Post on 14-Dec-2015
25,000L PBR
3d PBR Pond
M2.5 Supernatant
E-2
M3.5 Supernatant
E-3
E-1
M2.1 CO2
M7.3 Hot Air
M7.1 EvaporatedWaste Water
6000L PBRE-2 E-4E-3
E-8E-7E-6
PulveriserSpray DryerCentrifuge
M1 INOCULUM
M2.3 Medium
M2.2 AIR
M2 Cell Culture
M7 Algae Paste
M6 Sedimented
Slurry
M5 Cell Slurry
M4 Cell Culture
M3 Cell Culture
M8 Dried Algae
M1.1 CO2M1.3
Medium
M1.2 AIR
M3.1 CO2M3.3
Medium
M3.2 AIR
M4.1 CO2M4.2
Medium
M4.4 Supernatant
E-4
M7.2 Waste Air
M6.1 Supernatant
M1.4Waste Gas
M3.4Waste Gas
M2.4Waste Gas
M8.1 Biomass Waste
E-9
ExtractionM9
Sedimentation Tank
E-5
M5.1 Supernatant
E-10
Purification
M9.1 Biomass Waste
M10
M10.1 BiomassWaste
M10.2 Astaxanthin
M4.3Waste Gas
M7.4 Biomass Waste
Overall Process of 5 tons/year Astaxanthin production plant
• Biomass concentrations in Inflow and Outflow Basis:• Based on residence time 5 days and daily 6 hours of solar illumination in Kunming, China
(Ref 1).
• Method: biomass dry weight 0.0004 kg/L in the final pond culture
• In the ponds the cell culture is harvested but not grown. So the cell concentration in the pond will be 6x10^7cells/L
• Per cell biomass: = 0.0004/(6x10^7) = 6.67x10^-12 kg/cell, confirms with the 1x10^-12kg/cell from Ref 2.
• Biomass IN (kg/day) = Start cell biomass (cells/L) x per cell biomass (kg/cell) x Volumetric flowrate (L/day)
• Biomass OUT (kg/day) = End cell biomass x per cell biomass x Volumetric Flow rate
Start Cell biomass End cell biomass
6 x 10^7cells/L 5 x 10^8 cells/L
Mass Balance of Dry Biomass
• Nutrient medium: 10 mM KNO3, 2 mM Na2HPO4, 0.5 mM CaCl2, 0.5 mM MgSO4, 2 mM NaHCO3 (Ref 1)
• Air: Aeration rate 0.05 vvm (Ref 1)• Mass concentrations of components in Air: 23.2%
O2, 75.5% N2, 1.3% Ar. Assuming Oxygen is used fully, N2 and Ar are inert. Oxygen concentration 150% saturation is desired. (Ref 2).
• CO2 in: 15vol% going into 6000L and 25,000L PBRs (Ref 1)
• CO2 out: 75mass% going out from PBRs (Ref 3).
Mass Balance
E-16000L PBR
M1 INOCULUM M2 Cell Culture
M1.1 CO2
M1.3 Medium
M1.2 AIR
M1.4Waste Gas
Dry Biomass 1.38 kgKNO3 0.42 kgNa2HPO4 0.12 kgCaCl2 0.023 kgMgSO4 0.025 kgNaHCO3 0.070 kgWater 412.68 kg
CO2 5.18 kg
Oxygen 73.63 kgNitrogen 239.61 kgArgon 4.13 kg
KNO3 3.49 kgNa2HPO4 0.98 kgCaCl2 0.19 kgMgSO4 0.21 kgNaHCO3 0.58 kgWater 2960.90 kg CO2 3.89 kg
Nitrogen 239.61 kgArgon 4.13 kg
Dry Biomass 11.53 kgWater 3444.47 kg
Total mass going In = 3703.62 kg/dayTotal mass going Out = 3703.62 kg/dayResidence time 5 days
0 1 2 3 4 5 6 70
100000000
200000000
300000000
400000000
500000000
600000000
f(x) = 88000000 x + 60000000
Biomass Growth
Days
Biom
ass c
ells/
L
MASS BALANCES kg/day
25,000L
PBR
M2.1 CO2
E-2
M2.3 Medium
M2 Cell Culture M3 Cell Culture
M2.4Waste Gas
M2.2 AIR
CO2 43.2 kg
Oxygen 153.39 kgNitrogen 499.18 kgArgon 8.60 kg
KNO3 29.12 kgNa2HPO4 8.18 kgCaCl2 1.60 kgMgSO4 1.73 kgNaHCO3 4.84 kgWater 25134.34 kg
CO2 32.40 kgNitrogen 499.18 kgArgon 8.60 kg
Dry Biomass 11.53 kgWater 3444.47 kg
Dry Biomass 96.05 kgWater 28703.95 kg
Total mass going In = 29340.18 kg/dayTotal mass going Out = 29340.18 kg/dayResidence time: 5 days
MASS BALANCES kg/day
ENERGY BALANCES
Energy Balance for 6000L PBRs (Assume Turbulence power and solar radiation negligible at this stage)Cooling Duty = Energy In – Out + Turbulence Power + Solar Radiation
Air Supply (O2,N2,Ar) CO2 Supply Cell culture Medium and
Water Total
m (Kg/Day) 317.37 5.18 414.72 2966.35Cp (KJ/Kg/C) 1.005 0.8439 4.184 4.184Inlet Temperature 25C 25C 20C 25COutlet Temperature 20C 20C 20C 20C∆T 5 5 0 5Q (KJ/day) 1594.78 21.86 0 62056.04
Q(KW) 0.0185 0.000025 0 0.718 0.737 kW
• Energy Balance for 25,000L PBRs: • Cooling Duty = Energy In – Out + Turbulence Power + Solar Radiation
ENERGY BALANCES
Air Supply (O2,N2,Ar) CO2 Supply Cell culture Medium and
Water Total
m (Kg/Day) 661.17 43.2 3456 25179.87Cp (KJ/Kg/C) 1.005 0.8439 4.184 4.184Inlet Temperature 25C 25C 20C 25COutlet Temperature 20C 20C 20C 20C∆T 5 5 0 5Q (KJ/day) 3322.38 182.28 0 526762.88
Q(KW) 0.0385 0.00211 0 6.0968 6.137 kW
