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Techno-economic Assessment of
Microalgae Biodiesel
Hassan I. El-Shimi
Associate Lecturer
Chemical Engineering Department, Cairo University, Egypt
Email: [email protected] Phone: +2 01118087862
Wednesday March 2nd, 2016
The1st International Conference on
Applied Microbiology
entitled
Biotechnology and Its Applications in the Field of Sustainable
Agricultural Development
March 1 - 3, 2016 Giza, Egypt
Introduction
Why make algae a fuel?
Research Objectives
Experimental Work
Results
Conclusions
Acknowledgement
References
2 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Introduction
Ever-increasing of energy incentives the scientists to
search and develop renewable energy sources such
as biofuels.
Liquid biofuel is the unique alternative for
transportation fuel, while solar and wind energy is
better to utilize in electricity production.
Algal biodiesel is a technically attractive alternative
and renewable diesel fuel without excessive engine
modifications.
4 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Why make algae a fuel?
Microalgae can be cultivated in domestic
wastewater (1m3 of wastewater is
required to produce 800 g of dry algae).
Microalgae reduce emissions of a major
greenhouse gas (1 kg of algal biomass
requiring about 1.8 kg of CO2).
6 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Biodiesel from Algae
doesn’t conflict with the
food crisis.
7 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Microalgae reproduce themselves every few days.
High oil productivity (1000-6500 gallon/acre/year)
Oil yield exceed 10x the yield of the best oilseed crops.
8 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Research Objectives
10 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Biodiesel Production from Algae
Direct Transesterification of
Algal Lipids into Fatty acid
Methyl Esters (Biodiesel)
without Pre-extraction of Algal
Oil.
Extraction of Algal Oil
using Mechanical
Pressing followed by
Chemical Solvent
like Hexane.
Transesterification of
Algal Oil into
Biodiesel.
OR
Chemistry of Transesterification
11
Clean Burning Alternative fuel for diesel engines
Produced from Domestic Renewable Resources: any fat or oil, like vegetable oil, used greases, animal fat.
Meets health effect testing (CAA)
Lower emissions, better lubricity
High flash point (>170oC), Safe to store and burn
Biodegradable, Essentially non-toxic.
Chemically, biodiesel molecules are mono-alkyl esters produced usually from triglyceride esters
Research Objectives
Algal Biomass
CO2 Emissions
Wastewater
Egypt Desert
Highest Algal Biomass
Productivity and Lipids %
Direct Transesterification
Feasibility Study & Algal
Biodiesel
Commercialization
12 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Experimental work
Compounds %
Proteins 61.3
Lipids 11.05
Minerals 6.95
Fibers 4
Moisture 0.5
Carbohydrates 12.8
Nucleic acid 2.5
Spirulina-platensis
Materials
Microalgae were supplied from
Microbiology Department, Agricultural
Research Centre, Giza
Chemicals
Methanol CH3OH (99.9 % purity)
Sulphuric acid H2SO4 as a Catalyst (98% purity)
Hexane C6H14 for Decantation
Distilled H2O
All chemicals were purchased from El-Nasr
Pharmaceutical Chemicals Co. Egypt.
14 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Equipment
15 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Reactor
"Acidic
Methanol"
Obtain water layer:
glycerol + catalyst
+ excess methanol
Filtrate solution:
Biodiesel + Glycerol
+ Catalyst +
Methanol +
Unreacted Oilgae Water
Glycerol
Biodiesel
Microalgae
Powder
Algal cake
Hydrophobic
layer: hexane +
biodiesel +
unreacted
Oilgae
Filtration
over sodium
sulphate
Evaporation
Filtration
Generation
of two
layers
Methanol
Evaporation
Hexane
Direct Transesterification
16 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Alcohol/Oilgae
(wt./wt.)
