Printer Friendly

Making paper without trees.

Paper has not always been made out of wood. The ancient Egyptians made paper out of papyrus plants; the 3rd-century Chinese made it of flax and wisteria; the 8th-century Japanese made it of hemp; and the 12th-century Spanish made it of cotton. A 17th-century English preacher named Gcorge Fox, who practiced nonviolent resistance to tyranny three centuries before Mahatma Gandhi and Martin Luther King, wrote an account of his travels that was printed on a fine linen paper made of recycled rags. ("If they Strike thee on one cheek turn the other . . . fighters are not of Chrift's kingdom," reads one passage of the 800-page tome.) A surviving copy of the third edition, printed in 1765, sits on a shelf in the home of a World Watch writer. The original leather binding has dried up and turned to dust. The 228-year-old treeless paper, remarkably, is almost like new.

Good paper is still made from non-wood sources in many places: from rice and barley straw in China, from sugar cane waste ("bagasse") in Mexico and India, from bamboo in Vietnam, and from the kenaf plant in Australia. But since the early 20th century, the vast bulk of the world's paper has been produced from wood. An estimated 4 billion trees are cut for paper each year.' and while papermaking is not a primary cause of deforestation, the rapidly rising demand for wood pulp for paper mills puts increasing pressure on those forests that remain. The tree plantations that produce most pulp now stand where natural forests were cut-whether in Florida, Indonesia, or Thailand. With the world's paper demand expected to double by the year 2010, the need to expand tree plantations could also nearly double.

According to a report by Australian paper executive Andrew Kaldor in the October, 1992 TAPPI Journal of the Technical Association of the Pulp and Paper Industry, about 13 million hectares of wooded land are required to meet current world pulp requirements, based on an estimate that 70 percent of all pulp is made of virgin fiber. As recycling increases, the virgin portion is expected to drop to 55 percent by 2010. But even with that relief, the projected increase in paper demand will expand the requirement for wooded land by then to about 23 million hectares.

Because of the long lead times required for harvesting, meeting that demand would require planting about 10 million hectares of land each year from now on, according to the report - and that is not happening. The crux of the problem, then, is that the world will face a growing shortage of fiber around the turn of the century, and this will inevitably drive up wood prices. The result mill be "accelerated pressure for the exploitation of existing mature forest resources," says Kaldor-unless manufacturers can find more efficient means of using land to produce their raw materials.

Non-wood sources may offer such means. Kenaf, for example, is a fast-growing plant that produces two to four times more pulp, per hectare, than southern pine. Kenaf pulp has all of the technical characteristics needed for most grades of paper, according to studies by the U.S., Chinese, and Japanese governments, among others. Hemp, which is illegal in the United States but is grown commercially in many countries, is similarly productive.

The advantage of such crops is that they can be harvested annually - whereas trees require 7 to 30 years of growth. And while plant fiber crops require much loss land than tree farms, another non-wood source-agricultural waste-requires virtually none at all. The straw left over after a rice harvest can be made into paper without any land required other than that already set aside for the rice. India, for example, produces 100 million tons of rice straw per year - 15 times the amount needed to meet the country's entire paper needs.

Not surprisingly, the availability of such abundant resources has attracted growing interest - and investment - in countries where wood is scarce. While the world's wood-based paper production has increased by 22 percent in the last decade, non-wood capacity has grown by 74 percent - from 8.6 million to 15 million metric tons. In 1992, while global paper production reached a record high, wood pulp production actually declined slightly, thanks to the growing supply of the two alternatives that don't require the cutting of trees - recycled paper and nonwood fiber. In 1992, treeless paper was made in 45 countries, and accounted for 9 percent of the world's total paper supply, according to the U.N.'s Food and Agriculture Organization (FAO). As forests continue to decline, either in size or in biodiversity, that share could grow. In China, plant fibers - mainly grain straws, hemp, bagasse, and bamboo - last year accounted for over 80 percent of all paper pulp.

In most countries where such sources are used, the motivation is not primarily to save trees, but to find economical substitutes where trees have become too expensive. In China, the Sichuan Pulp and Paper journal Sichuan Zaozhi reported in 1993 that pulp made from kenaf costs only one-third as much to produce as imported wood pulp. A study comparing the costs of wood and plant-fiber pulp in Thailand, reported in 1990, found that pulp from kenaf cost 12 percent less than that produced from eucalyptus plantations in the same country. In Japan, where more than half of the wood used in 1990 was imported, concerns about cost prompted the government to undertake an intensive program to develop a domestic kenaf industry.

