Eija Alakangas, VTT, 10.12.2010
Questionnaire of wood pellets product standard for industrial use
Deadline: Replies to VTT to Eija Alakangas by 31 January 2011 (eija.alakangas@vtt.fi)
Target: 3 replies requested by partner, total 50 replies.
The aim of the questionnaire is to collect feedback from industrial pellets users (power or CHP
plants), pellet producers, national pellet or bioenergy associations and the European Pellet
Council. The aim is to clarify, if a special industrial wood pellet product standard is
needed. A product standard for non-industrial use (for appliances used in households, small
public and industrial buildings) will be published in the beginning of year 2011 for wood pellets
(EN 14961-2). See details about the pellet standards in a separate article. Results of the
questionnaire will be used for the ISO/TC 238 standard: Graded wood pellets.
Table 1. Information about the respondent
Organisation type
Name of organisation
Country
Wood pellet producer
Wood pellet user
Prepared by Laborelec
Europe
(power plant or CHP plant)
Association
Initiative Wood Pellets Buyers
Europe
Replies are handled confidentially and no organisation names will be published.
1. USE OF CEN PELLET STANDARDS (EN 14961-1 or EN 14961-2)
1.1 Are you going to use CEN wood pellet standards?
CEN standard
EN 14961-1 General
requirements (see Annex 2)
EN 14961-2 Wood pellets for
non-industrial use
Use of standard
(Yes or No)
Yes
No
Please explain
We will use the terminology in our specifications
for power plants and contracts
We only apply for industrial use
In EN 14961-1 General requirements (see Annex 2), each property class is selected separately and in EN
14961-2 Wood pellets for non-industrial use (see Annex 3) to specify pellets are to classes A1, A2 or B?
2. PRODUCT STANDARD FOR INDUSTRIAL WOOD PELLETS?
2.1 Is a industrial wood pellets product standard needed, or is it sufficient to use EN 14961-1
(see Annex 2 in attached article) as a common system of denominations to specify pellet
qualities?
Industrial wood pellets product standard is needed. Producers must comply with technical and legal
requirements of power plants.
2.2 It has been suggested to use the same specifications for industrial pellet as specified by EN
14961-2 and some additional parameters for industrial use.
a) Do you consider this approach is feasible? If so (or if not), please give reasons.
NO, see 2.1, significant specificities must apply for industrial pellets.
1
b) If feasible, which additional specifications should be required for industrial wood pellets? Please
fill in the Table 2, which properties are needed for industrial wood pellets. If you consider that
values can be same as in EN 14961-2, add this information in Comments column.
See also Excel sheet attached. Those specifications will be THE reference for big 7 utilities in Europe.
They have been agreed on our last IWPB meeting in Geneva on January 27 th.
Particle size distribution and ash melting temperature are two important additional specifications for
industrial pellets.
c)
If you consider industrial wood pellet classifications are needed and that they are different than
specified by EN 14961-2, please fill in Table 3 and make your own proposal for a specification of
industrial wood pellets.
Again, see attached Excel sheet.
3. CERTIFICATION
3.1 The European Pellet Council is launching ENplus certification systems for non-industrial
wood pellets, which is based on EN 14961-2 standard (see attached draft handbook). Is a
certification system needed also for industrial wood pellets?
GDFSUEZ/Laborelec is partner of PELLCERT project within IEE framework.
a) Yes, explanation
Yes, a certification system will help to achieve a constant technical quality, to guarantee best
practices are carried out and will help integrating sustainability criteria that are verified at all
steps of the supply chain
b) No, explanation
3.2 If a certification system is needed for industrial wood pellets, what additional requirements
or different requirements should it include compared to ENplus? Are there elements which are
unnecessary and/or too expensive to measure in ENplus. See attached draft ENPlus handbook.
Not all utilities in Europe do feel the necessity of a certification system because their position
on certification has not yet been outlined fully.
But some other utilities - like those having operations in BE, NL, UK - do feel this necessity.
Key elements would then be as follows.
- Constant wood pellets quality, especially ash content, chlorine, nitrogen, ash melting
temperature, particle size distribution, mechanical durability and fines according to
specs.
- Raw material: Classification of the origin and sources of solid biofuels in accordance
with EN 14961-2 (Table 1, EN 14961-1, see Annex XI).
If the raw material does not exclusively originate from an affiliated sawmill, the
suppliers and the origin of the raw material are to be specified according to EN 14961-1
Table 1.
- Existence of a tracking system for the suppliers of raw material to the pellet plant.
- Make the producer responsible for sustainable character of this raw material, especially
when round wood or cultivated wood is used, especially as far as protection of carbon
stock, biodiversity and soil quality is concerned.
- Make the producer able to report on its energy use for evaluating GHG balance of the
product.
ENplus Green integrating those sustainability requirements would be more than welcome.
4. RAW MATERIAL REQUIREMENTS
4.1 Should chemically treated material* be allowed? If Yes, what would be the requirements
for the material; or if No, why?
Answer
Yes
No
(mark X)
Explanation
X
Power plants do not use contaminated wood and are not permitted for
2
* In EN 14961-1 classification of raw material (see Table 1 in article) chemically treated wood residues
from wood processing (glued, painted, coated, lacquered or otherwise treated wood, 1.2.1) or used wood
(1.3.2) is allowed as long as they do not contain heavy metals or halogenated organic compounds as a
result of treatment with wood preservatives or coating. In EN 14961-2 chemically treated wood allowed
only in class B (see Annex 3 in article), but same threshold values for heavy metals as for chemically
untreated material to be met. In the ENplus certification no chemically treated wood is allowed.
5
3
. PRODUCT STANDARD FOR THERMALLY TREATED BIOMASS PELLETS
5.1 Do we need also product standard for thermally treated biomass pellets (e.g. torrefied
pellets)?
