Non-wood fibre and global fibre supply

H. Pande

H. Pande is with the University of Toronto Faculty of Forestry, Toronto Ontario Canada.

This article considers the impact that non-wood fibres could have on the total global fibre supply over the next two decades.

In the context of this article non-wood fibres are defined as non-woody cellulosic plant materials from which papermaking fibres can be extracted. The most widely used non-woods for papermaking are straws, bagasse, bamboo, hemp, kenaf, jute, sisal, abaca, cotton inters (short fibres left after ginning) and reeds. Most non-woods are annual plants that develop full fibre potential in one growing season.

Straw is the most commonly utilized non-wood fibre. In the photo: rice straw in India

Non-wood fibres in papermaking: A brief history

Currently, wood is by far the major raw material for the global pulp and paper industry. It is, however, a relatively new raw material in papermaking. Historically, paper was made exclusively from non-wood plant fibres. The first true production of paper is credited to T. S'ai Lun in AD 5 in China. This first paper was apparently made from textile wastes, old rags and used fishnets, which consisted of the fibres of true hemp and China grass (ramie) (Atchison and McGovern, 1993).

While non-woods were originally used for papermaking, in the late seventeenth century wood became the predominant fibre source in Europe. The seemingly inexhaustible supply and versatility of wood were the major causes of this shift. Today, most modern pulp and paper enterprises rely on wood (Smook, 1992).

The current situation

On a global scale, non-wood fibres are a minor part of raw material supply to paper and paperboard manufacture. In many countries, however, they are still widely used and are of significant importance in terms of overall volume and as a percentage of total pulp supply. Table 1 gives an idea of current use of non-wood fibres in papermaking in the 18 countries that account for nearly 98 percent of world supply.

The region that has invested the most time and resources into the pulping of non-woods is Asia and the Pacific. In particular, China and India are leaders in the utilization of non-woods for papermaking in terms of volume. In North America, Latin America, Europe, the Russian republics and Africa, the use of non-wood fibre sources has been relatively limited.

TABLE 1. Leading users of non-wood fibres in papermaking

Country	1993		1998 (estimate)
	Non-wood pulping capacity	Percentage of total pulping capacity	Non-wood pulping capacity	Percentage of total pulping capacity
	('000 tonnes)		('000 tonnes)
China	15246	86.9	16830	84.3
India	1307	55.5	2001	61.3
Pakistan	415	100	415	100
Mexico	321	29.2	324	29.3
Peru	298	95.2	296	95.2
Indonesia	267	22.1	267	10.1
Colombia	218	45.1	218	37.2
Thailand	209	100	509	100
Brazil	196	3.1	238	3.3
Venezuela	185	75.2	187	75.4
United States	179	0.3	204	0.3
Greece	150	85.7	160	84.2
Spain	140	7.9	141	7.7
Argentina	140	14.6	140	12.8
Egypt	127	100	127	100
Italy	120	13.3	120	13.3
Cuba	108	100	108	100
Turkey	103	16.5	103	16.5

Source: Oye et al., 1991.

Leading sources of non-wood fibres

At the present time, the most commonly utilized non-wood fibre is straw, which accounts for 46 percent of total production (see Table 2). This is followed by bagasse (14 percent) and bamboo (6 percent) (Atchison, 1995). Other non-wood fibres such as cotton, hemp, sisal and kenaf are also becoming more important in the manufacture of pulp and paper.

TABLE 2. Leading non-wood fibres

Raw materials	Non-wood papermaking pulp capacities
	1985	1988	1993	1998 (estimate)
	('000 tonnes)
Straw	6166	5260	9566	10187
Bagasse	2339	2267	2984	3682
Bamboo	1545	1674	1316	1850
Miscellaneous: cotton, reeds, sisal, jute, hemp, abaca, kenaf, flax	3302	6366	6870	7742
Total	13352	15567	20736	23471

Sources: Atchison (1995); FAO (1997).

Advantages and drawbacks of using non-wood fibre for papermaking

Some non-wood fibres used as raw materials for papermaking have high annual yields per hectare. The average annual yield per hectare of kenaf, a non-wood fibre, is about twice that of fast-growing softwoods (see Table 3) (Pierce, 1991). Non-woods have lower lignin content than woods and generally it is easier to delignify non-woods, as they have lower activation energies (Bobalek and Chaturvedi, 1989). Producing paper from non-wood fibres would help in reducing the need to procure pulpwood from natural forests, and for large-scale plantations. Under certain climatic conditions, non-wood fibre production may be a reasonable alternative to tree plantations.

