Chemometric analysis for the relationship between mineral contents, particle matter and bottom ash distribution during pellets combustion

Transcription

1 The 4 th International Conference on Sustainable Solid Waste Management Limassol, June 2016 Chemometric analysis for the relationship between mineral contents, particle matter and bottom ash distribution during pellets combustion June 25 th 2016 M. Jeguirim, A. Zorpas, N. Kraiem, M. Lajili, C. Guizani, Y. Leva, L. Limousy

2 Context Depletion of fossil fuel reserves Increase of energy price Increase of wood biomass demand Rapid growth in wood pellets production Unbearable pressure on the forest and wood industries Research of new alternative biomass sources 2

3 Context and objective Pellets production from agriculture and agrifood industry residues Low quality comparing to wood pellets : high ash, nitrogen, sulphur contents : Considerable amount of gaseous and particulate matter emissions in exhaust gases. Slagging, fouling or corrosion in combustion system Objective : Relationship between pellets properties, ash composition and PM emissions 3

4 Objectives Pellets Production and Characterization : o Different agrifood residues : Tomato Waste, Grape Marc, Exhausted Olive Mill Solid Waste, Olive Mill Wastewater, Sawdust o Physicochemical characteristics and energy contents o Mineral contents Combustion tests : o Combustion and boiler efficiencies o Gaseous emission characteristics o Particle Matters Emission Characterization o Bottom ash Characterization Chemometric analysis 4

5 Pellets Production and Characterization Part I : Pellets Production and Characterization 5

6 Pellets Production Pelletizer KAHL 15/75 Die diameter 6 mm, length 30 mm Frequency : Hz Temperature : C TW 50 GM/50 PS 50 TW/50 PS PS Pelletizer KAHL 15/75 Type IS EOMSW IEOMSW 6

7 Pellets Characterization Parameter Unit TW TW-PS GM-PS EOMSW IEOMSW PS IS Moisture (%, wb) Ash (%, db) ρ apparent (kg.m -3 ) LHV wb (MJ.kg -1 ) ED pellets (GJ.m -3 ) N (%, wb) S (g.kg -1 ) K (g.kg -1 ) Cl (g.kg -1 ) Ca (g.kg -1 ) Si (g.kg -1 ) Na (g.kg -1 ) P (g.kg -1 ) Mg (g.kg -1 ) Al (g.kg -1 ) Fe (g.kg -1 ) Mn (g.kg -1 )

8 Combustion Experiments Part II : Combustion Experiments 8

9 Combustion Experiments Combustion tests performed with a residential boiler : ELPI (Dekati) Portable analyzer (TESTO 350XL) Boiler 12 kw (Ökofen) 9

10 Combustion Experiments Sample q (kg h -1 ) λ η comb η boil O 2 CO 2 CO NO x VOC (%) (%) (mg.nm -3 ) at 10%O 2 PM TW TW-PS GM-PS EOMSW IEOSW PS IS

11 Characterization of PM Emissions Particle concentrations (mg/nm 3 ) TW TW-PS GM-PS EOMSW IEOMSW PS IS 0 <0,1 µm 0,1-0,25µm 0,25-1µm 1-2,5µm >2,5µm Particle size 11

12 Characterization of PM Emissions Particle mass (%) TW TW-PS GM-PS EOMSW IEOMSW PS IS 20 0 <0,1 µm 0,1-0,25µm 0,25-1µm 1-2,5µm >2,5µm Particle size 12

13 Bottom Ash Characterization Element PS IS EOMSW IEOMSW TW TW-PS GM-PS K 2 O SiO CaO Fe 2 O SO P 2 O Na 2 O MgO Cl Al 2 O TiO SrO CuO Cr 2 O ZrO ZnO Rb 2 O MnO Br Sum

14 Bottom Ash Characterization P (%) PS TW-PS IS TW EOMSW IEOMSW GM-PS Size (µm) 14

15 Chemometric Analysis Part III: Chemometric Analysis 15

16 Chemometric Analysis 1 Fe Na Cl -- axis F2 (21,26 %) --> 0,5 0 0,5 Cl/K <0,1 µm Cl/Si 0 Al Si Mn Ca S Mg K >2,5µm 1 2,5µm Tot P 0,1 1µm K/Si ,5 0 0, axisf1 (51,30 %) --> 16

17 Chemometric Analysis % bottom ash size > 500 µm y = 0,686x + 28,659 R² = 0, (K + Si )molar fraction 17

18 Conclusions Pellets produced from agriculture and agrifood industries residues are promising to reduce pressure on wood markets. Drawbacks : increase of PM emissions and ash deposition and agglomeration during combustion. PM emissions were dominated by PM 1 (0.25-1µm). These emissions were affected the presence of K, Na and Cl and correlated to the K/Si molar ratio PM emissions increase significantly for higher K/Si ratio. For lower K/Si ratio, K is retained by Si in the bottom ash. Low ash content and the presence of Ca lead to a homogenous bottom ash with lower particle size. High ash content and the presence of K and Si lead to an agglomerated bottom ash with large particles 18

19 The 4 th International Conference on Sustainable Solid Waste Management Limassol, June 2016 Chemometric analysis for the relationship between mineral contents, particle matter and bottom ash distribution during pellets combustion June 25 th 2016 M. Jeguirim, A. Zorpas, N. Kraiem, M. Lajili, C. Guizani, Y. Leva, L. Limousy