The influence of cultivation period on growth and biodiesel properties of microalga Nannochloropsis gaditana 1049

Abstract

This work reported for the first time the detailed impacts of cultivation period on growth dynamics and biochemical composition of a microalga strain Nannochloropsis gaditana 1049. The results shown either the biomass accumulation, lipid content, neutral lipid content, monounsaturated fatty acids composition or the favorable fatty acid profile of C16-C18 increased along with the cultivation period extension, but the lipid productivity displayed a decrease since cultured for 16 days, with the highest value reached 289.51 ± 16.34 mg L(-1) d(-1). Biodiesel properties of this microalga also changed with the cultivation period extension, with average unsaturated degree decreased from 1.24 ± 0.03 to 0.59 ± 0.02, cloud point increased from 3.39 ± 0.40 °C to 12.14 ± 0.32 °C, cetane number increased from 54.59 ± 0.20 to 58.96 ± 0.16 and iodine number reduced sharply from 105.15 ± 2.24 gI2/100g to 56.44 ± 1.76 gI2/100g, which all satisfied the specifications of biodiesel standard.

Glucose addition‐induced changes in the growth and chemical compositions of a freshwater microalga Chlorella kessleri

“…In the present work, some values of IV were greater than the restrictive maximum IV value of 120 gI 2 100 g −1 oil set by EN 14214, but several other biodiesel feedstocks, such as sunflower oil, soybean and linseed oil, also had higher IV . Although the values of DU were not mentioned in the two standards, DU of biodiesel from the oils of this alga ranged from 1.03% to 1.60%, values in accordance with that reported previously . There are no definite specifications of CP due to the different climate conditions in the United States and Europe; however, CP of biodiesel from the oils of this alga was in the range of −1.44 to 6.23 °C, which was in line with that reported by Hu et al .…”

Growing Chlorella vulgaris on mixed wastewaters for biodiesel feedstock production and nutrient removal

“…CP is the temperature at which the least soluble biodiesel component crystallizes from solution . Although there were no definite specifications of CP due to the different climate conditions in USA and Europe, CP of biodiesel from the oils of this alga was in the range 2.03–5.11 °C, which was in line with that reported by Hu et al . and Song et al …”

“…In this study, the DU increased from 1.11 to 1.34% with the increase of dilution multiple from 2 to 8. Although EN 14214 and ASTM D6751‐08 do not mention the values of DU, DU of biodiesel ranges from 0.6 to 1.6% according to the published literature . Thus, the DU of biodiesel from the oils of this alga was in accordance with that of biodiesel.…”

Phycoremediation of municipal wastewater by microalgae to produce biofuel

“…According to Knothe,46 fatty acids with chain lengths ranging from C16 to C18 should be high in potential feedstock for suitable biodiesel production. In order to compromise between cold flow and oxidative stability, Hu et al 47 suggested that FAME with high percentage of monounsaturation (C16-C18) is most desirable.…”

“…S1 by Mar et al 48 Besides, FAMEs with higher concentrations of palmitate and oleate indicate good biodiesel properties such as quality ignition, higher oxidative stability and lubricity. 49,50,47 Physical properties important to assess the suitability for biodiesel production were analyzed by FAME composition as shown in Table 4. Properties like density, viscosity, high heating value and saponification values were not significantly different between ASW and WW grown algae and complied to international standards (EN and ASTM standard).…”