Alexander Bismarck was vacationing in small village on Crete when he had an “Ah Ha” moment. He was watching goats grazing summer-dry grass when he realized that what comes out in the end is partially digested plant matter – including cellulose. His next thought was that all the chewing, and the digesting with enzymes and acids in the stomach, was similar to the process factories go through to turn wood fiber into pulp for paper. So, he, asked the question: would turning poop into paper require less energy and fewer chemicals than our current process?
Back at work at the University of Vienna in Austria, Bismarck, his postdoc, Andreas Mautner, and two graduate students, Nurul Ain Kamal and Kathrin Weiland, but the hypothesis to a test. They moved from goat manure, to dung from horses, cows, and eventually even elephants and found that turning poop to paper is very possible.
The researchers use a two step process. First they treat the manure with a sodium hydroxide solution which partially removes the lignin and other impurities. The lignin can be used later as fertilizer or fuel. The second step, bleaching the remaining material, results in a purified cellulose that requires little if any of the grinding required by conventional paper pulp production. The result is a “nanocellulose” with the same or even better properties than what is made from wood, and, because the animals did so much of the processing first, the product is more economical to produce.
Their successful first steps at sustainable paper production inspired them to see if they can go even further but first producing biogas from manure and then turning it into paper. The biogas, which is mostly methane and carbon dioxide, and be used for generating heat and electricity (maybe to make the paper?)
With elephants in parks in Africa producing tons of dung every day and feedlots and dairies yielding mountains of manure, Bismarck sees all kinds of potential, and he and his team are working with an industrial consortium at a variety of applications for their dung-derived nanopaper. It could be turned into filters that clean wastewater before it’s returned to rivers, it could be used as writing paper, and I’m sending them a suggestion to turn it into toilet paper. It seems like a fitting use for something that started as manure.
Here at On Pasture we get daily lists of articles about scientific discoveries that help us look at old problems in a new light. It gives us hope for the future.