Design, Construction, Testing, and Deployment of a Biochar Reactor: A Student Capstone

Project

Robert Prins and Wayne TeelJames Madison University

Presentation Map•Biochar Primer•what is biochar?•why should we care?•how is biochar produced?

•Student Capstone Project

What is biochar?•Biomass that has been processed into a soil amendment through pyrolysis•Historical usage dates to 450 BC•Terra preta sites in the Amazon

•Recent revival of interest as a carbon sequestration technique

What is biochar?

Value of Biochar as a soil amendment

•High microporosity (~1000 m2/g)•Low density (0.5g/cc)•High cation exchange rate

Feltz, 2010

Feltz, 2010

Value of Biochar as a carbon sequestration technique

•Atmospheric carbon is absorbed by plants •Plant based carbon is unstable, plant decay releases carbon to atmosphere•Biochar can remain in soil for 1000s of years

J. Lehmann, “Black is the New Green”, Nature, Vol 442, 10 August, 2006

Biomass to Biochar•Gasification of biomass via pyrolysis•Heating in the absence of oxygen•Initial heating drives off water vapor (100 C)•Further heating (~350 C +) drives volatiles out of carbon structure• synthesis gas (H2, CO, CO2 )

Glaser, 2007

Development of a Farm-Scale Reactor Project is well suited as a student project

•Student design, construction and deployment•Low-cost design approach

•Meets ISAT capstone project best practices:•Real world problem•Situated in a relevant social context• Includes hands-on work

Student Participation•Independent study• 2 students, FA08 – SP09• Biochar investigation• Initial design concepts•Senior Capstone Project• 4 students, FA09 – SP10• Final design• Implementation

JMU Biochar Processor Concept

Marier, Austin, Clark, Dick, 2010

JMU Biochar Processor (Gen. 1)•Chamber within chamber design•Syngas from feedstock is used to supplement heat source•21% net mass retention

JMU Biochar Processor1

6

54

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20”

28 1/2”

6 1/2”

21”

13 3/8”

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JMU Biochar Processor

51 1/2”36”

15”

54 1/2”

38 1/4”1

2

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4

JMU Biochar Processor Data

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0 10 20 30 40 50 60

Tem

pera

ture

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Time (Minutes)

Internal Barrel Temperature Over timeBurn 4

Desired Temperature

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Drying Wood

SyngasCombustion

Syngas Combustion

Summary•Biochar is a valuable soil amendment• Porosity• Density• Cation exchange•Biochar is produced from biomass via pyrolysis•Student project to develop a low cost processor was successful• Produced biochar (21% mass retention)• $800 in materials • Demonstrates win-win-win

Future work (Future Student Projects)

•Gen. 2• Improve sealing of outer chamber (roof, door)• Improve sealing on inner chamber door• Increase robustness of chamber walls• Improve heat recovery system•Gen. 2.5• Improve heat recovery system

Thank you

•Questions?

Thank you

•Questions?