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Chemical Hydrolysis Technology for organic waste streams TCBB/University of Limerick Technology Foresight Workshop 23/24 th April 2013 J J Leahy
Chemical Hydrolysis Technology for organic waste streams TCBB/University of Limerick
Technology Foresight Workshop
23/24th April 2013
J J Leahy
Can Occupy a Valuable Niche• Employ our chemical expertise to develop abiological processing methods for processing waste wood. (contaminated/hazardous)
• Chemical hydrolysis can be viable at small scales.
• Highly feedstock flexible (no concerns on biota inhibitors, water content, or gasifier performance).
• Acid-catalysed hydrolysis can produced value-added products directly from polysaccharides.
Acid Degradation of Cellulose
Acid Degradation of Hemicellulose
Markets for Products of Acid HydrolysisLevulinic acid, furfural, formic acid, lignin are valuable platform chemicals with huge potential…
Levulinic Acid Derived Chemicals
Chemicals Uses Means of Production
DALA Herbicides, Cosmetics, Diphenolic Acid Resins, Polymers,
Lubricants, PaintsReaction of LvA with phenol
Succinic Acid (SA) Food additives Oxidation of LvATetrahydrofuran PTMEG production,
Spandex, SolventCyclisation of SA
Furfural
Chemicals Uses Means of Production
FurfuralFurfuryl alcohol Resins, Hydrogenation of furfural(2,5)‐bis‐hydroxymethyl‐furan (BHMF)
Polyurethane, Polyesters
Formic Acid
Chemicals Uses Means of Production
Formic Acid Silage additive, Leather tanning, Drugs, Dyes, Insecticides
DIBANET process
Existing Processes
•Biofine:• 2-stage dilute acid hydrolysis at high T&P.• Most of the lignocellulse (lignin, condensed sugars) becomes a residue needed for process heat.
• Process not commercialised. Tested mainly on paper.
Dibanet -FP7 Call“Enhancing international cooperation between the EU and Latin America in the field of biofuels”
Levulinic Acid Formic Acid Furfural Solid Residues
Acid Hydrolysis
EsterificationEthanol
Ethyl Levulinate
Fast PyrolysisBio-Oil
BiocharUpgraded Oil
Upgrading
Grinding
Pretreatment
Partner Roles Development of core pretreatment and hydrolysis processes
Analysis of biomass, development of rapid (online) analytical methods
Thermochemical treatment and use of residues
Catalytic conversions of products
Evaluation of process, products and markets
IP Development at UL…A new cost effective process for the acid hydrolysis of lignocellulose waste to Levulinic Acid based on a novel Pretreatment Technology
Overview
• Technical context.• Limiting factors in LA production.• Kinetic model developed and validated.
• Motivation for and development of a novel pretreatment process.
• The pretreatment as the basis of an improved acid hydrolysis process.
• The design.
Processing Capacity
• Lab scale: • 0.1 Lt – 8Lt. • Atm – 50 Bar• In line sampling.
• Pilot scale: • Continuous system. • Up to 1Lt/min throughput.
Cellulose Hemicellulose LigninWheat Straw 38-45 18-25 10-25Rice Straw 35-45 18-25 10-25Newspaper 40-55 25-40 15-30Hardwood 40-55 20-40 18-25Softwood 45-50 25-35 25-35
Lignocellulose Feedstocks for Conversion to Platform Chemicals
• Lignin interference• Hemicellulose and cellulose
optimum conditions distinct• Physical state (Mass transfer)• Reactive intermediates• Optimum between speed/yields• Selectivity highly T dependent• Practicalities:
• T, P [Acid] effect on capital cost
Desired Hydrolysis Reactions Among Many Potential Unwanted Reactions
Originally DIBANET Targeted Improving on Biofine
Results of Kinetic Study
Cellulose Glucose LA + FAHMF
H2O H2O
H2O
TAR
Cellulose Glucose LA + FA
TAR
K1 K2
K3
k1 k2 k3Ao 1.980 x1018 2.529x 1014 1.93 x 1018
Ea 173919 144165 179165m 1.55 1.15 1.28
sec-1
kJ/kmol
Implications of Kinetics for Cellulose Conversion
• Cellulose Hydrolysis • Limiting reaction (high activation energy)
• Temperature • Increase temperature K3 gets faster relative to K2• Decrease yields of LA by increasing temperature
• Glucose concentration in solution is the key• Mass loading can be used to compensate for overall reduced rates at
lower temperature • [H+]
• Increased acid increased rates for all reactions
Existing Processes and PretreatmentsProcess attributes Organosolv/Acetosolv Biofine Milox Steam Explosion
Physical Pre-treatment Yes Yes Yes Yes
Heat Input +++ +++++ +++ +++++
Lignin Fractionation YES NO YES NO
Inherent Pressure Drop No YES NO YES
Holo-Cellulose Hydrolysis Moderate YES NO Moderate
Mineral Acid (H2SO4)
Yes Yes NO Yes/NO
Carrier Ethanol/Acetic acid H2O FA H2O
Objective Lignin recovery LA production Paper pulp Enzymatic feedstock
Ideal Process• Reduce mechanical energy inputs (grinding, chopping).• Fractionate and recover lignin• Increase the rate of cellulose hydrolysis reaction
• Swell/increase Surface Area• Reduce hydrophobicity by removing the lignin
• Operate at the lowest practicable temperature • Operate at the highest practicable acid concentration• Operate at the highest practicable biomass loading • Process the cellulose and hemi-cellulose separately
Oxidative Hydrolysis
• H2O2:• An oxidiser at ambient temperature in combination
with an organic acid yields per-acid: effective lignin dissolution medium.
