1. IIT Bombay 5th International Conference on Advances in Energy Research
Velentina Das1, Anuchaya Devi2,Vijay Kumar Das3, Dhanapati Deka4*
1,2,4Biomass Conversion Laboratory, Department of Energy,Tezpur University, Napaam , Assam, India
3Department of Chemical Sciences, Tezpur University , Assam, India
TEZPUR UNIVERSITY
MICROALGAE CHLORELLA: A POTENTIAL FEEDSTOCK FOR BIODIESEL PRODUCTION - A REVIEW
Microalgae are unicellular autotrophic/heterotrophic photosynthetically efficient organisms that uses light energy and carbon dioxide (CO2). Biofuel production from Microalgae Chlorella species have long been identified as potentially good source because of their high oil content, fast growth, easy cultivation, short life span. Chlorella parasitca is found to have symbiotic association in the cells of Paramecium and Hydra. Chlorella vulgaris, Chlorella conductrix, Chlorella Gonglomerata and C. parasitca are the common Indian species. Chlorella is represented by only eight species. Out of all these species, Chlorella vulgaris is one of the prominent algae species for producing biofuel because of its fast growth and easy cultivation.
The microalgal biodiesel have many advantages as it can reduce net carbon dioxide emission by 78% on a life-cycle basis as compared to traditional diesel fuel Microalgal biodiesel also contain little or no sulphur or aromatic compound but in conventional diesel, the sulphur lead to formation of sulphur oxide and sulphuric acid, while the aromatic compound also increase particulate matter and are considered carcinogens.
Table 2. Oil content in different microalgae
Table 3. Comparison between microalgal biodiesel and diesel fuel
Table 1.Different Esters present in Chlorella vulgaris
Microalgae
Oil content (% dry
weight)
Botryococcus braunii
25-75
Chlorella sp.
28-32
Crypthecodinium cohnii 20
Cylindrotheca sp.
16-37
Dunaliella primolecta 23
Isochrysis sp.
25-33
Nannochloropsis sp.
>20
Neochloris sp.
31-68
Monolanthus salina
35-54
Nitzchia sp.
45-47
Phaeodactylum tricornutum
20-30
Schizochytrium sp.
50-77
Tetraselmis sueica
15-23
PROPERTIES
BIODIESEL FROM MICROALGAL OIL
DIESEL FUEL
DENSITY (kgl-1)
0.864
0.838
VISCOSITY (Pa S)
5.2x10-4(40OC)
x10-4(40OC)
FLASH POINT (OC)
65-115 75
SOLIDIFYING POINT (OC)
-12
-50-10
COLD FILTER PLUGGING POINT (OC)
-11
-3.0(-6.7 max)
ACID VALUE ( KOH g-1)
0.374
0.5(max)
HEATING VALUE (MJ Kg-1) 41
40-45
HC RATIO
1.18
SOURCE : DEPARTMENT OF BIOLOGICAL SCIENCES AND BIOTECHNOLOGY,TSINGHUA UNIVERSITY,BEIJING,CHINA 2004
Sl.N
Ester from Chlorella vulgaris
Found (%) 1
Methyl octanoate(C8:0)
0.0544 2
Methyl decanoate(C10:0) 3
Methyl dodecanoate(C12:0)
0.0506 4
Methyl myristate(C14:0) 5
Methyl palmitate(C16:0) 6
Methyl palmitoleate(C16:1) 7
Methyl stearate(C18:0) 8
Methyl oleate(C18:1n9c) 9
Methyl linoleate(C18:2n6c) 10
Methyl linolenate(C18:3n3) 11
Methyl arachidate(C20:0) 12
Methyl behenate(C22:0) 13
Methylcis-13-decosenoate(C22:1n9)
Extraction
Lipid content
Algae culture
Transesterification
Renewable Catalyst
Table No 4. Chemical composition of algae expressed on a dry matter basis (%)
Recovery of the biodiesel by repeated washing
Strain
Protien
Carbohydrate
Lipids
Nucleic Acid
Scenedesmus obliquus
50-56
10-17
12-14
3-6
Scenedesmus quadricauda 47 -
1.9
Scenedesmus dimorphus
8-18
21-52
16-40
Chlamydomonas rheinhardii 48 17 21
Chlorella vulgaris
51-58
12-17
14-22
4.5
Chlorella pyrenoidosa 57 26 2
Spirogyra sp.
6-20
33-64
11-21
Dunaliella bioculata 49 4 8
Dunaliella salina 32 6
Euglena gracilis
39-61
14-18
14-20
Prymnesium parvum
28-45
25-33
22-38
1.2
Tetraselmis maculata 52 15 3
Porphyridium cruentum
28-39
40-57
9-14
Spirulina platensis
46-63
8-14
4-9
2-5
Spirulina maxima
60-71
13-16
6-7
3-4.5
Synechoccus sp. 63 11 5
Anabaena cylindrica
43-56
25-30
4.7
Analysis
Density
Viscosity
Solidifying point
Flash point
Acid value
Chlorella seems to be the dominating species in this field. Chlorella is found interesting for the development of second generation biofuel and because of being immense diversification among the other microalgal species found in different habitats of North East India. It can grow in salt water, freshwater or even contaminated water, or in ponds, and even on land which are not suitable for food production. On top of those advantages, algae can grow even better when fed extra carbon dioxide (the main greenhouse gas) and organic material like sewage. If so, along with biofuel production it can deal up with cleaning up other problems.
Construction of a Open raceway Photobioreactor.
Synthesis of renewable heterogeneous catalysts from egg shells for biodiesel production.
Velentina Das Thanks Tezpur University for the Institutional Fellowship.
IIT Bombay
ICAER 2015