Acknowledgements

considered the application of ASAM in the cooking process of both hard and soft wood. Table 5 gives the summary of the reported pulping of lignocellulose biomass using ASAM pulping process on different lignocellulose biomass compared with the ASAM pulped bamboo (G. scortechinii) species. At a constant ASAM pulping process at 170 and alkali ratio (Na2SO3/ NaOH; anthraquinone: methanol) of (80/20, 0.1%: 15%), it was found that ASAM pulped bamboo gave a characteristic high yield of 52.36%. Like the other ASAM pulped biomass (Table 5) this is quite higher than what is obtainable in kraft pulping. The highest yield was achieved by applying 14% sodium hydroxide and 90 min cooking time while the lowest Kappa number (10.38) was observed using 18% and 120 min. Further increase of both alkali and cooking time resulted in marked decrease in both Kappa number and pulp yield. From the result, ASAM pulping of bamboo (G. scortechinii) revealed a low Kappa number compared with what was obtained from Hibiscus cannabinus, whole jute plant, Eucalyptus globulus and Eucalyptus globulus labill as reported by Khristova et al. [54]; Jahan et al. [55]; Kordsachia et al. [56]; and Gominho et al. [58], respectively, despite the high ASAM pulping parameters used.

Table 5. Effects of ASAM pulping parameters on pulp and paper properties of various types of lignocellulosic materials.

Raw material Pulping parameters Total

18 Bamboo - Current and Future Prospects

NaOH: 16%; AQ: 0.1% Methanol: 15% Na2SO3/NaOH: 80/20 T: 90 min; Temp: 170C

NaOH: 17%; AQ: 0.1% Na2SO3/NaOH: 70/30 T: 120 min; Temp: 175C

NaOH: 22%; AQ: 0.1% Na2SO3/NaOH: 80/20 Methanol: 25% T: 60 min; Temp: 170C

NaOH: 22.5%; AQ: 0.1% Methanol: 25% Na2SO3/NaOH: 80/20 T: 135 min; Temp: 180C

0.1%; Methanol: 10% Na2SO3/NaOH: 80/20 T: 120 min; Temp: 170C

NaOH: 25%; AQ: 0.1% Methanol: 30% Na2SO3/NaOH: 70/30 T: 90 min; Temp: 170C

AQ = anthraquinone, T = time, Temp = temperature.

Trema orientalis NaOH: 17%; AQ: 0.1% Methanol: 20% Na2SO3/NaOH: 80/20 T: 120 min; Temp: 180C

Bamboo (G. scortechinii)

Hibiscus cannabinus

Whole jute plant

Eucalyptus globulus

Populus deltoids clone

Eucalyptus globulus labill yield

Kappa no.

Tensile index (Nm/g) Burst index (kPa.m2 /g)

49.06 14.17 20.86 10.83–9.27 20.86 39.32 Present

52.6 15.5 101.9 7.4 9.4 41.9 [54]

56.6 39.2 — 3.2 11.2 45 [55]

56.7 16.6 53.8 — 4.2 56.6 [56]

51 — 59.4 4.8 3.8 45.9 [57]

53.4 17 —— — 36 [58]

52.8 13.4 47.4 4.8 10.7 — [59]

Tear index (mN.m<sup>2</sup> /g) Brightness (%)

Reference

Study

The authors are thankful to the Institute of Tropical Forestry and Forest Products (INTROP), Universiti Putra Malaysia (UPM), and the Higher Institution Centre of Excellence (HICoE) Ministry of Higher Education Malaysia, Grant No. 6369107. Additional thanks are extended to the School of Industrial Technology, Universiti Sains Malaysia (USM) and the Federal Institute of Industrial Research Oshoidi Nigeria for technical support.
