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Paulownia elongota, one of the most fast growing species of the world, was evaluated as raw material for pulp and paper prodn. The chem., morphol. and anatomical aspects of paulownia wood were detd. The lignin, holocellulose and α-cellulose contents in P. elongota wood were comparable to those of some common non-wood and hardwood raw materials. Different chem. pulping procedures were applied to P. elongota wood to evaluate its pulping potential. Paper strength properties and acidic group content bound to the cell wall were detd. The alkali soly., water soly. and alc.-benzene extractive content were higher than those from wood and most non-woods. The fiber length of 0.83 mm was obsd., which is close to low end of the hardwoods but fiber diam. was very wide, similar to that of softwoods. The pulpability of paulownia wood was also studied. The pulp yield and viscosity were very low and the kappa nos. were high. The strength properties were comparable to those of some wood and non-wood pulps. Although, paulownia pulps are considered as low quality materials, it can be used for paper prodn. when mixed with long fibrous materials. [on SciFinder(R)]
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African Journal of Biotechnology Vol. 7 (22), pp. 4153-4158, 19 November, 2008
Available online at
ISSN 1684–5315 © 2008 Academic Journals
Full Length Research Paper
Characterization and evaluation of Paulownia elongota
as a raw material for paper production
Saim Ates1*, Yonghao Ni 2, Mehmet Akgul3, Ayhan Tozluoglu3
1Kastamonu University, Forestry Faculty, 37100, Kastamonu, Turkey.
2Limerick Pulp and Paper Centre, UNB, Fredericton, NB, E3B6C2, Canada.
3Duzce University, Forestry Faculty, 81100, Duzce, Turkey.
Accepted 23 September, 2008
Paulownia elongota, one of the most fast growing species of the world, was evaluated as raw material
for pulp and paper production. The chemical, morphological and anatomical aspects of paulownia wood
were determined. The lignin, holocellulose and -cellulose contents in P. elongota wood were
comparable to those of some common non-wood and hardwood raw materials. Different chemical
pulping procedures were applied to P. elongota wood to evaluate its pulping potential. Paper strength
properties and acidic group content bound to the cell wall were determined. The alkali solubility, water
solubility and alcohol-benzene extractive content were higher than those from wood and most non-
woods. The fiber length of 0.83 mm was observed, which is close to low end of the hardwoods but fiber
diameter was very wide, similar to that of softwoods. The pulpability of paulownia wood was also
studied. The pulp yield and viscosity were very low and the kappa numbers were high. The strength
properties were comparable to those of some wood and non-wood pulps. Although, paulownia pulps
are considered as low quality materials, it can be used for paper production when mixed with long
fibrous materials.
Key words: Paulownia elongota, chemical, morphological, anatomical properties, pulping.
Pulp and paper industry is facing ever-increasing demand
of quality paper and paperboard that is causing search for
new and hitherto unexploited sources of cellulosic fibers.
However, out of nearly 600 known species, less than a
dozen are in commercial use for pulp production. These
species, most frequently found in plantations in the diffe-
rent regions of the world, may not always be favorable
with regard to fiber quality and wood composition as well
as natural evolution and ease of hybridization (Khristova
et al., 2006).
Paulownia is a genus of about 20 native species in
China and South-East Asia and cultivated since as early
as 1000 BC. Its characteristics of rot resistance, dimen-
sional stability and a very high ignition point ensure the
popularity of this timber in the world market (Bergmann,
1998). Most species of paulownia are extremely fast
growing and can be harvested in 15 years for valuable
Corresponding author: E-mail:,
Tel: +90-5052243173; Fax: +90-3662152316
timber. Low quality lumber can easily be produced from 6-
7 years old tree. A full grown paulownia can reach a
height of 10 to 20 m and grows up to 3 m in one year
under ideal conditions. A 10-year old tree can measure
30-40 cm diameter at breast height (DBH) and can have
a timber volume of 0.3-0.5 m3 (Flynn and Holder, 2001).
The wood of paulownia is soft, lightweight, ring porous
straight grained, and mostly knot free wood with a satiny
luster. Average specific gravity of the wood is reported as
0.35 g cm-3 (Kalaycioglu et al., 2005).
Paulownia is also known as a fast growing tree. It can be
used for several applications; one of them is its use as
source for pulp (Virginia et al., 2008; Rai et al., 2000). It can
be characterized by a fast development and a uniform and
regular growth. Each paulownia tree could produce a cubic
meter of wood at the age of 5–7 years; it may grow in
intensive plantations with about 2000 trees ha-1. Based on
the above one can calculate that an annual production
would be 330 ton ha-1, a more conservative number would
be about 150 ton ha-1 (Caparro et al., 2008).
The main objective of this study was to establish the
suitability of Paulownia elongata as a potential source of
4154 Afr. J. Biotechnol.
lignocellulosic fibers for paper and composites materials.
In the present study, anatomical, morphological and
chemical characteristics were evaluated in order to obtain
more information about their suitability for pulp
For this study, a wood sample of the hybrid P. elongota (2 years-old
tree) was harvested from a plantation in the west of Turkey
(plantation of Bragfor Fidancılık). Several trees of about 6.0–7.5 m
high and 27-33 cm diameter at breast height were felt and the
stems were cut into 0.5-2.0 m wood logs that were air-dried and
used to make 2–3 cm chips in length for the pulping trials. A repre-
sentative part of the chips were also ground into 40–60 mesh wood
mills, 10 g of which were used for the chemical analyses.
