Production Scale Briquetting of Torrefied Biomass

Transcription

1 Production Scale Briquetting of Torrefied Biomass Wolfgang Stelte Danish Technological Institute DTI European Biomass Conference 2013 Copenhagen, 7 th June 2013

2 Danish Technological Institute Center for Biomass & Biorefinery Part of the Division for Energy and Climate Around 30 people in 4 locations in Denmark Grenå Algae Center Denmark Denmark Aarhus Biomass Laboratory and Offices Taastrup Offices Sdr. Stenderup Pilot plant and production facilities

3 Densification of Torrefied Biomass Densification of torrefied biomass is not straight forward Degradation of biomass polymers (hemicellulose/lignin) Removal of hydrogen bonding sites Brittle and porous material Reduced bonding properties Dust formation High energy uptake is seen in pelletization Development of a cost competitive process is a challenge Ongoing RND in industry and academia Briquetting and pelletization processes EU-Project SECTOR

4 EU-project SECTOR Production of Solid Sustainable Energy Carriers from Biomass by Means of Torrefaction 21 partners / 9 countries / 42 months Work package about Densification Focus on Pelletization and Briquetting Briquetting: Industry partner C.F. Nielsen Partners in SECTOR project:

5 Briquetting of Biomass Raw materials: wood, agricultural residues, waste High pressure and high temperature Release of lignin from Biomass Inter-particle bonding Formation of a high density briquette

6 Briquetting of biomass Generally we meet 3 types of briquetting presses Mechanical presses Hydraulic presses Screw presses C.F. Nielsen is the world leader within mechanical briquetting presses and offers also hydraulic presses Hydraulic and Mechanical presses ( kg/h) More than 70 years of experience Several hundred briquetting presses in operation spread over all 5 continents Wide range of raw materials (wood, agro residues, waste etc.) Individual design of briquetting press according to customer needs Experience with torrefied biomass

7 Briquetting of Torrefied Spruce

8 Briquetting of Torrefied Spruce Torrefaction: Reactor: Pilot Reactor at Energy Center of The Netherlands (ECN) Moving bed principle (Drying and Torrefaction Section) Capacity 50 kg/h Continuous operation 3 Batches: 240, 260 and 280 C / 30 Minutes residence time Raw material: Spruce chips (max 45x45x15 mm) Feeding of biomass on top of the reactor Torrefaction Section of the reactor

9 Briquetting of Torrefied Spruce Ash (550 C) H 2 O (105 C) Volatiles C H N O HHV Yield Fuel % (db) % % (db) % (db) % (db) % (db) % (db) MJ/kg % Spruce 0,36 12,6 81,2 49,2 6,3 0,1 46,1 20,2 100 Spruce 240 C 0,32 2,5 80,1 50,8 6,4 0,1 45,4 20,4 94,5 Spruce 260 C 0,39 2,3 76,75 53,2 6,2 0,1 42,9 21,5 85 Spruce 280 C 0,4 0,6 70,9 56,3 6,2 0,1 40,1 22,7 73 Data from ECN Spruce 240 C 260 C 280 C Increase of heating value and C/O Ratio

10 Briquetting of Torrefied Spruce Briquetting press (6500 BP Automatic, CFN) 200 kg of each sample 60 mm diameter Water addition for start up Determination of capacity Die temperature Briquette surface and inner temperature Unit density

11 C.F. Nielsen Briquetting press control unit

12 Feeding tank Conditioning of raw material : Water addition Briquetting press: outlet Cooling conveyor

13 Briquetting of Torrefied Spruce Results Spruce 240 C 260 C 280 C

14 Briquetting of Torrefied Spruce Results Raw material Spruce (fresh) 240 C 260 C 280 C Density (raw material) kg/m Moisture % 13,4 5,2 4,3 4,8 Particle size min mm 1x1 0,1x0,1 0,1x0,1 0,1x0,1 Particle size max mm 10x5 5x2 5x2 5x2 Process Power consumption A Die Temperature C Strokes per min 1/min Strokes number n Capacity (measured) kg/h Product Diameter mm ,5 Length mm Volume cm Weight g Density (briquette) kg/m Decrease of MC and particle size Stable power consumption and capacity Stable pellet quality

15 Key Results Continuous briquetting of torrefied spruce without stoppages Briquette quality is good but slightly decreasing for higher torrefaction temperatures Water addition can improve the briquette strength, there is an optimum moisture content further tests required to confirm Density is around 1000 kg/m 3 but can most likely be improved by adjusting die diameter and length and by adding additives. Latest developments shows densities up to 1300 kg/m 3 for small tests. Briquette surface is porous, flake like structures Latest developments shows improvements Process needs further optimization to obtain a sealed surface of the briquette Best results when briquettes remain under heat and pressure for longer time Baking of the briquette Friction increases with degree of torrefaction (Temperature increase), however capacity and power consumption of press remains stable

16 Briquetting of Torrefied Spruce Latest developments: - Sealed / Smooth surface water resistance - Density up to 1300 kg/m 3

17 Acknowledgements The present study was done under the frame work of the FP7 project SECTOR - Production of Solid Sustainable Energy Carriers from Biomass by Means of Torrefaction More information and results can be found on the project website:

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