On Kenaf
Given that paper can be made from nearly any plant, cutting down trees to make paper is absurd. It takes a huge amount space, time, energy, and chemical processing. Luckily the practice of clear-cutting virgin forests has been relegated to history, however still there are many fast growing plants that can be used to make paper. These plants can improve soil health and contributing to a diverse agriculture system.
So what plants make the best alternative to tree based papers? In 1960 the US ARS (Agricultural Research Service) studied 500 plants as alternatives to tree based paper and selected Kenaf as their top choice. Kenaf is a fast growing plant similar to hemp that grows well in warm humid areas, such as the American South. The two major benefits of Kenaf in paper making are the low lignin content and it’s high yield. Lignin is the naturally occurring substance in plant cell walls that when left untreated causes paper to yellow. Kenaf contains 12.5% lignin while most trees used in paper making contain 25% lignin. This lower lignin content translates to lower energy consumption and chemical use in the pulping process, particularly when it comes to bleaching the pulp. Furthermore Kenaf can be used to increase soil health, as its long roots can remove salt deposits and pull up lost nitrogen leached farther down into the soil.
An acre planted with Kenaf yield much more pulp than an acre planted with trees. Kenaf can grow up to 12 feet in as little as 4-5 months. And acre planted with Kenaf can yield up 6-8 tons of biomass per year.
So why isn’t most paper made with Kenaf? All the pulp mills in North America, as well as nearly all the mills around the world, are designed for wood pulp. In the pulping process, different plant fibers drain at different rates, so a wood pulp mill can not be easily be retooled to work with Kenaf. One day I’ll try to retool a pulp mill to process kenaf and find out for myself. But until then I guess I’ll have to take what I’ve read at face value. Anyways…Since the 1800’s nearly every piece of industrial paper making equipment has been designed for tree based paper. The economies of scale are difficult to overcome at this industrial level, and moreover the price of wood chips is maintained artificially low resource tax breaks and other give aways by public agencies that own large swaths of forestland.
So what can we do? I believe that design is the only effective tool to push our society away form tree based paper. By building prototypes of non-tree pulp packaging and convincing companies to go with these options for their aesthetic and performance benefits, we can let the almighty $ convince the lumbering dinosaur that is the pulp industry retool and accommodate more sustainable pulps.
Kinsella, Susan, et al. “Chapter 4: Tree Free Paper.” The Environmental Paper Listening Study, edited by Fiber Futures.
Kugler, D.E. 1990. Non-wood fiber crops: Commercialization of kenaf for newsprint. p. 289-292. In: J. Janick and J.E. Simon (eds.), Advances in new crops. Timber Press, Portland, OR.
Rymsza, Thomas A. 1994. "Answering your kenaf questions." Earth Island Journal 9, no. 3: 13. Academic Search Premier, EBSCOhost (accessed November 19, 2017).
Udohitinah, Jacob Smith, and Adiodun Oluwafemi Oluwadare. “Pulping Properties of Kraft Pulp of Nigerian-Grown Kenaf (Hibiscus Cannabinus).” Bioresources, vol. 6, no. 1, 2011, pp. 75–761.
