Alternatively Pulping Methods

Research is under way to develop bio pulping (biological pulping), similar to chemical pulping but using certain species of fungi that are able to break down the unwanted lignin, but not the cellulose fibres. In the bio pulping process, the fungal enzyme lignin peroxidase selectively digests lignin to leave remaining cellulose fibres. This could have major environmental benefits in reducing the pollution associated with chemical pulping. The pulp is bleached using chlorine dioxide stage followed by neutralization and calcium hypochlorite. The oxidizing agent in either case oxidizes and destroys the dyes formed from the tannins of the wood and accentuated (reinforced) by sulfides present in it.

Steam exploded fibre is a pulping and extraction technique that has been applied to wood and other fibrous organic material.

Bleaching 

The pulp produced up to this point in the process can be bleached to produce a white paperproduct. The chemicals used to bleach pulp have been a source of environmental concern, and recently the pulp industry has been using alternatives to chlorine, such as chlorine dioxide, oxygen, ozone and hydrogen peroxide.

Alternative to wood pulp 

Today, some people and groups advocate using field crop fibre or agricultural residues instead of wood fibre as being more sustainable.

There is enough straw to meet much of North America's book, magazine, catalogue and copy paper needs. Agricultural-based paper is a guaranteed way to reduce the stress of paper production on old growth and endangered forests. Some agricultural residue pulps take less time to cook than wood pulps. That means agricultural-based paper uses less energy, less water and fewer chemicals. Pulp made from wheat and flax straw has half the ecological footprint of pulp made from forests.

However, wood is also a renewable resource, with about 90 percent of pulp coming from plantations or reforested areas. Non-wood fibre sources account for about 5–10 percent of global pulp production, for a variety of reasons, including seasonal availability, problems with chemical recovery, brightness of the pulp etc. Non-wood pulp processing requires a high use of water and energy.

Nonwovens are in some applications alternatives to paper made from wood pulp, like filter paper or tea bags.

Comparison of typical feedstocks used in pulping

Component	Wood	Nonwood
Carbohydrates	65–80%	50–80%
Cellulose	40–45%	30–45%
Hemicellulose	23–35%	20–35%
Lignin	20–30%	10–25%
Extractives	2–5%	5–15%
Proteins	<0.5%	5–10%
Inorganics	0.1–1%	0.5–10%
SiO2	<0.1%	0.5–7%

Market pulp

Market pulp is any variety of pulp that is produced in one location, dried and shipped to another location for further processing. Important quality parameters for pulp not directly related to the fibres are brightness, dirt levels, viscosity and ash content. In 2004 it accounted for about 55 million metric tons of market pulp.

Air dry pulp

Air dry pulp is the most common form to sell pulp. This is pulp dried to about 10 percent moisture content. It is normally delivered as sheeted bales of 250 kg. The reason to leave 10 percent moisture in the pulp is that this minimizes the fibre to fibre bonding and makes it easier to disperse the pulp in water for further processing to paper.

Roll pulp

Roll pulp or reel pulp is the most common delivery form of pulp to non traditional pulp markets. Fluff pulp is normally shipped on rolls (reels). This pulp is dried to 5–6 percent moisture content. At the customer this is going to a comminution process to prepare for further processing.

Flash dried pulp

Some pulps are flash dried. This is done by pressing the pulp to about 50 percent moisture content and then let it fall through silos that are 15–17 m high. Gas fired hot air is the normal heat source. The temperature is well above the char point of cellulose, but large amount of moisture in the fibre wall and lumen prevents the fibres from being incinerated. It is often not dried down to 10 percent moisture (air dry). The bales are not as densely packed as air dry pulp.

Environmental concerns 

The major environmental impacts of producing wood pulp come from its impact on forest sources and from its waste products.

Forest Resources 

The impact of logging to provide the raw material for wood pulp is an area of intense debate. Modern logging practices, using forest management seek to provide a reliable, renewable source of raw materials for pulp mills. The practice of clear cutting is a particularly sensitive issue since it is a very visible effect of logging. Reforestation, the planting of tree seedlings on logged areas, has also been criticized for decreasing biodiversity because reforested areas are mono cultures. Logging of old growth forests baccounts for less than 10 percent of wood pulp, but is one of the most controversial issues.

Effluents from pulp mills 

The process effluents are treated in a biological effluent treatment plant, which guarantees that the effluents are not toxic in the recipient.

Mechanical pulp is not a major cause for environmental concern since most of the organic material is retained in the pulp, and the chemicals used (hydrogen peroxide and sodium dithionite) produce benign byproducts (water and sodium sulfate (finally), respectively).