Answer
Yes
No
(mark X)
Explanation
This is premature since the product has not been yet sufficiently
tested at large scale and so specifications have not yet been designed
5.2 What properties should be specified?
Make a list of properties (e.g. fixed carbon, particle size, moisture, net calorific value or what
else), which you see most important.
Key parameters will (probably) be:
- net calorific value,
- volatiles,
- ash content,
- ash melting temperature,
and in addition for fire & explosion risk: MIE and KSt
4
Table 2. What are the most important quality requirements for industrial wood
pellets? Shall they be normative (mandatory) or informative (voluntary)
Property class
Origin and source (raw material basis,
see table 1 in article)
Dimensions, diameter (D) and length
(L)
Moisture content, w-% wet basis (M)
Ash content, w-% dry basis (A)
Mechanical durability, w-% of pellets
after testing (DU)
Amount of fines, w-% (< 3,15 mm) (F)
Additives, w-% of pressing mass, type
and amount
Bulk density, kg/m3 (BD)
Net calorific value as received, MJ/kg
(Q) or kWh/kg
Nitrogen, w-% of dry basis (N)
Sulphur, w-% of dry basis (S)
Chlorine, w-% of dry basis (Cl)
Arsenic, mg/kg dry basis (As)
Cadmium, mg/kg dry basis (Cd)
Chromium, mg/kg dry basis (Cr)
Copper, mg/kg dry basis (Cu)
Lead, mg/kg dry basis (Pb)
Mercury, mg/kg dry basis (Hg)
Nickel, mg/kg dry basis (Ni)
Zinc, mg/kg dry basis (Zn)
Ash melting behaviour, oC
Particle size distribution
Normative*
(mark X)
X
Informative*
(mark X)
Comments (e.g. values of
EN 14961-2 can be used)
Important for sustainability
and permitting
X
X
X
X
Key quality parameter
Min. And Max. Values for
pulverising
X
X
No additives allowed for
legal reasons
X
X
Essential since payment is
directly related to this
NOx problematics
S is usually low in wood
Corrosion
ID of contaminated wood
For recycled fly ash
For recycled fly ash
X
X
X
X
X
X
X
X
X
X
X
X
X
Very important for slagging
Very important for PP
*Normative=mandatory property class, Informative= voluntary property class
5
Table 3. Proposal for the specification of wood pellets for industrial use
Replace X by your own proposal (number, see model from Annex 3 in attached article). If you find some
property class unnecessary, mark it by strikethrough.
Property class, Analysis method
Unit
I1
I2
All types of clean
wood by-products
and residues
allowed
1.1 Forest, plantation
and other virgin
wood, 1.2 byproducts and
residues
1.1 Forest, plantation
and other virgin wood,
1.2 by-products and
residues
mm
D06 to D08
D06 to D08
L < 4,0
L < 4,0
as received, w-%
wet basis
M10
M< 10%
M10
M< 10%
w-% dry
A 1.0
A< 1,0%
A 2.0
A< 2,0%
Mechanical durability, DU,
EN 15210-1
as received, w-%
DU97.5 – max. 99
DU96.5 – max. 99
Fines F, EN15210-1
The amount of fines shall be checked
when the pellets leave the final point
of loading for delivery to the enduser. i.e when loading at the harbour
w-% as received
Origin and source (see table 1 in
attached article and Annex 3 )
Diameter, D a and Length L, b
prEN 16127
Moisture, M
EN 14774-1, EN 14774-2
Ash, A EN14775
F4.0
F4.0
F< 4,0%
F< 4,0%
w-% dry
None
None
as received,
MJ/kg
Q16.5
Q>16,5
Q16.5
Q>16,5
kg/m3
BD600
> 600
BD600
> 600
Nitrogen, N, FprEN 15104
w-% dry
N0.5
< 0,5
N1.5
< 1,5
Sulphur , S, FprEN 15289
w-% dry
S0.05
< 0,05%
S0.4
< 0,4%
Chlorine, Cl, FprEN 15289
w-% dry
Cl0.03
< 0,03%
Cl0.1
< 0,1%
Arsenic, As, FprEN 15297
mg/kg dry
<2
<6
Cadmium, Cd, FprEN 15297
mg/kg dry
< 1,0
< 10
Chromium, Cr, FprEN 15297
mg/kg dry
< 15
< 50
Copper, Cu, FprEN 15297
mg/kg dry
Lead, Pb, FprEN 15297
mg/kg dry
Mercury, Hg, FprEN 15297
mg/kg dry
Nickel, Ni, FprEN 15297
mg/kg dry
Zinc, Zn, FprEN 15297
mg/kg dry
1200
1100
100%
>97%
>95%
>75%
>50%
< 3%
100%
>97%
>90%
Normative
Additives c
Net calorific value, Q,
EN 14918
Bulk density, BD, EN 15103
Ash melting behaviour, d prEN15370,
DT
Informative
Particle size distribution, prEN15149
% < 4.0 mm
% < 3.15 mm
% < 2.0 mm
% < 1.5 mm
% < 1.0 mm
% < 0.1 mm
o
C
w-% dry
>50%
< 5%
a
Selected size of pellets to be stated.
Amount of pellets longer than 40 mm can be 0 w-%. Maximum length shall be < 40 mm.
c
Type (e.g. starch, corn flour, potato flour, vegetable oil): no additives allowed, exceptionally pure vegetal additives could be accepted <5%
d
All characteristic temperatures (shrinkage starting temperature (SST), deformation temperature (DT), hemisphere temperature (HT) and
flow temperature (FT) in oxidizing conditions should be stated.
b
Note: for raw material specification use Table 1 in article (see model of Annex 3). If you do not
allow chemically treated material select classes from 1.2.1 and 1.3.1.
6