Characterization of raw materials
The raw materials were analyzed for holocellulose, -cellulose,
lignin, ash, alcohol–benzene extractable, cold and hot water and
1% soda soluble, in accordance with the applicable TAPPI
standards: T-203-0S-61, T-222, T-221, T-204, T-257 and T-212,
respectively. Five replicates were done for each experiment.
Morphological and anatomical properties
For the measurements of fiber length, fiber width, lumen width and
cell wall width, P. elongota wood (after removing barks) was mace-
rated in a solution containing 1:1 HNO3 and KClO3. For maceration,
wood samples taken from three parts of each P. elongota wood
were chosen. A drop of macerated sample was taken on a slide and
fiber length, fiber width, lumen width and cell wall thickness were
measured under a microscope. For measuring fiber length and
diameter, 200 fibers were measured from 10 slides and average
reading was taken.
For anatomical properties, paulownia wood chips of about 1 cm
was autoclaved followed by immediate storage in a mixture of equal
volume of glycerin, ethyl alcohol and water till sectioning with sliding
microtome. Then permanent slide was prepared and analyzed on a
microscope. The percentage of vascular bundles was calculated
from the vascular bundle area divided by total area.
Three different pulping processes were conducted: kraft-
antraqhinon (AQ), soda-AQ and ethanol (ALCELL). Pulping
experiments were carried out in 15 L electrically heated laboratory
type rotary digester and governed with digital temperature control
system. At the end of pulping, pressure was relieved to atmospheric
pressure then pulps were washed, disintegrated in a laboratory type
pulp mixer with 2 L capacity and screened on a Noram type pulp
screen with 0.15 mm slotted plate. Pulp yield was determined as
dry matter obtained on the basis of oven dried (od) raw material.
Kappa number and viscosity were determined in accordance with T
236 cm-85 and T 230 om-94, respectively. Hand sheets of un-
bleached pulps with a grammage of ~60 g m-2 were prepared
according to Tappi T 272 om-92. Before the ethanol pulp sample
was used in this study, displacement washing was performed with a
70% ethanol solution at 70°C a 10% pulp consistency, a superficial
velocity of 100 ml min-1 and a dilution factor of 4.5 ml g-1. The kappa
number of the washed pulp thus obtained was 42.06.
Acid groups
Paulownia wood sample was mechanically refined, then extracted
following TAPPI T-264-88 with the substitution of acetone before
determination of acid groups. The extracted sample and three
different P. elongota pulps were alternately soaked and rinsed two
times in 0.1 N HCl for 45 min. The pulp samples were dispersed
450 ml of 0,001 M sodium chloride and titrated with 0.1 M sodium
hydroxide. The alkali was added at a rate of 0.5 ml every 5 min so
as to allow sufficient time for equilibrium to be reached between
readings. Following titration, the pulp was washed and oven-dried
at 105oC. All titrations were followed both potentiometrically and
conductometrically (Katz et al., 1984).
Table 1 shows the chemical properties of P. elongota
wood and their comparison with bamboo, eucalyptus,
some annual plants, coniferous and deciduous wood
which are the main fibrous raw materials. As shown in
Table 1, lignin content of P. elongota was found as
20.5%, which is comparable with all annual plants and
hardwoods (17-26%) especially with eucalyptus (23.3%);
it is however, substantially lower than softwoods (25-
32%). The average holocellulose content of P. elongota
was found as 75.74% and it is fairly acceptable ratio when
compared with bamboo (70.5%), most annual plant and
coniferous (68-74%). The -cellulose in P. elongota wood
(43.61%) is higher than wheat straw, corn stalk, tobacco
stalk, sunflower stalk and kenaf (38.2, 35.6, 37.5, 37.5
and 37.4%, respectively) When compared with hard-
woods and softwoods, P. elongota have substantially
higher water, alkali and alcohol-benzene solubility, which
means lower pulp yield probably higher biological oxygen
demand (BOD) load in the effluent. P. elongota wood also
showed similar solubility with bamboo and eucalyptus and
better solubility values than wheat straw and than most
annual plants (Table 1).
The anatomical structure of P. elongota wood was
studied on transverse and tangential sections (Figure
1a,b). The light microscopy observation revealed the
prevalence of four distinct tissue systems: vessels,
parenchyma, rays and fibers. It can be seen from cross
section (Figure 1a) that the difference in vessel size
between early and late wood is three or five times.
Solitary vessels, simple perforation and tyloses in vessels
can be seen. Each vessel was surrounded by a large
number of paratracheal. Parenchyma can be seen mostly
clear around the vessels of late wood and wide strip-
shaped in early wood. Fiber cells are more in late wood
than in early wood. Rays are multiseriate, usually homo-
geneous and 1-40 cells high and 1-5 cells wide (Figure
1b). These anatomical properties are closely similar to
Paulownia fortunei wood studied by Hua et al. (1986).
The average content of parenchyma cells of P. elongo-
ta is about 53.8%. The percentage of parenchyma cells
for P. elongota differs from wood species (7 and 30% for
soft and hardwood, respectively) (Rydholm, 1976), but
resembles other non-wood like corn stalks, straw etc.
