to be cut down only to be used once and then thrown away.
According to a 2018 study 7 million disposable coffee cups are used on a daily basis and these add up to a staggering 2.5 billion every year – in the United Kingdom alone! These cups are said to be recyclable – as coffee companies proudly promoting on their packaging – however, due to the complicated way in which they are made, the majority of these cups never end up being recycled, nor reused.
Planting trees just to be cut out, processed and then thrown away is a waste we cannot afford nowadays, in this climatic crisis, as deforestation hugely contributes to global warming – a threat, which we are yet to solve.
Paper from Arundo donax: why choose the giant reed for paper production?
It is worth using giant reed for paper and pulp production from a financial point of view.
In 2002, the Samoa Pacific mill successfully completed the first commercial totally chlorine free (TCF) pulp run using 100% Arundo donax. They found that investing in timber farms in many cases is a 20-40 year investment. Giant reed, however, will provide economic returns within 1-3 years depending on the final product.
As a perennial rhizomatous grass, Arundo donax is widely distributed in all the warm temperate areas of Europe (mainly in the Mediterranean region) but can be easily adapted to different environmental conditions (Perdue, 1958), water scarce regions and marginal lands.
Huaiyu et al. (2006) prepared and pulped harvested material of Arundo donax to confirm the paper making qualities of the plant. Tests on the fibre and pulp quality of samples of giant reed stems confirmed that Arundo donax is a valuable non-wood paper alternative as a pulp feedstock for paper making.
Another advantage of Arundo donax was observed: it cooks more rapidly than wood and its cellulose yields are rather high, varying from 33% to 53%.
Another great advantage of using giant reed for paper production is that its bleach response is good, which means processing Arundo donax for paper requires less chemicals. The strength properties of Arundo donax were also proven superior to hardwood.
Paper from Arundo donax: giant reed vs. eucalyptus
The estimates of Huaiyu et al. (2006) indicated that
Giant reed has the potential to produce 500% more air dry pulp per hectare per year compared to blue gum (Eucalyptus globulus) hardwood trees.
In general, the kraft pulping of giant reed is characterised by a lower yield (43.8% vs. 52.4%) and a higher content of residual lignin, compared to kraft pulping of eucalyptus performed under identical cooking conditions (Valente et al., 1991). However, bulk of Arundo donax kraft pulps is higher compared to wood (2.05 cm3/gramm for Arundo vs. 1.63 cm3/gramm for Eucalyptus globulus), suggesting lower wet fibre compactability. Moreover, viscosity and, especially, tearing strength of pulps from Arundo donax are higher than those from Eucalyptus globulus.
Huaiyu’s study (carried out in Australia) concluded that Arundo donax can be grown at yields of up to 40 dry tonnes of stems per hectare per year and the stem material can be processed into a valuable alternative to hardwood for pulp and paper manufacturing. In the future giant reed is considered to replace part of the Eucalyptus hardwood feedstock used in paper making.
Paper from Arundo donax: pulp production
These botanically distinct parts of the stem of giant reed (nodes and internodes) showed some differences in chemical and anatomical composition and a different access to pulping. Under equal cooking conditions of a conventional kraft process, pulps with higher yield and lower content of residual lignin were produced from internodes. The strength properties as well asbrightness and viscosity were also higher for pulpsfrom internodes, compared to nodes.
Kraft pulps from giant reed showed much faster response on beating than wood pulps, and the strength properties were easily improved with minimal energy requirements on beating. Pulp beating improved much more actively the strength properties of kraft pulps from internodes.
The nodes of the plant stem can be reckoned as an undesirable component for pulp manufacturing which have an adverse effect on yield and properties of pulps from Arundo as a whole. However, this negative impact can be minimised using suitable screening techniques to eliminate nodes from the crushed stems before pulping.
To conclude, the internodes of the stems of Arundo donax are more suitable for pulping and the presence of nodes could have an opposing effect on pulp yield. This is indisputably connected with their anatomical structure, namely, with a pre-dominance of the non-fibrous short-cell tissues in the nodal diaphragm.
If you are interested in purchasing Arundo donax to produce paper do not hesitate to get in touch with us at info@arundobioenergy.com! Further information on paper and pulp production from Arundo can be found on our website.
