Cellulose from manure - cheap and environmentally friendly solution
Widely spread agricultural waste such as livestock manure may be well turn into a cheap and environmentally friendly source of cellulose raw materials for the industry. Innovative technology of processing organic waste into cellulose was presented at a recent forum of the American chemical society by Austrian researchers.
The idea of the project was born thanks to the observations of PhD Alexander Bismarck of the University of Vienna, who once during his vacation in a small village in Crete watched the goats, eating grass. “I realized what comes out in the end is partially digested plant matter, so there must be cellulose in there”, he said.
In the animal organism, the biomass, having cellulose content, is exposed to the enzymes and acids in the stomach. Final waste-manure - up to 40% consists of cellulose, which can be very easily produced at low energy costs. Thus, the cellulose nanofibers extracted from the digested material are similar to the traditional analogs made of wood pulp.
In practice, Bismarck and his team tried products of vital activity of other animals as well – for example, horse, cow and even elephant manure.
Initially, manure is treated with an alkaline solution of sodium hydroxide. This process partially removes lignin - a complex polymer compound, which also has found practical application as fertilizer and fuel. The material is bleached with sodium hypochlorite to completely remove lignin and obtain a white pulp, which through the grinding can be broke into nanofibers.
In traditional practice, in order to convert wood into cellulose microfibrils, a number of complex technological steps are required. Cows cope with this part of the production cycle faster. The source material (plants) chewed, that is, mechanically prepared for the further chemical process in the stomach, where is attacked by the acid and enzymes. The products is the same nanocellulose as derived from wood, only cheaper, with less chemical and energy costs.
Where it is possible to use cellulose nanofibers produced from manure? It is worth noting that Japanese researchers, who are the leaders in the field of basic research of nanocellulose, say this material is more than five times stronger than steel.
The team from University of Vienna, which already working with industrial consortium, offer to use their product in the production of composite polymer materials and water filters.
However, work on the innovative cellulose solution continues. Researchers are also exploring the possibility of complicating the process. At the first stage, it is proposed to produce biogas from manure, and at the second – to extract cellulose fibers from residue materials.
