Second Generation Torrefied Pellets for Sustainable Biomass Export from
Colombia
1. Context and reasons to start the project:
Colombia, being one of the most bio diverse countries in the world, is the 2nd biofuel
producer in Latin-America, with a rapidly growing agro-industry focusing on a local and a
worldwide biofuels market. This growing market needs to focus on sustainable biofuel
production which can improve both the competitiveness and social conditions for the
rural population as well as avoiding damage to vulnerable ecosystems. Bamboo, is a very
good carbon fixator, an erosion controller, and a water and biodiversity preserver.
Bamboo is also seen as a material with huge potential for poverty alleviation and
livelihood development in producing countries. As a resource it may total more than 36
million hectares worldwide. From these, 65% are in Asia, 28% in America and 7% in
Africa (Lobovic, 2007).
Bamboo has the potential to be a sustainable biomass source for renewable heat and
power production(Daza C.M., 2011). Bamboo shares a number of desirable fuel
characteristics with certain other bioenergy feedstocks. Its heating value can be higher
than many woody biomass feedstocks and most of agricultural residues, grasses and
straws. The use of bamboo replacing coal and charcoal for (domestic) heating is a
common practice in some producing countries. However the use of bamboo for power
generation is very limited, or even non-existent.
It is expected that clean woody biomass, extensively used today as the main biomass
source, will be phased out from the power industry and used as the feedstock for secondand third-generation biofuels because this is a product with a higher value than heat and
power. Therefore, there is a growing interest in the application of alternative feedstocks,
for both power generation and the production of transportation fuels.
In general biomass is a difficult fuel, it is tenacious and fibrous which makes it difficult
and expensive to grind. With torrefaction biomass becomes easy to grind, water resistant
and has a higher energy density. This results in energy savings in the operation of a cofiring power plant (i.e. the initial market aimed for) and reduced transport costs and
savings on transport related emissions. The torrefaction technology is therefore very
suitable for preliminary treatment of biomass in export countries.
Bamboo could fit in a long term vision for innovation and technology development for the
import of sustainable biomass to e.g. the Netherlands, ensuring a maximization of the
biomass share in the Dutch energy production sector. In order to simplify biomass
import, biomass upgrading, pre-treatment and feeding technologies will be optimized,
with torrefaction already in the stage of demonstration.
1
Technical, economic as well as sustainability issues within the overall supply chain of
bamboo; from cultivation and collection (in Colombia), to upgrading and transport, and
end use in the (Dutch) energy sector are however not yet assessed.
The technical issues related to the pre-treatment and final fuel application are of high
importance in the assessment of the complete chain. The ultimate goal of the technical
assessment is to address the suitability and options to adapt this promising fuel to the
existing power industry. This requires in-depth knowledge of the fuel behaviour in
thermal conversion systems as well as optimum pre-treatment conditions and
techniques. Exploratory and conclusive experimental work is required to tackle technical
aspects using any novel biomass fuel in the heat and especially the power industry.
The increased use of biomass for biofuels and bioproducts may produce conflicts as well
as synergies between socio-economic and environmental impacts, especially in
developing countries. The need for standards, as regards sustainability concerns, has
become more evident. This means that it needs to be ensured that any particular
production system is environmentally, socially and economically sustainable. It should
furthermore contribute to the reduction of greenhouse gases (GHG), not create negative
environmental and socio-economic impacts and contribute to positive social impacts.
2. Objectives of the project:
The primary goal of the project is to assess the techno-economic potential as well as the
sustainability of torrefied bamboo pellets import from Colombia to the Netherlands. The
assessment of the complete chain covers biomass cultivation & collection, the upgrading
via torrefaction in Colombia for the export of torrefied bamboo pellets, and the en use as
solid fuel in The Netherlands for electricity generation.
Figure 1. Biomass supply chain
The overall project targets are:



Collection of data of bamboo resources potential in Colombia
To assess the technical suitability of torrefaction and co-firing of torrefied
bamboo pellets for the Dutch power sector.
To assess the sustainability of the biomass chain.
2

Overall techno-economic assessment of the import of torrefied bamboo pellets
at the port of Rotterdam.
The generated knowledge and monitoring capacity aim to contribute to counteract the
undesired effects of biomass production for energy purposes and to promote sustainable
development.
3. Activities undertaken in the project:
The project combined the knowledge and expertise of ECN and three project partners,
assessing the whole chain of bamboo cultivation and collection via torrefaction upgrading
to application as biofuel. The project had a multidisciplinary structure, with the
Colombian partners: the Technological University of Pereira and the Colombian Bamboo
Society playing a key role in providing and collecting essential information as experts on
bamboo issues. The European partners, the Energy research Centre of the Netherlands
and Imperial College Consultants provided technology development and sustainability
assessment.
The performed activities were:




Data collection on bamboo availability and logistics
Torrefaction, co firing and gasification tests to assess the performance of
bamboo as energy source
Sustainability assessment
Techno economic evaluation of the import of torrefied bamboo pellets to
Europe via the port of Rotterdam
4. Results of the project
a. Bamboo species selection and potential in Colombia
An overview is generated for the national and regional potential of bamboo production
and a base case study area has been selected (Figure 3). The base case study area is
the coffee region in Colombia and specifically there 5 farms and one organization are FSC
certified (forest management certification (FSC) specific standard for Guadua stands) .
The experiences (data available, barriers and opportunities) of the certified farms were
taken as a base case for the project.
In Colombia more than 100 bamboo species have been registered. From these some
species (native and exotic) might have potential as biomass source. A selection among
these is presented in Table 1. The selection criteria included: biomass productivity,
growth site characteristics that include all climate zones (e.g. height above mean sea
level (amsl), topography, annual rainfall regime). A detailed description of species
properties is presented in (Daza, 2013).
Table 1: Selected bamboo species
Native (N)
Exotic (E)
N
N
N
E
E
Selected species
Guadua angustifolia Kunth
Guadua amplexifolia Presl.
Chusquea subulata L.G. Clark
Bambusa vulgaris var. vulgaris
Dendrocalamus strictus
3
Altitude amsl
900-1600
0-800
2200-2800
0-1500
0-800
Most of available information relates to the bamboo species Guadua angustifolia Kunth,
as it is the most utilized and abundant in the country. Guadua angustifolia is a woody
bamboo species, which is native to Latin America, particularly the regions of Colombia
and Ecuador, although it grows in other regions. G. angustifolia is considered to be one
the three largest species of bamboo and one of the 20th most used worldwide. For G.
angustifolia, up to 21 cm daily growth in height has been observed, so that it reaches its
maximum height (15 - 30 meters) in the first six months of growth and can be harvested
after 4 to 5 years. This growth is rarely surpassed by the native timber species of the
region. If handled properly, Guadua may have an unlimited production once it has been
established, without a great deal of care. (Guadua Bamboo, 2012). In Colombia and
particularly in the coffee region, G. angustifolia represents an important natural resource
traditionally used by farmers to build long-lived products such as houses, furniture,
handicrafts, veneers and flooring (Camargo, Moreno& Villota, 2010). A significant amount
of it is not suitable for manufacturing products and is available from processing sites and
from forest resource management. These residues could be used for bioenergy
production, providing a potential economic use for this material.
In Colombia, only 5% of Guadua forests are under correct management mainly due to
the lack of market opportunities.
Figure 2 Guadua angustifolia (Guadua pict source (Hidalgo, 1981))
Figure 3 Case study location (Coffee region) and biomass source cases
4
The estimation of bamboo (Guadua) potential production is based on two scenarios:
 Use of bamboo residues resulting from: a)processing sites, b)forests and plantations
management.
 Bamboo from a dedicated energy crop.
The scenario of residual streams excludes the material which has been chemically pretreated for preservation, as is the common practice in bamboo processing for furniture
production. Therefore the most suitable residual material is that from forest/plantations
residues. The plant section most suitable for solid fuel production is the lower part of the
culm, see Figure 2. Leaves and branches are usually left on the field for nutrients
recycling and their physicochemical properties are less favourable for pellets production
for the energy market.
The estimated potential production of Guadua angustifolia in the coffee region, is
between 600 kTon/year to 1,800 kTon/year. The potential in other regions and at
national level is unknown, therefore detailed studies are required.
b. Bamboo properties and characteristics
Bamboo presents common characteristics with many other biomass feedstocks regarding
heating value and chemical composition (Daza C.M., 2011). Literature presents a wide
range of biomass fractions. Typical ranges are listed in Table 2 and are compared with
other alternative feedstocks. Bamboo presents superior properties such as high yields
and biomass density which would result in positive impacts on production and transport
costs.
Table 2: Biomass properties
Feedstock
HHV (dry)
MJ/kg
3
Density
kg/m
Yield
Ton dwt/Hayear
Bamboo
culm
17-20
Cane
Bagasse*
18-20
Wheat
straw*
16-19
Wood
500-700
150-200
160-300
20-40
7-10
6-12
200500
10-20
17-20
Overall composition (dwt %)
Cellulose
40-60
35
38
50
Hemicellulose
20-30
25
36
23
Lignin
20-40
20
16
22
2-10
20
10
5
Others**
* Data is taken from (Brown, 2003). **Includes proteins, oils, minerals matter such as silica and alkali
As a biomass resource it has the potential as a lignocellulosic feedstock not only for the
energy, but also for the chemicals and materials sector, for the development of sugars
and lignin based biorefineries. In terms of overall techno-environmental performance, it
has potential advantages over other lignocellulosic feedstocks (e.g. straw) as it doesn’t
require the production of seeds, neither the use of plastics for baling, and require low (or
none) fertilizers application (LignoValue project consortium, 2011).
The overall biochemical composition varies according to the species and plant maturity
stage as shown in Figure 4. Therefore end use applications define the appropriate
harvesting time.
5
New shot
Guadua
angustifolia
Maturity stage vs time
0
1
Overmature
Mature
Young
2
3
4
5
6
7
8
Dry
9
10
11
Year
Major components
End Use
Celullose
Hemicellulose
Biorefining
Lignin
Construction
Fuel
Figure 4. Guadua angustifolia maturity stages vs. major components and
potential applications (Daza C.M., 2013a)
The selected bamboo species were subjected to ultimate, proximate and ash analyses.
Detailed compositions are shown in Table 3.
Table 3: Proximate and ultimate analyses of selected bamboo species compared with other biomass
feedstocks
Bamboo/
other
Guadua
angustifolia
Guadua
amplexifolia
Bambusa
strictus
Bambusa
vulgaris
Chusquea
subulata
Wheat
straw
Wood
Willow
Age (years)
Volatiles
HHV
(KJ/kg)
5
74
18351
NA
74
18781
NA
75
18728
NA
76
19050
NA
74
18557
NA
71
16570
NA
81
19350
ash @
815°C
C
H
N
O
S
Cl
4.9
7.8
1.5
47.00
5.90
0.70
42.00
0.07
0.11
43.82
5.28
0.42
43.31
0.11
0.27
44.70
5.70
0.20
46.15
3.00
0.01
Si
Na
K
Cl
S
As
Cd
Cr
Cu
Pb
Zn
P
Mg
Al
Ca
Ti
Mn
Fe
Sr
Ba
16453.0
6.3
10684.0
1086.0
736.0
< 1.4
< 0.1
1.1
2.6
< 0.6
8.0
869.0
253.0
8.5
260.0
0.5
2.6
16.0
2.1
2.4
20271.0
48.3
15466.0
2682.0
1100.0
1.0
0.3
4.7
3.7
0.0
28.7
1030.0
642.0
109.9
2282.0
1.4
28.1
114.6
8.2
42.2
69.1
127.2
1420.0
100.0
30000.0
0.7
1.9
2.1
3.1
1.9
61.8
651.0
378.0
18.9
3899.0
2.1
12.0
30.0
14.4
1.2
Proximate & ultimate (% mass, dry fuel)
3.8
5.6
2.7
6.9
47.00
47.00
48.00
46.10
6.00
5.90
6.10
5.40
0.80
1.20
0.60
0.80
43.00
41.00
43.00
42.20
0.19
0.16
0.05
0.13
0.09
0.04
0.02
0.12
Ash composition (mg/kg fuel, dry fuel)
6209.0
11.8
16402.0
859.0
1861.0
< 1.4
< 0.1
1.1
3.0
< 0.6
22.3
1283.0
290.0
13.0
380.0
0.6
7.4
20.2
1.7
1.2
21105.0
13.5
3656.0
438.0
1579.0
< 1.4
0.1
1.3
5.4
< 0.6
32.7
1786.0
1617.0
5.0
346.0
0.3
7.0
21.7
1.0
0.9
7570.0
5.0
6907.0
213.0
548.0
< 1.4
< 0.1
1.0
2.2
< 0.6
7.5
892.0
225.0
5.9
215.0
0.5
4.2
16.5
0.6
0.7
20259.6
13.5
7158.4
1205.0
1283.0
< 1.4
< 0.1
3.0
9.5
2.1
31.6
2766.2
481.9
20.8
379.5
1.2
8.9
53.7
4.8
2.9
In general, the bamboo composition presents critical fuel properties such as high alkali
metal content which requires special attention regarding processing and combustion
equipment.
6
c. Technical assessment
Bamboo is a difficult fuel and most thermal conversion processes have stringent fuel
specifications, which are challenging to fulfil with biomass streams. Bamboo is tenacious
and fibrous which makes it difficult and expensive to grind. Furthermore, the
characteristics with regard to handling, storage and degradability are not favourable for
biomass in general. The thermal pre-treatment torrefaction is a promising upgrading
technology that can enhance the fuel quality by addressing these issues.
Up to date, there are no studies on the use of the bamboo species Guadua angustifolia in
the heat and power sector. Issues such as pre-treatment options, as well as slagging and
fouling under standard power plant conditions have to be studied and evaluated for a