Ates et al. 4155
Table 1. Chemical analysis of Paulownia elongota wood
Holocellulose (%)
-cellulose (%)
Lignin (%)
Ash (%)
Alcohol benzene
1 % NaOH (%)
Cold water (%)
Hot water
(0.96) Determination
Eucalyptus 80.42 50.17 23.30 0.47 3.29 23.56 5.62 9.91 Ayata 2008
Bamboo 70.5 43.3 24.5 1.35 3.94 25.1 - 6.47 Deniz,and Ates
Wheat straw 74.5 38.2 15.3 4.7 7.8 40.59 10.75 13.99 Deniz et al.2004
Rye straw 74.1 44.4 15.4 3.2 9.2 39.2 10.2 13.0 Usta and Eroglu
Corn stalk 64.8 35.6 17.4 7.5 9.5 47.1 - 14.8 Usta et al. 1990
67.6 37.5 19.5 7.3 6.5 42.9 15.8 19.1
74.9 37.5 18.2 8.2 7.0 29.8 15.5 16.5
Cotton stalk 77.6 - 21.4 4.2 3.0 21.9 - -
Erolu et al. 1992
Reed 77.9 47.5 18.7 3.9 4.0 28.3 3.3 3.8 Kirci et al. 1998
Kenaf 81.2 37.4 14.5 4.1 5.0 34.9 11.7 12.8 Atchison
Hemp 86.77 63.77 6.59 - 4.23 29.55 7.75 9.06 Gumuskaya and
Usta 2006
Coniferous 68-74 40-45 25-32 <1 - - 2-6 2-5 Eroglu 1998
Deciduous 70-81 38-49 17-26 <1 - - 3-6 3-6
S.d. Standart deviation.
Figure 1. Transversal (a) and tangential (b) sections and macerated sample (c) of Paulownia
elongota wood. F: Fibers, P: parenchyma, R: rays, and T: trachea cells.
(Atchison, 1993). The similar ratio of tissue systems was
found by Jahan et al. (2006) for golpata fronds (Nypa
fruticans). The proportion of vascular tissues and fibers in
P. elongota (9.71 and 39.04%, respectively) are also
different from woods (30 and 50%), but close to other
materials like wheat straw (13.5 and 37.5%) and bamboo
(11 and 38%) (Shatalov and Pereira, 2006). When com-
pared with woody materials, P. elongota wood has lower
amount of fiber and higher content of short parenchyma
4156 Afr. J. Biotechnol.
Table 2. Morphological analyses of Paulownia elongota wood
Fiber length
Fiber width
Lumen width
Cell wall
thickness (m)
(Std. dev.)
(0.003) Determination
(E. globulus) 1.28 18.0 - 7.0 Teresa et al.
Bamboo 2.30 15.1 6.9 4.17 Deniz,and Ates
Wheat straw
(T. durum L) 0.74 13.2 4.0 4.6 Deniz et
Rye straw 1.15 14.7 4.2 1.1 Usta and
Eroglu 1987
Corn stalk 1.32 24.3 10.7 6.8 Usta et al.
Cotton stalk I.32 29.3 23.0 3.6
Tobacco straw 1.07 26.8 16..3 5.3
stalk 128 22.1 15.6 3.3
Erolu et al.
Reed 1.39 13.5 7.0 3.2 Kirci et al.
Kenaf 2.60 20.0 Atchison 1993
Coniferous 2.7-4.6 32-43 - -
Deciduous 0.7-1.6 20-40 - - Atchison 1987
Table 2 shows the morphological characteristics of P.
elongota and its comparison with other fibrous materials.
The image of the fibers can be shown in Figure 1c. The
average fiber length of P. elongota wood is 0.82 mm,
which is shorter than softwoods (2.7-4.6 mm) and close to
minimum value of hardwood fibers (0.7- 1.6 mm) and
almost the same with wheat straw fibers (0.74 mm).
However, the fiber lengths of eucalyptus, rye, and tobacco
stalk are 1.28, 1.15 and 1.07, mm respectively (Table 2).
The fiber width of P. elongota was found as about 36.3
m which was in normal range when compared to
hardwoods fiber (approximately 20.0–40.0 m) (Atchison,
1987). The fiber wall thickness of P. elongota is also
higher than the other fibrous materials. The physical
properties of a pulp sheet are closely related to morpho-
logical properties of pulp fiber (Young, 1981).
The strength properties of the papers were found to
positively correlate with the felting coefficient (fiber
length/fiber diameter). It is stated that if felting coefficient
of a fibrous material is lower than 70, it is invaluable for
quality pulp and paper production (Young, 1981; Bektas
et al., 1999). The felting coefficient of P. elongota fibers
was found as 22.7. Whatsoever high felting coefficient
means lower strength properties. Some authors have a
different opinion because not only strength properties
depend on felting coefficient, but also cell wall thickness
(Erolu, 1998). As depend on the cell-wall thickness,
rigidity coefficient (cell wall thickness x 100/fiber width) is
one of the important parameter. Rigidity coefficient was
calculated as 23.7 for P. elongota wood. Higher rigidity
ratio gives lower paper strength properties especially
lower burst, tear and tensile indexes (Bektas et al., 1999).
Strength properties of P. elongota obtained from three
different chemical pulping processes confirms these
results (Table 3).
Related with this expression, another criterion is
elasticity coefficient (Istas et al., 1954) for evaluating fiber
quality (lumen width x 100/fiber width). We calculated the
elasticity coefficient as 52.9 for P. elongota fibers. Ac-
cording to Istas et al. (1954), if the elasticity coefficient is
between 50 and 70, this kind of fibers easily can be flat
and give good paper with high strength properties. So, P.
elongota fibers with short fiber length, thick cell wall and
large lumen width can be used for paper production after
mixing with long fibrous materials.