Chemical pulp mills, especially kraft mills, are energy self-sufficient and very nearly closed cycle with respect to inorganic chemicals.

Bleaching with chlorine produces large amounts of organochlorine compounds, including dioxins.

Odor Problems 

The kraft pulping reaction in particular releases foul-smelling compounds. The hydrogen sulfide reagent that degrades lignin structure also causes some demethylation to produce methanethiol, dimethyl sulfide and dimethyl disulfide. These same compounds are released during many forms of microbial decay, including the internal microbial action in Camembert cheese, although the kraft process is a chemical one and does not involve any microbial degradation. These compounds have extremely low odor thresholds and disagreeable smells; a common saying in communities economically dependent on nearby papermills is "Smells like a job" or "Smells like money."

Applications 

The main applications for pulp are paper and board production. The furnish of pulps used depends on the quality on the finished paper. Important quality parameters are wood furnish, brightness, viscosity, extractives, dirt count and strength.

Chemical pulps are used for making nanocellulose.

Speciality pulp grades have many other applications. Dissolving pulp is used in making regenerated cellulose that is used textile and cellophane production. It is also used to make cellulose derivatives. Fluff pulp is used in diapers, feminine hygiene products and nonwovens.

Paper Production 

The Fourdrinier Machine is the basis for most modern pape rmaking, and it has been used in some variation since its conception. It accomplishes all the steps needed to transform a source of wood pulp into a final paper product.

- Wikipedia 

PAPERBOARD

Paperboard is a thick paper-based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker (usually over 0.25 mm, 0.010 in, or 10 points) than paper. According to ISOstandards, paperboard is a paper with a grammage above 224 g/m², but there are exceptions. Paperboard can be single- or multi-ply. Paperboard can be easily cut and formed, is lightweight, and because it is strong, is used in packaging. Another end-use would be graphic printing, such as book and magazine covers or postcards. Sometimes it is referred to as cardboard, which is a generic, lay term used to refer to any heavy paper pulp–based board. Paperboard is also used in fine arts for creating sculptures.

Corrugated fiberboard made from paperboard

Terminology and Classification

 Terminology and classifications of paperboard are not always uniform. Differences occur depending on specific industry, locale, and personal choice. In general, the following are often used:

• Boxboard or cartonboard – paperboard for folding cartons and rigid set-up boxes
  • Folding boxboard (FBB) – a bending grade capable of being scored and bending without fracture
  • Chipboard – a recycled, low quality board
    • White lined chipboard (WLC) – a white, often clay-coated chipboard
  • Kraft board – a strong virgin fiber board often used for beverage carriers. Often clay- coated for printing
  • Laminated board – a lamination of paperboards and other materials, for example liquid packaging board
  • Solid Bleached Board (SBB) or Solid Bleached Sulphate (SBS) – clean white board used for foods etc. Sulphate refers to the kraft process
  • Solid unbleached board (SUB) – board made from unbleached chemical pulp
• Containerboard – a type of paperboard manufactured for the production of corrugated fiberboard
  • Corrugated medium – the inner fluted portion of corrugated fiberboard
  • Linerboard – a strong stiff board for one or both sides of corrugated boxes. It is the flat covering over the corrugating medium.
• Other
• Binder's board – a paperboard used in bookbinding for making hardcovers.

Sculpture made of massive paperboard by Herbert Wetterauer

Production

Fibrous material is turned into pulp and bleached, to create one or more layers of board, which can be optionally coated for a better surface and/or improved visual appearance. Paperboard are produced on paper machines that can handle higher grammages and several plies.

Raw Materials

The above-mentioned fibrous material can either come from fresh (virgin) sources (e.g. wood) or from recycled waste paper. Around 90% of virgin paper is made from wood pulp. Today paperboard packaging in general, and especially products from certified sustainablesources, are receiving new attention, as manufacturers dealing with environmental, health, and regulatory issues look to renewable resources to meet increasing demand. It is now mandatory in many countries for paper-based packaging to be manufactured wholly or partially from recycled material.

Raw materials include:

• Hardwood: Ca. 0.05 inches (1.3 mm) in length e.g. Birch which has short fibres. It is generally more difficult to work with; however, it does provide higher tensile strength, but lower tear and other strength properties. Although its fibres are not as long and strong as those in softwood, they make for a stiffer product defined by some stifness tests. Hardwood fibres fill the sheet better and therefore make a smoother paper that is more opaque and better for printing. Hardwood makes an excellent corrugating medium.

