Biochar technologies, production and cost

Transcription

1 Biochar technologies, Presentation by Jim Bland (for Colin Stucley), Bioenergy Australia Conference, Melbourne 2008 December 2008 Page 1

2 Topics: Enecon What is biochar? How is it made? Equipment and scale Cost of production December 2008 Page 2

3 Enecon: Formed in 1998 by experienced engineers. Specialise in bioenergy Consulting work Technology development Also carry out assignments for other industries: particularly chemicals and minerals. Melbourne-based, work nationally. From studies through to commissioning. December 2008 Page 3

4 Enecon: Bioenergy experience around Australia Liq. fuels Bioenergy Bioenergy Charcoal IWP (inc. char) Pyrolysis and char Pellets December 2008 Page 4

5 Enecon: Integrated Wood Processing: CSIRO pilot plant technology for charcoal Fluid bed carbonising pilot plants: Batch Continuous December 2008 Page 5

6 Integrated Wood Processing: Demonstration plant, Narrogin WA December 2008 Page 6

7 Awards received for concept and demonstration Institution of Chemical Engineers Environment & Energy Award, UK Institute of Engineers Excellence Awards for (1) Environment and (2) Engineering for Rural Communities, WA and development work now underway for next stage. December 2008 Page 7

8 Now let s look at the characteristics of charcoal. Charcoal made from different feeds and different processes can show major variability across: Particle size Porosity Hardness Carbon content Other consituents December 2008 Page 8

9 Typical charcoal from a fast pyrolysis plant December 2008 Page 9

10 Australian hardwood carbonised in fluidised bed December 2008 Page 10

11 Wide range of material can be carbonised, virtually any carbon-containing organic material: Wood Bark Crop residues Organic wastes (manures etc) Mixed material (e.g. chicken litter) December 2008 Page 11

12 The carbonising process can be applied via: Combustion excess oxygen Gasification restricted oxygen Pyrolysis no oxygen December 2008 Page 12

13 The carbonising process. As temperature is raised.. First, drive off water. Then drive of volatiles. Fixed carbon content increases while yield decreases. Charcoal yield (from dry wood) may vary from less than 10% to more than 30%, depending on process and product characteristics. December 2008 Page 13

14 Commercial production technologies: Static kilns Rotating kilns Retorts Multiple Hearth Furnaces Fluidised beds December 2008 Page 14

15 Kiln for high quality lump cooking charcoal (bincho), in Asia December 2008 Page 15

16 Kiln for high quality lump cooking charcoal. Combustion raises temperature to 1,200 deg C or higher. December 2008 Page 16

17 Typical commercial scale rotating kiln, Australia December 2008 Page 17

18 Typical vertical retort for charcoal manufacture December 2008 Page 18

19 Commercial scale vertical retort, at SIMCOA silicon smelter, Kemerton, WA December 2008 Page 19

20 Multiple-hearth furnace December 2008 Page 20

21 Commercial scale multiple-hearth furnace, USA December 2008 Page 21

22 Fluid bed for controlled combustion and charcoal manufacture. IWP demonstration plant, Narrogin, WA December 2008 Page 22

23 Fluid bed for fast pyrolysis, to produce: Pyrolysis oil (60-70%) Charcoal (10-20%) Combustible gas (10-20%) Largest wood fast pyrolysis plant in the world: Dynamotive's 200 TPD plant near Toronto. December 2008 Page 23

24 Comparing process technologies indicative results (Actual results can vary with feed,equipment etc) Fluid bed Retort MH Furnace Kilns Feed size woodchips, splinters, sawdust wood chunks woodchips, splinters, sawdust wood chunks Feed moisture content (% wet basis) up to 50% up to 45% normally 10% up to 25% Operation continuous semi-continuous continuous batch Waste heat recovery? Integral optional optional no Charcoal type fines & small pieces lump fines & small pieces lumps Charcoal carbon content 70% 80-85% 80% up to 90% [1] Provided the ash content of the feed material is low December 2008 Page 24

25 What scale is best? Small scale has advantages: Lower capital cost Focus on local feeds Save money via reduced transport of feed and product Combine operation with other farm scale activities? December 2008 Page 25

26 What scale is best, cont d? Large scale also has advantages: Considerable economies of scale for capital cost and operating cost. Continuous, automated operation. December 2008 Page 26

27 Do large plants justify greater transport distances? Enecon: three separate studies looking at plants to manufacture between 4,000 and 30,000 tonnes char per year from wood. Our costing data indicate that, for a constant feed price in the field, economy of scale is often more important than transport distance. But individual circumstances must be considered in each case. December 2008 Page 27

28 Cost of production: Feed Plant capital cost Operation Co-products Incentives December 2008 Page 28

29 Feed cost 1. Charcoal yield is typically between 10% and 30% of the dry weight of the feed material. 2. Yield not so important for waste feed at no cost. 3. But for mallees at $40 /green tonne, and assuming 25% yield per dry tonne, the cost of feed alone will be more than $250 per tonne of charcoal. December 2008 Page 29

30 Capital cost: 1. Very dependent on plant size 2. May include feed storage, size reduction, feed drying, product handling and storage. Operating costs: 1. Energy particularly grinding and drying 2. Labour typically three shift plus reserves 3. Maintenance December 2008 Page 30

31 Co-products, vary with technology: 1. Several technologies produce wood gas may be burnt on site for heat or for electricity generation (if it can be properly cleaned). 2. Fast pyrolysis makes pyrolysis oil as main product can be transported to other markets. 3. Some technologies can produce pyroligneous liquors in small quantities. Used for variety of chemicals a century ago but rarely used now. December 2008 Page 31

32 Major incentives for biochar are enhanced soil productivity and carbon sequestration. But: 1. Other groups say coal-based char can also improve soils, and coal is cheap and abundant. 2. Using the biomass feed for renewable energy also provides GHG reduction. 3. Adding biochar may reduce N emissions from soil. Very good GHG reduction, but no policy in place yet to include in financial appraisal. December 2008 Page 32

33 Summary: 1. Multiple technologies already available for char manufacture. 2. Costs vary widely with feed and scale. Paying for feed adds significantly to final char cost. Large scale plants are much cheaper per tonne of product. December 2008 Page 33

34 Summary cont d: 3. Charcoal manufacture more is cost effective with coproducts, but only if markets for these products are available. 4. We must continue to quantify the benefits of biochar, so these benefits can: influence government policy, and allow biochar to succeed, in what will always be a competitive commercial environment. December 2008 Page 34

35 Thank you Colin Stucley - Director Suite 3, 651 Canterbury Rd, Surrey Hills, Victoria 3127, Australia Tel. (61 3) December 2008 Page 35