Small and highly efficient hydrothermal liquefaction (HTL) units for scalable mass implementation in biomass conversion Ib Johannsen , V.Milkevych, D.More, B.S.Kielsgaard, K.Anastasakis, P.Biller Bio2Oil IVS and Dept. of Engineering, Aarhus University, Aarhus, Denmark
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Small and highly efficient hydrothermal liquefaction …...Needfor innovation!! •Biomassdo not fit intoexisting technologyplatforms: •Present chemicaland refinery industryis basedon
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How to get a feedstock that warrant a HTL business in Europe
In a no subsidy environment its hard to make a viable HTL business Biomass costs in Europe approaching 80€/tonFeedstock cost >200 €/ton crude oil - no room for processing costs
Negative cost feedstocks seem attractive§ Waste water treatment sludges have negative cost
§ But are often available with low DM content (1-5%)
§ We noticed that our usual HTL feedstocks like wood chips are fibrous after extrusion
§ What if we could use this material for filtration – a filter aid?
§ The filter medium adds organic material for the HTL process to produce additional fuel
Sludge filtration using biomass
§ Filtration times reduced form ~ 20 mins to 1 min
§ Cake resistance reduced by orders of magnitude
§ 1 filter aid unit required per 4 units of dry sludge
§ Batch filtration studies used to calculate scaled up
continuous operation on continuous filter systems.
§ WWTP of 200,000 PE requires 3 tons of waste
biomass per day for all the sludge filtration on a
8m2 drum
07/06/201916/01/2018
Using biomass filter aid
Without biomass filter aid
Bio-crude from sludge
07/06/201923/05/2018
C H N S O
HHV
(MJ/k
g)
Energy
Recovery
(%)
With K2CO3
Sludge 72.8 9.7 2.3 0.8 14.4 36.1 55.5
Miscanthus 74.4 7.1 0.6 0.1 17.9 32.1 48.4
Pine 74.2 7.7 0.3 0.0 17.9 33.0 40.3
No catalyst
Sludge 74.6 10.1 2.5 0.7 12.2 37.7 66.8
Miscanthus 72.9 6.4 0.5 0.1 20.1 30.3 40.2
Pine 71.1 6.9 0.2 0.0 21.8 30.2 50.7
Sludge Co-liquefaction with biomass filter aid with
Miscanthus 74.3 9.3 2.4 0.5 13.6 36.1 80.5
Pine 73.8 9.3 2.2 0.5 14.2 35.9 79.7
Co-liquefaction of biomass filter aid and sewage sludge has synergistic beneficial effects:
Higher bio-crude yields than the separate counter parts
Higher energy recovery
Lower oxygen content
use of alkali catalysts for HTL of lignocellulosics is avoided
✘A part of nitrogen ends up in the bio-crude during co-
liquefaction
Initially we are aiming to make low grade fuel and bitumen
Bio-crude yield
Bio-crude composition
Carbon flow in a modern, fully optimized WWT plant
12% carbon
into fuel - CH4
Integration in WWT – what industry wants
• Solve our sludge problem (digestate)
• Posible but not optimal
solution
• High ash feedstock
Integration in WWT – the simple way
• Fits within normal plant design
• Solves the problem of
pathogens, plastics and drug
residues
• Significant reduction of aeration
costs
Carbon-balance
Phosphor recovery – ongoing research
§ At 350°C and 200 bar phosphates and other high valance salts are insoluble in water
§ Phosphate precipitates and is filtered out continuously
§ Phosphorous recovery in concentrated solid residue is >95%
§ We can combine the HTL process water rich in NH4 with PO4 in residue to produce struvite
§ Efficiencies recovery of ~90% P from incoming HTL feedstock
§ P is bioavailable
07/06/201916/01/2018
Much wider application
Other negative value feedstocs
• Industrial waste streams
• Municipal solid waste - organic fraction
• Waste wood
Once biocrude get accepted as a key ressource in the refinery
industry the economy will be fine for agricultural sidestreams if
credtis are taken into account
Summary
• It makes sense to go decentral
• Innovation is needed and it makes sense to take an engineeringapproach to bridge the gap between research and production
• Bio2Oil’s modular units are prone to become a game changer –