Paper from Agricultural Residues

Lead Author: Dr. Jim Bowyer

Publish date: 10.20.2004

 

Crop residues have been used as a source of papermaking fiber for centuries and were extensively used for this purpose within the United States for several decades following the onset of World War II. Today, the use of agricultural residues in paper manufacturing is growing slowly worldwide, and there is renewed interest in North America in industrial use of these materials. Significant quantities of agricultural residues are available in North America. Conservative estimates indicate that the current availability of agricultural residues could expand the supply of papermaking fiber in the U.S. by 7-10 percent if only cereal straws (stalks of wheat, barley, and oats) are considered, and by up to 40 percent if corn stalks also prove to be a viable source of industrial fiber.

 

It is today technically possible to produce pulp from agricultural residues using either chemical or mechanical processes, although technology development in both areas is needed to improve prospects for technology adoption. However, from an economic perspective, there is some evidence to suggest that near-term investment in dedicated agricultural residue-based pulping facilities is unlikely because of projections of unacceptably low financial rates of return. What does appear to have promise is co-pulping of agricultural residues (up to 10 to 15 percent by volume) along with wood chips in existing chemical pulp mills.

 

The environmental benefits of the use of agricultural residues as a source of fiber in papermaking are dependent on the specific region and situation. Some regions dealing with excess straw find disposal to be a problem requiring annual burning, and thus development of alternative uses for straw is both environmentally and economically attractive. Additionally, in chemical pulping processes straw can be pulped using smaller quantities of pulping and bleaching chemicals than when pulping wood. On the flip side, agricultural residues require relatively high primary energy demands in processing, greater energy consumption in transporting bulky raw materials, and there are difficulties in economically recovering pulping chemicals from the waste stream and treating resulting emissions.