Quality of ashes from thermal gasification of sewage sludge and biomass - for use as CPK fertilizers

Transcription

1 3rd of May 2017, IEA Task 33 workshop, MCI Innsbruck, Austria Quality of ashes from thermal gasification of sewage sludge and biomass - for use as CPK fertilizers Tobias Pape Thomsen Biomass Gasification Group Technical University of Denmark 1

2 Structure of presentation 1. Gasification at BGG 2. Ash quality at BGG why and how? 3. Result examples 4. General conclusions 2

3 Gasification at BGG TwoStage Down Draft gasification Small scale application (<2 MW TH ). Stand alone unit. Eff.: Cold gas efficiency 93% Current R&D focus: Gas synthesis, fuel/electrolysis cell integration and ash Fuel: Wood chips, sewage sludge pellets and straw with additives Low Temperature Circulating Fluidized Bed gasification (LT CFB/Pyroneer) Fully scalable. Stand alone (R&D) or w. boiler (current) Eff.: Hot gas efficiency up to 95% Current R&D focus: Gas cleaning, fuel & product flexibility and ash quality Fuel: Straw, sewage sludge, manure fibers, biogas fibers, various organic residues from food industry and fuel mixes 3

4 Introduction of the TwoStage gasifier 4

5 Introduction of the TwoStage gasifier Camilla Thermal capacity: kw Location: DTU Risø Campus Owner: DTU Viking Thermal capacity: kw Location: DTU Risø Campus Owner: DTU 5

6 Introduction of the LT CFB gasifier 6

7 100 kw LT CFB Location: DTU Risø Campus Owner: DTU 6 MW Pyroneer Location: Asnæs power plant Owner: DONG Energy 7

8 ASH FERTILIZER QUALITY AT BGG WHY AND HOW? 8

9 General motivation why ash? 1) Improve the life cycle impact of thermal gasification: Reduce pollution e.g. toxicity and eutrophication Recover and reuse critical elements Enhance soil quality and sequester carbon 2) Improve feasibility of thermal gasification in a circular economy: Develop new markets Valorise ash products 9

10 The BGG P vision 10

11 Ash investigations: Effect on plant yield 11

12 Ash investigations: Effect on plant yield 12

13 Ash investigations: Effect on plant yield 13

14 Ash investigations: Effect on plant yield 14

15 Ash investigations: Effect on plant yield 15

16 Ash investigations: Effect on plant yield 16

17 Ash investigations: Effect on plant yield 17

18 Ash investigations: Effect on plant yield 18

19 Ash investigations: Effect on plant yield 19

20 Ash investigations: BGG involvement Practical and legal aspects w. farmers & consultants Toxicological aspects w. KU, DTU ENV and RUC Fertilizer potential and value w. KU, AU, farmers and consultants Soil enhancement properties and value w. KU, RUC, farmers and consultants Influence of fuel characteristics w. DFBT, DONG, KU, AU Influence of thermal process design and operation w. DFBT, DONG, Dall Energy, KU Influence of post process treatment w. DTU BYG, KU 20

21 Ash investigations: How? Fuel and ash characterization e.g. Elemental content, solubility and speciation Content of PAH and other organic toxins ph Morphology and structure Application and handling test e.g. Pelletization and granulation properties Storage and transportation losses Distribution and field application System analysis e.g. Energy and mass balances Carbon footprint assessment Full life cycle analysis 21

22 Ash investigations: How? Soil incubation studies P & K fertilizer value ph of soil/substrate mixtures Carbon stability Water holding capacity Plant experiments (pot and field trials) P and K uptake Plant growth response (P and K) Leaching Soil structural changes, SOC, respiration and eco toxicology Liming effect 22

23 Ash investigations: How? 23

24 ASH FERTILIZER QUALITY AT BGG RESULT EXAMPLES 24

25 Result example: Tech. influence on ash quality Thomsen, T. P. (2016) Closing the Loop Utilization of Secondary Resources by Low Temperature Thermal Gasification, PhD thesis, Technical University of Denmark 25

26 Result example: Tech. influence on ash Cd load 100 Danish legal threshold Cadmium fertilizer load (µg Cd/g P) Tobias Pape Thomsen, Zsuzsa Sárossy, Jesper Ahrenfeldt, Ulrik Henriksen, Flemming Frandsen and Dorette Sophie Müller Stöver: Changes imposed by pyrolysis, thermal gasification or incineration on elemental composition and phosphorus fertilizer quality of municipal sewage sludge. Accepted for publication in: Journal of Environmental Management 26

27 Result example: Tech. influence P fertilizer value 120 P fertilizer value (AER) [% of mineral P reference] Tobias Pape Thomsen, Zsuzsa Sárossy, Jesper Ahrenfeldt, Ulrik Henriksen, Flemming Frandsen and Dorette Sophie Müller Stöver: Changes imposed by pyrolysis, thermal gasification or incineration on elemental composition and phosphorus fertilizer quality of municipal sewage sludge. Accepted for publication in: Journal of Environmental Management 27

28 Result example: Fuel influence P fertilizer value 60 P fertilizer value (water ex.) [% of mineral P reference] Tobias Pape Thomsen, Henrik Hauggaard Nielsen, Benny Gøbel, Peder Stoholm, Jesper Ahrenfeldt, Ulrik B. Henriksen and Dorette Sophie Müller Stöver: Low Temperature Circulating Fluidized Bed gasification and co gasification of Municipal Sewage Sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer. In review in: Waste Management 28

29 Result example: particle size influence P fert. val. P fertilizer value % of original substrate ,1 0,2 0,3 0,4 0,5 dp_average (mm) AER (soil 1) annealed y = 235,4x + 111,5 R² = 1,0 AER(soil 1) y = 144,1x + 92,3 R² = 0,7 AER (soil 2) y = 139,4x + 108,8 R² = 1,0 DGT (soil 2) y = 180,3x + 111,1 R² = 1,0 Thomsen, T. P. (2016) Closing the Loop Utilization of Secondary Resources by Low Temperature Thermal Gasification, PhD thesis, Technical University of Denmark 29

30 Ash quality: A few general conclusions Not simple! Substantial variation from Fuel Technology Post process treatment End use scenario General trends Generally low ECO tox of biomass ashes Highly stabile C content (carbon sequestration) Profound liming effect High loss of N, minor loss of P and K Increase water and nutrient retention Immense potential benefits Success only through cooperation 30

31 Acknowledgements DTU KT, DTU ENV, DTU MEK, DTU MAN, DTU CEN & DTU BYG KU PLEN & KU IGN RUC ENSPAC DFBT DONG Thank you for your time and attention AU FRICHS FORS BIOFOS ADELAIDE WERKSTATTEN EUDP (Danish Energy Agency) And many, many more 31