P. elongota wood was cooked by kraft-AQ, soda-AQ
and ethanol processes. Pulping conditions and results of
the characterization of unbleached pulp samples obtained
using three different methods, and of paper sheets made
from them are presented in Table 3. The conditions were
selected a series of pre-trial, just to evaluate P. elongota
wood as pulping raw material.
Ates et al. 4157
Table 3. Operation conditions used in the pulping of Paulownia elongota and results of the
characterization of unbleached pulp samples using three different methods and of paper sheets
made from them.
Parameter Kraft-AQ Soda-AQ Ethanol
Active alkali charge (%) 18 18 -
Sulphidity charge (%) 20 - -
Ethanol charge (%) - - 50
AQ (%) 0.1 0.1 -
Liquor to wood 6/1 6/1 8/1
Pulping time (Min.) 90 90 120
Pulping temp (oC) 160 160 180
Yield (%) 38.3 37.8 38.4
Kappa no 28.2 27.8 42.06
Viscosity (cP) 12.08 10.38 13.92
CSF 670 665 725
Bulk (cm³·g-¹) 2.15 2.13 1.90
Breaking length (km) 1.66 1.53 2.59
Brightness (%ISO) 21.83 24.03 32.86
Burst (kPa·m²·g-¹) 1.15 1.09 0.90
Tear (mN·m²·g-¹) 2.10 1.96 3.36
Coarseness (mg 100m-1) 10.5 10.5 14.6
Percent fines (0-0.2mm) 17.45 25.00 16.62
Curl Index 0.059 0.052 0.044
Kink Index 0.83 0.74 0.75
Fiber Length (mm) 0.450 0.427 0.508
Uncooked wood Kraft and Soda pulps E-OH Pulp
Strong acid (mmol·kg-¹) 370.1 356.7 333.3
Weak acid (mmol·kg-¹) 170.0 173.3 106.7
Total acid (mmol·kg-¹) 540.1 530.0 440.0
Table 3 showed that pulp yield in three processes were
lower for kraft-AQ, soda-AQ and ethanol pulps as 38.3,
37.8 and 38.4%, respectively, and kappa numbers were
little higher than other non-wood fibers. It can be ex-
plained with high amount of water and alkali solubility of
P. elongota wood (Table 1). At similar cooking conditions,
golpata fronds showed similar pulp yield and kappa
number (Jahan et al., 2006). Viscosity values were found
for kraft-AQ, soda-AQ and ethanol pulps as 12.08, 10.38
and 13.92 cp, respectively. The strength properties of P.
elongota wood for unbleached alkaline pulps are also
given in Table 3. The breaking length was higher than
that of pine and olive pulps (Jimenez et al., 1992). Burst
index for the kraft-AQ, soda-AQ and ethanol P. elongota
pulps (1.15, 1.09 and 0.90 kPa·m² g-1 respectively) are
comparable with the giant reed pulps obtained from
ethanol soda, ASAM, organacell and kraft pulping pro-
cess (1.42, 1.31, 1.08 and 0.96 kPa m2g-1 respectively).
Similar results for optimum P. fortunei organosolv pulp
were obtained by Caparro et al. (2008) as 38.4% yield,
46.9 kappa number, 27.4% ISO brightness, 28.87 Nm g-1
tensile index, 1.22 kPa m2 g-1 burst index and 1.23 kN m2
g-1 tear index.
Due to its higher content of fines and shorter average
fiber length, the soda-AQ pulp had lower breaking length
and tear index than the ethanol pulp. The reason is
probably the carbohydrates are being protected more
effectively against hydrolysis reactions in high alcoholic
environment (Akgul and Kirci, 2002) coupled with the
effect of the alkali in white liquor. Kraft-AQ pulp showed
similar characteristics with soda-AQ pulp. There is no
significant difference between the two alkaline pulps.
Table 3 also shows the acid groups bound to cell wall of
the P. elongota wood. The amount of acid groups on pulp
samples decreased after pulping process, decreasing
values for both soda-AQ and kraft-AQ pulps (from 540.1
to 530.0 mmol kg-1) obtained were the same. But in
ethanol pulping, the acid groups reduced rapidly after
pulping (from 540.1 to 440). The freeness (CSF) values of
the samples correct it. Acid groups in P. elongota wood
and pulp samples are extremely higher than wood (Hunt
et al., 2002). It can be concluded that, high amount of
total acid groups for P. elongota pulps do not significantly
affect the strength properties.
4158 Afr. J. Biotechnol.
The following conclusions may be drawn from this
investigation: The lignin, holocellulose and -cellulose in
P. elongota wood are comparable to hardwood and
common non-wood. P. elongota have substantially higher
water, alkali and alcohol-benzene solubility than that of
softwoods and hardwoods, which caused lower pulp yield.
P. elongota wood has lower amount of fiber and higher
content of short parenchyma cells. The pulp yields and
viscosities are lower and kappa numbers are higher than
some common wood and non wood raw materials. The
acid groups bound to cell wall decreased with chemical
pulping process. Ethanol process caused maximum
decrease on acid groups. P. elongota fibers have lower
felting coefficient and elasticity coefficient. Although these
kinds of fibers are considered as low quality materials, it
can be used for paper production when mixed with long
fibrous materials.