• Softwood: Ca. 0.13 inches (3.3 mm) in length e.g. Pine and spruce which have typically long fibres and make superior paperboard in services where strength is important. Softwood makes excellent linerboard.

• Recycled: Used paper is collected and sorted and usually mixed with virgin fibres in order to make new material. This is necessary as the recycled fibre often loses strength when reused; the added virgin fibres enhance strength. Mixed waste paper is not usually deinked(skipping the deinking stage) for paperboard manufacture and hence the pulp may contain traces of inks, adhesives, and other residues which together give it a grey colour. Products made of recycled board usually have a less predictable composition and poorer functional properties than virgin fibre-based boards.  Health risks have been associated with using recycled material in direct food contact. Swiss studies have shown that recycled material can contain significant portions of mineral oil, which may migrate into packed foods. Mineral oil levels of up to 19.4 mg/kg were found in rice packed in recycled board. 

• Others: It is also possible to use the fibres of Sugarcane Bagasse, Straw, Hemp, Cotton, Flax, Kenaf, Abaca and other plant products

Pulping

Two principal methods for extracting fibres from their sources are:

• Chemical pulping uses chemical solutions to convert wood into pulp, yielding around 30% less than mechanical pulping; however, pulp made by the kraft process has superior strength

• Thermo mechanical pulp is a two-stage process which results in a very high yield of wood fibres at the expense of strength.

Bleaching

Pulp used in the manufacture of paperboard can be bleached to decrease colour and increase purity. Virgin fibre pulp is naturally brown in colour, because of the presence of lignin. Recycled paperboard may contain traces of inks, bonding agents and other residue which colors it grey. Although bleaching is not necessary for all end-uses, it is vital for many graphical and packaging purposes. There are various methods of bleaching, which are used according to a number of factors for example, the degree of colour change required, chemicals chosen and method of treatment. There are three categories of bleaching methods:

• Bleaching by delignification using chlorine gas, which is a method that has been largely replaced by procedures which are gentler to the environment such as the use of oxygen as a replacement for the chlorine gas.
• Bleaching by oxidation using chemicals such as chlorine dioxide, hydrogen peroxide or sodium hypochlorite.
• Bleaching by reduction using chemicals such as sodium bisulphite.

Plies

Multi-ply paperboard generally has higher creasing and folding performance than single-ply as a result of layering different types of pulp into a single product. In cases where the same kind of pulp is being used in several layers, each separate layer is treated and shaped individually in order to create the highest possible quality.

Coating

In order to improve whiteness, smoothness and gloss of paperboard, one or more layers of coating is applied. Coated paper is usually made up of:

• a pigment, which could be china clay, calcium carbonate or titanium dioxide, usually a combination of two
• an adhesive or binder as styrene-butadiene emulsions or starches and water.

Additional components could be OBA (optical brightening agents).

Grades

The DIN Standard 19303 "Paperboard - Terms and grades" (Publication date : 2005-09) defines different grades of paperboard based on the surface treatment (first letter), the main furnish (second letter) and the colour (non-D grade) or bulk (D grade only) (numbering).

First letter (surface treatment)	Second letter (main furnish)	Number
A = cast-coated G = pigment coated U = uncoated	Z = bleached virgin chemical pulp C = virgin mechanical pulp N = unbleached virgin chemical pulp T = recycled/secondary fibre with white, cream or brown reverse D = recycled/secondary fibre with grey back	All except D grades: white reverse side cream reverse side brown reverse side D grades only: bulk ≥ 1.45 cm2/g 1.3 cm2/g < bulk < 1.45 cm2/g bulk ≤ 1.3 cm2/g

Example: GC1 would be a "pigment coated", "virgin mechanical pulp" board with a "white reverse side". Often the used paperboard type would be FBB, which was coated on both sides.

Common Terms

Basis Weight (US): Is the weight in 1,000 square feet (93 m²) of paperboard.

Brightness: Brightness is a technical term that is defined as the amount of blue-white light that a paper reflects. This property is very subjective and individual to each buyer and end use, as skin colour and food are better reproduced on ‘warm’ (yellow) whites and not blue whites.

Grammage: The grammage of the paperboard is assessed in accordance ISO 536. Grammage expresses mass per unit area and is measured in g/m².

PH: Surface pH is measured on a water extract and is on a scale of 0–14. 0 is acidic, 7 is neutral and 14 is alkaline.

Stiffness: Stiffness is one of the most important properties of paperboard as it affects the ability of cartons to run smoothly through the machine that erects, fills and closes them. Stiffness also gives strength and reduces the propensity of a carton to bulge under the weight of settling flowable contents such as cereals.

