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Issue 03/2016

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Materials Using biomass

Materials Using biomass side-streams for bioplastics in New Zealand Biomass side streams are finding their way into novel bioplastic composites in New Zealand thanks to local industries and innovative and imaginative scientists at Scion. Biomass side-streams and bioplastic applications are often mentioned in the context of circular economies and bioeconomy, two concepts that enable and complete each other. With circular economies promoting the maintenance of resources at their highest possible level of value at all times, waste becomes a resource fuelling economic growth. The bioeconomy becomes a perfect illustration of circularity when it builds on sustainably sourced and produced biomass for fuel, chemicals and other materials by using waste streams to underpin development of new sustainable products. A key element to both systems is considering the full potential of waste. Scion, a New Zealand research institute that concentrates on biomass production and utilisation, is continuously seeking new ways to convert primary industry side-streams into value-added products, contributing to the circular economy and the bioeconomy. The following case studies from New Zealand demonstrate how biomass side-streams can be successfully incorporated into bioplastic materials and products. Pomace has promise The fibrous mass that remains after the first step in winemaking, pressing the grapes, is called grape pomace or marc. Five tonnes of grapes produce one tonne of pomace. In 2015, the New Zealand grape harvest was 326,000 tonnes leaving the wine industry with around 60,000 tonnes of pomace to dispose of. Pomace is generally composted, but Scion has found one more use for this resource before it regenerates carbon back into the environment. Many wine makers have a strong desire to use sustainable practices to ensure the longevity of their industry. Scion discussed possible applications for using biodegradable products with a local winemaker. The polystyrene clips used to secure the netting that protects the ripening grapes from birds were identified as an ideal candidate for replacement. Millions of the clips are used every year. When the nets are removed, the clips break easily and litter the ground, where they persist for years. In response to this, scientists at Scion have produced bio-clips from rigid films containing red grape pomace and biodegradable polymers. The fibre from the skins both stiffens the clips and makes them easier to break. Four different bio-formulations were trialled at Villa Maria vineyards in Hawkes Bay during the run up to the 2016 harvest. None of the clips holding the nets gave way prematurely and the clips were all brittle enough to break when the nets were removed. The next step is to monitor the biodegradation of the clips in the vineyard. Scion is also working on other applications for grape pomace in biocomposites such as spray guards to protect newly planted vines. A future for dairy farm effluent Between 10 and 20 % of a dairy cow’s poo production is deposited in the area of the milking shed. A farmer milking an average herd of 420 cows deals with more than 200 kg of solids and 20,000 litres of effluent a day. Storing and managing dairy farm effluent (DFE) is a significant cost. DFE is usually contained in ponds and treated. A proportion can be used as fertiliser, although the amount has to be carefully managed to prevent contaminating waterways and ground water and preserve soil structure. The problem of managing and disposing of DFE is likely to worsen as New Zealand’s dairy herd increases and farming becomes more intensive and closer to international practice. In 2015, the national herd of just over five million milking cows produced around 2,800 tonnes of DFE solids daily. The solids contain a high proportion of cellulosic fibres. Applying circular economy thinking, this waste by-product of milk production – biomass processed (digested) via cow – is a fibre resource with potential for use in bioplastics. A grape pomace biocomposite clip holding netting to protect ripening grapes in place. 32 bioplastics MAGAZINE [03/16] Vol. 11

Materials By: Florian H. M. Graichen, Science Leader, Biopolymers and Chemicals Stefan J. Hill, Research Leader, Advanced Chemical Characterisation Dawn Smith, Research Leader, Polymers and Composites Scion, Rotorua,New Zealand The premier trade show for all biobased industries Objects made from 3D filament printing stock containing New Zealand paua (abalone) shell. Work at Scion has found that unique combinations of DFE biomass and additives results in bioplastics with an attractive balance of processability and mechanical properties. Polylactic acid (PLA)/DFE biocomposites have been shown to weather and disintegrate faster than PLA alone. Bioplastics with DFE are a win-win solution. Raw material processing via cow is free, the supply is large and continuous, value is added to a side stream that is costly to make safe and dispose of, the overall cost of the bioplastics is lowered and carbon is returned to the soil. Applications for the use of DFE bioplastics on dairy farms are being explored. Paua Power Paua is the New Zealand Maori name for abalone (Haliotis iris). Maori and later settlers value black-fleshed paua as a seafood and its beautiful iridescent, blue, green and pink shell, which is widely used in arts and crafts. Abalone is considered a delicacy in many countries, and it commands high prices. New Zealand exports paua harvested both from the wild and from aquaculture farms. The shells remain after paua processing. While one shell is a beachcomber’s delight, the tens of thousands of tonnes produced by the paua export industry becomes a management problem. Paua is a New Zealand treasure. Paua processors would like options to add value to the shells in New Zealand rather than selling them cheaply to off shore processors, as is currently the case. Materials scientists at Scion have been experimenting with adding ground shell (which is mostly calcium carbonate) to bioplastics to produce 3D printing filament stock. The next step in the development process is to develop bioplastics that capture the iridescence and colour of the original paua shells. Scion is also working with local designers and manufacturers to develop products that exploit both paua shell and the possibilities of 3D printing. Showcase your expertise in bio economy at the trade show that takes the bioeconomy from “let’s talk about it” to “let’s do it” 15 – 16 February 2017 Cologne · Germany industrial biotechnology · algae ·biomass · biorefinieries · biopolymers · bioenergy · biofuels · biobased chemicals · biobased lubricants · biobased surfactants · biobased materials bioplastics MAGAZINE [03/16] Vol. 11 33

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