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... The biomass is often used for the production of industrial wood and paper. The presence of lignin, hemicelluloses, and high content of cellulose (Yadav et al. 2013) makes their timber comparable to that of hardwoods (Ates et al. 2008), considered to be suitable as solid biofuel. As a good source of energy, it is used to produce bioethanol and biogas (Skibko et al. 2021). ...
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Short-rotation woody plants of the genus Paulownia are attracting more and more attention as trees that produce biomass and reduce the concentration of carbon dioxide in the atmosphere. However, plants growing in monoculture affect the properties and condition of the soil. One of the effects of changes in the soil environment is the growing population of plant parasitic nematodes (PPN). The article presents information about the PPN inhabiting the root zone of the Paulownia tomentosa plantation in Poland. In this study, the frequency and density of nematode populations in samples from seven plantations in Poland were determined. The extracted nematodes were identified at the species level on the basis of the male and female morphological characteristics according to several available identification resources. A total of 20 nematode species were identified, of which 9 were classified as accessory and 11 as occasional. Among them, Trichodorus viruliferus and Longidorus attenuatus belonging to the group of viral messengers were identified.
... Its high cellulose content (47.85%) makes it useful for the pulp industry, as indicated by Popovic and Radosevic [109], who also, however, noted that the chemical composition differed between the various species. Similar relationships and the suitability of Paulownia for cellulose production have also been pointed out in other studies [110][111][112], whereas in later studies, the biorefinery of paulownia wood has been improved in order to obtain lignocellulosic biomass for fuels, solvents and chemicals, etc. [113]. Due to paulownia wood's short production cycles, both the stem and branch wood can be used, although the latter is of lower value and is often accompanied by reaction wood; however, this can be used in paper, nanocellulose, charcoal and other applications [82,114,115]. ...
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This review aimed to determine the current state of research on the growth conditions and use pertaining to paulownia wood, mainly in European countries where paulownia has been introduced only relatively recently. Several studies carried out on Paulownia hybrids have shown significant differences in the growth dynamics of individual clones in their response to local environmental and climatic conditions. For example, dry biomass production yields in the second year of cultivation range from 1.5 t ha−1 to as much as 14 t ha−1. This diversity has manifested itself not only in growth characteristics but also in the properties of the wood and the possibilities for its use. Despite having clear similarities to the genus Paulownia, the cultivation of species and hybrids under different conditions has produced varying results. The best growing conditions for this wood (that make economic sense) are in the Middle East and Southern Europe. These regions have accumulated the most experience because of the earlier establishment of the crop. Today, paulownia cultivation is dominated by hybrids with selected traits that are propagated mainly in vitro. The most commonly planted hybrids include the clones in vitro 112, Cotevisa 2 and Shan Tong. The growth results and production capacity in central European countries are lower compared to Southern Europe. Experiments on paulownia cultivation are still relatively young, mainly consisting of replicating the cultivation of hybrids developed in Asia or Southern Europe. However, agronomic procedures are being developed and reactions to local climatic conditions are being studied. It is likely that, in the next few years, the profitability of growing paulownia in these regions will become apparent.
... On the other side, as known Paulownia spp. is a fast growing woody crops is a very important source for the generation of the bioenergetics biomass, and which multiple values and high adaptability with climate conditions (Icka et al., 2016). Each paulownia tree after (5 to 7) years old can generate 1 m 3 timber in a surface with density of (2000 plants/ha), offering a total production of (330 t/ha), (Ates et al., 2008). However, in 1974 the trees had grown with average dbh of 30.1 cm, 13.5 m height, 0.3927 m 3 individual timber volume with 400 trees per hectare totaling 153.2 m 3 /timber volume/ha (Rao, 1986). ...
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This work was carried out from 15 July 2021 in Grdarasha Field, College of Agricultural Engineering Sciences, Salahaddin University-Erbil. It aims to show the impact of using kenaf fibers as alternative materials in manufacturing. Global climate change and environment pollution cause to do this kind of researching. Kenaf (Hibiscus cannabinus L.) is a fast growing natural crops, belongs to the Malvaceae family. It is an industrial crop has high potential for cultivation in a tropical climate and also which resistance to various soil types and climate. Selecting the raw materials for industrial applications is more important. Actually, kenaf fibers have many advantages to use in wade range of applications, also it's fibers not just a part of plant useful as raw material but also leaves and seeds have many other advantages and uses. The results show that there is a significant between varieties on growth and fiber yield properties. The highest plant high was of FH952 by (368.33 cm), while the best values of total fresh and dry stem yields were found of HC2 and V36, by almost (219.33 and 60.93 t/ha), respectively. Providing these results through kenaf plant could be considered as substitute materials for timber and other biocomposite manufactures, and also it causes to safe environment by absorption optimal value of carbon dioxide (CO2), then cutting of woodland trees will be decreased. Finally recommended to cultivation fiber crops (kenaf) globally to conserve environment.
... The acceptable Slenderness Ratio for papermaking must be greater than 33 (Xu et al. 2006). Fibers with Slenderness Ratio >70 are considered to produce a good quality paper (Ates et al. 2008). The Slenderness Ratios of the materials used in this study were all above 33, which indicates that papers produced with them would be acceptable. ...
