1. Peter Fransham, PhD VP Technology ABRI-Tech Inc. Namur, Quebec
Pyrolysis 101
Peter Fransham, PhD
VP Technology
ABRI-Tech Inc.
Namur, Quebec

2. Case History – Two Pyrolysis Systems
Pyrolysis is a thermo-chemical process to convert biomass into liquid fuels.
Wood is a polymer and we are cracking that polymer into smaller molecules, some of which are liquid.
Objectives: maximize liquid yield and quality for use as a fuel. For now we will assume there is a market for the fuels.
Heat transfer from heat carrier to biomass

3. What are the Primary Constraints?
Selling gigajoules – a commodity with a price that varies internationally. The amount of revenue is largely out of our hands.
Capital and operating costs – The first rule of business is “don't loose money”!! You don't necessarily have to make money, just don't loose it.

4. DESIGN #1 CIRCULATING FLUID BED
BLOWER

5. CIRCULATING BED Circulating hot sand
Verical tube mixing sand and biomass
For commercial scale tube is 10 – 15 m high
Residence Time about 1 second
Velocity 10 – 20 m/sec
Circulating gas has to be continuously heated and cooled
All biochar and NCG gas is burned to provide process heat

6. As Built

7. DESIGN #2 AUGER WITH STEEL SHOT

8. AUGER PYROLYSIS CIRCULATES STEEL SHOT AROUND A LOOP
BIOMASS IS INCORPORATED INTO HOT SHOT AND PYROLYZED
CHAR STRIPPED FROM SHOT WITH CIRCULATING FAN AND CYCLONE
SIMPLE TUBE AND SHELL CONDENSERS
SYSTEM OPERATES AT +1 CM H2O

9. As Built

10. OBVIOUS COMPARISONS AUGER CFB
Mecanical mixing
Intimate contact
Dense high thermoconductivity heat carrier
Reactor temp 470 C
No fluidization blower and no carrier gas to heat and cool
Pneumatic mixing
Disperse contact
Low density low thermoconductivity heat carrier
Reactor temp 515 C
Energy consumptive blower and carrier gas

11. HEAT TRANSFER CARRIER AUGER CFB
Q= cp*Delta T* M
cp shot 0.5 kJ/kg-K
Thermconductivity 43 W(m-k)
Density 4.5 kg/l
Delta T 20 C
45 kJ/l
Pyrolysis heat 1000 kJ/kg
22 litres of shot per kg of biomass
Q= cp*Delta T* M
cp sand 0.8 kJ/kg-K
Thermconductivity 0.15 W(m-k)
Density 0.5 kg/l
Delta T 20 C
8 kJ/l
Pyrolysis heat 1000 kJ/kg
125 litres of sand per kg of biomass
Plus the inert gas moved

12. Basic Ecoomics What is important: Capital cost Operating cost
Revenue from products sold

13. Capital Cost Need to minimize capital cost Interesting problem
Use cheaper parts to minimize capital cost
Push maintenance onto the owner
Risk having reputation as a poor product
No simple answer.

14. Operating Cost Labour – Output per manhour
OSHA and Labour Legislation
Feedstock cost – need to minimize yet get quality
Maintenance – this is a big one
For many industries maintenance is between 3% and 5% of capital cost.
Back to the design and pushing the capital cost down at the expense of maintenance.
Since maintenance is a percent of capital it is important to design to minimize capital cost and keep it simple

15. Back to Case History 100 tonne per day
Parameter
Auger
CFB
Capital Cost
$5 million
$20 million
Electricity
.25 mW
1.3 mW
Operating hours
7500
Electricity Cost
$175,000
$975,000
Maintenance 5% Capital
$250,000
$1,000,000
Total
$425,000
$1,975,000
Production T/yr
21,450
23,100
Cost per tonne
$19.80
$85.50
Sale price Bunker C
$175/tonne
Biomass Cost $/dry tonne
$60.00
Minimum Profit 10%
$17.50

16. Summary Always look for the simplest solution
Avoid the trap of trying to look smart by a complex design
Continuously evaluate the factor of safety to make certain the design is safe but not excessively so.
Don't be afraid to back up and redesign – it is better than the concrete kayak that sinks.