Bioenergy in Agriculture1929

not just hot air

Co-production of Biochar and Heat 2008

Brian Burt and

Ruth Hayward

• Growers and Retailers of Annuals , Perennials and Shrubs • 50,000 sq. ft. of greenhouses • 40,000 sq. ft. of outdoor coverable heated beds• 6 retail garden centers from Belleville to Kingston

• Right handed hired man: Alex English• Programmer : Colin Beckingham

ing

Capabilities

We are also• Early adopters of technology from computer

systems to biological controls • Developers of new technologies (hardware

and software)• The builders or improvers of many of the

components which now make up our heating system

• not graphic artists

Were Curious about Biochar, Pyrolysis and Soil Fertility

We aim to:

• Produce char to support research in agriculture and environment

• Prove viability of co-generation of biochar and heat

• Develop a new marketable product

Lessons from the World of Top Lit Up Draft Stoves (T-LUD)or Low Tech Char Making Stoves

After Years of Working with Stovesand Combustion Analyzers

Air starved pyrolysis can be easy

1. Minimize under fuel air for Gas Qualityand an option for Char

2. Foster a flame ceiling for Low Emissions

What changes going from

Stoves to Boilers Batch to Continuous Vertical to Horizontal

Now Scale it Up with a Blue Flame Stoker : The chain grate is a 150 year old concept .

Start animation Start empty stoker film

Char Production

• Added air lock and better valves to our existing chain grate stoker to gain control of all combustion air

• Allows for air starved pyrolysis of fuel• Low velocity and particulate entrainment• Reduced Particulate Emissions ?

• Start combustion movie

Chain Grate Pyrolysis front , Gas fog , Flame curtain , Flaming

ceiling

Process Considerations

• Under fuel air or hot gas recirculation• Grate speed X 3-9, Transit Time• Char Temperature (800C +/- 100C)• Steady state operation and heat storage• Modulation and thermal “flywheels”• Control inputs?• Automated Oxygen trim for over fuel air control

and clean gas combustion (O2 8-12% in stack sample) (CO as low as 0%)

• Very low fuel moisture , auto pyrolysis?

Process Monitoring

Combustion Monitoring

Fuel or Feed stock

ok

Biochar Feed Stock

• Moisture content <20%• Particle size , fines and pile dynamics?• Contaminants , heavy metals and hardware• Dirty demolition waste• Clean construction waste? Green Buildings and Green

(Black)Roof• Crop Residues, Straw and Stover (clinker solution?)• Switchgrass and Miscanthus (self quenching ?)• Pellets, Cubes, Chopped (<4cm)• Rotary dryer

Char handling

• Play movie 1• Particle size (ultra light fines)• Air lock (water or mechanical)• Cooling (water or time) < 100C at pipe end• Wetting, Ageing, Composting• Automation (barn conveyor, sludge pump,

magnets)

Char acteristics Lehmann J 2007 Bio-energy in the black. Frontiers in Ecology and the Environment

Char Quality (PAHs)

Char Yield and Thermal Loss

• 0-23% Char • 0~45% Thermal loss• 2X fuel cost rule for minimum char

production cost• Chips at $50 tonne =char at ~$100 tonne• @20% yield char valued @ 5X the fuel cost

covers the total fuel cost.

BioChar Saleswholesale or retail

• Bagged garden soils $2-$5 25 litre bag• Bulk $200-$600 tonne • Horticultural peat mixes ~ $400

Tonne• Calcined Clay?• Stalite (kiln expanded slate)?

Collaborators

• Dr. Paul Voroney of Guelph University• Dr. Pascale Champagne of Queens University• Scott Environmental Group, Norterra

Organics Kingston, Ontario• Local enthusiastic farmers and gardeners,

both large and small

The path to achieving sustainable agriculture involves moving from an

acceptance of the status quo to a redesign of the whole agricultural system.

Stuart Hill Ecological Agriculture Project

McGill University MacDonald College

Thank You