• Can be catalytically triggered to decompose rapidly (Fe, Transition metals, pH).
• Decomposes exothermically (pressure).• Environmental. • available as a bulk chemical.
Suitability of Pretreated Pulp as a Feedstock for Bioethanol Production
Profile of glucose release during enzymatic digestion of Avicel (microcrystalline cellulose), raw and pretreated Miscanthus (5.0% and 7.5% H2O2) at 45 oC with a commercial cellulase enzyme mix.
Avicel
Raw (non-treated) biomass)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
0 0.45 1.5 7 24 48 72
Glu
cose
rele
ase
(DN
S a
ssay
), 54
0 nm
Duration of the enzymatic hydrolysis (hrs)
Substrate type
Pre-treated biomassFA/H2O2 -(5%)
Pre-treated biomassFA/H2O2 -(7.5%)
•No inhibition of enzyme activityby pre-treated pulp was detected(limiting factor with other pre-treatment)
•FA/H2O2 an effective way ofincreasing the enzymaticdigestibility for conversion intofermentable sugars
0
10
20
30
40
50
60
70
80
1 10 100 1000 10000
Levu
linic
Aci
d Yi
eld
(mol
%)
Time (mins)
Raw Miscanthus, 175C Raw Miscanthus, 150CPretreated 150C
Integrated Design Proposal Basis • Pre-treatment to yield two streams
• Cellulose rich sludge
• FA liquor with dissolved C5 sugars and Lignin
• Liquor is fed to CSTR for conversion of C5 to furfural• [FA] affects conversion
• The mixture is cleaned of humin and silicates
• Various evaporation and water addition steps are used to precipitate the lignin.
• A liquid stream containing FA, Furfural and Water is sent for product recovery and recycling
• Cellulose sent for conventional hydrolysis at 150 C in a series of CSTR’s
Aspen Simulations• Thermodynamics
• Azeotropic systems• FUR/H2O (good literature data)• FA/H2O (good literature data)• EtOH/H2O (good literature data)• OCT/H2O
• NRTL model with HOC adjustment for FA • Developed model for the Liquid-Liquid separation with Octanol
• Unit operation modelling• Distillation columns
• Edmister or Winn-Underwood-Gillian• Pretreatment reactor
• Fortran sub routines
Components and Properties
Mass Balance
Liquid-Liquid Extraction of LA from Aqueous Sulphuric Acid (SA)
• Literature state of the art• LA Loading in recovery stream 0.5-1%• Solvents tested in the absence of strong acid
• Esters (C4-C5)• Ketones (C5-C10)• Alcohols (C5-C10)• Typical KD 1.2-4
• Proposed additives for reactive extraction • quaternary salts, particularly ammonium and phosphonium, TBP, TOP have been
investigated in non acidic medium• In SAAQ the SA will be preferentially taken to the organic phase therefore must
be neutralised beforehand.• Our levulinic acid stream is 7%, therefore process efficiency is increased
without the use of reactive additives. SA available for recycling.
PRET-F INTER
Q-OUT2
Q
INTER2
CELL
Q-OUT1
Q
GAS
LIQ
BIOMS-IN
BIOMS-2
FA-RECYL
FA-IN
FA-1
H2O2-IN
H2O2-1
BIOMS-1
INTER-1
RECOVERY
LIGNIN
7
RECOV-C
SA-FED CELHYD-F
LA-1
RCRY-LA
RSTOIC
PRETRT-1
SEP
PRETRT-2
FLA SH2
PTRTRT-3
BIOMS-ST
FA-STORE
H2O2-ST
BIOMS-FS
SDPPERACD-M
XYL-CON
D
CEL-HYDM HYD-REAC
FL
RCVRY-M
SA-RCYL
Furfural Recovery and FA Recycle
12
14
15
DFUR
B1
10
20B2
4
B3
3
5
B4
7 DFUR2
8
9
Octan-2-ol for LA Recovery
TEST
OCT-FED
LA-SA-EX
LA-OCT2
SA-RCYL
OCT-RCYL
LA
OCT-COL
ETOH-FEDEL-ETOH
EL-CONVETOH-H2O
EL-OUT
EL-DECAN
ETOH-RCY
LA-H2O
ETOH-COL
FLSH-DRY
LA-RCYL
H2O-VAP
Overall Mass BalanceINPUT (MT) OUTPUT (MT)
Waste wood 1.1 Lignin 0.2
H2O2 (50%) 0.2 Furfural (94%) 0.1
Ethanol 0.1 EL (98%) 0.3
OCTANOL 0.002 Formic Acid (82%) 0.1
H2SO4 (98%) 0.002 Tar 0.2
CO2 Offset 1.9
Energy
Kw hr 1540
Cellulose Pulp Hemicellulose + Lignin (Soluble)
Pretreatment
Acid Hydrolysis
Levulinic Acid(258 kg)
Flash
Lignin(180 kg)
Furfural(127 kg)
Formic Acid(102 kg)
No Grinding Required
Residues(90 kg)
Residues(75 kg)
Combustion
Pretreatment Products
DIBANET Products
DownstreamConversion
Heat + Power
Value-Added-Chemicals biofuels
Catalytic Conversion
Bio-Products
(487 kg chemicals + 180 kg lignin)
1 Tonne of waste wood
Proposed Project
Year 1 Year 2 Year 3
Pretreatment + Furfural Production + Recovery
S2: Levulinic Acid ProductionCellulose
biopolymers
Furfural
Lignin
Primary Products
Potential Derivatives