TABLE 3. Average annual yields of different papermaking raw materials

Plant	Fibre yield	Pulp yield
	(tonnes/year/ha)	(tonnes/year/ha)
Scandinavian softwood	1.5	0.7
Fast-growing softwood	8.6	4
Temperate softwood	3.4	1.7
Fast-growing hardwood	15	7.4
Wheat straw	4	1.9
Rice straw	3	1.2
Bagasse	9	4.2
Bamboo	4	1.6
Kenaf	15	6.5
Hemp	15	6.7
Elephant grass	12	5.7
Canary grass	8	4.0

Source: Pierce (1991).

In terms of disadvantages, the availability of a constant, year-round supply of fibre is a primary concern for paper mills. Given that most non-woods are annual plants, a large storage capacity must be developed to ensure a constant supply. This is further complicated by the fact that most non-wood fibre sources are high in volume and low in density when compared with wood.

A high silica content is another problem with the non-wood fibres in general. Most non-wood paper mills are small and do not have adequate chemical recovery facilities to deal with the large volumes of silica that must be removed.

Another disadvantage of using non-wood fibre can be the high inputs required for growth and harvesting of these annual crops.

Bamboo in Uganda. Bamboo is widely available throughout the developing world

Current levels of availability

It has been estimated that the total availability of non-wood fibres suitable for papermaking worldwide is approximately 2.5 billion tonnes per year (Atchison, 1995; McCloskey, 1995). This figure refers to all non-wood fibre sources, including those used in the textiles and agricultural industries and, at present, only a small part of the total actually goes into papermaking. The remainder is either utilized in ways that are currently more profitable (e.g. cotton in textile production and straw as agricultural feed) or is not available because of logistical problems related to collection and transport costs.

Possible future trends in non-wood fibre production and use in papermaking

There are a number of factors that may result in an increased use of currently available non-wood fibres in paper-making, and even an increase in production of non-wood fibres specifically for use in the papermaking industry.

From an environmental perspective, there is growing interest on the part of activist groups and individual consumers in "tree-free" papers that may help to drive an increase in paper production from non-wood fibres. Another contributing factor may be pending environmental legislation imposing new regulations on the disposal of agricultural waste fibres.

Characteristics of non-wood fibres The average dimensions of various non-wood plant pulp fibres as compared with dimensions of wood pulp fibres are listed in the Table. The data show the wide variation in the fibre characteristics of non-wood fibres. Many of the non-wood fibres are similar to the short fibre hardwoods, while others are so long that they must be shortened to optimize their papermaking value. In general, the diameter of the non-wood fibre is small, resulting in lower coarseness from these pulps. These fibre dimensions provide an idea of the potential usefulness of these pulps in pulp and papermaking. In fact, from the technical and quality viewpoints, any grade of paper can be produced by using the appropriate combination of non-wood plant fibres.

Fibre dimensions of non-wood plant fibres

Non-wood fibre	Average length (mm)	Average diameter (microns)
Abaca (Manila hemp)	6.0	24
Bagasse (depithed)	1.0-1.5	20
Bamboo	2.7-4	15
Com stalk and sorghum (depithed)	1.0-1.5	20
Cotton fibre	25	20
Cotton stalks	0.6-0.8	20-30
Crotalaria sp. (sun hemp)	3.7	25
Esparto	1.5	12
Flax straw	30	20
Hemp	20	22
Jute	2.5	20
Kenaf bast fibre	2.6	20
Kenaf core fibre	0.6	30
Rags	25	20
Reeds	1.0-1.8	10-20
Rice straw	0.5-1.0	8-10
Sisal	3.0	20
Wheat straw	1.5	15
Wood fibres
Temperate zone coniferous woods	2.7-4.6	32-43
Temperate zone hardwoods	0.7-1.6	20-40
Mixed tropical hardwoods	0.7-3.0	20-40
Eucalyptus sp.	0.7-1.3	20-30

Source: Atchison and McGovern (1993).

