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

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

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.

DESIGN #1 CIRCULATING FLUID BED BLOWER

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

As Built

DESIGN #2 AUGER WITH STEEL SHOT

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

As Built

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

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

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

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.

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

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

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.