Although most paper strength properties increase with increasing sheet density, stiffness does not. A rule of thumb is that stiffness is proportional to the 1.6 power of sheet caliper.

The species of fiber used has an effect on stiffness, other things being equal. Northern softwood species impart superior stiffness compared to southern softwoods.

Other factors which affect board stiffness include coatings and moisture content.

Smoothness: Smoothness is particularly important when being used for printing, the smoother the paperboard, the better the image quality, because of better ink coverage. Smoothness is measured using air leak methods – the greater the rate of air leakage, at a specific air pressure, from under a cylindrical knife placed on the surface, the rougher the surface.

Caliper/Thickness: In the United States caliper is usually expressed in thousandths of an inch (0.001”) or points, where a sheet of paperboard with a thickness of 0.024” would be 24 points. In Europe it is often sold in g/m², however the thickness of the board is measured in micron (μm).

Paperboard also tends to be referred to with thickness rather than weight.

Whiteness: It refers ideally to the equal presence of all colours, because a truly white sheet will reflect all wavelengths of visible light equally.

Paperboard Industry

The paperboard sector is mainly looked at in conjunction with the paper industry. The Paper & Paperboard market size (2007) had a value of 630.9 billion USD and a volume of 320.3 million metric tons . 40.1% of that market is European. About 50% of all produced paper is used for packaging, followed by printing and writing. According to ProCarton, the consumption of paper and paperboard seem to correlate with economic trends (GDP). Sales of carton in Europe sum up to around 8 billion Euros worth. Over 1,100 printers produce 5.4 million tonnes of cartonboard yearly. Cartons make up one third of paper and board packaging and 15% of all packaging. A bit more than half (54%) of the European carton is produced using recovered fibre or waste paper.

The paper and paperboard industry is quite energy and capital intensive. Just a coated board machine itself can cost around 90 - 120 million Euros  (about 125 - 166 million USD in 11/2011). Economies of scale apply, because of which a few large players often dominate the market place. E.g. in North America the top 5 producers have a market share of 85%.

- Wikipedia 

FIBERBOARD

Fiberboard (American spelling) or fibreboard (Commonwealth spelling) is a type of engineered wood product that is made out of wood fibers. Types of fiberboard (in order of increasing density) include particle board, medium-density fiberboard, and hardboard. Fiberboard is sometimes used as a synonym for particle board, but particle board usually refers to low-density fiberboard. Plywood is not a type of fiberboard, as it is made of thin sheets of wood, not wood fibers or particles. Fiberboard, particularly medium-density fiberboard (MDF), is heavily used in the furniture industry. For pieces that will be visible, a veneer of wood is often glued onto fiberboard to give it the appearance of conventional wood.

Fiberboard is also used in the auto industry to create free-form shapes such as dashboards, rear parcel shelves, and inner door shells. These pieces are usually covered with a skin, foil, or fabric such as cloth, suede, leather, or polyvinyl chloride.

Certain types of fiberboard can be considered "green" building products. Consisting of bio-based, secondary raw materials (wood chip or sugarcane fibers) recovered from within 100 miles (160 km) of manufacturing facilities, the binding agent used in this type of fiberboard is an all-natural product, consisting of vegetable starch containing no added formaldehydes.

Fiberboard, classified by ASTM C208, Standard Specification for Cellulosic Fiber Insulating Board, has many benefits and is used in residential and commercial construction. Different uses and applications include:

• sound proofing/deadening,
• structural sheathing,
• low-slope roofing,
• sound deadening flooring underlayment,

RSI Direct, A bi-weekly e-newsletter covering the roofing, siding and insulation industries, promotes the use of fiberboard as a coverboard in roof systems:

High density coated wood fiber is an ideal cover board, and the industry apparently agrees. More than two billion square feet of this product have already been installed in the U.S. roofing market. In terms of cost and availability, wood fiber is hard to beat.

Other uses

In the packaging industry, fiberboard is often used to describe a tough kraft-based paperboard or corrugated fiberboard for boxes.

- Wikipedia 

NON-WOOD FIBER AND GLOBAL FIBER SUPPLY

In the context of this article non-wood fibers are defined as non-woody cellulosic plant materials from which paper-making fibers can be extracted. The most widely used non-woods for paper-making are straws, bagasse, bamboo, hemp, kenaf, jute, sisal, abaca, cotton inters (short fibers 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 paper-making. 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 inpaper-making 

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 fibers 

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-fibers 

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 forpaper-making 

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 inpaper-making 

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.

Sources FAO Report, Assessed on 22 February 2016