Non-wood fibers are projected as fast-growing resources and sustainable alternate materials to reduce deforestation and enhance efficiency in the pulp and paper industry. This paper addressed the paucity of data on the fiber morphological characteristics (Fiber Length, Diameter, Lumen Diameter, and Wall Thickness) and pulping properties (Slenderness Ratio, Rigidity Coefficient, Flexibility Coefficient, Runkel Ratio, Solids Factor, and Luce’s Shape Factor) for Silk Cotton, leaves and stalk of Elephant Grass and Sugarcane Bagasse found in Ghana, especially, as environmental variations may cause differences in regional data. Observed values for the studied parameters were within the suitable range for paper production and differed from those reported for other regions. Elephant Grass (stalk) and Bagasse that had higher values of Fiber Length (4101.42 ± 197.89 and 3960.20 ± 194.35 µm), Diameter (60.03 ± 1.82 and 59.85 ± 1.72 µm), Lumen Diameter (33.33 ± 1.76 and 35.97 ± 1.38 µm), Wall Thickness (13.35 ± 0.83 and 11.94 ± 0.55 µm), Slenderness Ratio (70.8 ± 4.2 and 67.2 ± 3.4), and Flexibility Coefficient (55.7 ± 2.3 and 55.7 ± 2.3) would perform better during paper production. They would exhibit good physico-mechanical properties suitable for manufacturing flexible, high tearing, elastic, dense, smooth, and well-formed papers with high tensile and bursting strengths. Silk Cotton may also produce good papers with low tearing index, well-bonded, rigid, bulky, and coarse textured.
... The strength properties of the papers are positively correlated with the slenderness ratio of fibers (Ates et al. 2008). A slenderness ratio greater than 33 means that fibrous material is suitable for papermaking (Xu et al., 2006). ...
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Many studies have been reported on the fiber morphology of stem wood and pruning residues of fruit trees. This chapter reviews the literature on the fiber morphology of stem or pruning residues from 26 fruit trees.
... Comparing to the woody materials, holocellulose content in M. oleifera SRRP was lower than the amount presented in Paulownia elongota wood (75.74%) 69 , Pinus pinaster wood (69.6%) 63 , Albizia lebbeck wood (78.60%) 70 , Eucalyptus globulus wood (80.5%) 63 , Acer rubrum wood (67.4%) 71 , Leucaena diversifolia wood (77.9%) 63 , and depithed Bagasse (72.38%) 72 . While it was higher than from those of Prosopis alba wood (63.6%) 63 , E. camaldulensis wood (56%) and Meryta sinclairii wood-branch (61%) 25 , and woods from Bougainvillea spectabilis (54.56%), ...
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In the present study, and for the waste valorization, Moringa oleifera seeds-removed ripened pods (SRRP) were used for papersheet production and for the extraction of bioactive compounds. Fibers were characterized by SEM-EDX patterns, while the phytoconstituents in ethanol extract was analyzed by HPLC. The inhibition percentage of fungal mycelial growth (IFMG) of the treated Melia azedarach wood with M. oleifera SRRP extract at the concentrations of 10,000, 20,000, and 30,000 µg/ mL against the growth of Rhizoctonia solani and Fusarium culmorum was calculated and compared with fluconazole (25 µg). The produced papersheet was treated with the ethanol extract (4000, 2000, and 1000 µg/mL) and assayed for its antibacterial activity against Agrobacterium tumefaciens, Erwinia amylovora, and Pectobacterium atrosepticum by measuring the inhibition zones and minimum inhibitory concentrations (MICs). According to chemical analysis of M. oleifera SRRP, benzene:alcohol extractives, holocellulose, lignin, and ash contents were 7.56, 64.94, 25.66 and 1.53%, respectively, while for the produced unbleached pulp, the screen pulp yield and the Kappa number were 39% and 25, respectively. The produced papersheet showed tensile index, tear index, burst index, and double fold number values of 58.8 N m/g, 3.38 mN m 2 /g, 3.86 kPa m 2 /g, and 10.66, respectively. SEM examination showed that the average fiber diameter was 16.39 µm, and the mass average of for elemental composition of C and O by EDX were, 44.21%, and 55.79%, respectively. The main phytoconstituents in the extract (mg/100 g extract) by HPLC were vanillic acid (5053.49), benzoic acid (262.98), naringenin (133.02), chlorogenic acid (66.16), and myricetin (56.27). After 14 days of incubation, M. oleifera SRRP extract-wood treated showed good IFMG against R. solani (36.88%) and F. culmorum (51.66%) compared to fluconazole, where it observed 42.96% and 53.70%, respectively. Moderate to significant antibacterial activity was found, where the minimum inhibitory concentration (MIC) values were 500, 650, and 250 µg/mL against the growth of A. tumefaciens, E. amylovora, and P. atrosepticum respectively, which were lower than the positive control used (Tobramycin 10 µg/disc). In conclusion, M. oleifera SRRP showed promising properties as a raw material for pulp and paper production as well as for the extraction of bioactive compounds. Moringa oleifera Lam. (family Moringaceae) is a fast-growing and drought-resistant tree, native to the Indian subcontinent with multipurpose uses 1. Fruits of Moringa are three-sided pods with pendulous and linear shape, also, the pod generally has 250-450 mm long contains approximately 20 globular seeds 2. From the literature survey, all the works are concentrated in how to use leaves, flowers, pods and roots of Moringa in different OPEN
... Even though it is paper detailing the genetics of the species, the authors' contributions are an attempt to create a species resistant to temperatures below -30 °C, with the aim of acclimatizing it in temperate areas with low temperatures during the winter. Ashori and Nourbakhsh (2009) and Ates et al. (2008) analyzed the use of Paulownia wood in the pulp and paper field. The superior qualitative indices of the anatomical elements make this species better than other deciduous species, through the superior strength properties of the obtained paper. ...