Paper production absorbs a substantial and increasing portion of the global wood harvest. In 1983, roughly 35 percent of the commercial wood harvest worldwide was used in the production of paper products, and this is projected to grow to 50 percent by the year 2000. In the United States, for example, 27 percent of the 1996 timber harvest was destined for domestic pulpwood production (Horn, 1975). Environmentalists' pressure to reduce wood harvests could lead to strong development of unconventional raw materials in pulp and papermaking (Mall and Upadhyay, 1989; Smook, 1992).

In developing countries with limited forest resources or environmental conditions that preclude the establishment of significant plantation resources, establishment of agro-industries focused specifically on the production of non-wood fibres for use in papermaking may become a part of overall plans for development and industrialization.

Three future scenarios

Given these considerations, three scenarios for possible future development of non-woods as a source of raw material for the pulp and paper industry have been developed (See Table 4).

TABLE 4. Three scenarios of non-wood fibre use versus total paper production, 1988-2010

Region	Scenario	1988	1993	2000	2010
		('000 tonnes)
Europe	Total paper production	64805	69304	86707	108914
	Non-wood pulp capacity:
	Scenario 1	-	512	580	558
	Scenario 2	-	512	2196	5446
	Scenario 3	-	512	697	878
Asia and Pacific	Total paper production	52169	68769	98850	138331
	Non-wood pulp capacity:
	Scenario 1	-	17924	24236	33396
	Scenario 2	-	17924	33967	69165
	Scenario 3	-	17924	23146	32391
North America	Total paper production	95988	94091	109758	130899
	Non-wood pulp capacity:
	Scenario 1	-	179	248	335
	Scenario 2	-	179	2319	6545
	Scenario 3	-	179	224	267
Latin America	Total paper production	9560	11306	13226	15783
	Non-wood pulp capacity:
	Scenario 1	-	1466	1684	1711
	Scenario 2	-	1466	1998	3157
	Scenario 3	-	1466	1546	1845
Africa	Total paper production	2588	2353	2922	3280
	Non-wood pulp capacity:
	Scenario 1	-	266	276	298
	Scenario 2	-	266	309	492
	Scenario 3	-	266	218	244
Russian Federation	Total paper production	10750	4536	593	593
	Non-wood pulp capacity:
	Scenario 1	-	-	-	-
	Scenario 2	-	-	-	-
	Scenario 3	-	-	-	-
World	Total paper and paperboard production	225887	250359	312056	397780
	Total non-wood capacity:
	Scenario 1	15567 1	20736	27140 1	36484 1
	Non-wood pulp in total paper (%):
	Scenario 1	6.9	8.3	8.7	9.2
	Total non-wood capacity:
	(Scenario 2)	15567 1	20736 1	40789	84805
	Non-wood pulp in total paper (%):
	(Scenario 2)	6.9	8.3	13.1	21.3
	Total non-wood wood capacity:
	(Scenario 3)	15567 1	20736 1	25832	35624
	Non-wood pulp in total paper (%):
	(Scenario 3)	6.9	8.3	8.3	8.3

¹ A miscellaneous amount of non-woods is included in some totals owing to the nature of the historical data (Atchison, 1995).

Scenario 1: continuation of historical trends. The first scenario for non-wood fibres uses a projection of the historical data over the next 15 years This was done by conducting linear regressions on published production data and then projecting the resulting trends. This method does not consider the possibility of radical shifts in the use of non-woods.

Under this scenario, with the exception of the Asia and the Pacific region, although there would be some increase in the use of non-wood fibres, production levels would remain low and the predicted increase in demand could easily be met from anticipated supplies (McCloskey, 1995). In Asia and the Pacific, on the other hand, consumption of non-wood fibres would almost double, driven by increases in China and India. In this region, it is not certain that available production of non-wood fibres would meet demand.

Scenario 2: optimal non-wood fibre use. This scenario is that of an ideal world, in which a set goal for non-wood usage would be met by every country on the planet. In order to conduct this scenario, figures were chosen based on current non-wood fibre use for each of the six global regions. For instance, the Asia and the Pacific region was given a target of 50 percent non-wood fibre content for all paper and paperboard products by the year 2010, as the use of non-woods is already very high in this region. Other ideal levels were based on estimates of the potential best usage that a region could expect in the time period allotted. The 15-year goals by region were, in terms of percentage non-wood fibre content: Europe, 5 percent; Asia and the Pacific, 50 percent; North America, 5 percent; Latin America, 5 percent; and Africa, 5 percent. The Russian republics were not included in these calculations because of a lack of data.