novel biofuel. Innovative sampling equipment has been applied for this work. An
evaluation of G. angustifolia samples took place based on its composition and physical
characteristics. The samples were first subjected to ultimate and proximate analyses, and
subsequently they were subjected to ECNs dry moving bed and wet (Torwash)
torrefaction technologies. Complementary, lab scale firing , co-firing and gasification
experiments were performed. As for the other selected bamboo species those were only
subject to chemical analyses (as presented in Table 3).
Torrefaction
During torrefaction, biomass is heated to 250-320°C in the absence of oxygen. At the
end of the process the material is milled and compressed into pellets. In this way, the
biomass becomes easy to grind, water resistant and has a high energy density. From the
dry biomass fed into the process, typically 70 wt.% is retained as a solid product,
representing 90% of the original energy content.
M = mass unit
Torrefaction
gases
E = energy unit
0.3M 0.1E
Biomass
Torrefied
biomass
Torrefaction
250-300°C
1.0M
1.0E
0.7M 0.9E
Figure 5: Typical mass and energy balance for torrefaction
Figure 5 illustrates one of the main characteristics of the process, being the high
retention of the chemical energy from the feedstock in the torrefied product, whilst fuel
properties such as density and grindability of the final product are improved.
Alternatively, wet torrefaction (Torwash) allows for combined torrefaction and washing of
the feedstock. Wet torrefaction, a form of hydro-thermal treatment, in addition to dry
torrefaction removes salts and minerals from biomass, improving even more the quality
of the product. This is in particular interesting for feedstocks like bamboo that contains
significant amounts of undesirable alkali and/or chlorine components that affect
combustion or gasification. With alkali and chlorine removal, corrosion and bed
agglomeration caused by high salt content during the combustion process are
substantially diminished.
Samples of Guadua angustifolia were received from a FSC certified plantation in
Colombia. The harvested Guadua was 3 and 5 years old. The 5 year samples were
subjected to Torwash experiments in a 20 l autoclave under elevated pressure and
200oC. The 3 and 5 year samples were subjected to Torrefaction experiments at
7
temperatures of 240, 255 and 270 oC. Table 4 shows the results from the product
characterization as the chemical composition of the material defines the fuel quality.
(Detail results data is presented by (Daza, 2013))
Table 4. Fuel analysis of raw and pre-treated Guadua angustifolia
Age
(years)
Material
5 years
Mature
Raw
Torwashed
Torrefied
240oC
255 oC
Raw
270 oC
3 years
Young
Torrefied
240 oC
255 oC
4,6
5,6
Proximate &ultimate (% mass, dry fuel)
Ash @
815°C
Volatiles
4,7
4,5
7,0
6,1
6,3
3,7
77
76
69
68
65
77
72
68
HHV
(KJ/kg)
18676
20000
19776
20504
21012
18631
20135
20811
C
46,50
50,00
49,00
50,00
51,50
46,50
48,00
51,00
H
5,90
5,80
5,60
5,60
5,55
5,95
5,60
5,60
N
0,33
0,27
0,41
0,37
0,35
0,24
0,24
0,26
O
43,00
ND
38,00
37,00
35,00
44,00
40,00
37,00
S
0,09
0,03
0,07
0,07
0,07
0,05
0,04
0,05
Cl
0,14
0,01
0,12
0,14
0,11
0,06
0,05
0,07
16260
19330
Ash composition (mg/kg fuel, dry fuel)
Si
13492
20000
25079
22921
22015
12005
Na
3,4
29,0
5,4
3,0
3,1
3,7
2,7
4,0
K
10539
510
10266
8868
10525
6401
6096
7530
Cl
1362
120
1150
1377
1130
1150
548
1150
S
868
260
691
714
705
492
447
509
As
<0,68
<0,68
<0,68
<0,68
<0,68
<0,68
<0,68
<0,68
Cd
<0,05
<0,05
0,05
<0,05
<0,05
<0,05
<0,05
<0,05
Cr
1,4
1,3
0,8
0,7
0,8
0,6
0,6
0,5
Cu
2,2
5,8
1,2
1,5
1,9
1,6
1,9
2,2
Pb
<0,24
0,33
<0,24
<0,24
<0,24
<0,24
<0,24
<0,24
Zn
5,2
2,7
8,6
2,6
4,3
3,4
3,6
4,5
Others1
1152
747
1257
999
1095
1663
1704
1978
From the preliminary test we conclude that Torrefaction doesn’t influence significantly the
chemical composition of the material, while Torwash removes most of the alkali (K) and
Cl content. The resulting compositions are among those recommended for pellets.
Additional to alkali removal, the Torwash treatment gave very promising results: A series
of single test pellets was made with a material density of 1200-1300 kg/m3, which
indicates that a somewhat higher density than regular torrefied pellets is possible,
exceeding the material density and energy density of regular wood pellets. The densities
of the untreated material were 630 and 560 kg/m3 for the 3 and 5 years samples
respectively.
Grindability
The energy consumption for grinding is presented in Figure 6 for bituminous coal, willow
and 5 year old Guadua angustifolia bamboo. Tests were also performed with 3 year old
bamboo, though the grindability did not differ significantly. The results for coal and willow
were obtained from previous tests (Verhoeff, 2011) in which willow was torrefied at
260°C after which the grindability was comparable with coal.
1 (P,Mg,Al,Ca,Ti,Mn,Fe,Sr,Ba)
8
90
Bamboe 5yr - Untreated
Bamboe 5yr - Torrefied 240°C
Bamboe 5yr - Torrefied 255°C
Bamboe 5yr - Torrefied 270°C
Bamboe 5yr - Torwashed
Willow - Untreated
Willow - Torrefied 260°C
AU bituminous coal
80
Power consumption (kWe/MWth)
70
60
50
40
30
20
10
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Average particle size (mm)
Figure 6: Relation between power consumption and average particle size after
grinding
As observed the untreated bamboo (Guadua angustifolia) is more difficult to grind than
willow, and as such a higher torrefaction temperature (270°C or even higher) is needed
in order to obtain a similar grindability as the bituminous coal and the torrefied willow
(260°C). When co-firing torrefied bamboo, the selection of the ideal torrefaction
conditions will be a trade-off between torrefaction efficiency and downgrading of power
plant capacity.
Combustion test
Combustions tests are part of the technical evaluation of G. angustifolia as a torrefied
fuel to address the suitability and options to adapt this fuel to the existing power
industry. The ash composition of the solid fuel determines its thermal conversion
behaviour; certain ash properties such as formation of low melting solutions can have
detrimental effect on the process.
The experimental work was carried out at the ECN Laboratory Combustion Simulator
(LCS) with the help of specially designed probes for gas and solids sampling. The LCS is
schematically shown in Figure 7. It has been designed to simulate pulverized fuel
combustion and dry-fed, oxygen-blown entrained flow gasification conditions in terms of
particle heating rates, reaction atmosphere, and temperature−time history.
Figure 7: Schematic of the ECN’s Lab-scale Combustion Simulator (LCS).
Lab scale test results on combustion and co-combustion of Guadua a. bamboo, either
9
non-pre-treated or torrefied (dry and wet), pure or in a blend with coal (80% weight coal
blend) provide insight into the combustion and deposition behaviour and the ash
characteristics for these selected coal and biomass blends. The aim is to suggest
technical solutions and/or improvement in the operation of the full scale power plants.
The testing includes:
(1) Deposition and heat exchange monitoring tests
(2) Ash sampling from the sensor and the fine ash filter
In order to compare the fuel behaviour of bamboo (raw or pre-treated) with other
previously used biomasses, Figure 8 presents the fouling behaviour of bamboo, wood and
a herbaceous biomass. The wood represents a commonly used (standard) clean woody biomass,
and the herbaceous biomass an energy crop, grown exclusively for fuel production, (Cynara
Cardunculus).
0.0014
0.0012
Fouling factor
0.0010
Untreated bamboo 5.1 (0.09 0.125μm)
Torr 5.1 270 (0.09 - 0.125μm)
0.0008
Colombian coal (0.090.125μm)
Blend 80/20 coal/torr bamboo
5.1
0.0006
Wood
0.0004
Cynara
torwashed bamboo 5.1 (0.09 0.125μm)
0.0002
0.0000
0
0.2
0.4
0.6
Ash fed (gr, cumulative)
0.8
Figure 8. Fouling factors versus accumulated feed rate for the tested fuels
under air combustion conditions (Fryda, 2013).
Figure 8 indicates that the untreated biomass shows more severe fouling behaviour than
the treated biomass, in accordance with the deposition tendency results. The particle size
though plays a role, with the large PSD torrefied bamboo showing the largest fouling
factors (not shown in this graph). In relation with wood and cynara, it is clear that
bamboo does not show any particularity; in fact the treated (torwashed) bamboo shows
fouling behaviour comparable to clean wood.
The burnout behaviour was good, with low CO and carbon-in-ash levels. The deposition
behaviour of the untreated biomass is increased compared to the treated (torrefied)
biomass, indicating a change of the chemical composition of the fuel ash between treated
and untreated bamboo. The untreated biomass show more severe fouling behaviour than