Sawdust specimens of two Paulownia species, namely Paulownia tomentosa and Paulownia elongata, were evaluated in order to obtain briquettes and pellets. Briquettes and pellets were manufactured from the sawdust, and their physical properties (density), mechanical properties (the resistance of the briquettes to breaking, and the shear resistance of the pellets), and energetic properties (caloric value, black ash content, and calcined ash content) were determined. The densities of the P. elongata and P. tomentosa briquettes were 790 kg/m3 and 934 kg/m3, respectively, while the pellets had densities of 1268 kg/m3 and 1266 kg/m3, respectively. These values were within the standardized limits, and the ash content had good values. The high calorific value of 16815 kJ/kg and the low calorific value of 16669 kJ/kg was acceptable, since they were greater than other vegetable resources. In conclusion, it was found that the two types of wood biomass are suitable for the production of briquettes and pellets, due to their good physical, mechanical, and energetic properties.
... Therefore, when the wood comes into contact with the metal salt solution under sunlight irradiation, the metal ions will be pumped out from the bottom of the solution and diffused in the middle channel, and reduced to metal nanoparticles by lignin. Paulownia is a kind of fastgrowing wood, which is distributed in various regions of China (Ates et al. 2008). It is a natural material with honeycomb units, high strength/stiffness weight ratio and high grade value (Janjić and Janjić, 2019). ...
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Wood has a natural three-dimensional porous structure. As one main component of wood, lignin is rich in a variety of reducing functional groups which can in situ reduce Au (III) into Au (0). Through this efficient, green and convenient method, gold nanoparticles (Au NPs) were generated and anchored in Paulownia Sieb. et Zucc. Chip to fabricate an Au NP/Wood membrane reactor. The characterization of Au NP/Wood by SEM, XRD and XPS showed that Au NPs were uniformly dispersed in wood. The catalytic capacity of the reactor for the reduction of methylene blue (MB) and 4-nitrophenol (4-NP) were evaluated. The Au NP/Wood exhibited the substantial catalytic capacity and the reaction rate constants were 0.162 min⁻¹ and 0.152 min⁻¹, respectively. As the filter membrane, the flowing catalytic capacity investigation revealed that the hydrogenation of MB and 4-NP was over 98% as the flux was 0.973 × 10³ L/m²·h. Even after eight cycles, the catalytic capacity of the membrane slightly decreased, while the hydrogenation still remained above 90%. This green synthetic Au NP/Wood has proved to be a viable and potential material for the treatment of dyes and nitroaromatic pollutants, in addition, using wood as a feedstock provides a sustainable feature of this work.
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The effects of CH3COOH and Na2SO3 pretreatment on the structural properties and hydrolyzability of fast-growing Paulownia elongate were investigated. Acetic acid increased cellulose’s crystallinity and hydrolyzability when combined with alkaline sodium sulfite and sodium hydroxide. The cellulose content increased by 21%, the lignin content decreased by 6%, and the product showed better enzymatic digestibility. With a cellulase dose of 30 FPU/g DM, after 72 h hydrolysis, the hydrolysis yields of glucose and xylose were 78% and 83%, respectively, which were 51% and 69% higher than those of untreated materials. When the enzyme dosage was 20 FPU/g DM, after 72 h hydrolysis, the hydrolysis yields of glucose and xylose were 74% and 79%, respectively. The high hydrolyzability, low enzyme loading, and high hydrolysis yield demonstrate the potential of the proposed system for producing platform sugars from fast-growing Paulownia elongate.
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The main objective of this study was to assess the growth of the established Paulownia cotevisa plantation during an extended time period and compare it with values reviewed in the literature. Seven years after planting, mean diameter at breast height and height of the aboveground part of P. cotevisa 2<sup>®</sup> (P. cotevisa) plantation were similar to values reported in the literature and they reached 21.5 cm and 11.2 m, respectively. Besides the crown damage caused by wind, development of the P. cotevisa plantation established in the Danubian Lowland was not affected by any other harmful environmental factor or biological pest. The results suggest that P. cotevisa could be used to a larger extent in diversification of biomass production on abandoned arable lands of the Danubian Lowland.
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In this study, carefully selected test materials were taken from calabrian pines growing naturally in Turkey. The aim of this research is was determine the morphological properties of the wood fiber of the Calabrian pine and the suitability of these properties for pulping. Twenty sample trees were collected from 5 different regions (Suçati- Kahramanmaraş, Edremit - Balikesir, Kemalpaşa - İzmir, Yilanli - Muǧla and Melli (Bucak) - Burdur) The test samples were taken from tree stems at a height of 2.30 m. In these tests, fibre length . fibre diameter, lumen dia and cell wall thickness were measured. The felting rate, elasticity coefficient, rigidity coefficient, Runkel classification. Muhlstep classification and F ratio were calculated from the wood fiber morphological properties and the effects of these properties on pulp strength properties were investigated. According to the results of this study, it was found that the Calabrian pine is quite suitable for pulping.
