Chemical composition of oil palm fronds

Oil palm frond (OPF)

Among various fibrous components of the oil-palm tree (i.e. trunk, frond, fruit bunch, mesocarp) frond fiber is the longest with an average length of 1.59 mm which is longer than that of most hardwood fibers (Wan Rosli et al., 2004).

On the average, the fronds are produced at the rate of two per month in a regular sequence. The length of the frond is typically about 7 meters, and each frond consists of a petiole, which is 150 cm long, and a rachis, which bears 250 to 350 leaflets. Each leaflet may be up to 130 cm long. The leaflets are arranged on two lateral planes (Chopra and Peter, 2005).

Chemically, the frond strands are rich in holocellulose (82.2%) and also high in α-cellulose (47.6%) as illustrated in Table 2.2, both of which are important parameters in determining the suitability of a raw material for papermaking. The lignin content (15.2%) is lower than normally found in common hardwood, which is not surprising since oil palm trees are non-woody and the requirement for structural support is lower compared to that of trees (Wan Rosli et al., 2007).

Table 2.2: Chemical composition of oil palm fronds.

Component	Oil palm fronds
Lignin (%) Holocellulose (%) α-cellulose (%) Alcohol-benzene extractives (%) Ash (%) Polysaccharide composition (%) Arabinose Mannose Galactose Glucose Xylose	15.2 82.2 47.6 1.4 0.7 1.5 2.2 0.9 66.6 28.9

(Wan Rosli et al., 2007)

The frond strands are comparatively less resinous than those of wood, as evidenced by the lower levels of extractives soluble in alcohol–benzene. It should also be noted that the frond strands, like other non-wood fibers, contain comparatively high ash content. The monomer composition of polysaccharides shows almost only glucose and xylose, with the other monosaccharide representing less than 6%, which is in broad similarity with that of hardwoods (Wan Rosli et al., 2007).