SECTOR - Production of Solid Sustainable Energy Carriers from Biomass by Means of Torrefaction

Transcription

1 SECTOR - Production of Solid Sustainable Energy Carriers from Biomass by Means of Torrefaction A European R&D Project funded within the Seventh Programme by the European Commission Biomass resources and quality requirements for torrefaction Helsinki, 17 September 2014 Principal scientist Eija Alakangas, VTT 1,5,6: ECN; 2-4 Jasper Lensselink 1

2 The SECTOR project Collaborative project: SECTOR Duration: Total budget: 10 Million Participants: 21 from 9 EU-countries Coordinator: DBFZ, Germany 2

3 Project structure DBFZ 3

4 Objectives of Biomass market assessment of feedstocks Assessment of available biomass potential for production of torrefied pellets for both forest and agricultural feedstock. Market demand and raw material and torrefied biomass quality requirements with special emphasis on cofiring with coal in PC-boilers. To select broad set of raw materials for experimental work in laboratory, pilot and demonstration scale. The work is to be performed by combining and updating the existing information from the partners and available literature and enquiries to market actors. Image from Andritz 4

5 Market assessment & selection of biomass feedstock Biomass potentials Based on existing studies technical available potential in EU and worldwide assessed Also price levels of raw material were estimated Quality demands from producers and end users End-users work carried out by first questionnaire to partners and also to some coal fired utilities using wood pellets Second questionnaire to producers (SECTOR partners and International Biomass Torrefaction Council (IBTC) members). Profiles of selected raw material Classification of raw material according to EN standard Done in 2 phases Property information from literature and SECTOR laboratory tests 5

6 Summary of woody biomass resources in Europe Source 1,000 solid m 3 PJ/a Stem wood Landscape management wood residues Forest residues By-products and residues from wood processing industry Used wood Total EU Other EUROPE Ukraine North-West Russia Belarus, Norway, Switzerland Sources: BEE-project and EU-Wood project 6

7 Wood energy potentials in EU-27 (PJ/a) Used wood Byproducts from forest industries Primary forest residues 0 Source: VTT 7

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9 Summary of agricultural biomass potentials in EU Resource PJ/a Source Cereal straw 560 BEE, Böttcher et al DBFZ, Thrän et al BIOMASS FUTURES, Elbersen et al MTT, Pahkala & Lötjönen 2012 Sugar beet 25 BEE, Böttcher et al MTT, Pahkala & Lötjönen 2012 (EU-25) Sunflower 34 BEE, Böttcher et al Rice husk 9 BEE, Böttcher et al Corn residues 85 BEE, Böttcher et al Pruning residues, total 423 BIOMASS FUTURES, Elbersen et al 2012 Vineyard residues 14 BEE, Böttcher et al Olive three prunings 28 BEE, Böttcher et al Energy crops, vegetable diet BEE, Böttcher et al Energy crops, mixed diet 742 BEE, Böttcher et al Perennial herbaceous biomass BIOMASS FUTURES, Elbersen et al 2012 Agricultural residues (sugar beet, legume, potato, oil 656 MTT, Pahkala & Lötjönen 2012 plants) Miscanthus RENEW, Seyfried et al Reed canary grass (theoretical) BEE, Böttcher et al Woody crops (poplar, theoretical) BEE, Böttcher et al Short rotation coppice RENEW, Seyfried et al

10 Global biomass potentials Global technical potential for straw is around 13,317 PJ/a maize, sugar cane, rice and wheat - China. Palm fruit residues has high potential, more than 260,000 PJ/a Malaysia and Indonesia. Bagasse 3,647 PJ/a Brazil, India, China Bamboo is cultivated in some 37 million hectares and growing stock is about 389 million tons. Global technical straw potential, PJ/a. Source: DBFZ 10

11 Requirements of raw material and quality of final product (producers) Raw material Only woody biomass (forest residues, segregated wood) has been used and no experiences of agrobiomass have been gathered. Quality: 9 MJ/kg (ar), 3 10% ash, particle size (30 50 mm, P31 or P45), moisture <50w-% (dried to 10w-%) Free of metals, plastics, stones and other impurities, not frozen, no glowing ambers Wood transported by trucks, ships and trains and stored indoor storage or sheltered by flying roof. Final product Pellets or briquettes Ash (0.5-10%), moisture (2-10%), Fines (1 5%), DU 90-98%, net calorific value (18-34 MJ/kg), bulk density ( kg/m 3 ), Volatile matter (65 80%), fixed carbon (15 30%) 11