the treated, in accordance with the deposition propensity results (Fryda, 2013).
The results show that the bamboo species Guadua angustifolia is a good candidate for
fossil fuel (coal) replacement in power plants, especially after it undergoes pre-treatment
such as dry torrefaction that improves grindability of the material or wet torrefaction
that in addition removes ash elements such as Cl and alkalis, that cause fouling and
deposition problems in the combustors. As for the evaluation of other bamboo species
and maturity stages, more detailed analysis and tests are required, however an
assessment based on their composition took place and results are presented somewhere
else (Fryda, 2013).
10
Gasification tests
Apart from biomass (co-)firing in coal-based systems another important application of
biomass is the production of syngas through entrained-flow (EF) gasification. Syngas is a
key intermediate product for a wide range of energy carriers and products, e.g., power,
fuels, chemical products, substitute natural gas, and hydrogen. One of the early markets
for biomass-based syngas production is power production.
Biomass materials such as straw, a range of palm oil residues, corn residues and grasses
have physical and chemical properties that are widely different from those of the widely
used wood, such as higher ash content which is also highly alkaline and rich in chlorine,
which is prone to cause operating problems when used at higher shares for co-firing in
existing coal PF infrastructure, especially with respect to slagging, fouling, and corrosion.
However, exactly this drawback (the low melting temperatures of the ash) make these
fuels potentially well-suited for slagging thermal conversion systems in which slag
formation on the gasifier walls is essential for the safe operation of these kinds of plants.
For the production of syngas from this kind of agricultural residue including bamboo it is
thus of key importance to know what the effects are of ashes on the slagging and fouling
behaviour.
Lab scale tests on gasification and co-gasification of torrefied bamboo (Guadua
angustifolia), pure or in a blend with El Cerrejon coal (80% weight coal blend) have been
performed. Tests provided the information on the conversion efficiency, the slagging
behaviour and the ash partitioning of the selected fuels. Several aspects have been
studied and presented by (Carbo, 2012).
The particulate matter emissions have been studied for blended samples (20/80 torr.
bamboo/coal) with and without the influence of the flux material. Results suggest a
positive effect on alkali capturing and decreased submicron particulates formation when a
flux is added. Even though the submicron fraction forms less than 1% of the total fly ash,
further attention must be paid to its chemical composition. Alkali salts and hydroxides
can cause ash deposition further in the system on heat exchanging areas.
High Temperature (HT) gasification of 100% biomass exhibits a low slagging potential
due to high silica oxide content in the fuel. It can represent eventually a drawback in
entrained flow gasifier and at the same time it could be beneficial in other thermal
conversion techniques (down draft gasifier; PF combustion, as reported in the previous
paragraphs on the combustion tests). Nevertheless the addition of the torrefied bamboo
to a low rank coal (alkali, iron or the ash rich) can be advantageous in entrained flow
gasification process.
d. Techno-economic assessment
The cost of bamboo cultivation and production are mainly dependent on: bamboo species
and plant section utilized, location and scale of production. The cost estimation is based
on overall literature and limited existing field data for the production of the species
Guadua angustifolia.
The estimation of biomass production costs considers two scenarios:
 Use of bamboo residues resulting from forest and plantation management
 Bamboo from a dedicated energy crop
The production costs are presented in detail elsewhere (Daza, 2013). Considering the
whole route of conversion of overseas bamboo to bio-product (being electricity, fuels or
chemicals) in the Netherlands, numerous processing steps at different locations along the
route can be defined. If the large-scale end-use is located in the Netherlands, the
11
bamboo can be imported as original feedstock (bamboo stems or chunks) or as biomass
intermediate (torrefied pellets).
Previous reported work on the several biomass to liquids options were evaluated on the
basis of biomass import to the Rotterdam harbour from overseas central biomass
gathering points transported via harbours (see (Zwart, Boerrigter& van der Drift, 2006).
The model applied for that evaluation has been the basis for the cost evaluation of the
import of torrefied bamboo pellets at the Rotterdam port. In Figure 9 the results are
summarized.
Following data has been updated and used in the evaluation of the complete bamboo
chain:
a.
b.
c.
d.
e.
f.
g.
h.
i.
Torrefaction related data
Investment based on reported costs of semi-commercial plants
Torrefaction efficiency as achieved for bamboo at a temperature of 270°C
Bamboo and product properties as achieved at a temperature of 270°C
Transport distances of 10,000 km from Colombian harbour to Rotterdam port
Bamboo costs 0-50 (residues) and 50-100 (energy crops) Euro per ton
Bamboo production of 15 (residues) and 30 (energy crops) tondry per ha per yr
Average transport cost to port (150-300 km) of 15 €/ tondry
International maritime transport cost 35 €/ tondry
10
Central gathering point in
Central gathering point out
Colombian harbour in
Colombian harbour out
Rotterdam port in
9
8
Product costs
(Euro/GJ)
7
6
5
4
3
2
1
0
Wood
pellets
2006
(10000 km)
Torrefied
Wood
Torrefied
wood
pellets
wood
pellets
2013
pellets
2006
(10000 km)
2013
(10000 km)
(10000 km)
Bamboo
Bamboo
residues
crops
(10000 km) (10000 km)
Torrefied
bamboo
pellets
residues
(10000 km)
Torrefied
bamboo
pellets
crops
(10000 km)
Product shape and transport distance
Figure 9: Bamboo costs at different locations of the transport chain
Concerning wood, the torrefied wood pellets currently are slightly more expensive in the
Rotterdam port than conventional wood pellets, due to the change assumed capital
investment required for torrefaction. The difference however is still limited and the choice
of traded product will still depend strongly on other properties, e.g. hydrophobicity,
grindability and durability.
Concerning bamboo, the costs of non-torrefied bamboo in the Rotterdam port are
considerably lower than for the torrefied bamboo. This is mainly caused by the already
relatively low moisture content of bamboo, but mainly due to its high bulk density (500700 kg/m3). Although bamboo stems can have a lower bulk density, the density of
bamboo chips (or crushed bamboo stems) is significantly higher than of wood chips. The
difference is that significant that the choice of traded product will less depend on other
properties.
The advantage of using bamboo residues for energy purposes is also clear. Due to the
lower costs in Colombia, the residues could land in the Rotterdam port for 4 to 5 Euro/GJ,
12
which is significantly lower than the current wood pellet price. If bamboo is specifically
produced as an energy crop, the costs of untreated bamboo in Rotterdam are still low,
whereas the costs for torrefied bamboo pellets become comparable with the costs for
torrefied wood pellets.
Nevertheless, the short or long term feasibility for the development of the biomass chain
based on residual streams or dedicated bioenergy crops depends on several aspects
which influence among others the security of feedstock supply, some of which are
presented in Table 5.
Table 5. Qualitative comparison Residues vs. Energy crops
Aspect
Residues
from forest
Yield per ha
Current
potential
Future
Potential
Cost
+
++
Residues
from
plantations
++
+
Bioenergy
crop
++
++
+++
++
++
+
Small holders
inclusion
GHG
emissions
reduction
potential
++
++
++
+
+
+++
Comments
+++
--
Forest exploitation needs permit in Colombia
Existing area covered/ Species
Suitable area
Main
production/management
cost
allocated to main product
Forestry nucleus figure/Associations
are
Use
of
residues
account
for
emissions/reductions
from
the
collection
pointDoes not include carbon stock
The regulatory framework for the Guadua chain in Colombia poses a barrier for market
development based on the use of natural forest as described by (Retz, 2010). The chain
development based on established plantations might be less problematic in terms of
required permits in the country.
e. Sustainability assessment
In Europe the Renewable Energy Directive on the promotion of the use of energy from