In tree-rich North America, non-wood fiber has been widely regarded as a poor second choice - a forgotten left-over from 19th-century industries like the one which once made paper from a vegetable called okra, on which an Alabama newspaper, the Mobile Register was printed in the 1880s before the development of tree plantations. But it may be a mistake to assume that plant-based paper is simply a more primitive industry on which developing countries are still stuck. Modern Asian plant paper industries appear to be the result not of resigned acceptance of second-rate materials, but of aggressive national research campaigns designed to make more efficient use of existing resources.

China's huge non-wood paper industry, in particular, has grown in response to a recognition that while forest resources were indeed scarce, the country's agricultural crops were generating huge amounts of fibrous waste-stalks or straws of plants from which the grains or seeds had been harvested - that were not being fully utilized. Some was used as cooking fuel, some as animal fodder, but much was being burned as waste - and producing polluted air to boot.

In the 1980s, China began conducting extensive research on the agricultural, technical, and economic aspects of plant fiber production. In 1992, an International Nonwood Fiber Pulping and Papermaking Conference assembled in Shanghai to examine the results of more than 100 studies of industries in a wide range of climates and economies.

Review of the research reported in Shanghai, and in subsequent symposia in the United States and Europe, shows that non-wood pulp has become dominant in many regional economies, and that a wide variety of sources are being used successfully. According to a survey by Finnish paper industry consultant Leena Paavilainen, over 300 mills now use non-wood fibers, worldwide. The raw materials for these mills are obtained from two broad categories: agricultural waste from food crops, and fiber crops grown specifically for pulp (see box).

There are some technical differences between non-wood and wood paper production, which complicate the question of pulp substitution. On one hand, some of the non-wood fibers have superior qualities of tensile strength (so the paper won't tear in the printing press or copier machine), or opacity (so printing won't show through), or whiteness (so the paper won't require heavy bleaching). And a study reported at the 1990 TAPPI Pulping Conference noted that straw pulp required only 25 to 30 percent of the total processing energy required by wood based pulp.

On the other hand, non-wood fibers pose some technical hurdles that have not been problems with wood. Because plants like kenaf are seasonal crops, careful storage and transportation are needed in order to assure a year-round supply to paper mills, which must operate nonstop in order to be profitable. Because field crops also have higher moisture content than wood, they can spoil in storage unless dried - a problem that has made some North American papermakers skeptical about their potential. The Chinese paper industry has apparently solved that problem, however, by inventing a system for drying and storing kenaf in ventilated stacks of concrete blocks.

Altogether, non-wood pulps offer an impressive range of potential environmental benefits: saving forests, adding nitrogen to soil, providing natural herbicides, rcducing the use of toxic chemicals in bleaching, reducing energy use in the pulping process, and providing a means of adding strength to recycled pulp without using virgin wood. Fiber crops like kenaf, hemp, and sisal are nitrogen-fixers, valuable for crop rotation as well as for their pulp. Hemp is also valued for crop rotation in some regions because it suppresses weeds, reducing the need for chemical herbicides. Kenaf and hemp are notable for their natural whiteness, producing pulps that require less chlorine bleach than wood to produce an equivalent paper. They share with wheat and rice straws the virtue of requiring less energy to process. And long fibered crops like hemp and kenaf can provide needed reinforcement to the chopped-lip fibers of recycled paper, precluding the need for virgin wood.

There are also potential environmental shortcomings, such as the use of pesticides in the storage of straw, the possible requirement for fertilizer or irrigation in growing fiber crops (though kenaf crops grown in the United States have required very little of either), and the long-range ecological problems associated with monoculture in general. And there are some important questions yet to be answered - such as how fiber crops (or food crops for which waste is not plowed back under) will affect soil nutrients over a number of generations.

But given the impending growth in global demand for paper over the next one generation, such unanswered questions only underscore the need for governments concerned with industrial policy to incorporate further plant-pulp research and development into their planning. In North America, where per-capita paper consumption is over six times the world average, and 99 percent of it is from wood, it may be time to evaluate what the results of a century of research on non-wood alternatives can mean for the next century, which is now less than one very fast-growing tree's life away.

In 1916, a USDA bulletin noted that one acre of cannabis hemp would produce 4.1 times as much pulp, over a 20-year period, as an acre of trees. In the 1950s, the USDA began an exhaustive study of 500 plant fiber alternatives for making paper, and after several decades of study concluded that kenaf is even better than hemp. In 1993, the California environmental magazine Earth Island journal published a section of one issue on paper made from unbleached kenaf that had been grown as a result of the USDA research. The editor, Gar Smith, said he was pleased with the result. The magazine's printer, Bob Alonzo, reported that "everything went perfectly."

