PAPER REVIEW

Evaluation of the potential of 10 microalgal strains for biodiesel

production

Name: Vijendren Krishnan

Supervisor: Prof. Dr. Yoshimitsu Uemura

In this study, the potential of 10 algae species for biodiesel production

were evaluated by determining their fatty acid profiles, biodiesel

properties besides growth rate, biomass concentration and lipid

productivity. Among seven strains with high growth and lipid

accumulation properties, excluding Kirchneriella lunaris and Lyngbya

kuetzingii, five species Selenastrum capricornutum, Chlorella vulgaris,

Scenedesmus obliqnus, Phaeodactylum tricornutum and Isochrysis

sphacrica were finally selected for biodiesel production due to their

possessing higher lipid productivity and favorable biodiesel properties.

The best strain was P. tricornutum, with lipid content of 61.43 ± 0.95%,

lipid productivity of 26.75 mg L1 d1, the favorable fatty acid profiles of

C16–C18 (74.50%), C14:0 (11.68%) and C16:1 (22.34%) as well as

suitable biodiesel properties of higher cetane number (55.10), lower

iodine number (99.2 gI2/100 g) and relatively low cloud point (4.47 C).

Introduction

• Microalgae posses high qualities such as rapidbiomass concentration, high lipid content, tolerant toextreme environment.

• Utilization of microalgae for biodiesel production isalso cost effective and environmental friendly.

• FA chain length and degree of unsaturation in FAMEinfluence:

* Kinematic viscocity * cloud point

* Specific gravity * iodine value

* Cetane number * Higher heating value

• FA chain length & degree of unsaturation in FAMEdetermine fuel properties:

• CN, Vis and CP increases with increasing chain length

• CN, Vis and CP decreases with increasing degree ofunsaturation

• SG, IV and HHV increases with increasing degree ofunsaturation

• SG, IV and HHV decreases with increasing chainlength

• Long chain length and low degree of unsaturation arepreferable biodiesel to get low temp performance andgood oxidative stability.

Objective

• To determine if common algae species in localwater system had the potential to accumulate lipidby assesing their growth and oil yield properties.

MethodologyCultivated in single batch 500ml for 15days.

Growth rate determined by Neubauerhaem

ocytometer slide every 2 days.

K = (lnN – lnN0)/ (t-t0)

Biomass DW determination

Total lipid extraction

FA profile analyses

Total Lipid extraction100mg dried algal transferred into 5 ml (CCl4/MeOH; 2:1)

Homogenized for 10min in ultrasonic homogenizer

Supernatant was collected in a separation funnel

Extraction was repeated twice.

Centrifuged at 4000rpm at 12oC for 10min

NaCl (0.9 v/v) added at proportion 1:5 v/v of lipid extract

Extract was shaken vigorously for 1min and allowed to

undergo phase separation for 15min

Organic solvent was dried off from the lower phase using

Nitrogen evaporator

Result

Conclusion

The best strain was P. tricornutum, with lipidcontent of 61.43 ± 0.95%, lipid productivityof 26.75 mg L1 d1, the favorable FA profilesof C16–C18 (74.50%) and C16:1 (22.34%)as well as suitable biodiesel properties ofhigher cetane number (55.10), lower iodinenumber (99.2 gI2/100 g) and relative lowcloud point (4.47 C).