12 Quality demands for final product (end-users) The most important properties are (end-users): net calorific value as received (Q) (19 23 MJ/kg) ash content (A) (2 3%, one response <10%) particle size distribution (P) and Typical requirements for particle size distribution of hard coal are less than 20% larger than 90 µm and 100% smaller than 200 µm. Particle size distribution for industrial wood pellets (EN ISO :2014) Property (standard) Unit I1 I2 I3 Particle size distribution of disintegrated pellets, (ISO 17830) w-% dry moisture (M) (<10w-%) Other properties 99% (< 3,15 mm) 95% (< 2,0 mm) 60% (< 1,0 mm) 98% (< 3,15 mm) 90% (< 2,0 mm) 50% (< 1,0 mm) 97% (< 3,15 mm) 85% (< 2,0 mm) 40% (< 1,0 mm) minerals like chlorine, calcium, potassium and sodium (so called alkalis). 12

13 Cofiring and use of coal mills (end-users) Current use of wood pellets/torrefied pellets and cofiring ratios Short term cofiring and cogasification tests with coal Both torrefied and steam exploded pellets used Possibilities to use coal mills To be checked the following: energy density, which affects to fuel volume flow, shape and structure, bulk density have impact to handling system Can easily be co-milled in the existing coal mills (torrefied are non-fibrous like white pellets) Requirements of particle size is important, risk of dusting, CO and VOC emissions to be checked. 13

14 Other still open questions (end-users) Investments needed for use of torrefied pellets Unknown, because no large-scale demonstration carried out. Possibility to store outdoor? Is investment needed for covered storage? Can not be conveyed with coal? Investment for parallel conveying system? Co-grindability? Can plant use same mill as for coal? 14

15 Use of agrobiomass and demand (end-users) Possibilities to use torrefied agrobiomass Only small amounts used, qualities and risks/benefits are unknown. Agrobiomass contains higher amounts of chlorine, potassium and sodium problems in steam boilers, if heat surfaces are not planned for fuels containing corrosive elements. Estimated cofiring ratio 10 to 20%. Fuel prices can become competitive. 15

16 Estimation of demand of pellets/torrefied pellets Wood pellet cofiring potential (5 % with coal) in more than 100 existing pulverised coal-fired plants in Europe Total coal use was 772 million tons in Europe in Biggest coal users in Europe are Germany, Poland, Ukraine, United Kingdom and Czech Republic. By torrefied pellets replacement could be as high as 50%*, this makes European market hugely significant. *Source: Wilén, C., Jukola, P., Järvinen, T., Sipilä, K. Verhoeff, F. & Kiel, J Wood torrefaction pilot tests and utilisation prospects, VTT Technology p. Source: Pöyry 16

17 Selected raw materials for lab and pilot tests No. Selected feedstock (pilot test marked by bold, 12 raw materials) Test type to perform 1 Delimbed coniferous stem wood without bark : Pine and spruce (Reference 1) Lab and pilot 2 Logging residue, coniferous Lab and pilot 3 Straw, wheat (Nordic conditions) Lab 4 Used wood post consumer wood, recycled wood, chemically untreated Lab and pilot 5 Bark Lab 6 Delimbed broadleaves stem wood with bark: Beech (Reference 2) Lab and pilot 7 Poplar Lab and pilot 8 Straw (Oat and wheat, Southern conditions) Lab and pilot 9 Prunings from olive trees woody biomass Lab and pilot 10 Eucalyptus Lab and pilot 11 Paulownia Lab and pilot 12 Bamboo Lab and pilot 13 Palm oil residues (e.g. Oil palm fruit bunch, palm kernel or shell) Lab 14 Bagasse Lab and pilot 15 Corn cobs Lab 16 Miscanthus Lab 17 Sun flower residues Lab 18 Willow (Salix) Lab and pilot 19 Reed canary grass Lab 20 Straw, barley (Nordic conditions) Lab 21 Rape straw Lab 17