Reaction
Time
Catalyst
Concentration
Temperature
Agitation
Mode
Biodiesel
Crude
Glycerol
Filtration
17 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Results
Component Value Unit
Carbohydrates 12.6 %wt
Protein 51.5 %wt
Moisture 1.5 %wt
Ash 7.5 %wt
Ca 400 mg/100 g algae
P 900 mg/100 g algae
Fe 70 mg/100 g algae
N 500 mg/100 g algae
K 1475 mg/100 g algae
Valid as a bio-fertilizer
Algalcake
The predominant fatty acid was the palmitic acid C16:0
(49.58% by mole), which makes the oil a promising
feedstock for biodiesel fuel synthesis.
Algal Oil
Fatty acid Spirulina Jatropha
Mystic (C14:0) 22.67 0
Palmitic (C16:0) 49.58 18.22
Palmitoleic (C16:1) 2.75 1.2
Stearic (C18:0) 5.56 5.14
Oleic (C18:1) 2.24 28.46
Linoleic (C18:2) 5.03 48.18
Linoleuic(C18:3) 7.41 0
Ecosanoic (C20:0) 1.06 0
Eicosenoic (C20:1) 3.69 0
Saturated 78.87 23.36
Monounsaturated 8.68 29.66
Polyunsaturated 12.44 48.18
Avg. Mwt. 845 Nil
900
500
1475
The acid value and viscosity of Oilgae were too much; 37.4 mg KOH/g and 58 cp,
respectively. Therefore the choice of acidic over alkaline catalysis for the direct
transesterification process was justified.
19 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Variables affecting the direct
transesterification
1. Effect of Alcohol/S.platensis mass ratio
Temperature: 65oC
Time: 8 hr
Catalyst conc. 100% wt.
Stirring: 650 rpm
73.2
81.79
84.7 84.7
y = 2E-07x3 - 0.0004x2 + 0.261x + 27.9
R² = 1
72
74
76
78
80
82
84
86
0 100 200 300 400 500 600 700
Alg
al
bio
fue
l c
on
ve
rsio
n (
%)
Methyl alcohol/S.platensis mass ratio
The studied range of methanol/feedstock mass ratio was: 267/1 – 667/1 that equivalent
to 40-120 ml for each 1g algal biomass.
No significant increase in algal biodiesel is reported above 533/1.
The H2SO4 load was
optimized to be 100%
(wt/wt oil); where further
increase had not
improved the process
efficiency .
21 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
2. Effect of Reaction Time and Temperature
Time, hr Yield %
27 oC 40 oC 50 oC 65 oC
2 1.35 25.11 38.2 43.1
4 10.62 45.81 70.5 76.22
8 30.22 62.3 81.54 84.7
10 34.71 62.512 81.63 84.82
To investigate the influence of
reaction time (2, 4, 8 and 10 hr) and
temperature (27, 40, 50 and 65C), a
methanol volume of 80 ml, 100% by
mol. catalyst conc. and continuously
stirring the reaction at 650 rpm
conditions were used.
The fact that the elevated temperatures (and pressures)
improved the initial miscibility of the reacting species,
leading to a significant reduction in the reaction times.
22 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
2. Effect of Reaction Time and Temperature
1.35
10.62
30.22
34.71
25.11
45.81
62.3 62.512
38.2
70.5
81.54 81.63
43.1
76.22
84.7 84.82
y = -0.1992x2 + 6.706x - 11.849
R² = 0.9955
y = -0.8537x2 + 14.809x - 0.6505
R² = 0.9979
y = -1.342x2 + 21x + 3.703
R² = 0.973
y = -1.375x2 + 21.09x + 8.884
R² = 0.978
0
10
20
30
40
50
60
70
80
90
100
0 2 4 6 8 10 12
Bio
die
se
l C
on
ve
rsio
n (
%)
Reaction Time (hr)
27C
40C
50C
65C
23 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
When the in situ
transesterification process
was conducted without
stirring, no reaction will be
obtained, and the equilibrium
conversion of the microalgae
oil content to biodiesel is
zero.
3. Effect of Stirring
0
10
20
30
40
50
60
70
80
0
58.7
76.22
Yie
ld %
No stirring
Stirred intermittently (1 h off, 1 h on)
Stirred continuously
Process conditions:
15g biomass, 80ml
methanol, 100% H2SO4
conc., at 65 C for 4 hrs.