renewable sources sets targets for GHG reduction. The Directive includes sustainability
requirements for biofuels (transport) and bio-liquids (electricity, heating and cooling) (Art
17-19). In Art 17(9), the European Commission announced a report and proposals on
requirements for a sustainability scheme for energy uses of biomass, other than biofuels
and bioliquids.
In February 2010, the European Commission adopted a report on requirements for a
sustainability scheme for solid and gaseous biomass used for generating electricity,
heating and cooling (EC, 2010). At that stage, no binding criteria were suggested on
European level. Nevertheless, the Commission formulated recommendations to Member
States developing sustainability schemes, mainly for imports. The Commission wishes to
ensure that national legislation concerning these biomass types is in almost all respects
compliant with the rules laid down in the Renewable Energy Directive (for liquid biofuels),
to ensure greater consistency and to avoid unwarranted discrimination in the use of raw
materials (Biobench, nd). To date there has not been further communication from the
Commission regarding obligatory criteria on this matter. Nevertheless, 12 different
voluntary schemes have been accepted by the EC to ensure sustainability compliance
with the RED. Some of these schemes are applicable not only to liquid Biofuels but also
to solid biomass.
The sustainability assessment focus on the requirements of the Dutch Sustainability
Standard NTA 8080 accepted by the EC in 2012. The NTA 8080 Standard is framed in 9
13
principles containing criteria and indicators. The EC also accepted the NTA 8081 which
includes the ‘rules’ to enable certification against the requirements of the NTA 8080. The
NTA8080 describes the requirements for sustainably produced biomass for energy
applications (power, heat & cold and transportation fuels). Biomass includes solid as well
as liquid and gaseous biofuels. The NTA 8080 is intended to be applied at organizations
that wish to sustainably: produce, convert, trade; or use biomass for energy generation
or as transporting fuel.
The sustainability assessment included the revision of the chain stakeholders, the
regulatory framework at national and international level, as well as the existing voluntary
certification schemes. As part of the screening of sustainability issues, several issues
were identified in the supply chain of Guadua Figure 10. According to (Diaz-Chavez,
2011) four pillars of sustainability need to be considered. They include the traditional
pillars of sustainability environmental, social and economic but a fourth one is considered
as policy and institutions should be also part of sustainability and not just a driver.
Figure 10 Sustainability screening for the project of torrefied pellets from
bamboo in Colombia (Diaz-Chavez, 2012)
As can be observed in Figure 10 other topics were identified including transport, access
to market and incentives in the economic pillar. In the environmental pillar selection of
species and conservation areas are examples of some of the considered issues.
In the social aspect, rural development was part of the screening and this is area topic
that should be further explored in different regions in Colombia. The country requires
alternatives for the rural population, mainly those that include small holders and require
low capital investments. Regarding policy institutions, other issues identified were the
incentives and institutions related to investment for industrial development such as the
free tax industrial areas and the local government.
The process of forest certification for Guadua bamboo forests started in 2002 in the
framework of the project “Manejo Sostenible de Bosques en Colombia” funded by GTZ. At
the moment, it is possible to commercialize transformed Guadua products with the stamp
of FSC. The forest certification has been promoted under the principles of the Forest
Stewardship Council (FSC); consequently specific standards were elaborated for Guadua
standard, because of particularities of this kind of forests. The criteria from FSC are
presented in Table 6.
14
Table 6: FSC standard principles
Number
Principles
1.
Laws and FSC principles
2.
Rights and responsibilities of land use
3.
Indigenous groups rights
4.
Community relationships and workers’ rights
5.
Forest benefits
6.
Environmental impact
7.
Management plan
8.
Monitoring and assessment
9.
Management of forests with a high conservation value
10.
Plantations
When comparing the overall sustainability criteria of NTA8080 vs. the FSC standard for
Guadua forest, the last does not yet include GHG emissions. We evaluated the complete
biomass chain and its relationship to the goals in reducing greenhouse gas emissions
according to the EC recommendations for solid biomass and the certification system
NTA8080. Additional to GHG emissions, other environmental impacts are assessed by
means of a screening LCA.
f. Life cycle assessment
The LCA approach allows quantifying and comparing the related impacts of bamboobased electricity production with those of coal-based electricity. The specific case
evaluated concern bamboo as a bio-energy crop. Additional to greenhouse gases
emissions we assessed potential environmental impacts such as: abiotic depletion,
human toxicity, fresh water aquatic ecotoxicity, marine aquatic ecotoxicity, terrestrial
ecotoxicity,
photochemical
oxidation,
acidification
and
eutrophication.
The
characterization step is carried out using the CML method developed by the Centre of
Environmental Science from Leiden University (2 ) version CML 2 baseline 2000 V2.05 in
SimaPro7.3.3. The reference data used is taken from the Ecoinvent database and the
functional unit is 1 MJ of electricity.
The reference GHG emissions value for coal-based electricity according to the EC (2010)
is 198 kg CO2/ MJ. The resulting GHG emissions of the bamboo chain are calculated as
26 kg CO2eq/MJ. The last doesn’t include the carbon stock values.
Table 7: Summary of GHG emission reductions of 1 MJ of bamboo-based
electricity as compared to fossil reference
Reference fuel comparison source
Coal based electricity reference emissions
Kg CO2 eq/MJ
EC
(2010)
198
NTA
8080
199
SimaPro
194
% GHG emissions reduction
Bamboo source
Bamboo exiting forest resource
26
87%
87%
87%
Residues from forest management
19.5
90%
90%
90%
Bioenergy crop from restoring degraded
land
Bioenergy crop including carbon stock
-3.0
102%
102%
102%
-320
262%
261%
265%
2 Centrum voor Milieukunde Leiden (CML)
15
When compared to coal-based electricity, the use of torrefied bamboo-Guadua as solid
fuel in NL results in a reduction of greenhouse gases emissions above 70%. When
including emissions saving from carbon accumulation and potential bonus for restoring of
degraded land, the GHG emissions reduction would increase substantially leading to C
storage opportunities. The results are dependent on the cultivation and harvesting
strategy.
The bamboo chain has the potential to comply with all sustainability requirements as
presented in NTA8080 and by the EC recommendations for solid biomass (COM 2010). It
can be an excellent reforesting crop with a carbon stock superior than most biomass
systems. The no yet clarity on definitions of degraded land doesn’t allow to include
additional bonus for restoring of degraded land. Additionally, the lack of standard data
(values) for crop emissions and savings pose a challenge as data must be demonstrated,
therefore emissions (carbon stock) should be monitored.
From the LCA results (see Figure 11), it is observed the superior environmental
performance of the bamboo chain as compared to the coal-based reference. This applies
for all impacts categories but not for acidification and photochemical oxidation. These are
mainly due to interoceanic transport fuel use related emissions.
100
90
80
70
%
60
50
40
Electricity, medium voltage, production
NL, at grid/NL S
30
Electricity by torrefied bamboo from
plantation
20
10
Figure 11: Comparison of the relative emissions related to environmental
impacts of the production of 1 MJ of electricity. Coal vs. Bamboo (Daza C.M.,
2013b)
5. Lessons learned:
Bamboo has the potential to be a sustainable feedstock in the bio-based economy, not
only for the energy but also for the chemicals and materials sectors. The technoeconomic potential of the biomass chain for the bio-based economy differ according to
the species, maturity stage, production site and cultivation practices (e.g. fertilizers
application), harvesting alternatives (e.g. selective harvesting vs. clear cutting), etc.
The project generated very interesting and promising results and knowledge related to
the technical suitability of bamboo as a potential solid fuel:

Quantitative baseline data on the project show that bamboo behaves differently in
torrefaction than other biomass species. In particular its high energy density will
require some consideration on both equipment design as well as operating
conditions.
16

The combustion tests did not reveal any unexpected or severe technical obstacles
towards utilizing pre-treated bamboo in large power plants as a partial coal
substitution. 100% bamboo combustion is still not recommended before extensive
and dedicated trials are carried out in specific boiler types, mainly due to the
increased alkali content of treated bamboo compared to clean wood. As for the
other untreated bamboo species, despite the lower alkali and chlorine content
compared to other herbaceous fuels, the risk of fouling and possibly corrosion
needs to be further assessed in e.g. pilot scale or with additional detailed labscale tests. In any case, the material needs to be grinded very fine, which is only
possible with torrefaction.

Furthermore, several other bamboo species are expected to be suitable
candidates as fuel substitutes as well, but they were not tested in the laboratory
scale facility. Instead, a brief evaluation of their fouling tendency was carried out
based on their elemental composition and their acidic and basic oxide contents, as
defined for indicators found in literature. It was concluded that several bamboo
species can be included in the fuel portfolio of modern pulverized fuel power
plants after a certain pre-treatment process.
Apart from the technical feasibility, the sustainability performance of the bamboo chain
has been assessed. The base case assessment considers a group of farms which already
are FSC certified. The representatives of the certified group were very relevant for the
project development and their experience helped to identify the barriers and
opportunities with FSC certification and with other certification schemes which would
apply to solid biomass such as NTA8080. The experience and knowledge gained by the
case study FSC certified farms in the coffee region could be reproduced in other regions
of the country with potential for bamboo production.

