Post on 03-Aug-2020
www.cranfield.ac.uk
Enzymatic hydrolysis: a forgotten step in AD
Dr Raffaella Villa
September 2017
2
Engineer out the step to increase the
overall rate
Pre-treatments
3
Enzymatic pre-treatment
4
What are enzymes? And how do they work?
Biological catalysts
• Reduce activation energy of reactions
• Specific• Stable and work in mild conditions
5
Advantages of enzymes
Energy Saving – mild conditions
Cost Saving – less chemicals
Cost saving – low CAPEX
Eco-friendly – biodegradable
High Specificity
6
Share of enzymes use in the industrial sector
Animal feed
Food and Beverages
Paper and textile
Medicine and
Biotech
Household care
Biofuel
http://www.kyrobio.eu/index.html
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SugarsProteins
Different pre-treatments = release of differentcompounds
sCOD
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Enzymes for biogas production
Pre-treatmentDirect addition
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Cellulases: not all the same
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
1 2 3 4
Incr
eas
e in
sC
OD
(m
g/l
)
Enzyme dose (U/g TS)
100
300
600
800
1500
3000
3000
9000
9000
18000
18000
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Biogas & methane increase
Enzymes for improved biogas production, Čermáková, A., Bajón Fernández,Y. and Villa, R. in preparation
0.0 1.0 2.0 3.0 4.0
Direct addition
Pre-treatment at50°C
with enzyme
Pre-treatment at50°C
Pre-treatment at37°C
with enzyme
Pre-treatment at37°C
Biogas and methane (Nm3/kg)
Increase in Methane Production (Nm3 CH4/kg of VSadded)
Increase in Biogas Production (Nm3/kg of VSadded)
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Different enzymes = different specificity
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Biogas and methane: different enzymes
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Different enzymes on food waste
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Direct addition of enzymes
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Extracellular hydrolytic enzymes
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Extracellular hydrolytic enzymes
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What’s next?
• Long term effect of enzymes at pilot scale
• Variation of HEE
• Tailoring from digestate
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Thank you for your attention
Thanks also to our funders and my co-workers on the project
Dr Yadira Bajón Fernández Jana Jantova Patel
www.cranfield.ac.uk
T: +44 (0)1234 750111T: +44 (0)1234 758363
Dr Raffaella Villa
r.villa@cranfield.ac.uk