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Stone Paper – The environmentally friendly paper of the future?

Stone Paper – The environmentally friendly paper of the future?

Producers are praising stone paper as particularly sustainable. But if all paper were replaced by stone paper, global plastic production would increase by up to two thirds! 
1409131438 Stone Paper – The environmentally friendly paper of the future? We Blue

For several years now, large stationary companies such as Oxford or Moleskine have been promoting the idea of replacing paper by so-called stone paper. Unlike common paper, stone paper is not made of wood but from pulverized limestone and plastic.  The producers are focusing their marketing on the eco-friendliness and resource efficiency of this new product. Since neither wood nor water are required for production, this “future paper” is praised as “super environmentally friendly”.

But what is really behind stone paper? Currently roughly one fifth of all cut tress are used to make paper, hence such an innovation could indeed hold great potential to reduce worldwide logging.
Stone paper consists of 60-80% calcium carbonate, i.e. pulverized limestone or marble. This raw material has been used in paper production for a long time, for example as a coating of normal paper to make it whiter and smoother. Calcium carbonate is a by-product of stone quarries and is usually considered a waste. The adhesive agent applied in stone paper is polyethylene resin, a widespread plastic also used in plastic bags or drink packaging.

As it happens, the production of stone paper requires only half the energy necessary to produce normal paper. In addition, neither bleach nor acids are used. These ecological benefits have lead to quite some attention for this new product over the past years. The product itself also has some striking characteristics: It is both tear- and waterproof, without needing the oil film regular paper would require.

However, several disadvantages are also inherent to stone paper which lead to a far inferior eco-performance than apparent at first sight. The stone components of the paper decompose after 14 to 18 months of direct sunlight; the plastic components remain and are not recovered nor biodegradable. The recycling potential of stone paper is generally a controversial question. While the producers claim that stone paper can be reused in many areas such as construction, there are critical voices stressing the fact that the plastic and stone components are leached out during recycling and end up in our wastewater. An additional plastic pollution of rivers and oceans is surely the last thing considered desirable from an ecological perspective! If stone paper is not subjected to direct sunlight, it cannot be decomposed at all.

An insightful calculation: in the year 2011, roughly 403 million tonnes of paper were produced worldwide – and the numbers are rising. If all of this paper were replaced by stone paper, and assuming the favourable case of 20% PE-components, that would amount to 81 million tonnes of plastic – at 40% PE-components it would even be 162 million tonnes. Knowing that globally, ‘only’ 250 million tonnes of petroleum-based plastic are produced every year, between one and two thirds more plastic would have to be produced every year to replace paper with stone paper. Assume we would try to substitute this PE with bioplastic, then today’s bioplastic production would have to increase by a factor of 14, i.e. 1,400 percent! About 80% of bioplastic is starch-based. Bearing in mind the devastating effect the rising demand just for the starch-source corn by biogas plants has had in many parts of the world on both rents for agricultural land as well as the corn price itself, this can hardly be considered an option.

Effectively, the production of stone paper replaces a renewable raw material with an indecomposable plastic. Due to the low distribution of this product to date, reliable data on recovery and recycling is inexistent – especially since it seems next to impossible to construe closed recycling loops for a single product.

From the perspective of the Blue Economy, products should be uncompromisingly sustainable and avoid systemic collateral damage to environment, economy and people to the greatest extent possible. In the case of stone paper, the potential contamination of water with PE-particles is simply not acceptable. Citing that the disposal through incineration causes little to no environmental damage is not good enough. ‘Blue’ products have a higher longevity and can be upcycled into a new, higher-value product at the end of their lifecycle – i.e. cascaded just like in an eco-system.

Blue Economy aspires to create value chains and networks which create more for everyone, including more jobs. If regular paper production were replaced by stone paper, jobs would simply shift from one factory to another. Assuming not petroleum-based plastic but rather ‘regional’ bioplastic were utilized, the starch plants would inevitably compete with the production of food – in a world where the amount of arable land is declining!

If stone paper is not the solution, what is a blue alternative in light of the less than ideal eco-balance of wood-based paper? The ideal solution from a Blue Economy perspective would be real biorefineries which utilize biological waste streams completely systemically, sustainably and in a socially responsible, economically attractive way. But despite many promising advancements, an industrial approach has yet to be developed. As long as biorefineries are still improving their processes in pilot plants, the recommendation is simply to resort to unbleached recycled waste paper.

Authors: Markus Haastert, Anne-Kathrin Kuhlemann
© 2014 Blue Economy Solutions GmbH

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