Quality Irish Wood FuelThe chemical composition

Miss Sarah Cooley & Dr Eleanor Owens

Dept. of Chemical & Life SciencesWaterford Institute of Technology

Forest Energy 2007 SeminarQuality-based forest fuel supply chains –

Forest Energy 2007

Objectives

Determine the chemical composition of four different assortments of various species of wood chip from Irish forests in the context of utilizing this material as a solid biofuel.

Establish any statistical differences across geographical locations, within assortments and species for the parameters studies.

To produce valuable information for the development of a sustainable, renewable and quality energy source.

Parameters measured:Percentage ash contentGross calorific valuesMajor elements: Potassium, Phosphorus, Iron & Sodium.Minor elements: Cadmium, Chromium, Copper & Lead.Hydrogen content (to convert to net calorific values)Water soluble chlorideTotal chlorine

All results were calculated to a dry basis (d.b.) and statistical analysis was carried out using two-away ANOVA on all results.

ExperimentalAnalysis carried out in accordance with CEN

technical specifications: CEN/TS 14780: Methods for sample preparation

CEN/TS 14774-3: Methods for the determination of moisture content-Oven dry method-Part 3: Moisture in general analysis sample

CEN/TS 14775: Method for the determination of ash content

CEN/TS 14918: Method for the determination of calorific value

CEN/TS 15290: Solid Biofuels - Determination of major elements

CEN/TS 15297: Solid Biofuels - Determination of minor elements

CEN/TS 15105: Methods for determination of the water soluble content of chloride, sodium and potassium

CEN/TS 15289:Solid Biofuels - Determination of total content of sulphur and chlorine

Locations of Study Sites

Toormakeady - Co.Mayo

Abbeyfeale – Co.Limerick

Ballybofey – Co. Donegal

Bweeng – Co. Cork

Dovea – Co. Tipperary

Stradbally - Co. Loais

Assortments studiedWhole tree - WTEnergy wood – EWFire wood – FWRound wood - RW

Species studiedSitka spruceLarchSycamoreDue to time restrictions, only SS data is presented here. Details of all results achieved so far will be published in the interim report (Dec 2007).

Percentage Ash Content

0.000.200.400.600.801.001.201.40

WT EW FW RW

Assortments

% A

sh (d

.b.)

Ballybofey Bweeng Toormakeady

Percentage Ash Content

There was statistical significant difference in mean Ash content between Assortments (p<0.001)No statistical significant difference in mean Ash content between sites (p=0.331)Ballybofey - highest levels of ash found in all assortments.

Gross Calorific Values

18

18.5

19

19.5

20

20.5

21

21.5

WT EW FW RW

Assortments

Gro

ss C

alor

ific

Valu

es (M

J/kg

)

ToormakeadyBallbofeyBweeng

Gross Calorific Values

There was no statistically significant differences in mean gross calorific values for both site and assortment.Whole tree assortment was found to have highest calorific values (20.93-19.96 MJ/kg) throughout sites.Ballybofey whole tree assortment had the highest energy content.

Cadmium Concentration

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

WT EW FW RWAssortments

Cad

miu

m (C

d) m

g/kg

ToormakeadyBweengBallybofey

Cadmium Concentration

There was no statistically significant differences in mean Cadmium concentrations for both site and assortment.Whole tree and round wood assortments had the highest cadmium levels (0.050-0.150 mg/kg)Ballybofey round wood had the highest levels of Cadmium detected.

Chromium Concentration

-0.1

0.1

0.3

0.5

0.7

0.9

1.1

1.3

1.5

WT EW FW RW

Assortments

Chr

omiu

m (C

r) m

g/kg

Toormakeady Bweeng Ballybofey

Chromium Concentration

There was no statistically significant differences in mean Chromium concentration for both site and assortment.Whole tree in Ballybofey was found to have the highest levels of Cr.

Copper Concentration

0

0.5

1

1.5

2

2.5

3

3.5

WT EW FW EWAssortments

Cop

per (

Cu)

mg/

kg

Toormakeady Bweeng Ballybofey

Copper Concentration

There was statistically significant difference in mean Copper concentration for both site and assortment, (p=0.003 and p=0.037, respectively)Whole tree assortment had the highest Cu concentration (2.72-1.5mg/kg) throughout sites.

Iron Concentration

0

20

40

60

80

100

120

140

160

WT EW FW RW

Assortments

Iron

(Fe)

mg/

kg

Toormakeady

Bweeng

Ballybofey

Iron Concentration

There was no statistically significant differences in mean Iron concentration for both site and assortment.Highest concentrations of Fe found in whole tree assortments throughout sites (130-5 mg/kg)

Potassium Concentration

0

500

1000

1500

2000

2500

WT EW FW RWAssortments

Pota

ssiu

m (K

) mg/

kg Toormakeady

Bweeng

Ballybofey

Potassium Concentrations

There was statistical significant difference in mean Potassium concentration for both site and assortment, (p=0.034 and p=0.002, respectively)Highest concentrations of K in whole tree assortment (1174-1965 mg/kg) throughout sites.

Sodium Concentration

0

50

100

150

200

250

300

350

400

WT EW FW RW

Assortments

Sodi

um (N

a) m

g/kg

Toormakeady

Bweeng

Ballybofey

Sodium Concentration

There was statistically significant differences in mean sodium concentration between sites (p=0.041)There was no statistically significant differences in mean sodium concentration for assortment.Whole tree assortments had the highest Na concentration (328-192 mg/kg) throughout sites.

Phosphorus Concentration

0

200

400

600

800

1000

1200

1400

WT EW FW RW

Assortments

Phos

phor

us (P

) mg/

kg

Toormakeady

Bweeng

Ballybofey

Phosphorus Concentration

There was no statistically significant differences in mean Phosphorus concentration for both site and assortment.Highest P concentrations detected (1171-825 mg/kg) in whole tree assortments throughout sites.

Work in progress

Seasonal variation analysis currently in progress.

Comparison of:

Freshly felled wood

Seasonally dried wood

Statistical Analysis of all results.

Conclusions

Ash ContentHighest values found in whole tree assortment at all sites – Ballybofey highest

Gross Calorific ValuesHighest values found in whole tree assortment at all sites – Ballybofey highest

Metal AnalysisAll heavy metal concentrations were within the expected range.No lead was detected in any site studied

AcknowledgementsAuthors would like to acknowledge the funding provided by COFORD - National Council for Forest Research and Development.Cathy Walsh & Maeve Kennealy.Sean Kelly, Enda Coates, Tom O’ Dywer and Tom Kent.Jim Stack