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The objective of this study was to determine some of the properties of experimental particleboard panels made from low-quality paulownia (Paulownia tomentosa). Chemical properties including holocellulose, cellulose, lignin contents, water solubility, and pH level of the wood were also analyzed. Three-layer experimental panels were manufactured with two density levels using urea–formaldehyde as a binder. Modulus of elasticity (MOE), modulus of rupture (MOR), internal bond strength (IB), screw-holding strength, thickness swelling, and surface roughness of the specimens were evaluated. Panels with densities of 0.65 g/cm3 and manufactured using a 7-min press time resulted in higher mechanical properties than those of made with densities of 0.55 g/cm3 and press times of 5 min. Based on the initial findings of this study, it appears that higher values of solubility and lignin content of the raw material contributed to better physical and mechanical properties of the experimental panels. All types of strength characteristics of the samples manufactured from underutilized low-quality paulownia wood met the minimum strength requirements of the European Standards for general uses.
Paulownia fortunei is a fast growing tree species; native to china and belongs to the family Scruphulariacea. It is a promising tree species for plantation as pulp wood. The proximate chemical analysis, pulping, papermaking and fibre characteristics of Paulownia fortunei is discussed in the paper and its comparison with Dendrocalamus strictus, Eucalyptus tereticornis and Populus deltoides are also discussed. The proximate chemical analysis of P. fortunei reveals that holocellulose content is 69.56% whereas in E. tereticornis it is 70.10%, in P. deltoides 75.10% and D.strictus 62.20%. The lignin content is 28.0% and it is found little higher than other two pulpwoods and bamboo. The average fibre length of P. fortunei is 1.42 mm, which is more than P.deltoides but lesser than E. tereticornis and D.strictus. The average fibre diameter of P. fortunei is 0.030 mm, which is more than other species from which its comparison is discussed. Kraft pulping with 14% total chemicals as Na2O, P, fortunei gave 51.0% pulp yield and Kappa number 25.00. On comparison with E. tereticornis and P. Deltoides under same chemical charge and cooking conditions the pulp yield obtained in case of E. tereticornis is 49.63% and for P. deltoides is 54.60% The Kappa numbers obtained (32.7-46.6) were much higher as compared to P. fortunei. The tensile index, burst index and tear index of P. fortunei were 106.12 Nm/g, 6.47 kPam2/g and 2.67 mNm2g respectively. It was observed that physical strength properties of unbleached pulp from P. fortunei compares well with the other three most widely used raw materials for pulp manufacture viz. D. strictus, E. tereticornis and P.deltoides.
Biopulping, the process of pretreating chips with fungus before mechanical pulping, results in significant energy savings and improved sheet strength. It has been assumed that biopulping fungi cause these changes by enzymatic depolymerization of lignin. This work presents constituent sugar analyses and titrations that suggest hydroxyl radicals may be used by Ceriporiopsis subvermispora to accomplish biopulping. Increases in acid groups within the fiber account for some of the property improvements observed in biopulped fiber.
The possibilities of dissolving grade pulp production from poplar by an ethanol-water process were investigated. The effects of ethanol ratio, cooking temperature and acid catalyst ratio on unbleached, bleached and alkali-purified pulps were studied. It was seen that catalyst ratios exceeding 0.01% caused serious yield and viscosity losses. The results showed that with the catalyst ratio to pulping liquor exceeding 0.01%. pulp yield and viscosity were reduced to an unacceptable level. The best pulping result was obtained at 40% ethanol consistency, 180°C pulping temperature and 150 min reaction time without the addition of acid catalyst to the pulping liquor. After bleaching and alkali purification, the pulp obtained had a 30.7% yield. 95.8% α-cellulose content, 677 cm3/g viscosity, 83% ISO brightness, 1.80% residual pentosans, 0.33% copper number and 0.14% ash content. However, brightness was increased to 88.5% ISO level with the application of a multistage bleaching (CEHDED) sequence instead of chlorite bleaching without serious losses in yield or α-cellulose content at normal viscosity levels. It is concluded that these pulps meet dissolving grade pulp quality requirements.
This study investigates the change in chemical and crystalline structure of pulp samples during alkali sulfite process at different cooking temperatures and time, TAPPI and SCAN standard test methods and X-ray diffraction and FT-IR spectroscopy were used. It was shown that the crystalline structure of cellulose in hemp (Cannabis sativa L.) bast fibers was very strong and stable. Crystallinity of alkali sulfite pulp samples obtained from processing at 140 up to 180°C increased, but then decreased at 200°C. The crystallite size of cellulose in alkali sulfite pulp samples increased with cooking temperature. The crystalline allomorph of cellulose in alkali sulfite pulp samples obtained at 200°C changed from monoclinic structure to triclinic structure. Crystalline structure of cellulose in alkali sulfite pulp samples was little affected by changing cooking time. It was concluded that cooking temperature during alkaline sulfite pulping process had more effect on carbohydrate components and crystalline structure of pulp samples than cooking time.
SUMMARY The axial variation of bark thickness and quantitative anatomical fea- tures of Eucalyptus globulus bark were analysed for one site based on individual measurements of ten 15-year-old trees at six height levels (DBH, 5%, 15%, 35%, 55% and 75% of total tree height). The param- eters studied were: length, tangential diameter and percentage of sieve tubes; length, width, cell wall thickness and percentage of fibres; height and percentage of rays; percentage of sclereids in the secondary phloem. Bark thickness decreases from base to top of the tree. Fibre width and wall thickness decrease from base upwards. No distinct axial patterns of variation were observed for the other biometric variables studied. Parenchyma is the main cell type of the bark (50%) followed by fibres (27.9%), rays (12.1%), sieve tubes (2.7%), and sclereids (7.3%). The cell type proportions vary significantly within the tree, i.e., parenchyma, ray and sclereid proportions decrease, fibre and sieve tube proportions increase towards the top of the tree.