The regions that show the greatest change in the volume of non-woods used are North America and Europe, which traditionally have high levels of paper production combined with very low levels of non-wood usage, and Asia and the Pacific, which has always utilized a great deal of non-woods in the papermaking process. Other regions show large percentage increases in non-wood use under this scenario, but their low paper production levels means that this does not affect overall production greatly. While this demand represents a massive increase in the amount of non-wood fibres needed, it should be noted that the present-day supply is more than adequate to meet this demand (McCloskey, 1995).

Scenario 3: minimal non-wood fibre usage. The third scenario makes an initial assumption that no further advances will be made in non-wood fibre usage. An analysis of the historical data shows that this has happened in the past in some countries. This scenario takes the worst-case approach, and shows the minimal levels at which non-wood fibre usage could remain.

Under Scenario 3, the only part of the world that will be seriously utilizing non-woods is Asia and the Pacific. Non-wood use in every other region will remain an insignificant fraction of overall pulp and paper production.

Of all the regions and under each scenario, the Asia and the Pacific region will remain the largest user of non-wood fibre sources through the year 2010 (see Table 4 for a comparison between utilization of non-woods and paper/paperboard production under the three projections described above). Native non-wood species suitable for fibre production exist in this region, and the technology to utilize them for fibre is already in place. India and China are likely to remain the two countries that rely most on non-woods.

Non-woods also have the potential to increase in importance in Latin America and in Africa, where technology is being introduced and choices for capital investment are being made. These regions have the necessary climate and long growing seasons necessary to make non-woods an attractive alternative to pulpwood forest plantations.

The North American and European regions are unlikely to use non-woods extensively, owing to the climate in these regions and the presence of existing, highly developed wood production and processing technologies.

No data are available on the Russian republics but their adverse climate and short growing season mitigate against any significant development of non-woods for fibre production.

FIGURE - Three scenarios of non-wood fibre use versus total paper production

Conclusion

This article (and the report on which it is based) has investigated the effect that alternative fibre availability might have on global fibre supply during the next 15 years. By examining each of the three scenarios, it is possible to view a range of availability for recovered and non-wood fibres which represents a set of possible outcomes. The scenarios have been designed to provide a high and low estimate of alternative fibre availability that define the limit of these possibilities as well as describing the general trend into the future.

Alternate sources of fibres, including non-wood fibres, are being used to an increasing extent by the pulp and paper industry. It is projected that the amount of non-wood fibres employed will increase steadily in countries that are deficient in wood, and parallel trends may also be seen in countries that are rich in forest resources as environmental and social pressures reduce the areas of forest available for wood supply. Thus, more substitution of non-wood fibres for wood fibres can be expected in future as the economic availability of pulpwood declines. The worldwide consumption of non-woods increased by more than 50 percent between 1983 and 1994, and a further increase of more than 120 percent by the year 2010 is projected.

While it is anticipated that non-wood fibre use will increase, the overall percentage of non-woods being used in the pulp supply will remain low. The percentage of non-woods utilized in global pulp production was 5.3 percent in 1983, a figure which rose to 11.7 percent in 1994. This fraction may reach a maximum of 19.8 percent by the year 2010; however, more realistic projections range from 12 to 15 percent of global pulp capacity. Environmental problems related to the use of non-wood fibres (for example, the high silica content referred to above), coupled with storage problems and a limited growing season through much of the world, have combined to keep the fraction of non-woods being used in global pulp production at a fraction of the total capacity.

Recycling of non-woods fibres In considering the impact of alternative fibres an the global fibre supply, at some point the potential for recycling non-wood fibres must be established. Preliminary studies have examined the effects of pulping and recycling of kenaf. It has been shown that most non-wood have a lower lignin content that wood and that it is easier to delignify non-woods, as they have a lower activation energy (Pande and Roy, 1996). There have also been investigations into the changes suffered by fibres during the recycling of wheat straw pulps (Xumei and Xiachun, 1996). The results of this work implied that wheat straw pulp did not behave differently from wood pulp during recycling.

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