Photo bioreactor process control parameters Values RangesBioreactor culture temperature Below 25 C 10-25 CBioreactor aeration rate 0.05v/v/mpH 6.5-7Starting cell concentration of PBRs 6 x 10^7 cells/l 5-8 x 10^7 cells/lFinal cell concentration for PBRs 5 x 10^8 cells/l 5-7 x 10^8 cells/lPhoto bioreactor process performance parameters Estimated values RangesPower consumption for cooling a 6000L PBR 60 kWh 0-120 kWhPower consumption for cooling a 25000L PBR 160 kWh 0-320 kWhPower consumption for turbulence a 6000L PBR 15 kWPower consumption for turbulence a 25000L PBR 67.5 kWAeration power input for the 6000L bioreactors 0.6 kWhAeration power input for the 25000L bioreactors 2.5 kWhDays for 6000L bioreactor cell culture to be ready 5 days 4-6 daysDays for 25000L bioreactor cell culture to be ready 5 days 4-6 days
Summary of Operational Parameters
6000L PBRs 5days = V / (3703.62 kg/day)V = 18518.1 kg 3 x 6000L PBRs needed
25,000L PBRs5days = V / (29340.18 kg/day)V = 146700.9 kg/ (1000kg/m3) = 146.70 m36 x 25,000L PBR needed
Mechanical Design for:
Equipment Volumes
• If one desires to provide large quantities of cheap/free light to the cultures, the cultures need to be taken outside.
• To be free from contamination they should be enclosed.
• Each 25,000L PBR module has 100m2 land surface area exposed to the sun
• Disadvantage: Large area needed (6x25000LPBRs need area of 780m2)
Mechanical design of 25,000L PBR
• 4 parallel plastic tubes each 0.41 m diameter 34.5 m length laid on an impermeable surface (Ref 2).
• Turbulence: air lift pump, Re ~ 4000• Air lift pump Duty: 2–3.4 kW m-3 • Cooler: To control temperature 15 to 25C. PBR
is automatically flooded with cold sea water from Kunming sea 600m under ocean surface.
• Cooler duty: 160 kWh
Mechanical design of 25,000L PBR
• Pumps• Air lift pump for cell culture going into PBRs• Centrifugal pump for outlet to the next PBR• Cascade Pumping System for cool water pump from deep ocean under 600m
deep to the cooling pool.• Air Compressor Duty: 1.25kW x 6• Filters• Air and CO2 filters: 0.2micrometre membrane filter• Medium filters:2micrometre membrane filter• Pipes and tubes: 0.41 m diameter 34.5 m length PVC Plastic Pipes, narrow PVC
tubes used for sparging CO2 and Air to PBRs• Line sizes for in and outflow of cell culture and medium: Nominal Size 2.5, OD
73 mm, Sch 40• Valves: Diaphragm valve for air, CO2 and water (fail-closed)
– Gate valve for cell culture• Tanks• CO2 Tank: Compressed tank stainless steel• Medium Tank: Stainless steel Tank
Specifications of Ancillary Items for 25,000L PBR
• An outline of the intended control system:
• Computer controlled parameters:• Nutrient concentration, Dilution rate,
Temperature, pH, Turbulence, Growth rate• Cell count system: Model Z1 Coulter Counter
Ref 2.
Control System Specification
1. Make sure all valves closed V-9, V-8, V-13, and V-102. Medium Supply valve is opened, V-103. The plastic tubes were filled with medium 4. Medium discharge V-11, V-12 is opened and medium pump E-4 started5. Medium drained to Supernatant storage6. Close V-10 Medium supply7. Close Drain valve V-128. Deep sea water V17 and V-18 opened and Pump E-6 was started9. Switch isolators: cell culture V-6, V-8 and E-3, CO2 supply V-1 and V-9,
medium supply V-10, Air supply V-4, V-16 valves were opened10. Conditions of supplies are fully computer controlled11. After the tube volume is filled, all incoming valves V-8, V-9, V-10, V-13
etc. are closed12. After 5 days V-13, V-14 opened and pump E-5 started to transfer to the
next PBRs
Start Up procedure of 25,000L PBR
1. All incoming valves and pumps to PBR is closed.
2. H2O cooler and all isolators switched off3. Close V-13, pump E-5, V-14 valve4. Open drainage valve fully V-125. PBR system was emptied of medium to
supernatant waste storage
Shutdown Procedure
• Ref 1: Jian Li, Daling Zhu (2011) An Economic assessment of astaxanthin production by large scale cultivation of HP
• Ref 2: Miguel Olaizola (2000) Commercial production of astaxanthin from HP using 25,000L outdoor PBR
• Ref 3: Shu KI Tsang (2004) Optimal Harvesting strategy for HP using stella based model
• Ref 4: http://www.tatup-journal.de/downloads/2012/tatup121_noua12a.pdf
• Ref 5: PBRs design and performance with respect to light and energy input Otto, Pulz (1998)
References