Pillar 1 : Going green Kenji Umemura Research Institute for Sustainable Humanosphere (RISH) Kyoto University

1. Kenji Umemura
Research Institute for Sustainable Humanosphere (RISH),
Kyoto University
Development of sustainable wood-based materials

2. +
=
Wood elements Adhesives
Wood-based materials
Composition of wood-based materials
Sustainability of resources
Sustainable wood-based materials
Renewability of raw materials is important.

3. 3950000
4000000
4050000
4100000
4150000
4200000
4250000
1990 2000 2010 2020
4200
4150
4100
4050
4000
(Million ha)
Year
Forest
area
178 million
Source: Global Forest Resources Assessment 2020, FAO
Change of global forest area
3
3950
4250
➢ The forest area declined gradually.
➢ 178 million ha have been lost.
➢ The rate of forest loss slows in recent years.
➢ This is due to forest preservation and
increase of plantation forest etc.
Forest area is expected to continue to decrease
considering deforestation and climate change.

4. 4
Fig. Global crops production.
3.0
2.5
2.0
1.5
1.0
0.5
Crops
production
Year
(Billion ton)
(FAO)
Global crops production
2.7
Wheat, rice, corn, sorghum,
sugar cane etc.
Agricultural wastes
(straw, stalks, bagasse)
・Population growth
・Economic development
We have to deal with these wastes.

5. 【Wood-based materials】 【Crops】
◼ Increase of production
◼ Deforestation
◼ Increase of production
◼ Increase of wastes (fibers)
◼ Prohibition of open burning
Utilization of agricultural wastes as raw materials for wood-based materials
should be investigated.
Alternative raw materials Utilization of wastes
➢ Population growth
➢ Economic development
➢ Climate change

6. +
=
Wood elements
Wood-based materials
Synthetic resin adhesives
Bio-based adhesives
Future global environment & Potential shortage of fossil resources
Reduction of the consumption of synthetic resin adhesives.
Replace
Synthetic resin adhesives
(Fossil resources)

7. ➢ Sweet sorghum has planted in large area as a multi purpose plant for
food, chemical agents, etc.
➢ The large amount of bagasse is generated as a waste.
➢ Possibility of bagasse utilization for raw material of
particleboard.
➢ Conventionally, it is used as silage. (Short term carbon stock)
(Long term carbon stock)
Utilization of sweet sorghum bagasse as a raw
material of particleboard
Dr. Sukma Surya Kusumah
Prof. Subyakto

8. Sorghum bagasse particleboard bonded with
citric acid and sucrose
Preparation of particleboard using sorghum bagasse and citric acid/sucrose.
Sorghum Bagasse
particles
+
Forming
Hot Press
Citric acid + sucrose
water solution
Citric acid Sucrose
200˚C, 10min
❖Resin content: 20wt%
❖Target Density：0.8g/cm3

9. 9
Adhesive type of Particleboard
Citric acid +
sucrose
PF resin
WSH (N) 525 652
MOR (MPa) 30.2 32.9
TS (%) 12 20.6
Table 2. Formaldehyde emission of citric acid + sucrose, and PF-boards.
Adhesive type of Particleboard
Citric acid +
sucrose
PF resin
Formaldehyde
emission (mg/L)
0 0.01
BioResources 12(4), 7498-7514 (2017)
Addition effects of sucrose
Citric acid : Sucrose
（10 : 90）solution
Adhesive content：20wt%
Hot press condition：200˚C, 10min
Target density：0.8g/cm3
Table 1. Wood screw holding power (WSH), MOR and thickness swelling of
particleboards bonded with citric acid + sucrose, and PF resin.

10. Adhesive type of
Particleboard
Termite resistance
Decay resistance
(Mass loss the specimen)
Termite mortality
(%)
Mass loss
(%)
Brown-rot fungus
(%)
White-rot fungus
(%)
Citric acid +
Sucrose
43.07 (2.14) 5.45 (1.26) 6.40 (0.9) 23.42 (6.9)
PF resin 46.4 (9.4) 3.92 (0.28) 5.79 (2.83) 9.09 (0.78)
pMDI 37.9 (2.1) 5.91 (0.90) 4.54 (0.63) 31.02 (5.41)
Control (Solid wood) 24.73 (5.84) 13.57 (2.35) 10.23 (4.77) 37.49 (6.05)
Table 3. Termite and decay resistances of particleboards bonded with citric acid + sucrose,
PF resin and pMDI.
It was clarified that the board bonded with citric acid and sucrose
had good biological durability.
BioResources 12(4), 7498-7514 (2017)
Particleboards using agricultural wastes and bio-based adhesives
have high potential.

11. 11
Social implementation of particleboard using sorghum bagasse and citric acid
Furniture company
Ironing board
Cabinet
Manufacture of 3-layer particleboard
Preparation of raw materials Particle mat Insert mat to hot press 3 layer particleboards

12. 12
3-layer particleboard using sweet
sorghum bagasse and citric acid
Cabinet made of sorghum bagasse particleboard
Social implementation of particleboard using sorghum bagasse and citric acid

13. 13
Strategies for developing sustainable wood-based materials
Bio-based adhesives
Sustainable wood-based materials
Lignocellulosic biomass
・Wood
・Agricultural wastes
・Grass plants
Laminated wood Plywood
Particleboard Fiberboard OSB CLT
Saccharide, Protein,
Tannin, Lignin, Oil etc.

14. Thank you for your attention