Because 87% of the equilibrium FAME conversion was
achieved after 1 h with continuous stirring under the
experimental transesterification conditions.
24 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Quality Assessment of Algal Biodiesel Property Unit Petroleum diesel Algal biodiesel Biodiesel (EN 14214)
Carbon range C8-C16 C12:0-C22:0 C14:0-C20:2
Density at 15oC g/cm3 0.83-0.84 0.864 0.86-0.90
Viscosity at 40oC cSt 1.2-3.5 5.2 3.5-5.0
Acid number mg KOH/g oil 0.023 0.75 <0.5
Pour point oC -15 to -3 -12 -
Cloud point oC -15 to +5 -3 -4
Flash point oC 60-80 189 >101
Aniline point 67 84
Distillation range oC 157-325 270-403 -
Auto-ignition point oC - - -
Water content ppm 52 39 <500
C %wt 87 76 -
H2 %wt 13 <12.7 -
O2 %wt 0 >11.3 -
S %wt 0.13 Nil <0.01
Calorific value MJ/kg 45.9 41 32.9
Cetane number 50 70 >51
Paraffins %wt - 79 (avg.) -
Olefins %wt - 20 (avg.) -
25 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
26
Algal Biodiesel Economics 2016
Economic assessment of algal biodiesel project
The feedstock is Nannochloropsis sp. of 44%wt lipid content.
The biomass cost is assumed to be $400/ton , and algal biodiesel price is suggested to be
$2500/ton.
The production capacity of algal biofuel is 0.5 million tons/year.
Operating hours based on three shifts (8h) per day and 300 working days per year.
The storage capacity is suggested to be only one week for raw materials and products.
The catalyst (H2SO4 conc.) will be supplied by Egyptian Armed-Forces Plants ($1250/ton).
Glycerin and algalcake are co-products that help to minimize the annual production cost.
Algalcake price is suggested to be $300/ton, whatever its utilization purpose as bio-fertilizer or
solid biofuel
80% of methanol is assumed to be recovered.
Depreciation estimated using straight line method for 15 years life span and the scrap value is
estimated to be 10 % of equipment cost (EC).
Electricity cost is $0.1/kWh, and the electricity consumption is assumed to be 70kWh/ton algal
biodiesel .
Working capital investment (WCI) is represent 20% of fixed capital investment (FCI); as the
products are not require marketing heads
10% of gross earnings is accounted for taxes expenses.
Assumptions
27 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Quantity (ton/yr) Unit cost ($/ton) Cost ($/yr)
Raw materials
Algal biomass 1341633.6 400 536653429.2
Methyl alcohol 1431075.8 440 62967335.7
H2SO4 catalyst 590318.8 1250 737898465.1
1337519230
Revenues
Biodiesel 500000 2500 1250000000
Glycerin 50000 750 37500000
Algalcake 841633.6 300 252490072
1539990072
Raw materials and revenues cost
28 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Equipment Unit No. Total cost ($)
Algae storage tanks (300 m3) 89 6675000
Belt conveyor 10 220000
Methanol storage tanks (200 m3) 142 7100000
H2SO4 storage tanks (200 m3) 59 2950000
Mixing vessels (100 m3) 57 1425000
Transesterification reactors (Jacketed & Agitated 100 m3) 95 28500000
Mixers (Propeller, 10 hp) 57 570000
Decanters/Centrifuges (bottom driven 3m diameter) 10 370000
Pumps (progressive cavity type, 30gallon/min) 20 220000
Extraction/Distillation columns ( 2m Diameter,20m Height) 38 19000000
Algal biodiesel storage tanks (200 m3) 50 2500000
Glycerin storage tanks (100 m3) 10 250000
Filters (Hydrocyclone, 1m diameter, 25-50 m3/h) 8 400000
EC 70180000
Equipment cost (EC)
29 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Capital investment category Cost ($)
Equipment cost (EC) 70180000
Equipment delivery cost 7018000
Installation cost 14036000
Piping 14036000
Buildings 7018000
Utilities 10527000
Instrumentation & Control 10527000
Site Development 7018000
Auxiliary buildings 3509000
Design and Eng. 28773800
Contractor' fee 28773800
Contingency 14386900
Legal expenses 14386900
FCI 230190400