18 Selection criteria of raw materials Availability of raw material based on resources available Raw materials were agreed jointly with involved partners and based on requirements of experimental work packages. Increased emphasis was laid on straw, forest wood and their residues Selection was made to raw material for laboratory or/and pilot tests Two materials were selected for reference material Coniferous wood chips from stem wood without bark Broadleaf wood chips with bark 18

19 Example of profile no 1 Reference raw material Description of feedstock Raw material according to EN Table 1 Traded form (e.g. wood chips) according Table 2 of EN or other Selection criteria for feedstock profile (e.g. high potential, availability) Remarks (e.g. biomass cutting step, place of origin, pretreatment etc.) Selected for laboratory and/or pilot tests PROFILE No. 1 CONIFEROUS STEM WOOD Stem wood, coniferous without bark (Reference raw material 1) Forest, plantation and other virgin wood Wood chips, saw dust High potential, total forest wood in EU-27 is about 678 million solid m 3 (Mantau et al 2009, SECTOR report D2.2) Cutting and delimbering trees, forwarding round wood to road-side and transporation to plant, debarking trees and chipping to wood chip. Laboratory test, yes Pilot test, yes 1. QUALITY OF RAW MATERIAL 1.1 Emissions/corrosion related compounds (w-% of dry matter, EN (N, S) and EN (Cl)) Component Nitrogen, N Sulphur, S Chlorine, Cl Typical value 0,1 <0,02 0,01 Variation (min-max) < 0,1 <0,01 < 0,01 0,5 0,03 0, Ash content, ash melting behavior and ash composition Parameter Ash content EN Ash melting behavior ( CEN/TS ) SST DT HT FT Unit % (DB) ºC ºC ºC ºC Typical value 0,4 variation 0,3-0, QUALITY INFORMATION FOR TORREFACTION 1.1 Quality data of biomass for torrefaction Property Typical value Variation (min. max.) Traded form (e.g. chips) EN , Table 2 Wood chips, saw dust Particle size, P (Dimension /nominal size, mm, P45 or P65(wood chips) use) EN , screen size according ISO 1 5 mm (sawdust) 3310 Bulk density (BD), kg/m 3 EN Moisture as received, M (w-%), EN or 3 < Amount of fines, F, w-% ( 3,15 mm) EN ,6 Hemicelluloses content, w-% dry *) Cellulose content, w-% dry *) Lignin content, w-% dry *) C (w-% dry), EN H (w-% dry) EN ,0 6 6,5 O (w-% dry) calculated Volatile content, VM (w-% dry) EN Net calorific value, dry MJ/kg EN ,3 18,5 19,8 Add other properties, S, w-% dry 0,05 Chlorine, Cl, w-% dry < 0,01 Source 1 : SECTOR Partners Source 2 : Alakangas, E. Analysis of particle size of wood chips and hog fuel ISO/TC 238, VTT-R p. 1.2 Reactivity of feedstock Macro elements CEN/TS Micro elements CEN/TS Composition Al Ca Fe Mg P K As Si Na Ti Unit Range mg/kg (DB) <0, <20 Composition Cd Co Cr Cu Hg Mn Mo Ni Pb Sb V Zn Unit Range mg/kg (DB) <0,05 <0,2 0,2 0,5 <0, <0,1 <0,5 0,01 <0,2 5 0,5 0, , ,5 <2 50 Indicator Torrefaction degree by TGA (Thermogravimetric analysis) Source: SECTOR Feedback Weight loss at C with residence time of 30 minutes at T> 200ºC (% AWL) ~28% 19

20 Summary Combination of a variety of existing studies with a focus on materials suitable for torrefaction, which has not been done before. This gives a comprehensive overview and a starting point for material selection with regard to torrefaction and leads to added value for the project partners and the wider torrefaction community. Results of questionnaires on quality demands of producers and end users helped to find key research challenges for further development in SECTOR project. Requirements of raw material and quality issues helps ISO/TC 238 WG2 to develop a product standard ISO for thermally treated and densified biomass fuels. 20

21 Karl-Heinz Liebisch/PIXELIO thank you very much for your attention Kiitos! SECTOR Coordination: Prof. Dr.-Ing. Daniela Thrän SECTOR WP 2 leader Eija Alakangas, principal scientist VTT eija.alakangas@vtt.fi DBFZ ggmbh Torgauer Str Leipzig Germany More information on SECTOR project info@sector-project.eu URL: 21