Now, it seems, the main hurdle to diversifying pulp production in North America is neither technological nor economic, but financial - a lack of investment capital in a market that has been suffering from a glut of wood-pulping capacity due to a binge of over-investment in the late 1980s. In such a market, no one wants to build new pulping plants of any kind - wood or non-wood. But that glut is probably temporary, and as demand catches up with capacity, North American and European manufacturers will take a harder look at the possibilities for tree-less paper. As Marvin O. Bagby, a USDA scientist, recently said, "Kenaf is a sleeping giant just waiting for the stimulating splash of a major pulp and paper conversion facility."

Pulp Sources for Treeless Paper

SOURCE CURRENT USE AND POTENTIAL

AGRO-WASTE: Presently accounts for more than half of all non-wood fiber, and about 6 percent of all paper produced worldwide. Agro-waste generates enough pulp to supply most (if not all) of the world's paper needs without any use of trees, thereby offering a means of alleviating future pressures to expand tree plantations at the expense of natural forest.
* Cereal Primarily from rice, wheat, oats, barley, and rye. Straw-based
 straws paper requires no land other than that used to produce food, and
 processing consumes only 24 to 30 percent as much energy as
 wood does. Production capacity totalled 5.3 million metric tons
 in 1993, of which 4 million were in China, 400,000 in India, and
 140,000 each in Pakistan and Spain.
 * Bagasse Stalks left after sugarcane harvest were made into more than 2
 million metric tons of pulp for paper in 1992. Mexico and Peru
 each produced about 300,000 tons. Other countries making paper
 from sugar cane include Indonesia, Colombia, Venezuela,
 Pakistan, Argentina, and Thailand.
* Other Seed grass straw, sorghum stalks, cassava, pineapple leaves
 sources: and cotton linters and stalks.


FIBER CROPS: Could require less than half as much land as trees to produce the same amount of paper, thereby reducing pressure to expand tree plantations at the expense of natural forests, As nitrogen-fixers, these crops are also valuable for crop rotation. Fiber crops presently account for about 4 percent of the world's paper production.
* Kenaf Paper can be made from bark or whole stalk. Bast (bark) pulp
 has longer fibers than most wood fibers, yielding high tensile
 strength. Kenaf can be combined with recycled paper to eliminate
 the need for wood altogether - or can be mixed with small
 amounts of wood to make newsprint, reducing tree content by
 up to 90 percent. Kenaf requires less land, energy, and chemical
 processing to produce than does wood pulp. It also requires
 less startup capital. In Thailand, kenaf is produced in lieu of soft
wood,
 which has been depleted by deforestation. Investment in
 commercial production is beginning in Japan and the southern
 United States.
 * Bamboo High fiber strength complements weaker fibers that are available
 in larger quantities. In India, rice straw is blended with 10 to 15
 percent bamboo. World capacity in 1993 was 1.7 million metric
 tons of bamboo pulp, of which 1.3 million was in India. The rest
 was produced mainly in Vietnam, Brazil, Bangladesh, and Thailand.
* Hemp More than 330,000 hectares of hemp are being grown legally in
 the Northern Hemisphere, for paper and other products - primarily
 in the former Soviet states, Eastern Europe, France, and
 China. Brazil has produced sunn hemp for paper since the
 1960s. Hemp uses much less energy than wood, serves as a
 natural herbicide, and is used to restore nitrogen to soil in crop
 rotation.
 Other sources: Jute, ramie, flax, sisal, roselle, and abaca.
COPYRIGHT 1993 Worldwatch Institute
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1993, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:includes related article; alternate sources for paper manufacture
Author:Ayres, Ed
Publication:World Watch
Date:Sep 1, 1993
Words:2479
Next Article:Not-yet-fossil fuel.
Topics:


Related Articles
Tree free by 2003? Entrepreneurs are hot on the Kenaf paper trail.
Making houses out of trash.
Rebuttal.
Supermarket sweeps.
From scribble to printed abstraction.
Paper forests.
Public outreach.
The paper chase: the paperless office is still a distant dream. In the interim, we should be recycling more and developing alternatives to wood-based...
Paper politics.

Terms of use | Copyright © 2017 Farlex, Inc. | Feedback | For webmasters