WCI 46038080
TCI 276,228,480
Capital investment (CI)
30 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Unit cost (US$) Cost ($/yr)
Direct Production Cost (DPC)
Raw Materials 1337519230
Miscellaneous materials 10% M&O 701800
Electricity $0.1/kWh 3500000
Maintenance and operational cost (M&O) 10%EC 7018000
Operating labor $13500/employee/year 2800000
Depreciation Striaght-line depreciation 4210800
Plant overheads 50% of labor and M &O 4909000
Interest 2% EC 1403600
Property insurance cost 5% EC 3509000
Indirect Production Cost (IPC)
Research and Development 5% of DPC 68278571.5
General expenses 25% of labor and M&O 2454500
Contingency
10% of labor, M&O and plant
overheads costs 1472700
ABC 1437777202
ABC/ton biodiesel 2875.5
Algal biofuel cost (ABC)
31 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Techno-economic indicators for algal biofuel production
based on the appreciated assumptions Item Value
Raw materials ($/yr) 1,337,519,230
Revenues ($/yr) 1,539,990,072
Total capital investment ($) 276,228,480
Total production cost ($/yr) 1,437,777,202
Net profit ($/yr) 91,991,583
ROR (%) 33.3
Pay-back time (yr) 2.4
Selection of microalgae strain
Algae lipid productivity and fatty
acid profiles that matching the
biofuel requirements are generally
used to select the appropriate
strain, however lipid content is of
great importance criteria for algal
biodiesel business.
For profitable algal biofuel
business, lipids content cannot less
than 37.3%; to get US$ 55245674
net profit and 3.8 years a payback
time.
0
1
2
3
4
5
6
-80
-60
-40
-20
0
20
40
60
0 20 40 60 80
Pay-b
ack p
eri
od (years
)
RO
R (%
)
Microalgae lipid (%)
ROR Pay-back period
Algae specie Oil %wt
Nitzschia sp. 45-47
Neochloris oleoabundans 35-54
Nannochloropsis sp. 31-68
Botryococcus braunii 25-75
Schizochytrium sp. 50-77
32 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Conclusions
Algal biofuel is interested in recent years; due to the unique benefits of microalgae
Oilgae extraction is one of the most costly processes which can determine the sustainability
of microalgae-based biodiesel. However, it is necessary to evaluate Oilgae properties and
determine the appropriate method for biofuel production.
The existence of C16:0-C18:3 in algal oil making it a promising feedstock for green fuel
production, but the high viscosity (58cp) and excessive FFA (~18%) resists its direct use as
a fuel
Direct transesterification (or in-situ) process integrates oil extraction and its conversion into
biodiesel in a single step; hence it minimizes the total manufacturing cost. Results reported
that methanol/Spirulina platensis mass ratio of 533/1 is recommended to be ideal; to yield
84.7% of algal biofuel at 65oC, 100% catalyst concentration and 8h with experimental error
of ±3.5%.
Biochemical analysis of algalcake proved its utilization as a bio-fertilizer, animal fodder, solid
biofuel, or a feedstock for bioethanol production according to economics view point.
Quality assessment of algal biodiesel confirm EN 14214 standards.
Preliminary economic analysis of algal biodiesel project show that TCI is US$ 276228480,
annual ABC is US$ 1437777202, annual net profit is US$ 91991583, ROR is 33.3% and
payback time is 2.4 yr for production capacity of 0.5Million tons based on algae lipid content
of 44% (Nannochloropsis), feedstock cost of US$400/ton and algal biofuel selling price of
US$2500/ton.
To obtain a profit, the algae oil content cannot be less than 37.3%.
34 El Shimi, H.I. 1st Applied Microbiology Conf. Egypt, March 2016
Acknowledgements
The author would like to express his appreciation to the
Faculty of Engineering, Cairo University, Egypt for the
technical and financial support.
References
Are available in the conference proceedings.
37