Post on 01-Apr-2021
Microalgae for valorization of industrial
wastes from pulp/paper mills and
oil refineries
Algae Biomass Summit 2014
A. Kuehnle, N.A. Nolasco, M. Perez, M. Johnson
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OVERVIEW: WOOD WASTE FROM PULP/PAPER MILLS
Bleached Southern
Pine hydrolysate
Southern Hardwood
Chips hydrolysate
Under USDA BRDI grant, Domtar teamed with KAS to valorize underutilized wood waste using microbial conversion into bioproducts.
Domtar
Largest uncoated freesheet (UFS) and paper grade pulp manufacturer in North America
Recently added diversity to its product mix, ventured into consumer products
Goal: “Fuel to feed”
Hog fuel into feed (and higher value algal bioproducts)
Wood hydrolysates produced by CSI, Cellulose Sciences International
PROCESS
Screen and select strains from KAS collection for growth on mixed sugars, tolerance to inhibitors in wood hydrolysates
Establish algal biomass productivity and sugar utilization (HPLC) using aerobic fermentation
Nutrient medium targeted biomass productivity (feed value and co-products)
Batch fermentation conditions T= 30°C, pH= 7.0, agitation = 300 rpm, DO2 = 100%, air
= 3.0 L/min
Hawaiian species, including Chlorella and Scenedesmus
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Hydrolysates profile: Salinity ranged 3.3% – 4.2%, pH: 5.5; undefined components Screening and controls: Standardized with C5 and C6 sugar equivalents
WOOD HYDROLYSATES FROM CSI
GROWTH VARIED WITH EACH TYPE OF WOOD
HYDROLYSATE
All five wood hydrolysates supported growth of algae
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WOOD HYDROLYSATES OUTPERFORM MODEL SUGARS
A 1.6-fold higher biomass productivity (2.87 g/L-day), was obtained with bleached southern pine (BSP) hydrolysate than with C5 and C6 model sugars alone (1.7 g/L-day).
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OTHER OUTCOMES
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C5 sugar effect
• Some strains thrive in hydrolysate vs in equivalent glucose alone
Excellent sugar utilization, varies with hydrolysate and impurities
• 2:1 sugars : biomass ratio (SHC), EtOH present as impurity
• Beneficial non-sugar components present in CSI hydrolysates
SHCBSP
Specific sugar utilization of algae in two
wood hydrolysates
2:1
5:1
CONCLUDING THOUGHTS
Opportunity to develop mill-based strategies matching hog fuel with strains
Can select preferred strain with lowest sugar requirement
Select strain that benefits from non-sugar components present
Select strains to utilize both the C5 and C6 sugars
Co-cultivate strains to match wood composition, efficiency
Product options for biomass Align volumes with off-take potential
Preferably match mill products with regional processors and off-takers
Next steps Validate metrics at next scale to meet targets in financial models
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Algae-wastewater pilot facility was designed, constructed and operated in 2013-2014 at Chevron Hawaii to demonstrate nitrogen and phosphorous reduction in refinery wastewater
Reduction in total suspended solids (TSS) in the effluent was also addressed, using tangential flow filtration
Utilized waste CO2 from refinery’s hydrogen formation plant, as previously demonstrated by KAS in EPA-award winning project
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OVERVIEW: WASTEWATER FROM OIL REFINERIES
ALGAE PILOT PLANT PBR AND SIMULATION TANK
PBR used Clear-Flex polyurethane tubing with sterile fittings fabricated to spec for KAS by Siftex (CT)
Simulation tank (10-feet deep) used basal pneumatic mixing with plant air and CO2 on discontinuous basis
System designed for future deployment into existing basins for minimal footprint
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EFFLUENT AND TEST PROTOCOL
Algae Pilot
Initial
TestAmerica:
NH3-N, NO3-NO2 N,
TKN, Total N, Total P
KAS: NH3-N, NO3-N,
PO4-P, algal count,
bacterial CFU, DW (or
TSS), DO, pH, temp
During the Test
(KAS)
NH3-N, NO3-N,
PO4-P algal count,
bacterial CFU, DW
(or TSS), DO, pH,
temp
Final
TestAmerica:
NH3-N, NO3-NO2 N,
TKN, Total N, Total P
KAS: NH3-N, NO3-N,
PO4-P, algal count,
bacterial CFU, DW (or
TSS), DO, pH, temp11
Chlorella-like
Scenedesmus sp.
Bacteria
•Triplicate grab samples- before and after treatment- were analyzed by TestAmerica
Wastewater rich in ammonia N
N and P levels significantly reduced in 3 d 97% reduction in Ammonia N, 69% reduction in Total N, 90% reduction in Total P
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Initial Final
Total
N
NH3
N
Total
P
69%
Reduction:
97% 90%
Scenedesmus thrived in the wastewater, compatible with the other microbes Previous work by KAS with this and other tested organisms showed
utilization of mixed N sources, and variable amounts of NH3 and NO3
Very important for fluctuating oil refinery wastewater profiles
Met end objective of using mixed microbes to best polish the wastewater
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KAS740
Hollow fiber filtration removed 99+% of total suspended solids; suited to solids recycle as needed
Basal pneumatic mixing system effective for deep ponds, promising for use in existing basins
For managing nutrient loads and suspended solids:
Results support final polishing of wastewater using KAS’s basis of design and P&ID solution
Used off-the-shelf industrial equipment and components in innovative manner for ease of deployment
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OTHER OUTCOMES
Using KAS solution, possibility to address targets in both
downstream and upstream pits/basins of the O&G industry
Potential $10 B O&G wastewater market in U.S. by 2025
Additional validation, deployment with engineering firm
Difficult to sell into this market without a partner
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CONCLUDING THOUGHTS