Biodiesel production from lipid generating microalgae
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Date
2014
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Publisher
CCSHAU
Abstract
In the present scenario, the future of crude oil looks quite bleak as it may lead to all oil resources coming close to a moribund one day. Moreover, consumption of present petroleum sourced fuels at the rocket speed rate has also led to various environmental problems. One of the major concern is global warming. To make a dent in global warming, bioenergy must be generated at a very high speed. Microalgae may be the best option to produce bio-energy at rates high enough to replace a substantial fraction of fossil fuel used by our society. The primary objective of this study was to isolate lipid generating microalgal isolates for biodiesel production. The microalgal water samples were collected from ponds of different locations of eight districts of Haryana including Hisar, Rohtak, Fatehabad, Sirsa, Panipat, Karnal, Ambala and Kurukshetra. The samples were analysed for pH, EC, salinity, turbidity, total nitrogen, phosphorous and potassium. The microalgal samples were enriched in
the Bold’s Basal medium and incubated at 23 ±10C, 50-55% humidity with 16:8 hours light: dark
photoperiod for 21 days. A total of twenty four microalgal isolates were obtained after purification.
Using Nile red staining technique microalgal isolates HMA-2 and FMA-2 were selected for further
study and grown in four media of different chemical composition viz., Soil extract, Chu-13, Kuhl and
Bold’s Basal medium. The microalgal isolates HMA-2 and FMA-2 produced maximum biomass (0.21
and 0.29g/l ) in Bold’s Basal medium whereas lipid content (29.6 and 25.2%) was maximum in Kuhl
medium when grown at 23 ±10C, 50-55% humidity with 16:8 hours light: dark photoperiod for 21 days.
Among the inorganic nitrogen sources tested potassium nitrate (original source) resulted in biomass
accumulation of 0.12 and 0.19 g/l with 29.4 and 25.2% lipid content in the microalgal isolates HMA-2
and FMA-2 respectively while among organic nitrogen sources, peptone supplementation showed
maximum lipid content of 38.2 and 22.1% from 0.04 g/l and 0.10 g/l biomass respectively. Similarly,
among the carbon sources, glucose had been found to be a better supplement as it produced biomass of
1.59 and 1.21 g/l with 57.6 and 50.2% lipid content in microalgal isolates HMA-2 and FMA-2
respectively. Lipid and biomass production studies at different pH, temperature and salinity indicated
biomass production of 0.14 g/l having 32.6% lipid at pH 8, 0.23g/l biomass having 42.4% lipid at 250C
and 0.07g/l biomass containing 61.4% lipid on 20 g/l sodium chloride supplementation in microalgal
isolate HMA-2 whereas in isolate FMA-2, 0.13, 0.21 and 0.11g/l biomass containing 26.1, 40.2 and
36.2% lipid was obtained under similar conditions respectively. Transesterification of algal oil of
microalgal isolate HMA-2 using NaOH as catalyst and methanol resulted in biodiesel production to the
tune of 9%.
Description
Keywords
lipids, productivity, biomass, inorganic acid salts, biological development, biodiesel, sampling, irrigation, oils, biofuels