The costs of NTA certification might be a barrier for the producers. Certification
costs have been covered through an initiative from GTZ for some of the producers
of Corguadua in the coffee region. It has been estimated by the producers that
without that project it would be too costly to continue the certification.

The permits required by the Colombian law for the exploitation of natural Guadua
bamboo forest results in vicious circles and lack of competitiveness of the sector
under the current market conditions.

The valorisation of residual streams from forest and plantations might represent
and incentive for increasing forest management. Alternatively, established
plantations don’t require permits for exploitation. The establishment of plantations
in unused/or degraded land as well as a reforesting crop might be a better
alternative for the development of the biomass chain.

The production of bamboo biomass is a low capital investment and labour
intensive activity which would lead to employment generation for the rural
population.
Additionally, the sustainability criteria which are not yet part of FSC standards specifically the GHG - could become an market opportunity for bamboo producers due to
the high productivity, the low fertilizers need of the plantations and the high carbon stock
related to bamboo-Guadua forest/plantations.
When calculated along the complete supply chain, GHG emissions reductions are above
70% when compared to coal-based electricity in the Netherlands. However, as bamboo
is not included in the list of the default biomass chains considered by the EC, it needs to
17
be “demonstrated” that the GHG emissions reduction is of at least 50-70% of the fossilbased route. As there are no default values in EU-RED for bamboo forest/plantations, the
GHG emissions reductions data needs to be demonstrated, therefore monitoring activities
are required.
With regards to macro monitoring of bamboo production issues to take into account
include biodiversity preservation, land use, food security, social well-being and local
prosperity, but specifically for bamboo also the competition to existing utilization
markets, i.e. furniture production. Competition with this existing market (in some
countries) is considered to be not an issue as the added value for this market is much
higher than for the energy market. Additionally, the access to international markets of
bamboo products from Colombia is very limited as the major global player is China;
therefore the opening of new markets (local and international) and products
diversification would highly benefit the bamboo sector.
From the overall economic model applied, and based on local data as well as on
estimates, the torrefied bamboo pellets could cost between 5-8 Euros/GJ (2012) at the
port of Rotterdam, depending on the source and local logistics strategies. This price
range is within the current price of white pellets, therefore there is a potential for the
economic competitiveness of the chain. Detailed feasibility studies need to be performed
for specific business cases.
The interest on bamboo as an alternative feedstock is increasing rapidly. However, the
end use of the feedstock and the supply chain development requires the direct
involvement of the private sector as well as the support of public institutions in both the
producing countries as well as end use countries. The development of the supply chain
requires an active role of all actors involved either in the international market as well as
the national market. The participation of end users in any follow up initiative is a must.
Additional relevant issues for the supply chain development are:



The recognition of bamboo as a biomass source for the local and international
market.
It is consider a priority that the Colombian public institutions (ministry of
environment and ministry of agriculture) develop a regulatory framework where
bamboo is clearly defined as an agricultural resource, a forestry resource or an
agro-forestry resource.
A multidisciplinary expertise on bamboo production, pre-treatment, conversion
and system assessments are of key importance in the successful integration of
bamboo in the bio-based market in Europe.
18
REFERENCES
Brown, R. (2003) Biorenewable Resources. Engineering new products from agriculture, Iowa State
Press.
Camargo, J. C., Dossman, M. A., Cardona, G., Garcia, J. & Arias, L. (2007) Zonificacion Detallada
Del Recurso Guadua En El Eje Cafetero, Tolima Y Valle Del Cauca, Pereira, ISBN ISBN978-958-8272-41-2.
Camargo, J. C.; Moreno, R. & Villota, N. (2010) Sustainable management of guadua bamboo
forest, Colombia, ETFR News 52.
Carbo, M.; Kalivodova, J.; Cieplik, M.; van der Drift, B.; Zwart, R. & Kiel, J. H. A. (2012) Entrained
Flow gasification of coal/torrefied woody biomass blends. Presented during the 5th
International Freiberg Conference on IGCL & XtL Technologies, 21 May 2012, Leipzig,
Germany .
Daza C.M.; Diaz-Chavez, R.; Camargo, J. C. & Londoño, X. (2013a) Bamboo: Alternative
Sustainable Feedstock for Fuels and Materials. Presented at 9th International
Conference on Renewable Resources & Biorefineries. June 5-7, 2013. Antwerp, Belgium.
Daza C.M.; Diaz-Chavez, R.; Camargo, J. C.; Londoño, X. & Zwart, R. (2013b) Sustainability issues
regarding bamboo as a renewable feedstock for fuels and materials. Presented at
BioEnergy IV: Innovations in Biomass Conversion for Heat & Power, Fuels and
Chemicals. June 9-14, 2013. Otranto, Italy.
Daza C.M.; Pels, J. R.; Fryda, L. E. & Zwart, R. W. (2011) Evaluation of Torrefied Bamboo for
Sustainable Bioenergy Production, IXth World Bamboo Congress (WBC), Antwerp 2012.
Daza, C. M.; Zwart, R.; Camargo, J. C.; Diaz-Chavez, R.; Londoño, X.; Fryda, L. E.; Jansen, A. E. &
Kalivodova, J. (2013) Torrefied bamboo for the import of sustainable biomass from
Colombia. Project Report., Unpublished.
Diaz-Chavez, R.; Daza Montano, C. M.; Camargo, J. C. & Londono, X. (2012) Sustainability
Assessment of Bamboo Torrefaction in Colombia, 20th European Biomass Conference
Milan.
Diaz-Chavez, R. A. (2011) Assessing biofuels: Aiming for sustainable development or complying
with the market?, Energy Policy 39/10, pp. 5763-5769,
EC (2010) Report from the comission to the council and the European Parliament on sustainability
requirements for the use of solid and gaseous biomass sources for electricty, heating
and cooling., COM(2010)11 final.
Fryda, L. E.; Daza C.M.; Janssen, A.; Pels, J. R. & Zwart, R. (2013) Technical Evaluation of the
Bamboo Species Guadua Angustifolia: Thermally Pretreated vs. Raw Material. Presented
at 21st European Biomass Conference and Exhibition. June 3-7, 2013. Copenhagen,
Denmark.
Guadua Bamboo Last update 2012: What is Guadua Angustifolia Kunth?,
http://www.guaduabamboo.com/guadua-angustifolia.html#ixzz1kNafYFRJ.
19
Hidalgo, O. (1981) Manual de construccion con bambu, Universidad Nacional de Colombia. Centro
de Investigacion de Bambu y Madera, Bogota.
Kleinn, Ch.; Morales-Hidalgo, D. (2006) An inventory of Guadua (Guadua angustifolia) bamboo in
the Coffee Region of Colombia , European Journal of Forest Research 125/4, pp. 361368.
Kumar, A.; Ramanuja Rao I.V. & Sastry, C. (2002) Bamboo for sustainable development,
Proceedings of the 5th international bamboo congress and the 6th international bamboo
workshop, San Jose, Costa Rica.
LignoValue project consortium (2011) High added value valorization of lignin for optimal biorefinery
of lignocellulose to energy carriers and products
(acronym: LignoValue)., EOS-LT05011.
Lobovic, M.; Paudel, Sh.; Piazza, M.; Ren, H. & Wu, J. (2007) World bamboo resources. A thematic
study prepared in the framework of the Global Forest Resources Assessment 2005,
FAO/INBAR, 18.
Retz, I. (2010) Understanding the dynamics behind the low adoption rate of standards and norms
for Guadua angustifolia Kunth in the Eje Cafetero using Conventions theory, Mastère
Spécialisé Développement Agricole Tropicale, option VALOR Institut des Régions
Chaudes - Montpellier SupAgro, Wageningen University.
Verhoeff, F.; Adell, A.; Boersma, A.; Pels, J. R.; Lensselink, J. & Kiel, J. H. A. (2011) TorTech:
Torrefaction as key Technology for the production of (solid) fuels from biomass and
waste , ECN Biomass, Coal and Environmental Research, ECN-E--11-039 .
Zwart, R. W. R.; Boerrigter, H. & van der Drift, A. (2006) The impact of biomass pre-treatment on
the feasibility of overseas biomass conversion to Fischer-Tropsch products, Energy and
Fuels 20, pp. 2192-2197.
20
Colophon
Date
Status
Project number
Contac person Ag NL
July 30th 2013
Final report
DBI02006
Sietzke Boschma
This study was carried out in the framework of the Sustainable Biomass Import
regulation, with financial support from < the Ministry of Foreign Affairs> or < the
Ministry of Economic Affairs > .
Name organization
Contact person
Address
Website for more info
Energy Research Centre of the Netherlands
http://www.ecn.nl/nl/
Biomass and Energy Efficiency
Claudia Daza Montaño
[email protected]
Westerduinweg 3
1755 LE Petten
www.ecn.nl
21

BIOGREEN CM600 - Western Renewable Technologies

MARK DAOVANNARY

ANNOUNCEMENT AND CALL FOR PAPER

Advantages and drawbacks for international trade of torrefied products

Presentation by Zina Sanyoura

Financing renewable CHP plants

Energy plantations technology on contaminated land

wt.% - NachhaltigWirtschaften.at

Bruce Duguid

¼Hkkjr ljdkj dk ,d miØe½ - Central Warehousing Corporation